Effect of coarse hard particles on high-temperature sliding abrasion of new metal matrix composites

Abstract

Iron-base and nickel-base powders as well as several powders of different hard particles were tested by microscratching and microindentation up to 900°C. Those most suited were mixed and hot compacted to give new metal matrix composites(MMC). Up to 50v/o of coarse WC W 2 C particles were dispersed in a high speed steel matrix or in a NiCr20AlSi matrix. The wear rate in three-body sliding abrasion by flint under an argon atmosphere decreases with temperature to about 700 °C due to the formation of a self-protecting flint layer and a change in the hardness ratio of the microstructural constituents and the abrasive. MMC with 30 v/o of hard particles in the steel matrix are suitable for service up to 650 °C and those with a nickel matrix up to 750°C.