Microstructure and wear characteristics of in-situ micro/nanoscale niobium carbide reinforced copper composites fabricated through powder metallurgy

Abstract

In this work, a highly wear-resistant cooper matrix composite reinforced by in situ formed nano-NbC particles was synthesized by hot pressing mechanically alloyed Cu+Nb+C powders. The composite possesses a smaller friction coefficient and displays a wear rate (2.6 × 10−5 mm3N−1 m−1) two orders of magnitude lower than the micro-NbC reinforced Cu composites (123.5 × 10−5 mm3N−1 m−1). Such property enhancement is attributed to the hardness improvement and the solid lubricating effects induced by nanoscale niobium carbides/oxides as well as iron oxides. The oxidation and pulverization of NbC during friction have played a key role in increasing the wear resistance and their mechanisms are discussed. The findings provided a strategy for developing other wear-resistant composite materials.