Abstract:In additive manufacturing, the forming process parameters are important factors affecting the microstructure and properties of superalloys. 15 sets of process parameters were designed for GH4169 alloy based on laser power, scanning speed, scanning distance and other variables, and the corresponding alloy samples were prepared by selective laser melting (SLM). The effects of different process parameters on the density, microstructure and residual stress of the samples were studied. The mathematical model of the influence of process parameters on sample density was established by using JMP software, and the main influencing factors were determined. The results show that the scanning speed has the greatest influence on the density, followed by the laser power and scanning distance. The density of molded samples is both 99.40% above, and the maximum value can reach 99.98%. When the laser power is 222 W or the scanning speed is 1 190 mm/s, unfused defects are more likely to occur. When the laser power is 403 W or the scanning speed is 573 mm/s, defects such as pores and keyholes are easy to occur due to high local temperature and the increase of recoil pressure. The residual tensile stress on the specimen surface rises with the increase of laser power and the decrease of scanning speed, and the maximum residual tensile stress is 853 MPa.