关键词: 热等静压, 近净成形, 镍基高温合金, 粉末盘, 有限元法

Abstract:

To once-forming Ni-based superalloys turbine disc, a NNS-HIP method was used. A shape follow-up and a longitudinal symmetry mold schemes were designed. A modified Shima's model was used to simulate the NNS-HIP process of inconel625 powder disk, and an optimal scheme was selected for the test. Simulation results show that the thin canning has large deformation and drives powder densification. The internal core has almost no deformation, and controls the complex internal shape of powder disk; The powder expands first and then compacts in a multi-stage mode. Experimental results show that the size simulation error is less than 3.57%, mainly caused by manufacturing and measurement errors. The simulation values in low density areas is smaller than actual values, because the simulation process ignores some microscopic behaviors such as movement and rearrangement of powder particles. The tensile strength of Inconel625 compacts is bigger than ASTM forging standard, and good plasticity can be received after solution treatment. The simulation can guide the mold's structure design of NNS-HIP.

Key words: hot isostatic pressing(HIP), near-net-shaping(NNS), Ni-based superalloy;powder disk, FEM