激光选区成形Cu-Al-Mn-Ti记忆合金的工艺及性能研究  

Properties of Cu-Al-Mn-Ti Shape-memory Alloy Processed by Selective Laser Melting

作　　者：党明珠 朱文志 田健 魏青松[1] DANG Mingzhu;ZHU Wenzhi;TIAN Jian;WEI Qingsong(State Key Laboratory of Material Processing and Die&Mould Technology,Huazhong University of Science and Technology,Wuhan 430074)

机构地区：[1]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

出　　处：《机械工程学报》2020年第15期110-117,共8页Journal of Mechanical Engineering

基　　金：武汉市应用基础前沿(2018010401011281);国家重点研发计划(2018YFB1105301);华中科技大学学术前沿团队;国家自然科学基金青年基金(51701078);中国博士后基金面上(2018M632846)资助项目。

摘　　要：采用激光选区熔化技术成形了Cu-11.85Al-3.2Mn-0.1Ti(质量分数)合金。采用排水法对成形块体试样进行了致密度测试,优化了工艺参数,对试样进行了物相分析和微观组织分析,利用优化的工艺参数成形了拉伸试样和变形测试试样,测试在不同温度下拉伸试样的力学性能,通过DSC曲线分析了试样的相变温度及变形试样的记忆性能。结果表明,当激光功率为270W,扫描速度为500 mm/s,层厚为0.025 mm,扫描间距为0.1 mm时,试样具有接近100%的致密度;试样的物相中主要为马氏体相和Cu2Al Mn相,微观组织中观察到了马氏体组织,并且多为层错结构;拉伸试样在200℃时具有最大抗拉强度825.6 MPa,延伸率为20.3%且延伸率随着温度的升高而增大;试样的马氏体相变开始温度约为260℃,结束温度约为249℃,奥氏体转变温度高于400℃,形变回复率在57%以上。The Cu-11.85 Al-3.2 Mn-0.1 Ti(wt.%)alloy is processed by selective laser melting and the parameters are optimized with the relative density result measured by the Archimedes principle. The phase and microstructures are characterized, and the tensile specimens are formed by using the optimized process parameters. The mechanical properties are tested under different temperature. The phase transformation temperatures are carried out by DSC curves, and the shape memory properties are analyzed. The results show that when laser power, scanning speed, layer thickness and scanning space are 270 W, 500 mm/s, 0.025 mm, 0.1 mm, the maximum relative density of samples is close to 100%. The XRD results and microstructure pictures show that martensite and Cu2 AlMn phase appeared in the samples and most of it is stacking fault structure. Besides, the higher tensile strength and elongation are 825.6 MPa and 20.3% at 200 ℃, the elongation increases with the temperature rises. Moreover, the austenite transformation temperature As and Af are 506 ℃, 532.5 ℃, and deformation recovery rate is over 57%.

关 键 词：激光选区熔化 铜基形状记忆合金 微观组织 力学性能 记忆性能 

分 类 号：TG146[一般工业技术—材料科学与工程]