PROGRESS TOWARD A DENSER METAL MATRIX COMPOSITE USING THE THREE DIMENSIONAL PRINTING METHOD

摘要

Metal matrix composite materials (MMCs) offer superior specific strength and stiffness as compared to the conventional monolithic materials. Near-net shaped MMC product fabrication is not easy with traditional composite processing. In this study, the three dimensional printing (3DP) process has been applied to explore the feasibility of fabricating MMC parts. Spherical 420 stainless steel (SS) and silicon nitride (Si_3N_4) powders were used to process a metal matrix composite material system. Si_3N_4 powder contents, sintering temperature and sintering time were varied in the experiments in order to understand the interdependencies among these process variables. The dimensional change was measured using a high temperature dilatometer during the sintering process. The volume and mass change caused by sintering were measured. It was clearly shown that the combination of 3DP method and optimal sintering condition had a high potential for obtaining uniform and dense MMC parts.