原位激光定向能量沉积NiTi形状记忆合金的微观结构和力学性能  

Microstructure and Mechanical Properties of NiTi Shape Memory Alloys by In Situ Laser Directed Energy Deposition

作　　者：陈斐[1,2,3] 邱鹏程 刘洋 孙兵兵 赵海生[4] 沈强 CHEN Fei;QIU Pengcheng;LIU Yang;SUN Bingbing;ZHAO Haisheng;SHEN Qiang(WuhanUniversityof Technology,Wuhan430070;nternational School of Materials Science and Engineering(School of Materials and Microelectronics),Wuhan University of Technology,Wuhan 430070,China;Hubei Longzhong Laboratory,Xiangyang 441000,China;HFYC(Zhenjiang)Additive Manufacturing Co,Ltd.,Zhenjiang 212132,China)

机构地区：[1]武汉理工大学材料复合新技术国家重点实验室,武汉430070 [2]武汉理工大学材料科学与工程国际化示范学院(材料与微电子学院),武汉430070 [3]湖北隆中实验室,襄阳441000 [4]航发优材(镇江)增材制造有限公司,镇江212132

出　　处：《金属学报》2023年第1期180-190,共11页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目No.51972246;广东省重大基础与应用基础研究项目No.2021B0301030001;湖北隆中实验室自主创新研究项目No.2022ZZ-32

摘　　要：以Ni粉与Ti粉为原料,采用激光定向能量沉积(LDED)技术制备NiTi形状记忆合金。利用XRD、物相拟合、SEM、EDS和DSC等测试方法,对NiTi合金的显微组织、物相含量和物相转变进行分析,随后采用压缩圆柱样品进行形状记忆效应测试,并评估其形状记忆效应。激光能量密度较低时,NiTi合金中产生大量Ni_(4)Ti_(3)相沉淀,随着激光能量密度增加,Ni_(4)Ti_(3)相消失。激光能量密度为20.0 J/mm^(2)时,NiTi合金具有2878 MPa的压缩断裂强度与34.9%的压缩失效应变,且样品在循环20 cyc后具有88.2%形状记忆恢复率。The NiTi alloy is a key material in aerospace and biomedical fields owing to its excellent superelasticity and high shape memory effect.Laser directed energy deposition(LDED),as an advanced additive manufacturing technology,made the preparation of NiTi alloys with high shape memory effect possible. In this study, the NiTi alloy was fabricated via LDED using Ni and Ti powder feedstock. The microstructure, phase content, and phase transformation of the alloy were analyzed by XRD, phase fittingSEM, EDS, and DSC. Next, the shape memory effect was tested using compressed cylindrical samplesWhen the laser energy density was low, several Ni_(4)Ti_(3), phases were produced in the NiTi alloy. The Ni_(4)Ti_(3) phase disappeared with an increase in the laser energy density. When the laser energy density was20.0 J/mm^(2), the NiTi alloy showed a high compressive breaking strength of 2878 MPa and a compressionfailure strain of 34.9%, and the sample also showed a shape recovery rate of 88.2% after 20 cyc of compression.

关 键 词：激光定向能量沉积 激光原位合成 NITI形状记忆合金 形状记忆效应 

分 类 号：TG139.6[一般工业技术—材料科学与工程]