采用激光选区熔化工艺制备TC4钛合金试样,并主要研究了TC4合金微观组织的演变规律。结果表明,马氏体α′相的形貌、分布与激光能量密度密切相关,随着激光能量密度的增加,基本遵循如下演变规律: 非常细小的Z状马氏体α′相—细小的针状马氏体α′相—粗大的板条α相。能量密度的不同导致试样制备过程中热循环的差异,进而影响马氏体相的形貌与分布,这直接导致了初生、二次、三次和四次马氏体相的体积分数差异。

The TC4 titanium alloy samples were fabricated by selective laser melting and the evolution of TC4 alloy microstructure was studied. The results show that the morphology and distribution of martensite α′ phase are closely related to the laser energy density. As the laser energy density increases, basically follow the evolution rule: ultrafine Z-zigzag martensite α′ phase—fine article martensite α′ phase—coarse lamella α phase. The difference in energy density leads to the difference in thermal cycling during the preparation of the sample, which in turn affects the morphology and distribution of the martensite phase, directly leads to the difference in volume fraction of the primary, secondary, tertiary and quadratic martensite phases.