Microstructure and mechanical properties of a copper stainless steel dual phase system prepared by spark plasma sintering
Spark plasma sintering (SPS) has been used to synthesise samples of a model dual phase (DP) system, consisting of copper and AISI420 martensitic steel. Mixed powders were sintered at different temperatures in the range from 850degC to 1000degC using a loading pressure of 60 MPa. Tensile testing revealed dimpled fracture surfaces in samples sintered at higher temperatures, indicating ductile failure and good interfacial bonding between the phases, with the best results overall obtained for samples sintered from wet mixed powders. The results show that by control of the mixing, sintering and post sintering heat treatment conditions, the fabrication of dense samples covering a range of DP microstructures is possible using SPS, with independent control of the microstructure and properties of the two phases.