Friction and Wear Behavior of Ni-based Alloy Reinforced with MoSi2

Ni-based alloys reinforced with MoSi2 were fabricated by hot pressing and sintering in vacuum. Tribological properties of the composites were evaluated by a THT friction and wear tester. Results indicate that addition of MoSi2 contributed greatly to the increase of microhardness and wear resistance of the Ni-based alloy and it had minor effect on the friction coefficient. The composite containing 30wt% MoSi2 had the highest microhardness and it exhibited better wear resistance. While the composite with 20wt% MoSi2 exhibited the lowest friction coefficient, thus it is suggested to keep the content of MoSi2 in the reinforced Ni-based alloy composite to be 30%, so as to acquire the optimized mechanical and tribological properties. The wear mechanism of composites varied from severe plastic deformation to microcracking with addition of MoSi2. In general, wear resistance of the composites reinforced by MoSi2 was attributed to the effect of dispersion strengthening and load-carrying of the MoSi2 hard particulates.