Heterostructured NiCr matrix composites with high strength and wear resistance

Self-lubricating composites are required to have excellent tribological performances and good mechanical properties when they are applied as mechanic parts. However, the brittle nature of most lubricants will weaken the mechanical properties of the composites where in order to get the lubricating ability proper amount of lubricants are usually incorporated, bringing challenges for them to get well-balanced mechanical and tribological properties. In this study, NiCr matrix self-lubricating composites with the addition of WS2 and nano-Ti were prepared via spark plasma sintering. The hard phase of Ni3Ti and the lubricant TiS were formed via in-situ reaction at the interface, which surrounded the soft alloy matrix and developed a heterostructure. Compared with the conventional NiCr-WS2 composite, the heterostructured composite exhibited a high yield strength of 1645 MPa, a low friction coefficient of 0.37 and a wear rate of as low as 2.25 x 10(-5) mm(3) N-1 m(-1) when sliding. Finite element analysis demonstrated that the heterostructure plays a key role to balance well the mechanical and tribological properties of the NiCr matrix composites. (C) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

This study investigates the fabrication and properties of NiCr matrix self-lubricating composites with the addition of WS2 and nano-Ti using spark plasma sintering. The heterostructured composite, with Ni3Ti and TiS as the hard phase formed at the interface, exhibits high yield strength, low friction coefficient, and wear rate compared to conventional composites. Finite element analysis confirms the crucial role of the heterostructure in balancing the mechanical and tribological properties of the NiCr matrix composites.