【摘要】 采用粉末冶金技术制备Ti-Al-Mo-Cr-Fe-B合金，通过扫描电镜(SEM)、X射线衍射(XRD)、准静态拉伸测试和显微硬度测试等方法研究Mo、Cr、Fe含量对钛合金显微组织、烧结致密化和力学性能的影响。研究结果表明，所有合金均由α相、β相和金属间化合物组成，Mo、Cr、Fe的添加降低了钛合金体系在缓慢冷却过程中形成α相的倾向，增加了β相和金属间化合物的比例。其中，Ti-3A1-1.5Mo-4Cr-1Fe-0.1B的性能最优，其致密度、显微硬度、极限抗拉强度和伸长率分别为(99.29±0.06)%、438.40±13.69(HV)、(1 124±119) MPa和(1.93±0.04)%。所有合金均以脆性断裂为主，其力学性能与残余孔隙率密切相关，孔隙率越高，合金强度和塑性越低。合金的致密化主要受到Cr、Fe原子快速扩散带来的综合影响，即快速扩散促进烧结致密化的积极效果与快速扩散导致孔隙形成的消极效果之间的交互作用。更多还原

【Abstract】 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.更多还原