动制备ZL101铝合金半固态浆料的工艺优化

基金项目:江西省自然科学基金项目资助(0650047)和江西省教育厅科技项目(G JJ 09229)。

收稿日期:2009-11-19轻合金及其加工半固态ZL101合金重熔加热时初生相的组织演变刘政1,胡咏梅2(1.江西理工大学机电工程学院,江西赣州341000;2.江西理工大学工程院,江西赣州341000)摘 要:利用低过热度浇注技术制备了半固态ZL101铝合金坯料,研究了半固态温度区间重熔加热时半固态ZL101铝合金坯料的初生相形貌的转变过程。

研究结果表明,在半固态两相区保温,半固态ZL101合金的初生相逐渐团球化,该过程随保温温度的升高而加快。

半固态ZL101铝合金晶粒的圆度与保温温度和保温时间的关系不大,但晶粒的尺寸随着保温温度和保温时间的增加而增大。

半固态ZL101合金试样重熔加热最佳工艺制度为583 下保温30m i n ,其晶粒平均等积圆直径为80 m,晶粒平均圆度为0.83。

关键词:半固态;Z l 101铝合金;重熔加热;组织演变中图分类号:TG146,TG244 文献标识码:A 文章编号:1002-1752(2010)09-65-5M icrostructure evol uti on of pri m ary phasei n se m i-soli d ZL101all oy duri ng reheatingLI U Zheng 1and HU Y ong-me i2(1.School of M echanical and E lectronic E ng ineering,2.Engineering Instit u te ,J iangx i University of S cience and T echno logy,G anzhou 341000,China )A bs tract :The s e m i-s o li d ZL101all oy b ill et i s p repared by l o w s uperheat pouri ng ,and the transfor m cou rse for p ri m ary phas e m orpho l ogy of the b ill et i s researc h ed duri ng reheati ng i n soli d -liqu i d phase regi on.The res u lts i nd i cate that the pri m ary phase of se m i-s o li d ZL101alloy i s gradu all y gl obulari zedduri ng the hol d i ng i n s oli d-li qu i d ph ase reg i on ,i n w h ic h gl obu larizati on i s speed ed up w ith the increas e of t h e hol d i ng t e m perat u re .There is a little effect of hol d i ng te mp erature and hold i ng ti m e on grai n roundness of se m i -solid ZL101a ll oy ,bu t t h e grai n s i ze of t he all oy i n creases w i th i ncreasi ng of t he ti m e and t h e te mp erature .The op ti m azing reheati ng t echnol ogy of se m i -s oli d ZL101alloy i s t h at the b illet i s h eld 30m i n at 583 ,i n wh ich t h e av erage equal-area-circl e gra i n dia m eter i s 80 m,and the average grai n roundn ess is 0.83.K ey words :se m i-s o li d ;ZL101alloy ;reheati ng ;m i crostr u cture evo l uti on在半固态金属触变成形中,金属坯料必须首先被重新加热至固液两相区的某一温度下,经过半固态重熔加热,此时,金属坯料一方面达到了预定的温度和预定的固相分数,获得了一定的触变性,满足触变成形的要求;另一方面,坯料的显微组织也经历很大的变化,发生低熔点组织的熔化、高熔点初生固相的部分熔化和组织形态的圆整化、初生固相晶粒的粗化[1]。

《SiCp-ZL101复合材料半固态模锻制备及性能研究》篇一SiCp-ZL101复合材料半固态模锻制备及性能研究一、引言随着科技的不断进步，新型复合材料的研究与开发已经成为当前材料科学领域的重要方向。

其中，SiCp/ZL101复合材料因其在强度、刚度及耐磨性方面的优越性能，广泛应用于汽车制造、航空航天及军事工业等多个领域。

然而，制备高效率、高性能的SiCp/ZL101复合材料，特别是在其成型过程中存在的难点与挑战仍然引人关注。

本论文针对SiCp/ZL101复合材料半固态模锻制备过程进行详细的研究，探讨其工艺优化和性能特点。

二、材料与制备方法（一）材料选择本实验选用的基体材料为ZL101铝合金，增强相为SiCp（硅碳颗粒）。

这种复合材料通过将SiCp颗粒均匀地分布在ZL101铝合金中，可以显著提高材料的力学性能和耐磨性。

（二）半固态模锻制备方法半固态模锻是一种新型的金属加工技术，其基本原理是在金属的半固态阶段进行模锻，使金属和增强相混合均匀，从而达到提高材料性能的目的。

在SiCp/ZL101复合材料的制备中，采用此技术能够获得致密度高、力学性能良好的复合材料。

三、制备过程与工艺优化（一）制备过程本实验的制备过程主要包括：合金熔炼、SiCp颗粒的加入、半固态处理和模锻成型等步骤。

在每个步骤中，都需要严格控制温度、时间等参数，以保证复合材料的性能。

（二）工艺优化针对半固态模锻过程中可能出现的缺陷和问题，我们进行了工艺优化。

首先，通过调整合金熔炼的温度和时间，使合金成分更加均匀；其次，通过优化SiCp颗粒的加入方式和时间，使颗粒在基体中分布更加均匀；最后，通过调整半固态处理的温度和时间，使模锻过程中的流动性更好，从而提高产品的致密度和力学性能。

四、性能研究（一）力学性能研究通过拉伸试验、硬度试验和冲击试验等方法，研究了SiCp/ZL101复合材料的力学性能。

实验结果表明，经过半固态模锻制备的复合材料具有较高的抗拉强度、硬度和冲击韧性。

专利名称：一种ZCuSn10P1合金半固态浆料的制浆成型一体化装置和方法
专利类型：发明专利
发明人：周荣锋,王静波,李璐,李永坤,蔡培霖,蒋业华
申请号：CN201910192823.1
申请日：20190314
公开号：CN109926564A
公开日：
20190625
专利内容由知识产权出版社提供
摘要：本发明涉及一种ZCuSn10P1合金半固态浆料的制浆成型一体化装置和方法，属于材料科学技术领域。

该ZCuSn10P1合金半固态浆料的制浆成型一体化装置，包括半固态浆料制备装置、冷却装置和底注式间接挤压铸造模具。

本发明将铸造生产中合金熔体的主要凝固阶段和零件成形阶段相结合，先对合金熔体进行阶段控制冷却，然后在模具中进行短时间类等温处理，以促使组织较均匀的熔体流入零件部位，通过对该熔体进行挤压铸造，获得固相内整体锡含量提高或者固相内较高锡含量面积显著增大的高强韧铸件，并且成形零件的组织均匀、晶粒为蔷薇状或等轴状。

申请人：昆明理工大学
地址：650093 云南省昆明市五华区学府路253号
国籍：CN
更多信息请下载全文后查看。

铝合金半固态浆料的剪切-振动耦合亚快速凝固高效制备技术与设备铝合金半固态浆料的剪切/振动耦合亚快速凝固高效制备技术与设备近年来，随着工业化进程的不断推进和科技的快速发展，铝合金作为一种重要的金属材料，在航空航天、汽车制造、电子设备等领域具有广泛的应用前景。

因此，如何高效制备高质量的铝合金材料一直是研究者们关注的焦点之一。

本文将介绍一种新兴的铝合金半固态浆料制备技术，即剪切/振动耦合亚快速凝固技术，并介绍相关的设备。

铝合金半固态浆料是指铝合金在其液态温度下的部分结晶态态，具有较高的塑性和可变性。

相较于传统的铸造技术，半固态浆料制备技术可以使铝合金材料具有更好的工艺性能和力学性能。

而剪切/振动耦合亚快速凝固技术是一种将剪切力场和振动力场相结合的新型制备方法，可以快速凝固半固态浆料并控制其结晶态。

在剪切/振动耦合亚快速凝固技术中，通过加入特定的剪切或振动力场，可以促使铝合金浆料快速凝固，从而提高生产效率。

剪切力场可以通过剪切装置传递到浆料中，打破其内部的结晶并促进新的晶核形成。

振动力场则可以通过振动设备引入，产生微小的振荡效应，从而使浆料颗粒达到更细致的分散状态。

通过剪切和振动的相互作用，可以形成均匀分散的浆料，并在凝固过程中控制晶体生长速率，进而得到具有良好力学性能的铝合金材料。

剪切/振动耦合亚快速凝固技术的设备主要由剪切装置和振动设备组成。

剪切装置采用专门设计的剪切头进行剪切作用，通过调整剪切装置的参数可以控制剪切力的大小和剪切频率。

振动设备则通过电机和振动器实现，可以产生不同频率和振动幅度的振荡效应。

这两种设备可以独立使用，也可以同时使用，根据浆料的类型和要求进行合理的选择。

通过剪切/振动耦合亚快速凝固技术和相应的设备，可以实现铝合金半固态浆料的高效制备。

该技术不仅提高了生产效率，还能够获得具有优良力学性能的铝合金材料。

此外，该技术还具有简单易行、灵活可调和可重复使用等特点，使其具备较大的应用潜力。

ZL101A铝合金车轮热处理工艺的优化实验摘要: 汽车车轮是车辆承载的重要安全部件。

铝合金以其优异的比强度和比刚度，成为汽车轻量化的首选材料，使用比例逐年提高。

本文以某公司现有较为成熟的ZL101A铝合金车轮T6热处理工艺为基础，参照国内外热处理经验，通过调整热处理工艺参数，合理安排工艺，确保铝合金车轮原有性能不变或有所提高。

通过实验确定较为合适的固溶加热温度为535℃～540℃，在535℃、540℃固溶时，分别保温6h、5h可获得更高的力学性能；最适宜的时效温度是130℃、140℃，最佳时效保温时间为3.5h、4h。

关键词：ZL101A铝合金车轮；T6热处理工艺；固溶；时效Abstract:Wheel is an important safety component of vehicles. Aluminum alloy with its excellent specific strength and stiffness has been selected to use widely by cars as a lightweight material.Taking a more mature T6 heat treatment for ZL101A alloy wheels reference from a company, based on experience at home and abroad about the heat treatment process, by adjusting the heat treatment parameters, a reasonable arrangement process, to ensure that the performance of the original aluminum alloy wheels maintained or improved .Experimental results showed that a more appropriate solution to determine the heating temperature is 535～540 ℃. at 535 ℃, 540 ℃solution, respectively, insulation 6h, 5h obtain higher mechanical properties; and the most appropriate in this aging temperature is 130 ℃, 140 ℃;the optimum holding time is 3.5h and 4h.Key words: ZL101A aluminum alloy wheels; T6 heat treatment; solution; aging目录1 绪论 (1)1.1 铝合金车轮概述 (1)1.2 国内外铝合金车轮制造业现状 (1)1.2.1 国外铝合金车轮制造业现状 (1)1.2.2 国内铝合金车轮制造业现状 (2)1.3 铝车轮热处理工艺的研究背景及意义 (2)2. ZL101A铝合金车轮的生产工艺概况 (3)2.1 熔炼 (3)2.2 变质 (4)2.2.1 变质方法 (4)2.2.2 孪晶凹谷机制变质机理 (4)2.3 晶粒细化 (5)2.3.1 细化方法 (5)2.3.2 晶粒细化的机理 (5)2.4 铸造 (5)2.4.1 低压铸造的基本原理 (6)2.4.2 低压铸造的工艺流程 (6)3. ZL101A力学性能的主要影响因素 (7)3.1 合金元素的影响 (7)3.2 微观组织的影响 (8)3.3 熔体处理及热处理的影响 (8)4 ZL101A常见的冶金缺陷分析 (8)4.1缩孔 (8)4.2疏松 (9)4.3裂纹 (9)4.4偏析 (10)4.5夹杂 (11)4.6淬火加热过烧 (11)4.7针孔 (11)4.8气孔（气泡） (12)4.9固溶强化相溶解不完全 (13)4.10变质处理不足和变质过度（过变质） (13)5. ZL101A铝合金车轮热处理工艺的优化实验 (13)5.1 铝合金热处理工艺概述 (13)5.2 铝车轮热处理工艺优化试验方案的设计 (15)5.3 实验材料的制备 (16)5.4 实验设备的校验 (17)5.5优化试验工艺参数的确定 (19)5.6 实验制度的确定 (20)5.6.1 固溶制度的确定 (20)5.6.2 时效制度的确定 (21)5.7 实验结果分析 (23)5.7.1固溶实验结论与分析 (23)5.7.2时效实验结论与分析 (23)5.7.3综合实验结论与分析 (23)6.优化实验工艺与原试验工艺比较 (24)6.1化学成分的测定 (24)6.2力学性能的测定 (24)6.3金相组织检验 (25)7.结论与展望 (26)参考文献 (27)1 绪论1.1 铝合金车轮概述汽车车轮是车辆承载的重要安全部件。

zl101a铝合金车轮热处理工艺的优化与研究
铝合金车轮热处理工艺的优化与研究是针对提高铝合金车轮性能和延长使用寿命的关键研究方向。

优化研究主要包括以下方面：
1. 材料选择：研究不同品种的铝合金材料的性能，选择适合车轮的材料，比如常用的A356和A357铝合金。

2. 合金配方：根据车轮的工作环境和要求，优化铝合金的配方，调整合金元素的含量和比例，以提高车轮的强度、硬度和耐腐蚀性能。

3. 预处理：在车轮加工前对铝合金进行预处理，如去除表面氧化层、清洗、除油等，以减少车轮在加工过程中的变形和表面缺陷。

4. 热处理工艺：确定适宜的热处理工艺参数，包括加热温度、保温时间和冷却速度等，以获得理想的组织和性能。

常用的热处理工艺包括固溶处理、时效处理和球化处理等。

5. 热处理设备：选择适当的热处理设备，如电阻炉、盐浴炉或气氛炉等，以保证热处理工艺的可行性和稳定性。

研究热处理工艺的目的是为了获得以下效果：
1. 提高车轮的强度和硬度，增加承载能力和抗疲劳性能。

2. 改善车轮的耐腐蚀性能，抵抗酸碱腐蚀、高温氧化和盐雾腐蚀等。

3. 控制车轮的组织结构，实现晶粒精细化和相组织的均匀分布，以提高材料的塑性、可加工性和密度。

4. 减少车轮的变形和残余应力，提高车轮的尺寸精度和外观质量。

5. 延长车轮的使用寿命，提高整体经济效益。

总而言之，铝合金车轮热处理工艺的优化与研究是为了提高车轮的性能、延长使用寿命和保证产品质量，促进铝合金车轮行业的健康发展。

Trans. Nonferrous Met. Soc. China 26(2016) 1820−1825Preparation of semi-solid ZL101 aluminum alloy slurry by serpentine channelShu-jian CHENG, Yu-hong ZHAO, Hua HOU, Yu-chun JIN, Xiao-xiao GUOSchool of Materials Science and Engineering, North University of China, Taiyuan 030051, ChinaReceived 19 September 2015; accepted 9 December 2015Abstract: Semi-solid slurry of ZL101 aluminum alloy was prepared using serpentine channel. The influences of the pouring temperature, the number of curves and the serpentine channel temperature on the microstructure of semi-solid ZL101 aluminum alloy were investigated. The results show that, satisfied semi-solid slurry of ZL101 aluminum alloy was prepared with pouring at 630−680 °C. The morphology of primary α(Al) grains transforms from rosette to spheroid with the decrease of pouring temperature. At the same pouring temperature, increasing the number of curves can improve the morphology of primary α(Al) grains and decrease the grain size. Qualified slurry can be attained with lowering the pouring temperature when the serpentine channel temperature is higher. The alloy melt has the effect of “self-stirring” in the serpentine channel, which can make the primary nuclei gradually evolve into spherical and near-spherical grains.Key words: ZL101 aluminum alloy; semi-solid; slurry; serpentine channel1 IntroductionAs a kind of new near net shape metal processing technology, semi-solid processing (SSP) has the brightest future in the 21st century. A key step of semi-solid processing technology is an economical production of semi-solid metal slurry with fine grain microstructure [1−4]. In order to meet this demand, strong convection or shearing is often applied during the solidification, such as mechanical stirring [5,6], electromagnetic stirring [7,8]; however, the former pollutes alloy readily and the latter has low electromagnetic stirring efficiency. Recently, a controlled nucleation method has been reported, which is simple, practical and less expensive because of no application of stirring. These preparation methods include new rheocasting [9,10], vertical pipe [11,12], vibrating wavelike sloping plate process [13−15], inverted cone pouring channel [16,17] and cooling slope process [18−20]. These techniques have similarities, such as pouring the alloy melt through a plate or tube without stirring. Therefore, they reduce the energy consumption and save the cost of production greatly.On the basis of controlled nucleation method, serpentine channel process (SCP) was presented. The serpentine channel was made of stainless steel and consisted of two symmetrical blocks locked together by sleeve. During the period of preparing semi-solid slurry, the direction of alloy melt changed several times in the field of gravity, which made alloy melt have the function of “self-stirring” [21−25]. With the effect of stirring in serpentine channel, primary nuclei gradually evolved into spherical and near-spherical grains. In this work, an innovative processing technique of semi-solid metal slurry, namely serpentine channel process, was introduced, and effects of pouring process parameters on the microstructure of semi-solid ZL101 aluminum alloy slurry were investigated.2 Experimental2.1 Materials and apparatusIn the experiment, a kind of commercial aluminum alloy named ZL101 was used. Its chemical composition is 6.6% Si, 0.28% Mg, <0.16% Fe, <0.10% Mn, <0.10% Zn and balance Al (mass fraction). Its liquidus and solidus temperatures are 615 and 556 °C, respectively, which were tested by differential scanning calorimetric (DSC) method.Foundation item: Projects (51204147, 51274175) supported by the National Natural Science Foundation of China; Project (2014DFA50320) supported by the Ministry of Science and Technology of China; Projects (2013081017, 2012081013) supported by the International Science andTechnology Cooperation Project of Shanxi Province, ChinaCorresponding author: Yu-hong ZHAO; Tel: +86-150********; E-mail: zyh388@DOI: 10.1016/S1003-6326(16)64293-0Shu-jian CHENG, et al/Trans. Nonferrous Met. Soc. China 26(2016) 1820−1825 1821The schematic of SCP equipment and slurry preparation process is shown in Fig. 1. The serpentine channel was made of stainless steel, which consisted of two symmetrical blocks locked together by sleeve. The collective crucible, with sizes of d69 mm × 150 mm, was made of stainless steel. The melting apparatus was a crucible resistance furnace. The temperatures of the liquid aluminum alloy, semi-solid slurry and inner wall of serpentine channel were measured by Ni−Cr/Ni−Si thermocouple. The temperature accuracy was ±1 °C.Fig. 1Schematic diagram of preparing semi-solid ZL101 aluminum alloy slurry by serpentine channel: (a) Melt; (b) Preparation of semi-solid slurry; (c) Cooling (1—K-type thermocouple; 2—Serpentine channel; 3—Pouring cup; 4—Serpentine bend; 5—Diversion pipe; 6—Melting crucible; 7—Collective crucible; 8—Slurry; 9—Cold water)2.2 MethodsThe alloy was melted in a crucible resistance furnace at 720−730 °C, and then incubated for 15 min. The melt was cooled to the chosen pouring temperature and cast into collective crucible via serpentine channel, and then quenched in cold water rapidly to obtain high temperature solidification microstructure. Collective crucible was at room temperature and serpentine channel was preheated to 100 °C or at room temperature before pouring. The processing parameters and characteristic sizes of semi-solid slurry are listed in Table 1.The metallographic specimens were cut from the center of quenched slurry and then roughly ground, finely ground, polished and etched with 0.5% HF aqueous solution. The microstructures of specimens were investigated using a ZIESS optical microscope. A professional image analysis software (Image-Pro Plus) was adopted to analyze equivalent diameter (D) and shape factor (F s) of primary α(Al) grains which were calculated by the following equations:D=2(A/π)1/2(1) F s=4πA/P2 (2) where A and P are the area and perimeter of a particle, respectively. The F s varies from 0 to 1. When the value of F s is close to 1, the shape of particle approaches to a circle. Average particle diameter (APD) and average shape factor (ASF) are based on counting the equivalent diameter and the shape factor of all primary α(Al) particles in a photograph.3 Results3.1 Microstructural evolution of semi-solid slurryfabricated by SCPThe outlet temperature of slurry is varied as the ZL101 aluminum alloy melt flows through serpentine channel. Undercooling contributes to nuclei. Besides, the internal surface of serpentine channel is concave, which is beneficial to nucleating. The ZL101 aluminum alloy melt becomes semi-solid slurry with the “self-stirring”. The microstructures of quenched slurry prepared under different processing parameters are shown in Fig. 2. The white phase is primary α(Al) and the black matrix is eutectic phase.Table1 Processing parameters and characteristic sizes of semi-solid slurrySample No.CurvenumberCurvediameter/mmPouringtemperature/°CSerpentine channeltemperature/°CPouringtime/sSlurrymass/kgAverage particlediameter/μmAverageshape factorA 4 25 690 25 2 1.02 75 0.49B 4 25 670 25 2 0.98 68 0.56C 4 25 650 25 2 1.00 63 0.64D 5 25 690 25 2 1.04 65 0.53E 5 25 670 25 2 1.06 63 0.58F 5 25 650 25 2 0.98 58 0.67G 4 25 670 100 2 1.05 72 0.52H 4 25 650 100 2 1.10 65 0.54I 4 25 630 100 2 0.99 56 0.66Shu-jian CHENG, et al/Trans. Nonferrous Met. Soc. China 26(2016) 1820−18251822Fig. 2 Microstructures of semi-solid ZL101 aluminum alloy slurry prepared by three kinds of serpentine channels: (a) Sample A; (b) Sample B; (c) Sample C; (d) Sample D; (e) Sample E; (f) Sample F; (g) Sample G; (h) Sample H; (i) Sample IIt can be seen from Fig. 2 that non-dendritic primary α(Al) particles are uniform throughout the entire cast. The phenomenon indicates that once the collective crucible is filled completely, the solidification of remaining liquid may occur throughout the entire component [19]. In addition, there are two main constituents in the microstructure: the relatively large α(Al) globules (marked as α1(Al)) with particle diameter of 30−80 μm, and the numerous very small α(Al) particles (marked as α2(Al)) of approximately 15 μm in diameter. There are two distinct solidification stages in the SCP. The solidification of slurry in serpentine channel is referred to as the first solidification, and the solidification of slurry in collective crucible is referred to as the secondary solidification. The temperature declines rapidly, creating numerous nuclei in the slurry, and larger α1(Al) particles grow in serpentine channel. The particles morphologies are almost spherical. Besides, the particles distribute uniformly throughout the entire cast. When the slurry is poured into the collective crucible, heterogeneous nucleation recurs in remaining liquid. All these nuclei grow and solidify within a short time, forming smaller α2(Al) particles, creating the ‘‘secondary solidification’’. The solidification time is very short because of quenching, and as a result, the primary α2(Al)particles are very small and less spherical in shape.All in all, the contributions of serpentine channel making semi-solid slurry are “self -stirring”, undercooling and beneficial curved surface to nuclei.The average particle diameter and average shape factor of primary α(Al) grains are listed in Table 1. Figures 2(a)−(c) show the microstructures of ZL101 aluminum alloy semi-solid slurry poured at 690, 670 and 650 °C by serpentine channel with 4 curves, respectively, and the average particle diameter and average shape factor of primary α(Al) grains are 75, 68, 63 μm and 0.49, 0.56, 0.64, respectively. Figures 2(d)−(f) show the microstructures of ZL101 aluminum alloy semi-solid slurry poured at 690, 670 and 650 °C by serpentine channel with 5 curves, respectively, and the average particle diameter and average shape factor of primary α(Al) grains are 65, 63, 58 μm and 0.53, 0.58, 0.67, respectively. Desired quality of slurry can be also achieved with lower pouring temperature when the serpentine channel is preheated. Figures 2(g)−(i) show the microstructures of ZL101 aluminum alloy semi-solid slurry poured at 670, 650 and 630 °C by serpentine channel with 4 curves, respectively, and the serpentine channel is preheated to 100 °C before pouring, and the average particle diameter and average shape factor ofShu-jian CHENG, et al/Trans. Nonferrous Met. Soc. China 26(2016) 1820−1825 1823primary α(Al) grains are 72, 65, 56 μm and 0.52, 0.54, 0.66, respectively.3.2 Effect of pouring temperature on microstructureThe serpentine channel with 4 curves was used and three kinds of pouring temperatures were adopted, as listed in Table 1. As shown in Figs. 2(a)−(c), primary α(Al) grains are more spherical with decreasing the pouring temperature. Figure 2(a) shows that when the pouring temperature is 690 °C, the morphology of primary α(Al) grains is irregular. A similar micro- structure can be seen in Fig. 2(b) and there are more non-dendritic primary α(Al) grains. Figure 2(c) shows that primary α(Al) grains are mainly near-spherical and spherical with decreasing the pouring temperature to 650 °C. With the decline of pouring temperature, the average particle diameter of primary α(Al) grains decreases and the average shape factor increases, as shown in Fig. 3. The initial temperature of serpentine channel is low which has chilling effect that decreases the critical energy of nucleation and critical nucleus radius and increases the nucleation ratio. Therefore, a large number of primary α(Al) nuclei will be generated rapidly which is useful for decreasing the grain size. The inner wall of serpentine channel will be heated when the pouring temperature is high, causing the chilling effect to be weakened and the nucleation ratio to decrease. The grains have more time to grow, which leads to larger grain size. It is harmful to the mechanical property.Fig. 3 Effects of pouring temperature on APD and ASF The temperature of alloy melt in serpentine channel will drop rapidly to the liquidus temperature when the pouring temperature is lower. It is helpful for nucleation. However, when the pouring temperature is too low, the thickness of solidified shell in the serpentine channel increases markedly, and the chilling effect of serpentine channel will be weakened. Moreover, the productivity will be lower because of larger solidified shell. The semi-solid slurry can be prepared with satisfied quality when the pouring temperature range is between 630 and 680 °C.3.3 Effect of curve number on microstructureIt can be seen from Figs. 2(b) and (e) that, under the same condition, the microstructures are varied because of different numbers of curves. Primary α(Al) grains made by 5 curves serpentine channel are smaller and more spherical. It can be seen from Fig. 2(b) that a small number of fine rosettes or dendrites primary α(Al) grains except near-spherical or spherical grains. In addition, almost all of primary α(Al) grains made by 5 curves serpentine channel are near-spherical or spherical, as shown in Fig. 2(e). However, hanging slurry increases with increasing the number of curves. The variation of average particle diameter and average shape factor with different numbers of curves is shown in Table 1. The graphs about average particle diameter and average shape factor of primary α(Al) grains prepared by two kinds of serpentine channels with 4 curves and 5 curves are shown in Fig. 4, which indicates that at the given pouring temperature of serpentine channel, the average particle diameter of primary α(Al) grains decreases and the average shape factor of primary α(Al) grains increases with increasing the curve number. The inner wall of serpentine channel which acts as the concave nucleation substrate has a favorable effect on the heterogeneous nucleation, so many primary α(Al) nuclei form in a heterogeneous nucleation pattern. More crystal nuclei can be generated as the area of heterogeneous nucleation substrate enlarges with increasing the number of curves. Meanwhile, the self-stirring of alloy melt is strengthened with the increase of curve number, which has a favorable effect on breaking dendrites and refining primary α(Al) grains. It can be seen from a series of experiments that better slurry can be obtained with 5 curves serpentine channel, but hanging slurry is aggrandized. Therefore, serpentine channel with 4 curves is appropriate.Fig. 4 Effects of curve number on APD and ASFShu-jian CHENG, et al/Trans. Nonferrous Met. Soc. China 26(2016) 1820−1825 18243.4 Effect of serpentine channel temperature onmicrostructureFigures 2(h)−(i) show the microstructures of semi-solid slurry prepared by the serpentine channel preheated at 100 °C. Primary α(Al) is composed of vast small spherical grains and a small number of fine rosettes. Comparing Figs. 2(h)−(i) with Figs. 2(a)−(c), the average particle diameter increases and the average shape factor decreases under the same condition with increasing the serpentine channel temperature. The weight of hanging slurry decreases when the serpentine channel is preheated. It can be seen that qualified slurry can be received by lowering the pouring temperature when the serpentine channel temperature is high, as shown in Fig. 5(b). The number of crystal nuclei reduces when super-cooling is little, which is not good for refining grains. The number of crystal nuclei can be enlarged with decreasing the pouring temperature when the serpentine channel temperature is high, getting favorable slurry.Fig. 5 Microstructures of semi-solid ZL101 aluminum alloy slurry prepared by two kinds of serpentine channel temperatures at pouring temperature of 650 °C: (a) Sample C;(b) Sample HIt is good for nucleation with large super-cooling. Cooling serpentine channel contributes to getting larger super-cooling and receiving desired slurry. But it is difficult to control the serpentine channel temperature through cooling process which increases the cost. The super-cooling becomes more little when the serpentine channel is preheated or pouring long time. So, investigating the relationship between the pouring temperature and serpentine channel temperature is more important. The slurry temperature continuously drops and its viscosity increases with decreasing the temperature when the alloy melt flows through the serpentine channel. At the same time, the friction between the alloy melt and inner wall is varied with viscosity, resulting in different displacements in different points of the alloy melt, which will lead to shearing forces. What is more, the shearing forces are diverse in different points of alloy melt, so primary α(Al) grains in the alloy melt will self-rotate. It can be seen that decreasing the pouring temperature can solve the problem and receive desired slurry. It is good for continuous production and saving cost.4 Conclusions1) The semi-solid ZL101 aluminum alloy slurry with desired quality can be generated by pouring through serpentine channel. The average particle diameter of primary α(Al) grains decreases while the average shape factor of primary α(Al) grains increases with decreasing the pouring temperature, and the desired pouring temperature is in the range of 630−680 °C.2) Under the same condition, increasing the curve number of serpentine channel can decrease the average particle diameter of primary α(Al) grains and increase the average shape factor of primary α(Al) grains. Considering about hanging slurry, 4 curves serpentine channel is appropriate.3) Semi-solid slurry can be obtained at high serpentine channel temperature by lowing the pouring temperature. It assures continued access to slurry and reduces the preparation cost.References[1]FAN Z. Semisolid metal processing [J]. 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[25]ZHU Wen-zhi, MAO Wei-min, TU Qin. Preparation of semi-solid7075 aluminum alloy slurry by serpentine pouring channel [J].Transactions of Nonferrous Metals Society of China, 2014, 24(4): 954−960.蛇形通道法制备ZL101铝合金半固态浆料程书建，赵宇宏，侯华，靳玉春，郭晓晓中北大学材料科学与工程学院，太原030051摘要：采用蛇形通道法制备ZL101铝合金半固态浆料，研究浇注温度、弯道数量、蛇形通道温度对ZL101铝合金半固态浆料显微组织的影响。