Study of solid-state phase transformations during additive manufacturing of Ti6Al4V

X-ray diffraction was used to study solid-state phase transformations, lattice strain evolution, and evolution of crystallographic defects and texture due to Solid-State Thermal Cycling (SSTC) in situ during Laser Metal Deposition (LMD) of Ti6Al4V. To perform the experiments we have developed a novel mini-LMD machine dedicated to synchrotron beamlines. Microstructure evolution due to SSTC during LMD of Ti6Al4V using different LMD parameters and residual stresses measurement in each sample after cooling down to room temperature were investigated.

本研究采用X射线衍射（X-ray diffraction）技术，针对Ti6Al4V合金激光金属沉积（Laser Metal Deposition，LMD）过程中，原位固态热循环（Solid-State Thermal Cycling，SSTC）引发的固态相变、晶格应变演化、晶体缺陷与织构演变展开系统研究。为开展该实验，本团队自主研发了一款专为同步辐射光束线（synchrotron beamlines）设计的新型微型激光金属沉积（mini-LMD）装置。此外，本研究还探究了不同工艺参数下Ti6Al4V合金激光金属沉积过程中，固态热循环引发的微观组织演变规律，并对所有试样冷却至室温后的残余应力进行了测试与表征。