Microstructure and mechanical properties of powder metallurgy Ti-Al-Mo-Cr-Fe-B system
Ti-Al-Mo-Cr-Fe-B alloys were prepared by powder metallurgy technology.The effects of various alloying element content on the microstructure,sintering densification and mechanical properties of titanium alloy were studied by scanning electron microscopy(SEM),X-ray diffraction(XRD),quasi-static tensile test and microhardness test.The results show that all alloys are composed of α phase,β phase and intermetallic compounds.The addition of Mo,Cr and Fe reduces the tendency of titanium alloy systems to form α phase during slow cooling,and increases the proportion of β phase and intermetallic compounds.Among them,Ti-3Al-1.5Mo-4Cr-1Fe-0.1B alloy has the best performances,and its density,microhardness,ultimate tensile strength and elongation are(99.29±0.06)％,438.40±13.69(HV),(1 124±119)MPa and(1.93±0.04)％,respectively.The fracture mode of all alloys is mainly brittle fracture,and their mechanical properties are closely related to residual porosity.The higher the porosity,the lower the strength and plasticity of the alloy.The densification of alloys is mainly affected by the comprehensive influence of the rapid diffusion of Cr and Fe atoms,that is,the interaction between the positive effect of rapid diffusion promoting sintering densification and the negative effect of rapid diffusion leading to pore formation.
万方数据
维普
