Abstract: 　　This paper investigates the influence of heat treatment systems on the microstructure evolution and mechanical property optimization of hot-pressed sintered GH4099 superalloy by using solution treatment followed by aging processes. The results show that the GH4099 superalloy with excellent density can be successfully prepared by using the hot isostatic pressing process at 1200℃ and 130MPa for 4 hours. The microstructure of the alloy is mainly composed of equiaxed grains with an average grain size of 38 μm. A large amount of carbides are continuously distributed at the grain boundaries, and the boundaries of some original particles are still clearly retained under this process. The yield strength of the formed alloy is 700.42 MPa, the tensile strength is 1167.21 MPa, and the elongation is 27.91%. Solution treatment had no significant effect on the grain size of hot-press sintered GH4099 superalloy, but improved the distribution of intragranular and grain boundary carbides, thereby enhancing both the strength and elongation of the alloy. The sample treated with solution treatment at 1100°C for 2 hours followed by aging at 800°C for 8 hours had a yield strength increased to 789.53 MPa, a tensile strength increased to 1207.23 MPa, and an elongation increased to 29.23%.
　　Keyworlds: Hot pressed sintering, powder metallurgy, GH4099 superalloy, microstructure, mechanical properties