热等静压温度对激光选区熔化成形GH3536裂纹和组织性能的影响

利用激光选区熔化(Selective laser melting,SLM)技术制备了GH3536镍基高温合金，研究了不同热等静压(Hot isostatic pressing,HIP)温度对SLM成形GH3536合金裂纹和组织性能的影响。利用X射线衍射仪(X-ray diffraction,XRD)、扫描电镜(Scanning electron microscope,SEM)、电子背散射衍射(Electron backscatter diffraction,EBSD)、电子探针显微分析仪(Electron probe microanalyzer,EPMA)等方式表征了GH3536相组成和组织演变，利用高温持久性能试验机测试合金室温和高温拉伸性能。结果表明：经HIP后，SLM成形GH3536合金相组成保持不变，均为γ相，但晶格常数降低，且随着HIP温度的升高而降低。SLM态合金中存在10～100μm的微裂纹和气孔缺陷，微裂纹主要存在于熔池边界。经HIP后，合金中微裂纹完全消除，但仍存在少量孔洞。GH3536合金经高温高压处理后，晶粒尺寸增大，抗拉强度有所降低。其中SLM态试样室温抗拉强度...

Effect of Hot Isostatic Pressing Temperature on Microcrack,Microstructure and Mechanical Properties of GH3536 Nickel-based Superalloy Fabricated by Selective Laser Melting

The GH3536 nickel-based superalloy was fabricated by selective laser melting(SLM), and the effects of hot isostatic pressing(HIP) temperatures on the cracks and microstructure properties of GH3536 were studied. Characterizations of phase composition and microstructure evolution of GH3536 were conducted by XRD, SEM, EBSD and EPAM et al. Besides, the high-temperature endurance testing machine was used to test the alloy’s room temperature and high-temperature tensile properties. The results indicated that the phase composition of GH3536 alloy formed by SLM remains unchanged after HIP, both consisting of ^γ phase. But the lattice constant decreased, and decreased with the increase of HIP temperature. Micro-cracks could be observed in the matrix after SLM process, which mainly existed at the boundary of the molten pool, and the length was measured ranging from 10 to 100 µm. After HIP, the microcracks were completely eliminated, but there still existed some holes. After GH3536 alloy underwent high temperature and pressure treatment, the grain size increased, resulting in a decrease in tensile strength. Among them, the room temperature tensile strength and elongation of the SLM specimen are 871 MPa and 26.2%, respectively. After HIP treatment, the elongation is increased by 13.7% and the strength is reduced by 13.0%. The tensile strength and elongation of the SLM specimen at 900 ℃ are 247 MPa and 5.7%, respectively. After HIP treatment, the elongation is increased by 13.4% and the strength is reduced by 10.1%.