The present work indicated that both the microstructure morphology and occupation of the selective laser melting processed Ti-6Al-4V exhibited regular transformation as the sampling height varied. In turn, the mechanical performance changed accordingly. Due to the great temperature gradient, the microstructure mainly consisted of martensite α′. Additionally, as the sampling heights increased, the microstructure transformed as the following rule: coarse lamellar α′—fine articular α′—ultrafine Z-zigzag α′. Close examination indicated that the martensite phase can be further distinguished into primary α′, secondary α ′, tertiary α′ and quartic α′ based on the size and the generating location. With the sampling height increased, both the size and volume occupation of tertiary and quartic α′ decreased. The generation and transformation of the tertiary α′ and quartic α′ were significantly affected by the thermal cycle intensity and times. Correspondingly, the tensile strength increased slightly as the sampling height increased.

目前的工作表明，选区激光熔化处理的 Ti-6Al-4V 的显微组织形态和占有率都随着取样高度的变化而呈现规律的转变。反过来，机械性能也相应改变。由于温度梯度大，显微组织主要由马氏体α '组成。此外，随着取样高度的增加，显微组织按以下规律转变：粗层状α'-细关节α'-超细Z字形α '。仔细观察表明，马氏体相可进一步区分为初生α '、次生α '、三次α '和四次α。' 基于大小和生成位置。随着采样高度的增加，三次和四次α '的大小和体积占有率均下降。三次α '和四次α '的生成和转化受热循环强度和次数的显着影响。相应地，随着取样高度的增加，拉伸强度略有增加。