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.