Effect of Fe on the high-temperature tribological behavior of NiAl/WC-Fexself-lubricating composites produced by thermal explosion

Abstract

In order to improve the self-lubricating properties of NiAl-WC composite, a novel solid-lubricating material, NiAl/WC-Fex (x=5, 10, 15 and 20 in weight percent) composites were synthesized by thermal explosion using Ni-Al-WC-Fe mixed powders. The microstructure, phase constituent, and tribological behavior of NiAl/WC-Fex composites at 800° Cwere studied. According to the results, the addition of Fe could reduce the cracks of the composites. Compared with NiAl/WC, the increased Fe content could reduce the friction coefficient and high-temperature wear rate due to its enhanced ductility, oxidation, and low shearing strength. In particular, composite with 10 wt% Fe content had the lowest friction coefficient and wear rate because of the self-lubricating behavior of Fe at elevated temperature. The result also showed that the wear mechanism of NiAl/WC-Fex is related to Fe content at high-temperature.