HIP treatment of superalloy Rene88DT prepared by laser rapid forming

The effects of hot isostatic pressing (HIP) on the cracks and tensile properties of laser rapid forming (LRF) superalloy Rene88DT were investigated by metallography, scanning election microscopy and tensile test. Due to the heat affected zone crack in the LRF Rene88DT superalloy, the mechanical properties are severely degraded. HIP treatment (1160°C, 2 h, 200 MPa) is used to try to eliminate such defects. The results show that after HIP treatment, the cracks in the heat affected zone are obviously healed, while MC carbides precipitate along the healed crack area. Through further solution/aging treatment after LRF+HIP, the tensile properties of the Rene88DT samples can be improved considerably, and nearly reach that of the P/M Rene88DT standard.