On the properties and tribological behaviors of P/M iron based composites reinforced with ultrafine particulates

This paper describes the changes of structure, some mechanical and tribological properties of P/M iron based composites reinforced with ultrafine additives. Nanocrystalline additives of oxides, borides and diamond in the base material allow increasing the compressive strength and the tensile strength 1.5-3 times. An introduction of 0.2-0.3 wt% of ultrafine-grained diamonds, 0.5 wt% of chromium borides and 0.2-0.5 wt% of alumina or oxides mixture provides the best results. The coefficients of friction of MMCs containing nanocrystalline particulates are reduced 2-3 times compared to the base P/M material while the critical seizure pressure is enhanced 2-5 times. The wear resistance of the MMCs increases 2-4 times.