应用激光, 2017, 37 (6): 779, 网络出版: 2018-01-10
工艺参数及热处理对选区激光熔化Ti6Al4V性能的影响研究
Effects of Process Parameters and Post-heat Treatment on the Properties of Selective Laser Melted Ti6Al4V
选区激光熔化 致密度 工艺参数 热处理 selective laser melting density process parameter heat treatment Ti6Al4V Ti6Al4V alloy
摘要
探索不同激光加工参数对选区激光熔化成形Ti6Al4V质量的影响从而得到最佳工艺参数, 在此基础上研究不同热处理工艺对选区激光熔化成形Ti6Al4V力学性能的影响。在230、280 W两种功率下设计5种不同的扫描间距, 并改变功率和扫描速度以获得7种不同的线能量密度。设计三组热处理工艺, 分别为625、950 ℃保温30 min炉冷, 950、1 080 ℃保温30 min水冷以及950、1 080 ℃保温30 min水冷后时效。进行金相观察、硬度测量以及拉伸试验, 用电子探针观查断口形貌。结果: 280 W下的致密度最高达到99.96%。P=150 W, V=1 250 mm/s时试样侧面的粗糙度最低为20.7 μm。950 ℃退火后针状马氏体变成粗大的片状α板条组织, 950 ℃固溶时效后生成等轴α相以及α的混合组织。硬度最高达到418 HV0.3。利用最佳工艺成形Ti6Al4V后, 950 ℃保温30 min并炉冷可以得到较好的综合力学性能。
Abstract
To investigate the effects of different selective laser melting (SLM) parameters on forming qualities of SLM Ti6Al4V, and obtain the optimum process parameters. After that, to study the influences of different heat treatments on mechanical properties of SLM produced Ti6Al4V. Five different scan distances were used with the power of 230 W and 280 W. Seven line energy densities were designed via changing the power and scanning speed. Three groups of heat treatment processes including 625 ℃ and 950 ℃ annealing, 950 ℃ and 1 080 ℃ solution, 950 ℃ and 1 080 ℃ solution aging were applied. Microstructure and property analyses including metallographic observations, microhardness and tensile test were carried out. The density in power of 280 W reaches to 99.96%. The lowest roughness of side is 20.7 μm. The microstructure changed from acicular martensite to lath-shaped α after 950 ℃ annealing treatment. A mixed phase consisting of a few equiaxial α and α+β was observed after 950 ℃ solution aging treatment. The value of highest microhardness after heattreatment was 418 HV0.3. The heattreatment based on optimal parameters has a negligible promotion on properties of Ti6Al4V alloy but it can refine microhardness or increase its ductility.
李敬, 刘敏, 马文有, 曾德长. 工艺参数及热处理对选区激光熔化Ti6Al4V性能的影响研究[J]. 应用激光, 2017, 37(6): 779. Li Jing, Liu Min, Ma Wenyou, Zeng Dechang. Effects of Process Parameters and Post-heat Treatment on the Properties of Selective Laser Melted Ti6Al4V[J]. APPLIED LASER, 2017, 37(6): 779.