Microstructure and tribological behavior of NiAl/WC composites fabricated by thermal explosion reaction at 800 °C

Abstract

In order to improve the tribological properties of NiAl intermetallic compound at high temperature, NiAl/WC composites with addition of 5, 10, 20 and 30 wt% WC are successfully fabricated by self-propagation high-temperature synthesis with thermal explosion mode. The composition, microstructure and microhardness of the composites were characterized. It is found that the composites consisted of only NiAl and WC phases. Tribological behavior is studied on the HT-1000 ball-on-disk high temperature tribometer at 800 °C. The results show that both the friction coefficient and wear rate of the composites decrease with the increase of WC content. The NiAl/WC composite with 30 wt% WC content has the lowest friction coefficient and wear rate. The incorporation of WC particles significantly improves tribological properties at elevated temperature.