Densification behavior of high Co-Ni steel prepared by spark plasma sintering

High Co-Ni steel with excellent mechanical properties has been extensively used in aerospace and military industries. In this study, spark plasma sintering (SPS) method was used to sinter high Co-Ni steel powders. The powder compacts were heated at 100 C/min to the desired sintering temperature under 40MPa with 10 min holding. Microstructure of the samples sintered at different temperatures were observed and their mechanical properties were tested. The results show that the as-sintered sample obtained at 1050 C is nearly full density. The sintered high Co-Ni steel mainly composed of lath martensite shows a high level of ultimate tensile strength and yield strength.