Application of MIM Process for Nickel Base Superalloy

Superalloys have been used especially for aerospace and atomic energy applications because of their excellent attributes of high corrosion and oxidation resistance, and high temperature strength. A Inconel 718 is one of representative Ni-base superalloys. However, it is not easy to produce the complicate shaped parts with low cost due to their poor workability. In this study, Metal Injection Molding (MIM) process, one of near net-shape forming of powders, has been applied to fabricate the Inconel 718 alloy compacts using different type of powders; gas and water atomized powders. By optimizing the MIM process, their obtained relative density was near full density (98∼99 %) and the tensile property of as-sintered compacts was the strength of 1000 MPa and the elongation of around 10 %, which are similar to those of wrought materials. The tensile properties were improved to the strength of 1250 MPa and the elongation of around 8 % by heat treatment.