β热处理对SEBM Ti-6Al-4V Diamond点阵材料显微组织和力学性能的影响

Microstructure and Mechanical Properties ofβHeat-treated Ti-6Al-4V Diamond Lattice Prepared by SEBM

采用电子束选区熔化(SEBM)技术制备Ti-6Al-4V Diamond点阵材料,研究β热处理(1100℃/2 h/FC)对其显微组织与力学性能的影响。结果表明,经β热处理后,Ti-6Al-4V Diamond点阵材料的显微组织由原始β柱状晶转变为等轴晶,针状马氏体α′相以及α+β细片层组织转变为相互平行的α+β粗片层组织,且α片层平均厚度由0.8μm增加至7.4μm。此外,Ti-6Al-4V Diamond压缩应变增加,最大可达13.1%,但强度降低;热处理对点阵材料的模量影响较小。点阵材料的结构与材料具有独立性,热处理不会改变Ti-6Al-4V Diamond点阵材料强度、模量与相对密度的指数关系。

Ti-6 Al-4 V Diamond lattice materials were manufactured using selective electron beam melting(SEBM).The microstructure and mechanical properties of the as-built andβheat-treated(1100℃/2 h/FC)Ti-6 Al-4 V Diamond lattice materials have been investigated.The results show that originalβcolumnar crystal transforms to equiaxed crystal,acicular martensiteα′phase and fine lamellarα+βphase transform to paralleled coarse lamellarα+βphase after heat treatment.Most importantly,αlath average thickness increases from 0.8μm to 7.4μm after heat treatment.And the compressive strain of Ti-6 Al-4 V diamond lattice materials increases to 13.1%,but the strength decreases after heat treament.The heat treatment has slight effect on the modulus of Ti-6 Al-4 V Diamond lattice materials.The structure and material of Diamond lattice materials is independent,and heat treatment can not change the exponential relationship of the strength-relative density and the modulus-relative density of Ti-6 Al-4 V Diamond lattice materials.