通过对激光立体成形(LSF)TC17钛合金沉积态、去应力退火后状态及时效热处理后状态下的微观组织分析,研究了不同热处理方式对激光立体成形组织的影响。结果表明,沉积态组织由贯穿多个熔覆层呈外延生长的粗大柱状晶组成,柱状晶主轴垂直于激光扫描方向或略向扫描方向倾斜;沉积态原始β晶内组织是编织极其细密的网篮组织,α板条长度为1~3μm,宽度仅0.1~0.2μm,为典型的α+β两相组织特征。沉积态试样经600℃保温1 h,炉冷(FC)退火后,显微组织无明显变化,仍为典型的网篮组织,但α板条长度和宽度有所增加,长宽比减小;经550℃保温4 h,空冷(AC)退火后,显微组织中出现部分等轴α相。对沉积态试样进行时效热处理时,随着保温时间的增加,α相呈长大趋势,长宽比逐渐减小,当保温时间达到8 h时,α相发生明显的球化,仅残留有少量的α板条。 The effects of different heat treatment methods on the laser three-dimensional forming microstructure were studied through the microstructure analysis of the as-deposited, as-annealed and as-annealed TC17 titanium alloy of LSF. The results show that the deposited microstructure consists of coarse columnar crystals grown epitaxially through multiple cladding layers and the columnar crystal axis is perpendicular to the laser scanning direction or slightly to the scanning direction. The original β crystalline structure in the as-deposited state is a very fine mesh In baskets, the length of α - lath was 1 ~ 3μm and the width was only 0.1 ~ 0.2μm, which was typical α + β two - phase microstructure. After being annealed at 600 ℃ for 1 h, the microstructure of the as-deposited samples remained unchanged. However, the length and width of α-laths increased and the aspect ratio decreased After isothermal heat treatment at 550 ℃ for 4 h, some equiaxed α phase appears in the microstructure after air cooling (AC) annealing. The α phase grows up and the aspect ratio decreases gradually when the heat treatment time is prolonged. When the holding time is up to 8 h, the α phase is obviously spheroidized and only remains A small amount of α laths.