Influence of ultrasonic vibration on micro-extrusion

超声波振落的原理English:The principle of ultrasonic vibration is based on the phenomenon of the piezoelectric effect. Piezoelectric materials, such as quartz crystals or certain ceramics, can convert electrical energy into mechanical vibrations and vice versa. When an alternating current is applied to the piezoelectric element, it causes the crystal lattice to vibrate at a specific frequency, producing sound waves in the ultrasonic range. These sound waves are then transmitted through a medium, such as air or water, and can be used for various applications.Ultrasonic vibrations have several unique properties that make them useful in different fields. One important property is the high frequency range they operate in, typically above 20 kHz. This high frequency allows for precise control and fine detailing in applications like ultrasonic cleaning, cutting, or welding. Another property is the directionality of ultrasonic waves. They can be focused into a narrow beam, allowing for precision targeting in medical imaging or non-destructive testing. This focused energy can also be used to break down particles or remove dirt through a process known as cavitation.Cavitation occurs when the high-frequency sound waves create alternating pressure waves in a liquid or fluid medium. As the pressure decreases during the rarefaction cycle, the liquid can vaporize and form small gas-filled bubbles or cavities. When these bubbles collapse, they produce intense heat and shock waves, creating tiny shockwaves that dislodge particles or dirt from surfaces. This phenomenon is commonly used in ultrasonic cleaning devices or medical procedures like lithotripsy, where the shockwaves are used to break down kidney stones.The translation in Chinese: 超声波振落的原理基于压电效应。

超声振动作用原理Ultrasonic vibration is a process in which high-frequency sound waves are used to agitate and generate mechanical energy. 超声波振动是利用高频声波来激发和产生机械能的过程。

This technology is widely used in various industries, including medical, automotive, and manufacturing. 这项技术广泛应用于医疗、汽车和制造等各个行业。

The principle behind ultrasonic vibration lies in the conversion of electrical energy into mechanical vibrations through the use of piezoelectric transducers. 超声波振动的原理在于通过压电换能器将电能转换为机械振动。

One of the main applications of ultrasonic vibration is in ultrasonic cleaning, where the high-frequency sound waves are used to remove dirt and contaminants from various objects. 超声波振动的主要应用之一是在超声波清洁中，高频声波用于从各种物体上去除污垢和污染物。

This process is highly effective in cleaning delicate and intricate parts that are difficult to reach using traditional cleaning methods. 这个过程在清洁难以用传统方法清洁、精细复杂部件时非常高效。

Manufacture of Overhanging Sharp Corner by Means of 6-Axis Control Machining with the Application of Ultrasonic Vibrations feliciano H.JAPITANA**,koichi MORISHIGE**,shugo YASUDA** and yoshimiTAKEUCHIThe study proposes a new machine method to creat an create an overhanging sharp corner. Sharp corners on overhanging surfaces are difficult to machine in conventional way or even in 3 to 5-aixs EDM especially if the surfaces have different angles. This is due to the limitation of the feed direction and the structure of the electrode wherein it must be symmetrical with the target shape. In present research, we try to machine the sharp corner with overhanging surfaces using the new machining method. The 6-axis control machining is applied to set a non-rotational tool at an arbitrary position with arbitrary position with arbitrary attitude against the workpiece. During cutting, the ultrasonic vibration is applied on the cutting edge of the tool, while the tool travels along the feed direction. As the cutting is performed, the 6-axis (X,Y,Z,A,B and C) move simultaneously, depending on the tool attitude at a certain cutting point. Form the experimental results, it is shown that the 6-axis control ultrasonic vibration cutting is capable of producing a sharp overhanging surface.Key Words: 6-axis Controlled Cutting, CAD/CAM System, Bore Byte Tool, Overhanging Sharp Corner, Ultrasonic Vibration Cutting Tool1.introductionThe flexibility of products may be extended greatly if the restriction in manufacturing process can be minimized or eliminated. If rotational tools such as ball end mills or square end mills are used in the production of a mould with an overhanging sharp corner (OHSC), it seems difficult to clearly obtain the target shape with sharp edge lines. This is due to the result of processing with the rotational tools, Which are symmetrical with the rotation. The arc-like radius remains are produced on adjoining surfaces, as shown in Fig.1 Conventionally, most of overhanging or inclined surface can be machined by setting the workpiece at a certain angle in the vise, swivelling the universal vise, or by setting the tool head to a certain angle and feeding the cutting tool head, as shown in Fig.2(a). In this process, the overhanging surfaces and the sharp edges at the bottom are produced. However, if the target is an OHSC consisting of two overhanging side surfaces, and theinclination angle of surface is not uniform, the processing of the target shape is difficult to achieve since the cutting direction in the process is fixed and limited only to linear cutting. Thus ,it needs a lot of jigs and fixtures to hold a workpiece ,to position correctly with respect to a machine tool and to support it during machining.Fig.1 5-axis control machining using rotational toolFig.2 method of producing sharp corner with overhanging surfacesThe other possible method to produce such a shape is multi-axis Electric Discharge Machining (EDM), as shown in Fig.2(b).However, even using this method ,it is difficult or impossible to produce an OHSC with different angle .It needs 6 degrees of freedom to fully execute the machining of the required shape.In the previous researches, ultrasonic vibration (USV) was applied in turning of ductile material and milling of glassfiber-reinforced plastic. The cutting force with USV is considerably reduced. However , in the former process ,the workpiece is rotated or moves to towards the cutting tool, and in the latter, machining is limited only to 2 or 3 axis control one. In the other field of research, multi-axis control machine tool is used to complete a machining in one setup, which leads to the production of workpiece with high accuracy and quality and to the reduction in machining time.In this study, 6-axis control cutting using a non-rotational cutting tool with the application of ultrasonic vibration (USV) is used, as shown in Fig.2(c).It is applied to scrutinize the validity of the method in the fabrication of OHSC, The C-axis rotates the non-rotational tool simultaneously together with X,Y,Z,A or B axis during machining .The movement of the axes is based on the tool attitude and the cutting point generated by a developed CAM software. The CAM program generates a collision free tool path to assure the safety of the process. The 6-axis control machine tool provides easily the machining capability of OHSC, since 6degrees of freedom make the machining execute fully the required product shape. Also, with the application of USV, a bore byte tool is utilizded, considering its size and stiffness during machining operation since the cutting force is greatly reduced.2.Experimental procedureThe experiment steup is shown in Fig.3, wherein the workpiece is mounted on the table of the 6-axis control machining center. The bore byte tool is mounted in the USV tool using an adaptor. The USV tool is turn mounted on the main spindle of the 6-axis control machining center.2.1Multi-axis control machine tool and bore byte toolThe 6-axis control machining center used in the study is shown inFig.4. The machining center provides multi-axis CNC machine tools.The 6-axis control machine tool has 3 rotational axes A,B and C. It is constructed by adding the rotational function C on the main spindle of a 5-axis control machining center which has 2 rotational axes,namely;A, which is a rotary tilting table and B, which is the rotary index table. The, and that of rotational one A,B minimum unit for translation movement X,Y and Z is 1mand C is 0.36 arc second. In the case of cutting of OHSC, A axis is used for determination of side surface and the inclination angle of sharp corner ,B axis for workpiece rotation ,C axis for determination of cutting tool direction, X and Y axis for the determination of feed direction of feed direction while the depth of cut is determined by Z axis. Fig 5 shows the non-rotational cutting tool (bore byte tool) used in the study. It is made of tungsten carbide usually used here in 6-axis control cutting. The total length and diameter of the tool are70mm and 6mm respectively.2.2Ultrasonic vibration toolFif.6 is a commercially available USV tool (SB-150:Taga Electric Co). used in the study. The USV is applied on the cutting edge of the tool.In order to perform an efficient and effective vibration cutting, the vibration direction must be set parallel to the cutting direction. Since the vibration direction is not always parallel with the feed direction, the tool attitude of the bore byte tool is subjected to arrangement. As illustrated in fig.7(a), the tool axis vextor T and the tool direction vector D and modified by arranging the rolling and the inclination angle respectively. These are converted into modified tool axis vector T and modified tool direction vector D, as shown in fig.7(b). The transformation of the tool axis vector and the tool direction vector are carried out in cutter location (CL) conversion.2.3CAD/CAM systemThe configuration of 6-axis CAD/CAM system is shown in fig.8, where 3D-CAD data of the target shape is generated . The type of bore byte tool must be selected, based on the target shape. The main processor generates the collision free CL data on the bases of tool information and tool orientation as well as 3D-CAD data of the target shape.The post processor converts CL data generated by the main processor into 6-axis control NC data suitable for the coordinate system of the machining center with reference to the structure information of the machining center, setting information, cutting condition and vibration condition. In addition, so-called linearization operation is dine in order to keep the feed rate to the machining center structure constant and to minimize the tool path deviation. It leads to assure the smoothness of the product surface especially in dealing with curve surfaces.Before converting CL data into NC data, CL data must be firstly checked for collision to assure the safety of the machining process .If the collision is detected in this stage, the modification of CL data is carried out, using the main processor.3.Manufacture of Sharp Corner with Overhanging Surface3.1Determination of tool attitudeIn order to expresshe entire tool attitude for 9-axis control ultrasonic vibration cutting, the tool attitude of the bore byte tool, as shown in Fig.9, is appointed by the coordinates P for cutting point, the tool axis vector T and the tool direction vector D. These PTD coordinates are converted to NC data, and are in turn used in machining operation. In6-axis control cutting with application of ultrasonic vibration, the movement and the attitude of the tool must be determined in consideration of the vibration direction. Since the cutting direction changes rapidly, the tool attitude changes a lot to keep the tool angle constant to the surface shape.3.2Generation of tool pathThe tool path generating method for OHSC can be described as follows; the OHSC is composed with two ridgelines, as illustrated in Fig.10. The intersecting line is called as a bottom ridgeline and the cross section line is called as a side ridgeline .Finishing the side ridgeline as well as the bottom ridgeline is required to make a sharp corner.3.2.1Generation of tool path for side surfaceThe surface that makes a side ridgeline is composed with left and right surfaces respectively. In producing a side ridgeline of the sharp corner, machining of left and right surfaces is necessary. The outline of the tool path generation method for side surfaces of the OHSC is described in Fig.11.The side to be machined and the tool feed direction must be selected at first, based on the type of bore byte tool and the target shape. The adjoining surfaces that make a side ridgeline, is expressed with parameters u and v. The fix curve , which is equal to parameter v, is generated on the side from the upper part of the surface to the bottom. The division number of surface is input to sequentially generate the number of cutting points. Each cutting point on a reference line are generated, using the value of parameter u, so that the distance between the cutting points may settle below in the specified value.Changing the tool attitude at every point of the cutter location ,the tool moves sequentially on each cutting point from the start point until the side ridgeline is formed. Although the cutting point is connected each other in order to acquire the tool path, it is difficult to process both adjoining sides by one direction due to the tool structure and the target product shape. In addition , the collision may take place between the tool and the workpiece. In this situation, the tool starts from the start point of the tool path to process the left side surface, and ends at the corner where the ridgeline is to be formed. Thus is repeated until it reaches to the bottom surface. The depth of cut is based in the division number of the total length of curve for curve surface. The same thing is done on the right side surface since there is still an arc-like remain at the corner part of the side surface. The procedure is almost the same as with the processing of the left side surface, however thecutting end point is the same with the end point of the left side processing, to form the clear ridgeline .Processing of the right side surfaces is also done using the left hand tool.The tool direction vector D during the tool path generation for side surfaces is rotated by 10degrees to make the vibration direction parallel to the feed direction vector F. The tool path is generated by connecting the cutting points in order from the starting point to the end point. The tool attitude during cutting is determined from the normal vector N and the tool feed direction vector F at the cutting point. The tool feed direction vector D and the tool axis vector T can be expressed as D=F*N and T=N respectively.3.2.2Generation of tool path for bottom surfaceFigure 12 describes that tool path generating method for bottom surface that makes the bottom surface that makes the bottom ridgeline of the OHSC. After generating the tool path for side surfaces, the tool path for bottom ridgeline is successively generated, where the tool is inclined to the bottom surfaces. There are two methods of generating a tool path for bottom surfaces; one is one-path method shown on the upper left part, and the other multi-path method shown in the upper right part of the figure. In one –path method ,the cutting tip of the tool directly makes contact with the location of the bottom ridgeline. In this operation, the tool inclination angle is necessary to fully remove the arc-like remains on the bottom surface and to form a clear ridgeline. During the tool path generation, the tool axis vector T is inclined, based on the calculated inclination angle against the bottom surface and the clearance angle of the cutting tool, which is 5 degrees.The method of determining the cutting start point as well as the cutting end point is the same as that of generating a tool path for side ridgeline.In multi-path method, the pitch from the bottom surface is expressed by use of parameters u and v. The generation range of a cutting reference line is determined from the shortest distance between the arc-like remains after rouging and the reference line of thebottom ridgeline. Cutting points is generated on the basis of parameter v in each reference line. The systems determines the tool attitude during cutting from the tool axis vector N at the bottom surface and the tool feed vector F at cutting point along a cutting reference line. The tool axis vector T and the tool direction vector D can be express as T=N and D=N*F respectively. The cutting start point is assumed near the arc-like radius remains and it ends at the last point of the generated cutting point in the reference line. Moving the tool along each neighboring cutting point can make the tool path.4.Experimental Results4.1Effect on cutting forceThe cutting force was measured by use of piezoelectric dynamometer (9257B,Kistler Co,Ltd), thus averaging the measured cutting force and processing it in the root mean square(rms) manner.table1 measured cutting forceMachining was conducted both with USV and without USV. The cutting conditions used are as follows: feed speed of 400mm/min and different depth of cut of 0.1,0.2,and 0.3mm respectively. The vibration conditions are in the following; frequency of 19kHz,and rolling angle of 10 degrees. The acquired result is shown in amplitude of 36mTable1. It can be seen that the cutting force in cutting with USV is much smaller as compared to cutting without USV. Since the cutting force was greatly reduced, the stiffness of the tool can be maintained all throughout the process.4.2Machining of OHSCThe cutting experiment was also made in order to scrutinize the validity of the new machining method. The workpiece size used for the experiment is 100×100×20 mm and the material is an aluminimu alloy(JIS A5052), which is also commonly used for low cost mould with low molding pressurre such as blow moulding, vacuum forming, rubbermoulding,etc.Two types of OHSC model were tired in the experiment, one is OHSC with plane surface and the other is OHSC with curve surface. The side surfaces consist of different inclination angle. The inclination angle o the surface at the cutting start point is not the same as the inclination angle at the cutting end point. In this condition, the inclination angle is not uniform all thoughout.Shown in Fig.13(a) is the machining model for OHSC with plane surfaces, rugh cutting must be at firdt done in order to perform an effcient cutting by 5-axis control machining, using the rotational ball end mill with a radius of 3mm and 1.5mm respectively. Machining is carried out until the target product shape is almost obtained. Since the target sharp corner is not clearly obtained due to the arc-like remains, as shown in Fig .13(b), finishing will be performed, using the 6-axis control cutting with the application of theUSV. with plane surface. Inthis process ,the left side or right side surface is firstly machined, depending on the choice.Let us assume that the left side surface is machined. The cutting and vibration conditions listed in Table 2 were used in machining on the basis of NC instructions generated by the developed CAM program. After machining the side surface, the bottom surfaces is machined in the next step, using the one path method. The cutting conditions listed in Table 2 were also used except for the inclinations angle of 9 degrees and the depth of cut of about 1.5mm. The depths of cut were based on the arc-like remains of the ball end mill used during roughing.Machining of the left side surfaces is done, using the right hang tool.After finishing the machining of the left side surface, the right side is processed in the next step under almost the same conditions as the processing of the left side except that the tool used is a left hand too. Shown in Fig.13(d) is the result of machining experiment.The machining model for OHSC with curve surfaces is shown in Fig.14(a). In machining OHSC with curve surface, roughing must also be performed, as shown in Fig.14(b). The sequence of operation from roughing to finishing is almost the same as described previously. However, so-called linearization operation is required to make the product surface smooth. To process the bottom surface that makes the ridgeline, the multi-path method was emplyed since the method is suitable in curved surfaces. Table 2 lists the cutting and vibration conditions used in the process. Also, shown in Fig.14(c) and Fig.14(d) are the actual machining and the product after finishing process respectively. The total machining time with this experiment is 112 minutes including rough cutting time. Only one machine was used as well as one steup of the workpiece in the entire process.The cutting effciency has been drastically improved due to the increase of cutting speed by applying of ultrasonic vibration since the normal cutting speed of non rotational cutting tools is equal to the feed rate.ConclusionThe experimental results show that the usage of bore byte tool is maximized and that the tool stiffness is enough to carry out machining due to the significant reduction of cutting force by applying the ultrasonic vibrations. It is found that only one machine can cope with machining of the product from roughing to fingshing , which leads to the potential of cost saving since the extra process like set-up from one machine to another can be eliminated. As a result, the validity of the developed CAM to machine OHSCs with plane and curve surface is experimentally confirmed throughout the study.AcknowledgementThe authors would like to express their sincere appreciation to Mr.Crisanto de laCruz(MIRDC-DOST) and Mr.Tohru Ishida (The University of Elector-Communications) for their valuable support and information.A part of the study is funded by the grant in aid for Scientific Research of the Ministry of Education (B12450057).references(1)Cecil, J A Clamping Design Approach for Automated Fixture Design, The InternationalJournal of Advanced Manufacturing Technology, V ol.18, No.11(2001),pp.790-793. (2)Moriwaki, T, Shanmoto ,E. and Inoue, K,Ultrapresicion Ductile Cutting of Glass byApplying Ultrasonic Vibration, Annals of the CIRP,V ol.41, No.1(1992),pp.141-144. (3)Takeyama, H. and Iijima, N, Machinability of Glassfiber Reinforced Plastics andApplication of Ultrasonic Machining, Annals of the CIRP, V ol.37, No.1(1998),pp.93-96.(4)Shamoto, E. and Moriwaki, T, Study on Elliptical Vibration Cutting, Annals of theCIRP, V ol.43,No.1(1994),pp.35-38.(5)Moriwaki ,T. and Shamoto, E,Ultrasonic Elliptical Vibration Cutting ,Annals of theCIRP, V ol.44,No.1 (1995),pp.31-34.(6)Takeuchi, Y. and Suzuki, H. Efficient and Accurate Manufacturing by means ofMulti-Axis Control Machine Tools, Proceedings of the Japan-USA Symposium on Flexible Automation, ASME and ISCIEJ, Boston, Massachusetts, July7-10,1996,V ol.1,pp.343-347.(7)Radzevich, S.P. and Goodman, E .D, Efficiency of Multi-Axis NC Machining ofSculptured Surface, Proceedings of the International Conference on Sculptured Surface machining, Nov.9-11,1998,pp42-56.(8)Morishige, K, Kase,K and Takeuchi, Y, Collision-free Tool path Generation GenerationUsing 2-Dimensional C-Space for 5-Axis Control Machining, The International Journal of Advanced Manufacturing Technology, V ol.13, No.6(1997),pp.393-400.(9)Morishige, K, Kase,K and Takeuchi, Y, six Axis Control Character Line FinishingUsing Ultrasonic Vibrational Cutting Tool, 10th International Conference on Precision Engineering (ICPE), Yokohama, Japan, July 18-20,2001,pp.249-2563.。

P roc edia CIRP 1( 2012 )359 –364Available online at 2212-8271 © 2012 The Authors. Published by Elsevier B.V. Selection and/or peer-review under responsibility of Professor Konrad Wegener/ 10.1016/j.proc ir.2012.04.0645th CIRP Conference on High Performance Cutting 2012A study on ultrasonic assisted creep feed grinding of nickel basedsuperalloysD. Bhaduri a , S.L. Soo a,*, D.K. Aspinwall a , D. Novovic b , P. Harden c , S. Bohr d , D. Martin eaMachining Research Group, School of Mechanical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UKbTurbines, Rolls-Royce plc, Derby, DE24 9BD, UK cElement Six Ltd., Shannon, Co. Clare, Republic of IrelanddSaint-Gobain Diamantwerkzeuge GmbH & Co. KG, Schützenwall 13-17, D-22844 Norderstedt, GermanyeHardinge Machine Tools, Whetstone, Leicester, LE8 6BD, UK* Corresponding author. Tel.: +44-121-414-4196; fax: +44-121-414-4201.E-mail address: s.l.soo@.AbstractThe paper initially reviews research relating to ultrasonic (US) assisted grinding of various workpiece materials. Results from experimental trials to evaluate the influence of applying US vibration when creep feed grinding Inconel 718 with an open structured, alumina based grinding wheel (POROS 2) are then presented. A full factorial experimental array comprising 18 runs was conducted involving variation in wheel speed (30, 35 and 40m/s), table speed (200, 250 and 300mm/min) and grinding condition (with and without vibration). For tests with US vibration, the workpiece was actuated at a constant frequency (~20kHz)via a specially designed block sonotrode attached to a 1kW piezoelectric transducer-generator system. Reductions in vertical (F V )and horizontal (F H ) grinding force components of up to 23% and 43% for F V and F H respectively and surface roughness (S a ) of the ground slots by up to 45% were observed in the majority of tests when utilising US assisted operation. In terms of surface quality,SEM micrographs revealed greater side flow/ploughing and overlapping grit marks in slots machined with the workpiece vibrated in comparison to standard creep feed ground specimens. Three dimensional topographic measurement of grinding wheel surface replicas indicated that US vibration led to an increase in the number of active cutting points on the wheel.© 2012 Published by Elsevier BV. Selection and/or peer-review under responsibility of Prof. Konrad Wegener Keywords: Grinding; nickel; ultrasonics; vibration.1. IntroductionThe use of ultrasonic actuation as a method formaterial removal was first proposed in a paper by R.W.Wood and A.L. Loomis in 1927, with the first patent granted to L. Balamuth in 1945 [1]. Developments sincethen have seen ultrasonic machining (USM) applied to the cutting of hard but brittle materials such as glass, ruby and ceramics. Traditional USM operation involves a horn and tool arrangement vibrated at frequencies of20kHz with relatively small amplitudes of ~10-20μm,that is used to impact against an abrasive slurry betweenthe tool and workpiece causing localised fracture. The scope of the technology was further expanded to encompass ultrasonic vibration as an assistive mechanism in a ‘hybrid’ configuration with conventional metal cutting (turning, drilling, milling & grinding) aswell as metal forming processes.Some of the earliest work relating to ultrasonic assisted grinding (UAG) dates back to the mid-1950’s [2] and highlighted benefits such as reductions ingrinding temperature and workpiece tensile residual stresses, albeit at a cost of lower G-ratios due to a greater degree of wheel breakdown. Several years later, a project undertaken by the United States Air Forcereported work on excitation of the grinding wheel in a radial direction by attaching the transducer to a half-wave bar (the wheel hub) [3]. A novel technique involving the use of US vibration to clean and prevent loading of pores in a grinding wheel was proposed by Kaliszer and Limb [4], which utilised a special coolantactivator oscillating along its axis and radial to the wheel © 2012 The Authors. Published by Elsevier B.V . Selection and/or peer-review under responsibility of Professor Konrad WegenerD. Bhaduri et al. / P rocedia CIRP 1( 2012 )359 – 364 360periphery. The ultrasonically cleaned wheels exhibited greater permeability, higher G-ratio and reduced chatter vibrations in comparison to the non-ultrasonically treated wheels.The majority of published work on UAG over the past ~20 years can be broadly divided into two sub-categories, depending on whether the vibration was applied to the grinding wheel or workpiece. Nakagawa et al. [5] studied the effects of vibrating a cast iron fibre bonded diamond wheel during the grinding of alumina, silicon nitride and tungsten carbide. They found that larger depths of cut were possible leading to higher material removal rates (MRR) and improved dimensional accuracy, together with a 60-70% reduction in normal grinding force. A similar system was also shown to be capable of fabricating precision micro cylindrical tools and micro drills [6], as well as producing machined features having non-circular cavities and blind holes with sharp corners [7]. While not generally recommended for ferrous alloys, Hara et al. [8] demonstrated that it was possible to produce mirror surfaces when grinding die steel (NAK80) with diamond electroplated tools vibrating at a frequency of 60kHz and an amplitude of 4μm. Use of a vibrating CBN wheel for grinding small holes in stainless steel was also found to reduce both normal and tangential forces as well as workpiece surface roughness by ~20% [9].Research involving vibration of the workpiece has been more extensive, primarily due to the comparatively simpler experimental setup. Spur and Holl [10] utilised a workpiece based US assisted creep feed grinding system to achieve a 50% reduction in normal force when machining sintered silicon nitride and alumina, but at the expense of a marginal increase in wheel wear due to higher amounts of micro-splintering of grits under the hybrid configuration. A similar wear mechanism was observed by Uhlmann [11], whose study also revealed that vibration rendered an intermittent cutting action together with higher mechanical but lower thermal loads on the grits. Several investigations with nano-zirconia based ceramics revealed that the material removal mechanism changed from fracture in conventional grinding to a ductile regime when using UAG [12-13].Wu et al. [14] detailed the development of an innovative elliptic ultrasonic vibrating shoe (instead of two separate transducers) for centreless grinding, which was subsequently utilised in fabricating microscale cylindrical tungsten carbide components with a diameter of 60ȝm over a length of 15mm (aspect ratio of 250) [15]. In an attempt to minimise/eliminate the need for coolant, ultrasonic assisted operation was implemented to investigate the feasibility of dry surface grinding soft steels including 100Cr6 [16-17] and 42CrMo4 [18]. Significant reductions in normal and tangential forces (~30-50%) were obtained when applying ultrasonic actuation, which also decreased thermal damage/ grinding burn, thereby improving workpiece surface finish.The body of research on UAG to date has mainly focussed on the surface grinding configuration of materials such as ceramics, glass and various grades of steel (stainless, plain carbon, alloyed etc.), but little information is available on ultrasonic assisted grinding of advanced aerospace materials such as nickel based superalloys. The aim of the current work was to investigate the effect on grinding forces (vertical and horizontal), workpiece surface roughness/quality (2D and 3D topographical parameters) and wheel wear (G-ratio), when employing ultrasonic vibration during creep feed grinding (CFG) of Inconel 718with an alumina wheel.2.Experimental detailsThe experimental trials were conducted on a Bridgeport FGC1000 flexible grinding centre, with a maximum spindle speed of 6000rpm and power rating of 25kW. Rectangular blocks of solution treated and aged Inconel 718 (hardness of ~44±1HRC) measuring 110×50×10mm were used as the workpiece material. These were clamped onto a specially designed aluminium table/block sonotrode (similar to the one detailed by Azarhoushang and Tawakoli [19]) mounted on the machine worktable, which was connected to a 1kW piezoelectric transducer-generator system, see Fig.1. The transducer was attached to transmit the US vibration in a direction parallel to grinding feed. The alumina grinding wheels known commercially as POROS 2, had a plain geometry, vitrified bond, open structure (specification: 25A601 I 74 VPMCNN), a diameter of 220mm and a width of 25mm.The full factorial experimental array comprised 18 tests involving variations in wheel speed (30, 35 and 40 m/s), table speed (200, 250 and 300 mm/min) and grinding condition (with and without vibration). Depth of cut/pass was fixed at 1.0mm with all trials performed in a down grinding creep feed mode without spark-out. The experimental array is shown in Table 1. Each test involved a single pass of the workpiece (50mm cut length).Dressing of the POROS 2 wheel (after each trial) was carried out using a diamond roller dresser (ĭ 105mm) with an average grain size of ~800μm and spacing of ~1.5mm. Two high pressure pumping systems were used to supply fluid for wheel cleaning (70bar) and into the grinding zone (28bar) via laminar flow nozzles having rectangular cross-sectioned orifices measuring 0.5×20mm and 2×20mm respectively (25mm wide nozzles were not available). The grinding fluid was aD . Bhaduri et al. / P rocedia CIRP 1 ( 2012 ) 359 – 364 361water-based synthetic oil product, Trim C270, with a concentration of 7–10%.Fig. 1. Experimental setup; (a) Block sonotrode and transducerarrangement, (b) on-machine configurationTable 1. Full factorial experimental arrayTest no. Wheel speed, V c (m/s ) Table speed, V w (mm/min ) Condition ofvibration 1 30 200 OFF2 30 200 ON3 30 250 OFF4 30 250 ON5 30 300 OFF6 30 300 ON7 35 200 OFF8 35 200 ON 9 35 250 OFF10 35 250 ON 11 35 300 OFF12 35 300 ON13 40200 OFF14 40 200 ON15 40 250 OFF16 40 250 ON17 40 300 OFF18 40 300 ONFor trials involving US vibration, the workpiece was actuated at a constant frequency of ~20kHz, while the amplitude of vibration was specified on the generator interms of a percentage scale ranging from 0 to 50%. The actual amplitude of the block sonotrode under zero-load condition (workpiece mounted but without grinding) and vibrating at the 50% setting was measured using a Polytech OFV 3001 Laser Doppler Vibrometer coupled to an OFV 303 sensor head. The maximum amplitude recorded was 4.2μm, depending on the positions of the nodes and anti-nodes on the surface of the sonotrode.The block sonotrode exhibited multi-modal vibration in all 3-axes.Vertical (perpendicular to feed direction) and horizontal (parallel to feed direction) grinding forces were measured using a Kistler 9257A 3-component piezoelectric dynamometer coupled to charge amplifiers and a PC running Dynoware software. In order to determine the G-ratio, wheel diameters were measured before and after each grinding trial using a DEA Swift manual coordinate measuring machine (CMM)connected to a computer programmed with Delcam Power Inspect software. The wheels were assessed at 30different points around the periphery, each at 5 different levels of the wheel width.Both 2D and 3D topographical profiles of the ground workpiece surfaces were recorded using a Taylor Hobson Form Talysurf 120L, with 2D assessment involving a 0.8mm cut-off. Micrographs of the ground surfaces were taken using a JEOL 6060 scanning electron microscope (SEM). Due to space restrictions inthe SEM chamber, wheel surface topography was assessed by producing negative and positive replicas using a graphite block and rubber-resin compound respectively. For the former, the worn wheel was used to grind a graphite block at a wheel speed of 15m/s, table speed of 150mm/min and depth of cut of 1.0mm. Theresulting surface profiles were then traced, which represented negative profiles of the wheel surface (assumed zero wear from grinding of graphite block). In contrast, positive replicas of the wheel surfaces were obtained using a synthetic rubber and resin replicating compound (Microset), after which 3D surface profiles were measured using the Form Talysurf system. 3. Results and discussion 3.1. Grinding forces, radial wheel wear and G-ratio Figure 2 details the vertical (F V ) and horizontal (F H )grinding forces both with and without US vibration. It was observed that when operating without ultrasonics,grinding forces generally increased as the table speed was varied from 200 to 300mm/min due to a corresponding rise in the undeformed chip thickness.Conversely, no such trend was apparent with theincrease in wheel speed from 30 to 40m/s. TheD . Bhaduri et al. / P rocedia CIRP 1 ( 2012 ) 359 – 364362application of US vibration however led to lowergrinding forces in the majority of tests, although reductions in F H was more prominent and varied between 26 to 43%. This was most likely due to the intermittent cutting action of the abrasives under vibration leading to reduced frictional forces in the contact zone between the grits and workpiece as well as smaller average chip thicknesses, despite the modest amplitude generated by the ultrasonic transducer-generator system.Fig. 2. Vertical (F V ) and horizontal (F H ) forces under different grinding conditionsThe effects of operating conditions on radial wheel wear and G-ratio are shown in Fig 3. In general, radial wheel wear (RWW) decreased as the table speed increased from 200 to 300mm/min when operating under standard CFG mode. This was attributed to the shorter contact time between the wheel and workpiece material.Fig. 3. Radial wheel wear and G-ratio under different grinding conditionsWith the hybrid configuration, wheel G-ratio was seen to improve by between 7 to 45% in 5 of the 9 trials (Tests 2, 4, 6, 14, 18), although it was also found to decrease in 3 of the remaining 4 experiments (Tests 10,12, 16). The reason for the latter is unclear, but the highly porous and open structure of the alumina wheel could have led to errors during measurement of wheel diameters using the contact based CMM probe. 3.2. Workpiece surface topography and quality Fig. 4 details the 3D surface topographical parameters (S a , S t , S z ) measured for all tests, while Fig. 5 shows representative 3D topographies of the workpiece surfaces ground with and without ultrasonic assistance respectively. Average surface roughness (S a ) was generally lower when employing US vibration except for tests at the highest parameters (40m/s, 250mm/min and 40m/s, 300mm/min). This was possibly due to the increased incidence of overlapping cuts/greater number of active cutting points per revolution of the wheel compared to when machining under normal grinding conditions, see Fig. 6(a) & 6(b). Conversely, peak to peak (S t ) and 10-point average roughness (S z )parameters were generally higher with surfaces machined under US assisted mode. This was thought to be due to the vibration along the Z-axis of the sonotrode,i.e. in a direction radial to the wheel surface.Furthermore, greater levels of smearing and side flow/ploughing of the workpiece material were evident from the majority of samples analysed when operating with US vibration, which also suggested increased plastic deformation occurred [10], see Fig. 6(c).Fig. 4. 3D topographical parameters of ground workpiece surfacesV w V c G r i n d i n g f o r c e s (N )V c V w G-ratioR a d i a l w h e e l w e a r (μm )V c V w 3D t o p o g r a p h y p a r a m e t e r s , S a , S t , S z (μm )D . Bhaduri et al. / P rocedia CIRP 1 ( 2012 ) 359 – 364 363Fig. 5. Representative 3D topographies of ground surfaces produced; (a) with ultrasonics; (b) without ultrasonicsFig. 6. SEM micrographs of representative ground workpiece surfaces machined; (a) without ultrasonics, (b), & (c) with ultrasonics3.3. Grinding wheel surface evaluationThe average surface roughness (S a ) of the graphite blocks and density of peaks (S ds ) from the resin replicas are shown in Fig. 7. The former value is representative of the post-grinding wheel surfaces, whereas the S ds parameter provides an indication of the static cutting edge density, according to Blunt and Ebdon [20].In general, S a increased as V w was incremented from200 to 300mm/min, irrespective of the wheel speed.Although not shown here, this trend corresponded to equivalent 2D roughness parameters of the ground workpiece surfaces. However following activation of US vibration, the roughness of the graphite replicas/wheel surface decreased in most cases compared to plain grinding, which suggested greater uniformity of the resulting grit heights. This was most likely caused by the ‘conditioning effect’ as a result of the vibration, which also translated to the lower workpiece surface roughness (S a ) detailed in the previous section.Fig. 7. S a of graphite replicas and S ds of resin replicas of the grinding wheel surfaceThe density of peaks (S ds ) of the resin (positive)replicas was found to increase in the majority of tests where vibration was applied (see Fig. 8), although slight reductions were observed in the 3 trials operating at a table speed of 250mm/min (Tests 4, 10 & 16).Fig. 8. Representative 3D topographical plots of wheel surfacesfollowing grinding; (a) with ultrasonics, (b) without ultrasonicsV c V w S ds of resin replica (pks/mm 2)S a o f g r a p h i t e r e p l i c a (μm )D. Bhaduri et al. / P rocedia CIRP 1( 2012 )359 – 364 364It has been reported that a decrease in wheel S ds is generally allied to a rise in workpiece surface roughness, and vice versa [21]. This was in line with results detailed in Fig. 4 & 7 where an increase in S ds (under vibration) corresponded to a lower workpiece surface roughness (S a). This was attributed to the greater number of active cutting points per grain (due to grit fracture) generated with use of US vibration. Butler et al. [21] further suggested that a decrease in S ds value signalled loss of grain sharpness, implying that wheels became sharper when using ultrasonic assisted grinding. In addition, no wheel loading was observed in any of the tests.4.Conclusions•The use of ultrasonic assisted operation typically resulted in the reduction of grinding forces and associated workpiece surface roughness when creep feed grinding Inconel 718 superalloy. Similarly, a corresponding reduction in radial wheel wear and improvement in wheel G-ratio of between 7 to 45%was obtained when grinding in the hybrid configuration.•In terms of surface quality, SEM micrographs revealed greater side flow/ploughing in slots which were machined with the workpiece vibrated in comparison to standard creep feed ground specimens. Furthermore, larger numbers of overlapping grit marks were visible on surfaces subject to ultrasonic assisted grinding.•Three-dimensional topographic measurements of grinding wheel surface replicas indicated that use ofUS vibration generally led to an increase in the number of active cutting points on the wheel. This subsequently resulted in a decrease of correspondingaverage workpiece surface roughness (S a).AcknowledgementsWe are indebted to Dr. A.C. Mathieson and Prof. M. Lucas from the University of Glasgow for the provision of facilities to measure the vibrational amplitude of the block sonotrode. Technical advice from M. Prokic of MP Interconsulting on the ultrasonic transducer and generator system is also gratefully acknowledged. Thanks are also due to Rolls-Royce, Element Six, Saint-Gobain Abrasives and Hardinge Machine Tools for additional funding, tooling and technical support.References[1] Thoe TB, Aspinwall DK, Wise MLH. Review on ultrasonicmachining. Int J Mach Tools Manuf 1998; 38:239-255. [2] Colwell LV. The effects of high-frequency vibrations in grinding,Transac ASME 1956;78:837-45.[3] Anon. Ultrasonic vibrations help grinding. Steel, TheMetalworking Weekly 1963;152:56-58.[4] Kaliszer H, Limb M. Application of ultrasonic technique ingrinding processes. Int J Mach Tools Des Res 1968;8:189–201. [5] Nakagawa T, Suzuki K, Uematsu T, Kimura M, Yoshida KogyoKK. Development of a new turning centre for grinding ceramicmaterials. CIRP Ann 1988;37:319–22.[6] Onikura H, Ohnish O, Take Y. Fabrication of micro carbide toolsby ultrasonic vibration grinding. CIRP Ann 2000;49:257-60. [7] Suzuki K, Tochinai H, Uematsu T, Mishiro S. A new grindingmethod for ceramics using a biaxially vibrated non-rotationalultrasonic tool. CIRP Ann 1993;42:375–8.[8] Hara K, Isobe H, Kyusojin A, Okada M. Study on mirror surfacegrinding of die steel by using ultrasonically assisted diamondtools. Int J Abrasive Technol 2008;1:265–73.[9] Nomura M, Wu Y, Kuriyagawa T. Investigation of internalultrasonically assisted grinding of small holes: effect of ultrasonic vibration in truing and dressing of small CBN grinding wheel. JMech Sci Technol 2007;21:1605-11.[10] Spur G, Holl SE. Ultrasonic assisted grinding of ceramics. J MaterProcess Technol 1996;62:287-93.[11] Uhlmann E. Surface formation in creep feed grinding of advancedceramics with and without ultrasonic assistance. CIRP Ann1998;47:249-52.[12] Yan Y, Zhao B, Liu J. Ultraprecision surface finishing of nano-ZrO2ceramics using two-dimensional ultrasonic assisted grinding.Int J Adv Manuf Technol 2009;43:462-7.[13] Gao GF, Zhao B, Xiang DH, Kong QH. Research on the surfacecharacteristics in ultrasonic grinding nano-zirconia ceramics. JMater Process Technol 2009;209:32-7.[14] Wu Y, Fan Y, Kato M, Kuriyagawa T, Syoji K, Tachibana T.Development of an ultrasonic elliptic-vibration shoe centerlessgrinding technique. J Materi Proc Technol 2004;155-156:1780-7.[15] Wu Y, Fan Y, Kato M. A feasibility study of microscalefabrication by ultrasonic-shoe centerless grinding. Prec Eng2006;30:201-10.[16] Tawakoli T, Azarhoushang B. Influence of ultrasonic vibrationson dry grinding of soft steel. Int J Mach Tools Manuf2008;48:1585-91.[17] Tawakoli T, Azarhoushang B, Rabiey M. Ultrasonic assistedgrinding of soft steel. Ind Diamond Rev 2009;1:40-44.[18] Tawakoli T, Azarhoushang B, Rabiey M. Ultrasonic assisted drygrinding of 42CrMo4. Int J Adv Manuf Technol 2009;42:883-91.[19] Azarhoushang B, Tawakoli T. Development of a novel ultrasonicunit for grinding of ceramic matrix composites. Int J Adv Manuf Technol 2011;57:945-55.[20] Blunt L, Ebdon S. The application of three-dimensional surfacemeasurement techniques to characterizing grinding wheeltopography. Int J Mach Tools Manuf 1996;36:1207-26.[21] Butler DL, Blunt LA, See BK, Webster JA, Stout KJ. Thecharacterisation of grinding wheels using 3D surfacemeasurement techniques. J Mater Process Technol 2002;127:234–7.。

平面振动存在对摩擦减小的影响C. C. Tsai ·C. H. Tseng摘要：在不同的实验中已经观察到通过振动来减少摩擦。

通过调节振动，可以应用这种影响来控制摩擦力。

而且，控制摩擦力通常的方法依赖于润滑剂和适当的材料组合。

振动的叠加可以进一步降低摩擦力。

这项研究基于Dahl摩擦模型得到一种理论方法：描述了在任意角度的切向振动的存在下观察到的摩擦减小。

分析结果表明，在建立减小摩擦中振动的影响模型时，切向应当被考虑。

在任何的振动角度，触头的切向降低减小摩擦的效果。

平行于宏观速度的振动可以最有效的减小摩擦。

关键词：摩擦，振动，建模，Dahl1.介绍在不同的实验中已经观察到通过振动来减少摩擦。

振动的方向可以是接触表面的法向或者切向。

这种影响可以用于减小制造过程中的过程力，像是超声波加工和超声振动图，或者是解决在高真空环境中的位置控制问题，如电子显微镜，可以通过振动振幅的变化来控制摩擦。

探讨超声诱导减少摩擦的起源，Hesjedal和Behme实验研究在微观机械接触摩擦减少的现象。

他们得到结论：摩擦力减少的效果结果完全来自于垂直振动分量。

然而，以往的实验研究上的切向振动显示摩擦减少。

基于该刚性库仑摩擦的定量分析模型显示出相同的趋势作为实验数据，但这些模型有较低的价值。

对于这些类型的联系，以小幅度滑动位移的，Tani表明，刚性库仑摩擦模型是不足以形容摩擦性能的。

在微观水平上，显然光滑表面还是“粗糙的”，表面形貌在表面相互作用中起重要作用。

当这些表面彼此压靠，所述真实接触面积通常为用肉眼观察到的表观面积的1/400至1 / 10,000，如图1所示。

突起的特征被称为粗糙。

最古老，最简单的微模型是格林伍德威廉姆森模型，该模型假设表面是由半球形的凹凸倾1斜。

这些凹凸具有均匀球体半径和凸起体高度的对称高斯分布。

赫兹公式中球体和半空间的弹性接触被用来计算负荷，接触面积，和变形凹凸的接触压力。

实验已经观察到，当两个接触面互相滑动，实际体滑动开始之前，一个表面的运动比其他要早。

Modeling and Simulation 建模与仿真, 2023, 12(2), 1512-1522 Published Online March 2023 in Hans. https:///journal/mos https:///10.12677/mos.2023.122141基于超声振动辅助车削的建模与仿真研究钱兆峰，王 艳上海理工大学机械工程学院，上海收稿日期：2023年2月13日；录用日期：2023年3月21日；发布日期：2023年3月28日摘要超声振动辅助车削相对于传统车削加工有提高车削效率、提高刀具使用寿命、提高材料加工表面完整性等优点。

本文分析了车削加工中的振动机理，阐述了超声振动对传统车削加工的影响，同时以钛合金(TC4)为研究对象，基于振动学理论，建立了一种表征传统车削振动系统的解析模型，并使用ABAQUS 软件建立了二维车削有限元切削仿真模型，开展了传统车削与超声振动辅助车削两种工艺的TC4切削仿真模拟。

仿真结果表明，当超声振幅在4 μm~12 μm 内时，超声振动辅助车削加工相较于传统车削加工，刀具受到的径向力下降了11.4%~20%，TC4加工表面最大压应力下降了7.8%~19.4%，且加工表面压应力和径向力均随着超声振幅的提高而下降。

关键词车削，钛合金(TC4)，超声振动，ABAQUSModeling and Simulation Research Based on Ultrasonic Vibration Assisted TurningZhaofeng Qian, Yan WangSchool of Mechanical Engineering, University of Shanghai for Science and Technology, ShanghaiReceived: Feb. 13th , 2023; accepted: Mar. 21st , 2023; published: Mar. 28th , 2023AbstractCompared with traditional turning, ultrasonic vibration assisted turning has the advantages of improving turning efficiency, improving tool life and improving surface integrity of material processing. In this paper, the vibration mechanism in turning is analyzed, and the influence of ul-trasonic vibration on traditional turning is expounded. At the same time, taking titanium alloy (TC4) as the research object, an analytical model characterizing the vibration system of traditional turning is established based on the theory of vibration. The two-dimensional turning finite ele-ment cutting simulation model is established by using ABAQUS software, and the TC4 cutting si-钱兆峰，王艳mulation of traditional turning and ultrasonic vibration assisted turning is carried out. The simu-lation results show that when the ultrasonic amplitude is within 4 μm~12 μm, compared with the traditional turning, the radial force of the tool is reduced by 11.4%~20%, and the maximum com-pressive stress of the TC4 machined surface is reduced by 7.8%~19.4%. The surface compressive stress and radial force decrease with the increase of ultrasonic amplitude.KeywordsTurning, Titanium Alloy (TC4), Ultrasonic Vibration, ABAQUSThis work is licensed under the Creative Commons Attribution International License (CC BY 4.0)./licenses/by/4.0/1. 引言钛合金(TC4)是一种难加工材料，具有材质较轻、强度硬度高、耐热性强、抗腐蚀性好等优点[1]。

摘要摘要随着矿产资源勘探深度的增加，复杂地层与难钻地层钻遇率升高，硬岩层所占比例越来越大，现有钻探技术已不能完全满足当今钻井作业需求。

尤其是在硬岩地层的钻进中，常规钻探方法存在钻头寿命短、钻进效率低、钻探成本高的技术问题。

因此，亟须研究一种高效碎岩技术来解决这一钻进难题，从而提高钻进效率，降低钻进成本。

本文针对上述钻进难题，提出采用超声波振动辅助碎岩的方法。

超声波振动的频率较高，可以达到硬岩的固有频率，岩石在共振条件下会产生较大的振幅，此时岩石内部裂纹裂隙极易发育、扩展及贯通，造成岩石破碎难度的大幅度下降。

但是，随着岩石力学性能劣化现象的产生，其固有频率的下降规律以及其本身的固有频率范围还有待测试研究。

因此，进行超声波振动频率对硬岩破碎规律的研究很有意义，通过研究岩石的破碎规律，一方面可以估算硬岩的固有频率，另一方面可以确定岩石频率的改变规律，用以确定超声波振动频率的加载范围及加载方式，为超声波振动辅助硬岩钻进提供理论指导及技术支持。

本文的研究对象为花岗岩，以试验研究为基础，辅以理论分析及数值模拟分析的研究手段，开展超声波振动频率对硬岩破碎规律的研究。

本论文的主要研究内容及成果如下：（1）结合断裂力学理论和共振碎岩理论，从理论上分析超声波振动下岩石破碎的机理。

建立超声波振动力学模型，开展超声波振动频率对岩石破碎影响规律的分析。

研究结果表明在固有频率范围之内对岩石进行振动加载能更有利于岩石的破碎，系统的阻尼越强则对振动的抑制效果越强。

（2）采用ANSYS/WORKBENCH软件对模型进行了有限元模拟分析。

研究岩石内部裂纹参数对模型模态频率、谐响应频率、应力强度因子以及应力应变变化规律的影响。

研究发现裂纹的走向、尺寸、数量均会造成岩石颗粒模型的模态频率降低的现象，并且岩石应力、应变的峰值随着振动频率的增加呈现先增大后降低的趋势，在振动频率为35KHz时出现最大值。

（3）研制了超声波振动试验台，对花岗岩样品进行超声波振动试验，并对试验前、后的花岗岩样品进行核磁共振检测以及单轴抗压强度测试。

第53卷第6期表面技术2024年3月SURFACE TECHNOLOGY·11·激光熔覆铁基合金涂层的研究进展李垭焓1，谭诚香1，李梦瑶1，田煜博1，王然1，张亚龙1，王茜1*，张峻巍1，张亮2，叶风3（1.辽宁科技大学 材料与冶金学院，辽宁 鞍山 114051；2.抚顺隆烨化工有限公司， 辽宁 抚顺 113217；3.沈阳防锈包装材料有限责任公司，沈阳 110033）摘要：激光熔覆技术作为一种先进的材料表面改性技术，具有加工效率高、涂层稀释率低且与基体结合强度高、自动化程度高、环境友好等优点。

在各类熔覆材料中，铁基合金在成分上与钢铁材料最为接近，且其成本相对较低，近年来在设备零部件表面强化和再制造领域得到广泛应用。

结合国内外最新相关研究成果，从材料体系、工艺参数、外场辅助技术等方面对激光熔覆铁基合金涂层的研究进展进行了综述。

总结了熔覆材料的选材依据以及铁基自熔性合金粉末、不锈钢粉末、铁基非晶合金粉末、铁基复合粉末等各类材料的特点和应用。

系统讨论了激光功率、扫描速度、光斑直径、送粉速率等工艺参数对铁基涂层成形质量和微观组织及性能的影响机制，并介绍了工艺参数优化在高质量熔覆层制备中的应用。

同时，论述了超声振动、电磁场、温度场等外场辅助技术在激光熔覆铁基合金涂层中的应用，阐明了外加能场对激光熔覆过程中熔池及凝固组织的作用机理。

最后对激光熔覆铁基合金涂层未来的发展方向进行了展望。

关键词：激光熔覆；铁基涂层；研究进展；材料体系；工艺参数；外场辅助中图分类号：V261.8 文献标志码：A 文章编号：1001-3660(2024)06-0011-17DOI：10.16490/ki.issn.1001-3660.2024.06.002Research Progress of Laser-cladding Fe-based Alloy CoatingLI Yahan1, TAN Chengxiang1, LI Mengyao1, TIAN Yubo1, WANG Ran1, ZHANG Yalong1,WANG Qian1*, ZHANG Junwei1, ZHANG Liang2, YE Feng3(1. School of Materials and Metallurgy, University of Science and Technology Liaoning, LiaoningAnshan 114051, China; 2. Fushun Longye Chemical Co., Ltd., Liaoning Fushun 113217, China;3. Shenyang Packaging Materials Co., Ltd., Shenyang 110033, China)ABSTRACT: As an advanced material surface modification technology, laser cladding uses laser beam with high energy density as the heat resource. By melting and solidifying the cladding material and substrate surface rapidly and simultaneously, the cladding layer with specific properties can be prepared on the substrate. Compared with other technologies, laser cladding has the advantages of high processing efficiency, low dilution rate, high bonding strength with substrate, high degree of收稿日期：2023-03-12；修订日期：2023-08-13Received：2023-03-12；Revised：2023-08-13基金项目：国家自然科学基金项目（51874091, 52101087）；教育部产学合作协同育人项目（220607018162819）；辽宁科技大学大学生创新创业训练计划项目（S202310146035）Fund：National Natural Science Foundation of China (51874091, 52101087); University-Industry Collaborative Education Program of Ministry of Education (220607018162819); Innovation and Entrepreneurship Training Program for College Students in University of Science and Technologly Liaoning (S202310146035)引文格式：李垭焓, 谭诚香, 李梦瑶, 等. 激光熔覆铁基合金涂层的研究进展[J]. 表面技术, 2024, 53(6): 11-27.LI Yahan, TAN Chengxiang, LI Mengyao, et al. Research Progress of Laser-cladding Fe-based Alloy Coating[J]. Surface Technology, 2024, 53(6): 11-27.*通信作者（Corresponding author）·12·表面技术 2024年3月automation and environmental friendliness, thus it has been successfully applied in machining, transportation, petrochemical and other fields. Among all kinds of cladding materials, Fe-based alloys are most similar to steel materials in composition, and their cost is relatively low compared with that of Ni-based and Co-based alloys. In recent years, Fe-based alloys have been widely used in the fields of surface strengthening and remanufacturing of equipment parts. Based on the latest studies in China and abroad, the research progress of laser cladding Fe-based alloy coatings is reviewed from the aspects of material system, process parameter, and application of external field auxiliary technology. Cladding materials play a crucial role in the properties of the coatings. The compatibility, wettability, chemical composition, and physical property differences between the cladding materials and substrate materials should be fully considered on the basis of working condition and performance requirement for selection of cladding materials. The characteristics and applications of various materials including Fe-based self-fluxing alloy powder, stainless steel powder, amorphous alloy powder, and Fe-based composite powder are summarized. The process parameters during the laser cladding process also play a significant role in the deposition rate, forming quality, phase composition, microstructure, and comprehensive properties of the coatings. The effect mechanisms of process parameters such as laser power, scanning speed, laser spot diameter, and powder feeding rate on the forming quality, microstructure, and properties of Fe-based coatings are systematically discussed. It is worth noting that actual laser cladding process is the interaction between multiple parameters, which can lead to a complex nonlinear relationship between the process parameters and quality of the cladding layers. Thus, the application of process parameter optimization in the preparation of high quality coatings is also introduced.Moreover, reasonable cladding material design and optimization of laser cladding process parameters can reduce the number of defects in the coating to a certain extent, but it is still difficult to completely eliminate the cracks in Fe-based coatings with high hardness. Meanwhile, the solidification characteristics of laser cladding through rapid heating and cooling can result in insufficient diffusion of elements in the molten pool, resulting in poor microstructure uniformity of the cladding layer, which ultimately affects its performance. Therefore, the applications of external field auxiliary technologies including ultrasonic vibration field, electromagnetic field, and temperature field in the laser cladding of Fe-based alloy coating are discussed in detail. The mechanism of external energy field on the melting pool and solidification structure during the laser cladding process is illustrated. Finally, the future development direction of laser cladding Fe-based alloy coating is prospected.KEY WORDS: laser cladding; Fe-based coating; research progress; material system; process parameter; external field auxiliary激光熔覆是一种先进的表面改性和修复技术，它利用高能量密度的激光束作为热源，通过将熔覆材料和基体材料快速熔化并凝固，在基体表面形成具有耐磨损、耐腐蚀等性能的强化层[1-2]。

S. Square has dedicated in ultrasonic field over 21 years since 1980 and earned a worldwide reputation for his specialty, flexibility and sincerity in the past decades.The ultrasonic vibration micro nozzle consists a piezoelectric ceramic and a metal foil, on which over thousands micro nozzles formed. Using the same principle as inkjet printer, this transducer atomizes water or liquids through a matrix of micro holes of around 7-10 m.The micro nozzles ultrasonic atomizing transducer can use siphon to draw small amount liquids to the surface of metal foil and then to atomize, which is much efficiency than the conventional ultrasonic atomizer for which a liquid tank with high level liquid has to be always loaded on the surface of ultrasonic transducers.Featuresz Fine and consistent misted particle sizez Adjustable misted particle sizez No loaded liquids require as comparing with conventional atomizersz High atomizing efficiencyz Less power consumptionz High stability and durability Applicationsz Humidification in refrigerated food displays and storage, living environments,and air conditioning plants.z Inhalation and disinfecting equipmentz Humidification in industrial process control for lubrication, coating and etc.z Liquids dispensing systems Specification:Model NumberM2313500ResonantFrequency135.0±5KHzImpedance 10 Ohm typ.Capacitance2450±20%pFDimensions L:W:T:t:29.20 mm17.35 mm1.0 mm (PZT Element)50 m (Metal)Metal Material Ni-Co AlloyNozzle size 7 – 10 mImpedance/Phase Angle:110100100010000100000120123126129132135138141144147150Frequency (KHz)Impedance(Ohm)-90-60-30306090PhaseAngle(Degree)S. Square Enterprise Company, LimitedPro-Wave Electronics CorporationSupplied by Midas Components Ltd, , tel: +44 1493 602602, fax: +44 1493 665111Construction:Remark: The negative side faces to the opening, the positive side faces to the liquid source, if driving circuit uses NPN transistor.。

DOI：10.16662/ki.1674-0742.2024.07.014超声龈下刮治和手工龈下刮治应用于轻中度慢性牙周炎治疗中的效果对比李叶丰，林晓鹭，王美燕厦门医学院附属口腔医院牙周病科，福建厦门361016［摘要］目的分析超声龈下刮治和手工龈下刮治治疗轻中度慢性牙周炎的效果。

方法回顾性选取2022年6月—2023年6月厦门医学院附属口腔医院80例慢性牙周炎患者的临床资料，根据治疗方式不同分为超声组和手工组，各40例。

超声组采用超声龈下刮治，手工组采用手工龈下刮治。

比较两组治疗效果。

结果治疗后，超声组菌斑指数、简化软垢指数、简化牙石指数、龈沟出血指数、牙龈指数和疼痛评分均低于手工组，差异有统计学意义（P均<0.05）。

超声组不良反应发生率为10.00%，与手工组的15.00%比较，差异无统计学意义（χ2=0.457，P>0.05）。

结论超声龈下刮治治疗轻中度慢性牙周炎的效果确切，可有效改善患者牙面清洁情况和牙龈情况，缓解疼痛。

［关键词］慢性牙周炎；超声龈下刮治；牙面清洁；牙龈情况；炎症反应［中图分类号］R5 ［文献标识码］A ［文章编号］1674-0742（2024）03(a)-0014-05Comparison of Effect of Ultrasonic Subgingival Scaling and Manual Sub⁃gingival Scaling in the Treatment of Mild to Moderate Chronic Periodonti⁃tisLI Yefeng, LIN Xiaolu, WANG MeiyanDepartment of Periodontology, the Affiliated Stomatological Hospital of Xiamen Medical College, Xiamen, Fujian Prov⁃ince, 361016 China[Abstract] Objective To analyze the effects of ultrasonic subgingival scaling and manual subgingival scaling in the treatment of mild to moderate chronic periodontitis. Methods The clinical data of 80 patients with chronic periodonti⁃tis in the Affiliated Stomatological Hospital of Xiamen Medical College from June 2022 to June 2023 were retrospec⁃tively selected. According to different treatment methods, the patients were divided into ultrasonic group and manual group, 40 cases in each group. The ultrasonic group was treated with ultrasonic subgingival scaling, and the manual group was treated with manual subgingival scaling. The therapeutic effect of the two groups was compared. Results Af⁃ter treatment, the plaque index, simplified soft scale index, simplified calculus index, gingival sulcus bleeding index, gingival index and pain scores in ultrasound group were lower than those in manual group, and the differences were statistically significant (all P<0.05). The incidence of adverse reactions in the ultrasound group was 10.00%, com⁃pared with 15.00% in the manual group, and the difference was not statistically significant (χ2=0.457, P>0.05). Con⁃clusion Ultrasonic subgingival scaling is effective in the treatment of mild to moderate chronic periodontitis, which can effectively improve the cleaning of the tooth surface and the condition of the gum, and relieve the pain.[Key words] Chronic periodontitis; Ultrasonic subgingival scaling; Dental surface cleaning; Gingival condition; Inflammatory response[作者简介] 李叶丰（1985-），男，本科，主治医师，研究方向为慢性牙周炎。

扬州市人民政府关于2017-2019年度扬州市自然科学优秀学术论文评选结果的通报
文章属性
•【制定机关】扬州市人民政府
•【公布日期】2021.03.05
•【字号】扬府发〔2021〕16号
•【施行日期】2021.03.05
•【效力等级】地方规范性文件
•【时效性】现行有效
•【主题分类】科技成果与知识产权
正文
市政府关于2017-2019年度扬州市自然科学优秀学术论文评选结果的通报-市政府文件-政府办
各县（市、区）人民政府，经济技术开发区、生态科技新城、蜀冈—瘦西湖风景名胜区管委会，市各委办局（公司），市各直属单位：
为提高我市自然科学学术水平，鼓励全市科技工作者开展学术创新服务发展，促进全市科技人才成长，2020年我市开展了2017-2019年度扬州市自然科学优秀学术论文评选工作，共征集到701篇论文，其中675篇论文通过资格审查。

经评审委员会评定，分理工类、农业类、医药类、管理教育类，共评出优秀学术论文269篇，其中一等等次33篇、二等等次101篇、三等等次135篇。

经研究，市政府决定对评选出的269篇优秀学术论文给予通报并颁发证书。

希望全市各级科技团体和广大科技工作者，以科技赋能产业为己任，积极开展学术研究，主动投身科技创新，脚踏实地，严谨求是，把“好地方”扬州建设得好上加好、越来越好做出积极贡献。

附件：2017-2019年度扬州市自然科学优秀学术论文评选结果
扬州市人民政府
2021年3月5日附件
2017-2019年度扬州市自然科学优秀学术论文评选结果
一等等次（33篇）
二等等次（101篇）
三等等次（135篇）。

第52卷第8期表面技术2023年8月SURFACE TECHNOLOGY·433·超声微锻Ti3Al熔覆层组织与性能的实验研究高国富，潘贤荣，常黎明，王得宇，赵波（河南理工大学，河南 焦作 454003）摘要：目的采用超声振动与微锻技术相结合的表面改性技术，在Ti-6Al-4V基体上获得组织优良、物理性能好的Ti3Al熔覆层。

方法搭建超声微锻装置，采用单因素实验研究超声振幅、加工温度、锻打力、锻打时间对熔覆层金相组织、晶粒以及显微硬度的影响规律。

借助金相显微镜（OM）、扫描电子显微镜（SEM）、显微硬度计对熔覆层的宏观形貌、微观组织及显微硬度进行分析和测试。

结果在超声微锻处理下，熔覆层组织与性能得到显著改善。

熔覆层表面平整度与超声振幅呈正相关，随着超声振幅、锻打力的增大，粗大的树枝状α2相逐渐锻碎细化为大量的短棒状α2相和针状α2相以及少量的片层状α2相和等轴α2相，等轴晶的含量与分布范围增大，晶粒细化效果越来越明显。

熔覆层各区域的显微硬度值均随着超声振幅、锻打时间的增加而有不同程度的提高。

当超声振幅为7 μm时，熔覆层顶部、中部、底部的显微硬度分别提高了18.4%、22.8%、51.5%。

当锻打时间为5 s时，熔覆层顶部、中部、底部的显微硬度分别提高了15.5%、15.8%、37.8%。

熔覆层顶部显微硬度值随着锻打力的增大呈现出逐渐升高的趋势，显微硬度最高可达55.1HRC，其他区域的硬度呈现逐渐降低的趋势。

结论超声微锻能够有效改善熔覆层的宏观形貌以及内部组织，细化晶粒，选择合适的工艺参数可进一步提高其显微硬度值。

因此，超声微锻可作为一种有效的熔覆层改性技术。

关键词：超声微锻；Ti3Al；熔覆层；微观组织；显微硬度；工艺参数中图分类号：TG174 文献标识码：A 文章编号：1001-3660(2023)08-0433-11DOI：10.16490/ki.issn.1001-3660.2023.08.039Experimental Study on Organization and Properties of UltrasonicMicro-forging Ti3Al Cladding LayersGAO Guo-fu, PAN Xian-rong, CHANG Li-ming, WANG De-yu, ZHAO-Bo(Henan Polytechnic University, Henan Jiaozuo 454003, China)ABSTRACT: The work aims to achieve Ti3Al cladding layers with superior structure and good physical properties on Ti-6Al-4V substrate, by applying the surface modification technology combining ultrasonic vibration and micro-forging. In this work, a ultrasonic micro-forging device was built and the effect of ultrasonic amplitude, processing temperature, forging force and forging time on the metallographic organization, grain size and microhardness of the cladding layer was investigated by single-factor test. The macroscopic morphology and microstructure of the forged cladding layer were observed by a metallographic microscope (OM) and a scanning electron microscope (SEM). The microhardness of the forged cladding layer收稿日期：2022-09-16；修订日期：2022-11-11Received：2022-09-16；Revised：2022-11-11基金项目：国家自然科学基金（51875179）Fund：The National Natural Science Foundation of China (51875179)作者简介：高国富（1970—），男，博士，教授，主要研究方向为精密超精密技术与装备。

New Journal of Glass and Ceramics, 2012, 2, 144-149doi:10.4236/njgc.2012.24021 Published Online October 2012 (/journal/njgc)Influence of Composite Non Magnetic Ions (Cd-Ti) Doping on Structural and Electrical Properties of Li-Mn Ferrite Vidya J. Deshmukh1, Pragati S. Jadhav2, Ketaki K. Patankar2*, Sharad S. Suryawanshi3, Vijaya R. Puri4 1Ramkrishna Paramhansa Mahavidyalaya, Osmanabad College, Osmanabad, India; 2Physics Department Rajaram College, Kolhapur, India; 3Physics Department, Solapur University, Solapur, India; 4Physics Department, Shivaji University, Kolhapur, India.Email: *Received May 6th, 2012; revised July 23rd, 2012; accepted August 16th, 2012ABSTRACTThe Li-Mn ferrites with composite divalent and tetravalent non-magnetic ions doping were prepared by ceramic method and studied for the first time to investigate their structural and electrical properties. It has been confirmed from the studies that these materials result in properties suitable for microwave applications. The structural properties have con- firmed the formation of cubic spinel ferrite and the substitutions of non magnetic ions have resulted in increase of unit cell dimensions and hence the grain size with increase in dopant content. An IR study asserts the same. Electrical Prop- erties show increase in dc resistivity and decrease in dielectric loss tangent with increase in dopant concentration. Keywords: Electronic Materials; Magnetic Ceramics; Electrical Characterization; Powder Diffraction1. IntroductionLi ferrite is becoming increasingly attractive for micro- wave applications replacing garnets and other spinel fer- rites [1-3]. Microwave devices such as circulators, isola- tors, magnetostatic resonators, filters, switches, limiters and tunable electroptic modulators are the microwave applications of Li ferrites [4]. Recent exponential growth in microwave communication through mobile and satel- lite communications has further stressed the worldwide need for extremely low-loss and economical microwave devices using ferrite materials. In preparation of micro- wave ferrite materials, particular attention should be given to the purity of the raw materials, stoichiometry of the composition and porosity as well as grain characteris- tics of the final product. Characteristics of various mi- crowave ferrites have been minutely reported by Voron- kov et al. [5]. The emergence of Li ferrite as a competent material in microwave devices has resulted from some appropriate chemical substitutions made in it, which in turn result in low dielectric loss tangent, a low magnetic loss tangent at the operating bias field, a low coercive force and a large remanence ratio [6-8]. Low dielectric and magnetic losses are the essential requisites for mi- crowave applications Small amounts of Mn3+ is added to microwave Li ferrites to ensure an acceptably low di- electric loss tangent [9]. Moreover, manganese addition also alter the hysteresis property, reduces magnetocrys- talline anisotropy and magnetostriction in ferrites [9]. Non magnetic ions like Cd2+ and Ti4+ substitutions have been found to be most suitable to obtain high resistivity [10,11]. The site occupancies of the various cations known from earlier works are given as follows. Li1+ has strong preference for B-Site [12], Cd2+ has strong preference for A site [1], Ti4+ also has strong preference for B-site [13], Fe2+ has strong preference for B-site [1] and Mn3+ has strong preference for B-site [14]. From the above survey, it can be envisaged that investigations on the electrical properties of composite non-magnetic ions doping in Li-Mn ferrite may lead to more interesting results as the studies on their independent doping in Lithium ferrites have al- ready resulted in properties suitable for microwave ap- plications [10,11].In this view, the present paper aims to communicate structural and electric properties in Li0.35Cd x Ti x Mn0.1 Fe2.55–2x O4 where x varies from 0 to 0.5.2. ExperimentalSix samples of different compositions were prepared by standard ceramic technique using pure metal oxides in the form of a series Li0.35Cd x Ti x Mn0.1Fe2.55–2x O4 with x = 0.0, 0.1, 0.2, 0.3, 0.4 and 0.5. AR grade chemicals of Li2CO3, CdO, TiO2, Mn2O3 and Fe2O3 were used for the preparation of various compositions in the above ferrite series. These oxides were weighed in the required mole proportions using a single pan balance having least count 0.001 gm and mixed thoroughly in the agate-mortar in acetone for about 2 hrs. The mixture was sieved using a*Corresponding author.Influence of Composite Non Magnetic Ions (Cd-Ti) Doping on Structural and Electrical Properties of Li-Mn Ferrite 145sieve of mesh size 200 micron. The mixture of each com- position was preheated in platinum crucible and were presintered at 300˚C for 2 hours and followed by 600 Influence of Composite Non Magnetic ions (Cd-Ti) Do- ping on Structural and Electrical Properties of Li-Mn Ferrite for 4 hrs and finally sintered at 1000˚C for 8 hours.X-ray Diffractograms of various compositions were obtained using X ray diffractometer Model PW 3710. The various parameters used for X ray diffraction were Target—Cu Kα; Wavelengths λ1 = 1.54056 Å and λ2 = 1.54439 Å; Rate of Scanning—2˚/min and scanning an-gle range 2θ—20˚ to 90˚. Micrographs of various sam- ples were obtained using the scanning electron micro- scope SEM (model JSM-6360A). IR absorption peaks of various compositions were studied using PerkinElmer IR spectrometer (Model 783) with KBr as a solvent. DC resistivities of various prepared samples were studied using two probe set up. Dielectric constant and loss tan- gent in the frequency range 100 Hz - 1 MHz were also measured using HP LCR meter 4284A model.3. Results and DiscussionThe X-Ray diffraction patterns for Li0.35Cd x Ti x Mn0.1 Fe2.55–2x O4 system show sharp peaks indicating formation of single phase spinel ferrite for all compositions. How- ever trace amount of α-Fe2O3 phase is found for x = 0.3 sample. Hence the XRD of x = 0.3 composition is given in the Figure 1. The α-Fe2O3 phase is formed because at higher sintering temperature (>500˚C) there is possibil- ity for a fraction of ferric oxide to get converted into α-Fe2O3. The presence of such a phase in different ferrite is already reported by earlier workers [15].The lattice parameter increases with increasing the content of Cd2+and Ti4+ ions and is shown in Figure 2. This is in accordance with Vegard’s law. The Cd2+ ions have larger ionic radius (0.97 Å) as compared to Fe3+Figure 1. Fe2O3 pattern XRD of Li0.35Cd0.3Ti0.3Mn0.1 Fe1.95O4.Figure 2. Variation of lattice parameter with Cd and Ti content [x] in Li0.35 Cd x Ti x Mn0.1Fe2.55–2x O4 series.(0.65 Å), Ni2+ (0.74 Å) and Li1+ (0.71 Å) ions. The Cd2+ ions successively replace Fe3+ ions on A-site this results in an increase of lattice parameter with Cd content. Same is true for Ti ions at B-sites. Similar results were ob- tained when Cd and Ti were separately doped in Li fer- rite [10,11]. The compositional variations however sug- gest that the lattice parameters for composite non-mag- netic ions doping is increased to larger extent in com- parison to their separate doping in ferrites.The SEM technique was studied to understand the surface morphology of the samples. All compositions have grains with sharp boundaries indicating that grains are fully developed, well packed, crack free with clear grain boundaries. The grain boundaries are district and grains are closely packed in some cases which suggest that compositions exhibit high density values. The SEM images denoted by a, b, c, d, e, and f shows micrographs for compositions x = 0.0, 0.1, 0.2, 0.3, 0.4, and 0.5. With the addition of Cd-Ti ions the average grain size in- creases as shown in the Figures3(a)-(f). The increase in grain diameter with Cd and Ti content is attributed to the smaller solid solubility of lithium in the samples. It is obvious from the generic formula.The IR spectra of one representative member of ferrite series i.e. x = 0.3 is shown in Figure 4. The IR absorp- tion bands were observed in the range 600 cm–1 to 400 cm–1. The absorption bands obtained in the present investi- gation are found to be in the range reported for many other lithium containing ferrites [16,17]. The difference in band position ν1 and ν2 is expected because the Fe3+-O2–distance for B site (0.199 nm) is different from that of A site (0.189 nm). The tetrahedral vibrations are of bond stretching type while octahedral vibrations are of bond bending type. These types of vibrations also affect the absorption frequency. The octrahedral complex band is found to be suppressed with increase in composite non- magnetic ions content in the ferrite. This can be attri- buted to increase in the lattice parameter and average grain size with increase in Cd-Ti content.Influence of Composite Non Magnetic Ions (Cd-Ti) Doping on Structural and Electrical Properties of Li-Mn Ferrite 146(a) (b) (c)c(d) (e) (f)Figure 3. SEM of series Li0.35Cd x Ti x Mn0.1Fe2.55–2x O4 with x = 0 to 0.5.Variation of logρ vs 103/T for the samples Li0.5Cd x Ti xMn0.1Fe2.55–2x O4 and Li0.35Cd x Ti x Mn0.1Fe2.55–2x O4 with x =0, 0.1, 0.2, 0.3, 0.4, and 0.5 are shown in Figure 5. Allthe plots exhibit a linear relationship suggesting that theresistivity obeys a relation ρ =ρ0 exp(ΔE/kT) and cha-nge in slope is observed in case of all the compositions.From figure, it is seen that the variation is almost linearup to Curie temperature where a break occurs indicatinga change of magnetic ordering from ferrimagnetic to para-magnetic. The temperatures where breaks occur coincidewith the Curie temperature determined by permeabilitymeasurements which is not reported here. The exponen-tial increase in resistivity on decrease in temperature isdue to decrease in thermally activated mobility of thecharge carrier. The change in slope is attributed to thechange in the activation energy due to phase transition ofthe material from ferromagnetic to paramagnetic state.This anomaly strongly supports the influence of magneticordering upon the conductivity process in-ferrites. Manyworkers have studied logρ vs (1/T) and observed similarbehaviour suggesting that resistivity obeys the Arrheniusrelation [11,18]. Resistivity studies show that resistivity(ρdc) of the samples in the compositions increase as theCd2+, Ti4+ concentration increases similar to that reportedin 10 and 11 D.C. resistivity of Li-Cd-Ti ferrite can beexplained on the basis of a model based on phonon as-sisted electron hopping. Trace amount of Fe2+ ions arepresent in the present ferrites. The electrons are known toparticipate in the exchange process by the following re-action Fe2+↔ Fe3+ + e. Hence these electrons arestrongly coupled to the lattice and tunnel from one site tothe other due to phonon induced transfer mechanism.Ti4+ ions, being tetravalent, localize Fe2+ ions in the sys-tem and tunneling of electrons by transfer mechanism isretarded due to the reduction of Fe3+ ions which enhancesthe resistivity. The activation energy is estimated to be0.21 eV, which in turn confirms the conduction in pre-sent ferrites are due to small polarons [18].The dielectric constant decreases with increase in fre-quency showing dielectric dispersion as depicted in Fig-ure 6. The decrease in ε with frequency is natural be-cause of the fact that any species contributing to polar-izability is found to show lagging behind the appliedLi-Cd-Ti ferrite can be explained on the basis of a modelbased on phonon assisted electron hopping. Traceamountof Fe2+ ions is present in the present ferrites. The electronsare known to participate in the exchange process by thefollowing reaction Fe2+↔ Fe3+ + e. Hence these elec-trons are strongly coupled to the lattice and tunnel fromone site to the other due to phonon induced transfermechanism. Ti4+ ions, being tetravalent, localize Fe2+ions in the system & tunneling of electrons by transfermechanism is retarded due to the reduction of Fe3+ ionswhich enhances the resistivity. The activation energy isestimated to be 0.21 eV, which in turn confirms the con-duction in present ferrites are due to small polarons [18].Influence of Composite Non Magnetic Ions (Cd-Ti) Doping on Structural and Electrical Properties of Li-Mn Ferrite 1474. ConclusionThe Li 0.35Cd x Ti x Mn 0.1Fe 2.55–2x O 4 system has been suc- cessfully prepared with standard ceramic technique. The most intense (311) peak in XRD pattern confirms the formation of cubic spinel ferrite. The SEM micrograph shows the agglomerated grain structure with sharp grainboundaries due to high sintering temperature. The IR studies show the absorption bands which are in good agreement to the studied literature. The electrical proper- ties study shows the Li-ferrites are the n-type semicon- ductors. The dielectric constant shows usual dispersionbehaviour.Figure 4. IR spectra of Li 0.35Cd x Ti x Mn 0.1Fe 2.55–2x O 4 with x = 0.3.123456789101111.522.533.5Figure 5. Variation of log ρ vs 103/T for Li 0.35Cd x Ti x Mn 0.1Fe 2.55–2x O 4.14822.533.544.555.56Figure 6. Variation of dielectric constant Є vs logf for ferrite system Li 0.35Cd x Ti x Mn 0.1Fe 2.55–2x O 4.33.544.555.56Figure 7. The plot of dielectric loss tangent (tan δ) vs logf for ferrite system Li 0.35Cd x Ti x Mn 0.1Fe 2.55–2x O 4.5. AcknowledgementsAuthor K. K. Patankar is thankful to UGC, New Delhi for the financial assistance in the form of major research project extended to her.REFERENCES[1] R. G. Kharabe, R. S. Devan, C. M. Kanamadi and B. K.Chougule, “Dielectric Properties of Mixed Li-Ni-Cd Fer- rites,” Smart Materials and Structures , Vol. 15, No. 2, 2006, pp. 229-334. doi:10.1088/0964-1726/15/2/N02[2] S. R. Sawant, D. N. Bhosale, N. D. Chaudhari and P. P.Bakare, “Electric Properties of NiCuZn Ferrites Synthe- sized by Oxalate Precursor Method,” Journal of Materi- als Science , Vol. 3, 2002, pp. 617-622. [3] B. P. Ladgaonkar, P. N. Vasambekar and A. S. Vain-gankar, “Structural and DC Electrical Resistivity Study of Nd3+ Substituted Zn-Mg Ferrites,” Journal of Materials Science Letters , Vol. 19, No. 5, 2000, pp. 1375-1377. doi:10.1023/A:1006713518433 [4] M. Pardavi-Horvath, “Microwave Applications of SoftFerrites,” Journal of Magnetism and Magnetic Materials , Vol. 215-216, 2000, pp. 171-183.Influence of Composite Non Magnetic Ions (Cd-Ti) Doping on Structural and Electrical Properties of Li-Mn Ferrite 149doi:10.1016/S0304-8853(00)00106-2[5]V. Voronkov, “Microwave Ferrites: The Present and Fu-ture,” Journal of Physics IV (Paris), Vol. 7, No. 1, 1997, pp. 35-38.[6] D. Ravinder, “Dielectric Behaviour of Lithium-CadmiumFerrites,” Physica Status Solidi (A), Vol. 129, No. 2, 1992,pp. 549-554. doi:10.1002/pssa.2211290225[7]S. S. Bellad, S. C. Watawe and B. K. Chougule, “SomeAc Electrical Properties of Li-Mg Ferrites,” Materials Re- search Bulletin, Vol. 34, No. 7, 1999, pp. 1099-1106.doi:10.1016/S0025-5408(99)00107-5[8]V. P. Reddy and D. V. Reddy, “Far-Infrared Spectral Stu-dies of Some Lithium-Nickel Mixed Ferrites,” Journal ofMagnetism and Magnetic Materials, Vol. 136, No. 3, 1994,pp. 279-283. doi:10.1016/0304-8853(94)00321-1[9]P. P. Hankare, R. P. Patil, U. B. Sankpal, S. D. Jadhav, I.S. Mulla, K. M. Jadhav and B. K. Chougule, “Magnetic and Dielectric Properties of Nanophase Manganese-Sub- stituted Lithium Ferrite,” Journal of Magnetism and Mag-netic Materials, Vol. 321, No. 19, 2009, pp. 2977-3372.doi:10.1016/j.jmmm.2009.05.074[10]R. G. Kharabe, R. S. Devan and B. K. Chougale, “Struc-tural and Electrical Properties of Cd-Substituted Li-Ni Fer-rites,” Journal of Alloys and Compounds, Vol. 463, No.1-2, 2008, pp. 67-72.[11] D. Kothari, S. Phanjoubam and J. S. Baijal, “ElectricalConduction and Dielectric Behaviour of the Oxidic SpinelLi0.5+0.5x Cr0.3Ti x Fe2.2−1.5X O4,” Journal of Materials Sci- ence, Vol. 25, No. 12, 1990, pp. 5142-5146.doi:10.1007/BF00580142[12]S. Chander, M. P. Sharma, A. Krishnamurthy and B. K.Srivastava, “Mössbauer Study of Nano-Particles of SpinelFerrites Li x Fe3−x O4,” Indian Journal of Pure and Applied Physics, Vol. 45, No. 10, 2007, pp. 816-821. [13]K. P. Chaea, J. G. Lee, H. S. Kweona and Y. B. Lee, “TheCrystallographic, Magnetic Properties of Al, Ti Doped CoFe2O4 Powders Grown by Sol-Gel Method,” Journalof Magnetism and Magnetic Materials, Vol. 283, No. 1, 2004, pp. 103-108. doi:10.1016/j.jmmm.2004.05.010 [14]K. K. Patankar, “Synthesis and Characterization of Mag-netoelectric Composites,” Ph.D. Thesis, Shivaji Univer-sity, Kolhapur, 2000.[15] A. F. Junior, E. C. de O. Lima, M. A. Novak and P. R.Wells, “Synthesis of Nanoparticles of Co x Fe(3−x)O4 by Combustion Reaction Method,” Journal of Magnetism and Magnetic Materials, Vol. 308, No. 2, 2007, pp. 198- 202. doi:10.1016/j.jmmm.2006.05.022[16] B. K. Bammannavar, L. R. Naik, R. B. Pujar and B. K.Chougule, “Preparation, Characterization and Physical Pro- perties of Mg-Zn Ferrites,” Indian Journal of Pure and Applied Physics, Vol. 14, No. 5, 1998, pp. 381-385. [17]P. V. Redy and V. D. Reddy, “Far-Infrared Spectral Stud-ies of Some Lithium-Nickel Mixed Ferrites,” Journal of Magnetism and Magnetic Materials, Vol. 136, No. 3, 1994, pp. 279-283. doi:10.1016/0304-8853(94)00321-1[18]R. S. Patil, S. V. Kakatkar, S. A. Patil, P. K. Maskar andS. R. Sawant, “Electrical Properties of Ferrites,” IndianJournal of Pure and Applied Physics, Vol. 29, 1991, pp.131-135.[19]V. P. Reddy and D. V. Reddy. “Far-Infrared SpectralStudies of Some Lithium-Nickel Mixed Ferrites,” Journalof Magnetism and Magnetic Materials, Vol. 136, No. 3, 1994, pp. 279-283. doi:10.1016/0304-8853(94)00321-1 [20]S. A. Rahman, “Temperature, Frequency and Composi-tion Dependence of Dielectric Properties of Nb Substi- tuted Li Ferrite,” Egyptian Journal of Solids, Vol. 29, No.1, 2006, pp. 131-141.。

CBN 超硬磨粒工具的超声振动辅助钎焊结合界面微观组织和力学性能*蔡开达1， 赵　彪1， 吴帮福1， 丁文锋1， 徐九华1， 赵正彩1， 温学兵2， 李邵鹏2， 陈清良3（1. 南京航空航天大学 机电学院，南京 210016）（2. 中国航发动力股份有限公司，西安 710000）（3. 成都飞机工业（集团）有限责任公司，成都 610092）摘要　采用高频感应钎焊方法制备钎焊CBN 工具存在钎料层厚薄不均匀、连接界面内部易出现气孔等问题，导致钎料对磨粒的把持强度大幅下降、工具使用寿命显著降低。

提出用超声振动辅助钎焊的工艺方法制备钎焊CBN 工具，借助超声波在钎焊过程中的空化效应和振荡作用减少钎料合金内部的气孔，同时细化晶粒，以大幅提升磨粒的把持强度。

结果表明：相比于普通钎焊工艺，采用超声振动辅助钎焊工艺的钎料合金铺展更均匀，区域内部气孔尺寸变小，相同面积上气孔数量减少了75%，单颗CBN 磨粒的剪切力提高了27.7%。

通过Ti-6Al-4V 钛合金磨削对比试验可知：相比普通钎焊工具，超声振动辅助钎焊工具的法向磨削力降低了4.1%～19.6%，切向磨削力降低了8.3%～26.4%，磨削温度降低了5.3%～17.9%。

此外，在相同材料去除体积下，超声振动辅助钎焊CBN 工具的磨粒大块破碎现象明显减少，大幅提升了工具的耐磨性和使用寿命。

关键词　超声振动辅助钎焊；磨粒工具；微观形貌；连接强度；磨削性能中图分类号　TQ164; TG74; TG58　文献标志码　A 文章编号　1006-852X(2023)05-0568-11DOI 码　10.13394/ki.jgszz.2022.0190收稿日期　2022-11-07　修回日期　2023-01-04钎焊超硬磨粒工具由于具有磨粒结合强度高、容屑空间大、自锐性好等优异性能，在航空航天等难加工材料加工领域受到了越来越多的关注[1-3]，如钎焊磨粒工具在韧性材料[4-5]和硬脆材料的磨削加工[6-7]中都有着广泛的应用。

超声振动对软组织穿刺过程中摩擦力的影响魏鹏鹏;张勤河;谭磊;徐英强;张洪才【摘要】背景:摩擦是非常复杂的非线性现象,软组织穿刺过程中的摩擦力是针管与组织间相互作用力的重要组成部分,对穿刺活检取样效率和精度有重要影响.但是目前有关超声振动对穿刺过程中摩擦力的研究较少.目的:明确超声振动辅助穿刺软组织过程中振动振幅对摩擦力的影响规律,并验证摩擦模型的正确性,为超声振动辅助取样装置的设计和开发提供理论依据,提高穿刺活检取样效率和精度.方法:基于LuGre模型,引入超声振动因素,建立活检针表面与软组织之间的摩擦模型.通过新摩擦模型分析附加超声振动后摩擦力减小的原因,并通过实验验证摩擦力随振幅增大的变化规律并证明理论模型的正确性.结果与结论:附加超声振动后,软组织穿刺过程中的摩擦力显著减小.摩擦力随振幅的增大基本成指数为-1的幂函数关系减小.结果显示基于LuGre模型的新摩擦模型能够正确反映超声振动辅助穿刺软组织穿刺过程中振幅对摩擦力的影响规律.超声振动辅助穿刺软组织过程中振幅对摩擦力的影响规律得到明确.【期刊名称】《中国组织工程研究》【年(卷),期】2018(022)024【总页数】6页(P3818-3823)【关键词】穿刺活检;软组织;超声振动振幅;摩擦力;LuGre模型;组织构建【作者】魏鹏鹏;张勤河;谭磊;徐英强;张洪才【作者单位】山东大学机械工程学院,山东省济南市 250061;山东大学机械工程学院高效洁净机械制造教育部重点实验室,山东省济南市 250061;山东大学机械工程学院,山东省济南市 250061;山东大学机械工程学院高效洁净机械制造教育部重点实验室,山东省济南市 250061;山东大学机械工程学院,山东省济南市 250061;山东大学机械工程学院高效洁净机械制造教育部重点实验室,山东省济南市 250061;山东大学机械工程学院,山东省济南市 250061;山东大学机械工程学院高效洁净机械制造教育部重点实验室,山东省济南市 250061;山东大学机械工程学院,山东省济南市 250061;山东大学机械工程学院高效洁净机械制造教育部重点实验室,山东省济南市 250061【正文语种】中文【中图分类】R318文章快速阅读：文题释义：活检：活体组织检查简称“活检”，亦称外科病理学检查，简称“外检”；是指应诊断、治疗的需要，从患者体内切取、钳取或穿刺等取出病变组织，进行病理学检查的技术。