采用激光选区熔化技术制备GH3536合金纵向和横向试样,经热处理和热等静压处理后,将一部分试样机加工成光滑表面试样,与打印表面试样进行对比,研究了表面状态对拉伸性能和疲劳性能的影响。结果表明:光滑表面试样和打印表面试样纵向室温拉伸性能差异很小,表面状态对拉伸性能没有显著影响;与光滑表面试样相比,打印表面试样的应变疲劳寿命略低,而应力疲劳寿命显著降低,为光滑表面试样的2%~8%;光滑表面试样裂纹源区裂纹呈放射状,扩展区呈脉状,瞬断区有大量韧窝;打印表面试样没有明显的放射状裂纹,为多源开裂,断口为解理断裂。

GH3536 alloy longitudinal and transverse samples were prepared by selective laser melting. After heat treatment and hot isostatic pressing treatment, some samples were machined into smooth-surface samples. The influence of surface state on tensile and fatigue properties was studied by comparing with build-surface samples. The results show that there was little difference in the longitudinal room temperature tensile properties between smooth-surface samples and build-surface samples, so the surface state had no significant effect on the tensile properties. Compared with that of smooth-surface samples, the strain fatigue life of build-surface samples was slightly lower, and the stress fatigue life of build-surface samples was significantly reduced, which was 2%-8% of smooth-surface samples. The cracks in the crack source region of the smooth-surface samples were radially shaped, those in the propagation region were vein-like, and there were a lot of dimples in the instantaneous fracture region. There were no obvious radial cracks in the build-surface samples, which was multi-source cracking, and the fracture was cleavage fracture.