PDF《——半固态加工——特种铸造及有色合金》

――半固态加工――特种铸造及有色合金 2011年年会专刊 间接超声振动工艺制备金属半固态浆料技术的研究 吴树森 吕书林 朱泽明 安萍 毛有武 (华中科技大学材料成形与模具技术国家重点实验室) 擒 耍将变幅杆直接插入金属熔体液面以下进行超声处理能够制备出质量较好的半固态浆料.

但与熔体的直接接触容 易引起变幅杆的腐蚀.为了解决这一问题.本研究开发出间接超声振动制浆工艺,即工具头在盛熔体的金属杯外面的底部 进行超声振动.研究了间接超声振动时间对A356铝合金半固态浆料组织和流变成形件力学性能的影响.结果表明.在液 相线附近开始对合金熔体进行50 s的间接超声处理.可获得初生相尺寸和形状系数分别为75 t.tm和0.62的半固态浆料. 超声作用时间对流变成形件的力学性能影响显著.超声处理50 s的流变成形件力学性能最好.其铸态下的抗拉强度和伸长 率分别达到了244 MPa和7.5%.与液态压铸件相比.分别提高了10%和75%.此外.探讨了间接超声振动制备铝合金半 固态浆料的机理. 关键词间接超声振动I半固态浆料;

半固态组织#力学性能;

空化效应 中圈分类号TG249.2 文献标志码 A 文章编号2011(S)一0347一05 Study on Preparation Process of Semi-solid Metal Slurry with Indirect Ultrasonic Vibration Wu Shusen.LO Shulin.Zhu Zeming.An Ping.Mao Youwu (State Key Lab of Materials Processing and Die{5L Mould Technology. H uazhong University of Science and Technology) Abstractl Direct ultrasonic vibration(DUV)method by dipping the horn into the melt can be used to make semi―solid metal slurry,but application of this process is impeded because of the erosion problem of titanium-alloy horn by aluminum melts.In order to avoid this problem,a slurry―making process with in― direct ultrasonic vibration(IUV),in which the horn is vibrated under the outside of the metallic cup con- taining alloy melt,has been developed in this research.Semisolid slurry of A356 AI alloy was prepared by this process,and the effect of IUV treatment time on the morphology of the primary a―AI phase and me― chanical properties of rheocast samples were studied.The results indicated that excellent semisolid slurry of A356 AI alloy could be obtained within 50s by applying IUV near its liquidus temperature.and the av― erage diameter and shape coefficient of the primary a―A1 particles were 75/Ⅱm and 0.62,respectively.IUV 收甍日期:2011―05―09 奠一作者简介:吴树森.男.1961年出生.教授.华中科技大学材料成形与模具技术国家重点实验室.武汉(430074).

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