A STUDY ON THE TRIBOLOGY CHARACTERISTICS OF MoSi2 INTERMETALLIC COMPOUNDS UNDER DIFFERENT SINTERING TEMPERATURES

Abstract

Molybdenum disilicide ( MoSi 2) is considered to be a promising high temperature material for turbojet and hypersonic engines in aerospace and various industrial applications, because of a high melting point (2030°C), adequate density (6.3g/cm3) and an excellent oxidation resistance. Some researches on MoSi 2 have been carried out but the wear behavior of this material is seldom studied. This paper focused on the effect of sintering temperature of MoSi 2 on the wear behavior. MoSi 2 powder was evaluated from the variation of fabricating conditions such as preparation temperature 1250°C, 1350°C and 1500°C. Wear tests were performed with a sliding speed of 5.21mm/sec and a normal load of 8kgf. Each test was run over a period of 6 hours. The wear behavior is evaluated with respect to the hardness of materials. Hardness test was carried out with a Micro-Vickers hardness tester. As a result of the tests, the friction coefficient was decreased with the increasing sintering temperature of MoSi 2 but the friction coefficient did not vary much for all specimens at temperatures. Hardness values decreased with a decrease in sintering temperature because the indentation under a lower temperature probably contained more defects.