熔粉式激光直接沉积成形TC11钛合金工艺性研究(英文)

Formability of TC11 Titanium Alloy Fabricated by Direct Laser Deposition

试验采用同轴送粉式激光直接沉积成形技术,分别使用脉冲式和连续式的激光方式在TC11合金锻件基体上沉积TC11钛合金。利用OM、SEM对沉积层的微观组织进行了分析,测试了沉积层的显微硬度。结果表明,纵观整个沉积层组织,两者沉积层表面光滑、均匀、连续,而且无结构缺陷;从微观组织上看,连续式具有枝晶组织,且具有外延生长特性,而脉冲式枝晶组织不明显;从晶粒形核生长形式看,两者非均匀形核特征显著;而且激光直接沉积成形层硬度与基体相比,两者都有较为明显的增强。

TC11 titanium alloy was fabricated by direct laser deposition with pulse and continuous laser power separately,and effects of laser power patterns on its microstructure and hardness were investigated in order to fabricate and repair the forged components.The results show that there are smooth,uniform and continuous surfaces and no defects in the two as-deposited samples are observed no matter by pulse laser or the continuous.Moreover,the obvious dendritic structure exists and grows epitaxial in the continuous-laser deposited layers,and there are equal-axis grains in the pulse-laser ones.In addition,the microstructure of the forged TC11 alloys is like net-basket,and its hardness is lower than that of the pulse-laser and continuous as-deposited samples.