激光选区熔化成形Ti-12Mo-6Zr-2Fe(TMZF)合金微观组织及力学性能的研究

Microstructure and mechanical properties of Ti-12Mo-6Zr-2Fe(TMZF) alloy formed by laser selective melting

为了探究激光选区熔化(Selective laser melting,SLM)Ti-12Mo-6Zr-2Fe(TMZF)合金的微观组织与力学性能,采用TMZF合金粉进行激光增材制造,研究了铸造TMZF合金与SLM TMZF合金试样微观组织与力学性能的差异.结合X射线衍射仪(XRD)、金相显微镜(OM)、扫描电子显微镜(SEM)及能谱分析(EDS)等材料表征手段,对TMZF合金试样的物相分布、微观组织结构、元素分布及试样拉伸断口进行了对比分析.结果表明:SLM TMZF试样与铸造TMZF试样的组织中都含有大量β-Ti组织;SLM TMZF试样的平均显微硬度为355.7±5.64 HV_(0.2),铸造TMZF试样的平均显微硬度为354.8±5.44 HV_(0.2);SLM TMZF试样的屈服强度为934±4.1 MPa、抗拉强度为993±2.4 MPa、延伸率为14.4±0.6%,而铸造TMZF试样的屈服强度为1052±12.1 MPa、抗拉强度为1055±11.7 MPa、延伸率为10.4±1.2%.为进一步探究激光选区熔化制备TMZF的后处理打下基础.

In order to investigate the microstructure and mechanical properties of selective laser melting(SLM) Ti-12Mo-6Zr-2Fe(TMZF) alloy,TMZF alloy powder was used for laser additive manufacturing,and the differences of microstructure and mechanical properties between casting TMZF alloy and SLM TMZF alloy were studied. The phase distribution,microstructure,element distribution and tensile fracture of TMZF alloy samples were compared and analyzed by means of X-ray diffraction(XRD),metallographic microscope(OM),scanning electron microscope(SEM) and energy dispersive spectroscopy(EDS). The results showed that both SLM TMZF samples and casting TMZF samples contain a large amount of β-Ti phase. The average microhardness of SLM TMZF sample was 355.7±5.64 HV_(0.2),and that of casting TMZF sample was 354.8±5.44 HV_(0.2). The yield strength of SLM TMZF sample was 934±4.1 MPa,the tensile strength was 993±2.4 MPa and the elongation was 14.4±0. 6%;the yield strength of casting TMZF sample was 1052±12.1 MPa,the tensile strength is 1055±11.7 MPa and the elongation is 10.4±1.2%. It laid the foundation for further exploring the post-processing of TMZF prepared by laser selective melting.