Preparation and properties of MOSi2 composites reinforced by TiC, TiCN, and TiB2

Molybdenum disilicide (MoSi2)-based composites reinforced by TiC, TiCN, and TiB2 were fabricated by hot-pressing. The microstructures, the mechanical properties at room temperature and the tribological properties of these materials were characterized. MoSi2 -based composites reinforced by TiC, TiCN, and TiB2 exhibited higher microhardness (HV) and bending strength than that of monolithic MoSi2. The wear behavior of monolithic MoSi2 and its composites for sliding against Ni-Cr alloy at room temperature have been correlated with their mechanical properties. At 600 degrees C, the tribo-oxidation together with the transfer of Ni-Cr alloy to the surface Of MoSi2 -based composites is found to be the predominating wear mechanisms. The morphology and chemistry of oxide layer have a role to play in the wear resistance of monolithic MoSi2 and its composites. (c) 2005 Elsevier B.V. All rights reserved.