【摘要】 为提高选区激光熔化Ti-6Al-4V合金的低周疲劳性能，利用OM、SEM、TEM、室温拉伸及低周疲劳试验研究了热处理对选区激光熔化Ti-6Al-4V合金组织及性能的影响。结果表明，沉积态组织表现为外延生长的β柱状晶及晶内呈一定取向关系的针状马氏体α′，经退火后α′发生分解转变为网篮编织状的α+β，经循环热处理后板条α发生球化，组织由等轴α、板条α和残余β构成。经热处理后，退火态低周疲劳性能达到锻件的87%以上，循环热处理态达到锻件的90%以上。更多还原

【Abstract】 In order to improve the low cycle fatigue property of selective laser melting Ti-6Al-4V alloy, the effects of heat treatment on the microstructure and properties of selective laser melting Ti-6Al-4V alloy were studied by OM, SEM, TEM, room temperature tensile and low cycle fatigue tests. The results show that the as-built microstructure is characterized by epitaxially grown β columnar grains and acicular martensite α′ with a certain orientation in the grains. After annealing, α′ decomposes and is transformed into basket-weave α+β.After cyclic heat treatment, lath α becomes globularized, and the microstructure is composed of equiaxed α, lath α and residual β. After heat treatment, the low cycle fatigue property of the annealed alloy reaches more than 87% of that of the forgings. Besides, the property of cyclic heat treated alloy reaches more than 90% of that of the forgings.更多还原