纤维多孔金属的流阻率分形模型研究_陈卫华
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前沿技术L eading-edge technology 耐热镁合金材料的研究和应用现状郑 伟1,柳叶芳1,业 飞1,陈 雪1,展卫星2(1.江苏省产品质量监督检验研究院,江苏 南京 210007;2.盐城市联鑫钢铁有限公司,江苏 盐城 224100)摘 要:镁合金是比重最轻的结构材料。
具有高比强度、高比刚性、良好的磁屏蔽性、优异的制造性和加工性。
镁和镁合金作为轻金属材料是非常重要的金属材料。
廉价耐热镁合金的应用研究对汽车轻量化和扩大镁合金的应用具有重要意义,但大部分合金只能在室温下使用。
当温度超过120℃时,合金的机械特性显著降低,高铝合金也是如此。
因此,在要求高使用温度的汽车零部件中,限制了具有优秀铸造加工性的低成本镁合金的使用。
因此,近年来,高性能、低成本的阻燃耐热镁合金的开发成为材料科学和产业界关注的焦点之一。
关键词:镁合金;稀土;应用现状中图分类号:TG146.22 文献标识码:A 文章编号:1002-5065(2021)04-0125-2Research and application status of heat resistant magnesium alloy materialsZHENG Wei1, LIU Ye-fang1, YE Fei1, CHEN Xue1, ZHAN Wei-xing2(1.Jiangsu Institute of product quality supervision and inspection,Nanjing 210007,China;2.Yancheng Lianxin Steel Co., Ltd,Yancheng 224100,China)Abstract: Magnesium alloy is the lightest structural material. It has high specific strength, high specific stiffness, good magnetic shielding, excellent manufacturability and processability. Magnesium and magnesium alloys are very important metal materials as light metal materials. The research on the application of low-cost heat-resistant magnesium alloys is of great significance to the lightweight of vehicles and the expansion of the application of magnesium alloys, but most of the alloys can only be used at room temperature. When the temperature exceeds 120 ℃, the mechanical properties of the alloy decrease significantly, so does the high aluminum alloy. Therefore, the use of low-cost magnesium alloy with excellent casting processability is limited in automotive parts requiring high service temperature. Therefore, in recent years, the development of high-performance, low-cost flame-retardant and heat-resistant magnesium alloys has become one of the focuses of materials science and industry.Keywords: magnesium alloy; rare earth; application status镁合金是当前是工程建设中使用最为广泛的轻金属材料,有“绿色工程材料”的美誉,是当下材料开发与应用方面的重点研究方向。
华东理工大学学报(自然科学版)Jour nal of East China U niver sity of S cien ce and T echnology (Natural Science Edition )Vol.35No.32009-06收稿日期:2008-08-13基金项目:上海市科委资助项目(05d812019)作者简介:郑建华(1983-),男,江西上饶人,硕士研究生,主要研究方向为粉体材料与电子浆料。
E -mail:zh engjianh ua0920@ 通讯联系人:杨云霞,E -mail:yan gyunxia@文章编号:1006-3080(2009)03-0396-04银浆流变性能对硅太阳电池电性能的影响郑建华, 张亚萍, 花 巍, 杨云霞, 陈国荣(华东理工大学材料科学与工程学院,无机材料研究所,上海200237)摘要:通过改变有机相中乙基纤维素的质量分数,制备了具有不同流变性能的银浆,并应用于硅太阳电池。
对银浆流变性能、电池正面电极形貌和电池电性能等的分析测试结果表明,银浆的流变性能影响所印制电池的电极形貌及其电性能。
当有机相中乙基纤维素质量分数为6%时,银浆具有较高低剪切速率下的黏度和较低高剪切速率下的黏度,能使所印的电极栅线边缘整齐,具有较高的高度和较小的线宽,所印制电池电性能优越,具有较好的填充因子(FF )和转换效率(G )。
关键词:流变性;电性能;银浆;太阳电池中图分类号:O373;TM 24文献标志码:AEffect of Rheological Property of Silver Conductive Paste onElectrical Property of Si Solar CellsZH EN G J ian -hua, ZH A N G Ya -p ing , H UA Wei, YAN G Yun -x ia , CH EN Guo -rong(I nstitute of I nor ganic Mater ials,S chool of Mater ials S cience and Engineer ing ,East China Univer sity of Science and Technology ,Shanghai 200237,China)Abstract:Different silver conductive pastes w ere prepared and applied in solar cell.T heir rheolog ical pro perties w ere adjusted by chang ing ethy-l cellulose contents in the org anic v ehicle.With the measurem ent of rheo logical properties of silver conductive pastes and g rid m orpho logies as w ell as electr ical pr operties of the cells,it w as found that rheo logical pr operties of silver conductive pastes affected the electrical proper -ties o f the cells.When the ethy-l cellulo se in the organic vehicle w as as high as 6%,the paste had high vis -cosity in low shear rate and low viscosity in high shear rate,w hose frontal electrodes had slicker fring e,hig her height and sm aller w idth,w hile the cells had better electr ical pr operties w ith high filled factor(FF )and co nv ersion efficiency(G ).Key words:rheolog ical proper ty ;electrical pr operty;silv er co nductiv e paste;so lar cells与普通电池一样,晶体硅太阳电池也有两个用于引出电流的电极。
第27卷第4期粉末冶金材料科学与工程2022年8月V ol.27 No.4 Materials Science and Engineering of Powder Metallurgy Aug. 2022 DOI:10.19976/ki.43-1448/TF.2022016短碳纤维增强铜复合材料的计算细观力学模型及力学性能何东浪,方华婵,李郁兴,李金伟(中南大学粉末冶金国家重点实验室,长沙 410083)摘要:针对粉末冶金法制备的短碳纤维增强铜复合材料(C Sf/Cu),采用有限元方法建立细观力学模型,研究材料的拉伸损伤演化和断裂力学行为,并分析弱界面对复合材料拉伸性能的影响。
结果表明,C Sf/Cu复合材料的拉伸过程可分为弹性阶段、塑性硬化阶段、起始损伤阶段和损伤演化阶段。
纤维端部的应力集中造成端部界面脱黏、轴向界面的损伤演化以及纤维桥联,基体损伤及其伴随的界面损伤造成基体破坏是材料断裂的主要机制。
碳纤维长度大于60 μm时,纤维的轴向应力分布呈现“w”形,纤维有较强的承载能力;纤维长度为20 μm时,纤维几乎没有承载能力。
纤维承受载荷越高,越容易造成界面破坏,随纤维长度从20 μm增加到140 μm,C sf/Cu复合材料的抗拉强度从146 MPa下降到102 MPa。
关键词:短纤维;铜基复合材料;细观力学;有限元;内聚力单元中图分类号:TF125文献标志码:A 文章编号:1673-0224(2022)04-382-07Computational meso-mechanical model and mechanical property of short carbon fiber reinforced copper matrix compositesHE Donglang, FANG Huachan, LI Yuxing, LI Jinwei(State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China)Abstract: For the short carbon fiber reinforced copper matrix composites (C Sf/Cu) prepared by powder metallurgy, a model was established to analyze the tensile damage evolution, fracture mechanical behavior and the influence of weak interface on mechanical properties of composites. The results show that the composites can be divided into elastic stage, plastic hardening stage, damage initiation stage, and damage evolution stage. The stress concentration at the fiber end causes the debonding of the end interface, the damage evolution of the axial interface and the fiber bridging. The damage of the matrix and the accompanying interface are the main fracture mechanism of the material. When the fiber length is greater than 60 μm, the axial stress of the fiber presents a “w” shape, and the fiber has a strong bearing capacity. When the fiber length is 20 μm, the fiber has almost no bearing capacity. The higher the load on the fiber, the easier it is to cause interfacial damage. With increasing fiber length from 20 μm to 140 μm, the strength of the composite decreases from 146 MPa to 102 MPa.Keywords: short fibers; copper matrix composites; meso-mechanics; finite element; cohesive element短碳纤维/铜复合材料兼具铜的高导热、导电性能以及碳纤维的高比模量和高比强度,因此具有优异的力学性能、耐磨性能和良好的导热性能,广泛应用于高效散热器、电接触材料和耐磨器等[1]。
基于响应面法的纤维金属层合板抗弹性能优化设计
孔祥韶;杨豹;周沪;郑成;刘芳;吴卫国
【期刊名称】《爆炸与冲击》
【年(卷),期】2022(42)4
【摘要】纤维金属层合板因其复合材料的各向异性和层合结构特征而具有较好的可设计性,开展金属纤维层合板的优化设计研究对其力学性能的增强和轻量化具有重要意义。
为提高纤维金属层合板的抗弹性能,基于响应面分析法对纤维金属层合板的铺层方向和铺层厚度进行了优化设计。
采用Box-Behnken方法进行方案设计,以纤维金属层合板各铺层相对厚度比为设计变量,以结构的比吸能为设计目标,根据设计的方案进行参数化建模获取样本点,在对设计样本进行方差分析和参数估计的基础上,建立了结构比吸能的响应面模型并验证了其精确度。
采用遗传算法对响应面方程进行寻优分析,通过显式动力学计算程序ABAQUS/Explicit验证优化效果。
最终,在最优的铺层方案下,层合板的质量减小了11.70%,能量吸收增加了19.40%,抗弹性能显著提升。
【总页数】13页(P109-121)
【作者】孔祥韶;杨豹;周沪;郑成;刘芳;吴卫国
【作者单位】武汉理工大学绿色智能江海直达船舶与邮轮游艇研究中心;武汉理工大学船海与能源动力工程学院;武汉理工大学交通与物流工程学院
【正文语种】中文
【中图分类】O342;TB333
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Heteropore covalent organic framework for solid phase extraction of 16PAHs from waterLU Qiuyu 1,2,LI Mingtang 1,HE Peiqiao 2,ZHANG Danyang 2,JIANG Hongxin 2*,LIU Xiaowei 2*(1.School of Resources and Environment,Jilin Agricultural University,Changchun 130012,China;2.Key Laboratory of Environmental Factor Control for Agro-product Safety,Ministry of Agriculture and Rural Affairs /Agro-Environmental Protection Institute,Ministry of Agriculture and Rural Affairs,Tianjin 300191,China )Abstract :To provide a simple and efficient method to adsorb trace polycyclic aromatic hydrocarbons (PAHs )from complex,real samples,heteropore covalent organic frameworks (HCOFs )crystalline porous material with two different kinds of pores was prepared through a solvothermal method.The HCOFs structure and morphologies were characterized by scanning electron microscopy,powder X-ray diffraction analysis,Fourier transform-infrared spectroscopy,and Brunauer-Emmett-Teller analysis.The ability of the HCOFs as a solidadsorbent for 16PAHs from real water samples was investigated.Based on gas chromatography-mass spectrometry analysis,the contents of 16PAHs were detected after treatment with HCOFs.The experimental results indicated that the prepared HCOFs displayed intriguing properties such as high crystallinity,large surface area,and high porosity,bearing both micro-pores (hexagonal )and mesopores (trigonal ).This HCOFs can be used as an adsorbent for the rapid adsorption of 16PAHs in environmental water samples.The absorption equilibrium was achieved after only 15min oscillation,while that of the enrichment factor can be up to 40times more.The method presented suitablelinearity in the range of 0.25~50μg·L -1for the 16PAHs with a satisfactory regression coefficient (R 2>0.99).The detection limits for the method based on a signal-to-noise ratio of 3were in the range of 0.04~0.08μg·L -1.For the actual water samples,the recoveries of 16PAHs ranged from 82.3%to 110.1%.These results demonstrated this method has advantages such as its simplicity,speed,cost-双孔COF 材料用于固相萃取水体中16种多环芳烃鲁秋玉1,2,李明堂1,何沛桥2,张丹阳2,姜红新2*,刘潇威2*(1.吉林农业大学资源与环境学院,长春130012;2.农业农村部农产品质量安全环境因子控制重点实验室/农业农村部环境保护科研监测所,天津300191)收稿日期:2021-01-12录用日期:2021-03-19作者简介:鲁秋玉(1996—),女,吉林长春人,硕士研究生,从事纳米材料的开发及其在污染物吸附富集方面的应用研究。
异形纤维的截面形态的表征方法和其特征值的意义纺1:黄宇特征参数王府梅等[1] 根据截面轮廓线多次凹凸变化的三大特征,即形成叶片或凸起的粗糙小块、外轮廓线的内包络线形态、截面内有否空隙及其大小,提出了凸叶高度D、椭圆度!、截面曲角" 及空隙率#。
韩春燕[3] 针对四孔中空纤维提出了中空度。
吴兆平等[4] 针对羊毛截面特征提出反映截面特征的三个形状因子[5]:圆形、长形、径向异形因子。
徐回祥等[6] 针对混纺织物中棉芒麻纤维的纵向和截面的外形特征提出纤维横截面CV 值、棉纤维边界曲线扭曲数麻纤维表面横节等参数。
李艰等[7]通过分析丝和毛的截面形态,提出了截面积、圆整度、异形度三个参数。
Smuts S 等[8] 根据马海毛纤维截面的几何形状,提出髓腔率,即髓腔直径与纤维直径的比值,以识别不同级别的马海毛。
Mat!ic-leigh R [9] 等人通过对棉纤维横截面的图像进行分析提出胞壁厚度、纤维宽度、成熟度系数、成熟度比率及胞壁厚度系数等指标。
D Robson [10] 利用图像处理技术测定了羊毛和羊绒的各种鳞片结构,提出描述各种羊毛鳞片的不同形态特征的面积、圆整度、矩形充满度、形状系数等16个特征参数异形度:异形度是表示纤维截面形状异形化的程度[11]。
异形纤维最常见的异形度指标[12]有圆系数、周长系数和表面系数。
在化纤异形度标准[2] 中,反映截面特征的异形度指标有径向异形度D、截面异形度S 和特征异形度C。
不过,一般情况不用特征异形度,只有当前两种指标无法表达纤维截面特征时,拓拓进特征异形度。
中空度:是指纤维截面中孔洞横截面积A,占纤维表观横截面A1的百分比H;空隙率:如果存在多微孔结构,且孔径大小不一,则用空隙率表示。
中腔率:纤维的中腔率是体积比德概念,一般中腔的截面不同,而且两端和中间都可能封闭,不同于化纤中空那样,两端开口,中间孔洞连续。
中空偏心:中空偏心在天然纤维和化学纤维中一般极少发生,其绝大多数单中腔的轴心一致,只有多中空结构是,各中腔的轴心于纤维不一致。