Grain refinement: A mechanism for graphene nanoplatelets to reduce friction and wear of Ni3Al matrix self-lubricating composites

• Published in: Wear 2014-02, Vol.310 (1-2), p.33-40
• Main Authors: Zhai, Wenzheng, Shi, Xiaoliang, Wang, Mang, Xu, Zengshi, Yao, Jie, Song, Siyuan, Wang, Yufu
• Format: Article
• Language: English
• Subjects: Applied sciences; Contact of materials. Friction. Wear; Dispersion hardening metals; Electron microscopy; Exact sciences and technology; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Powder metallurgy. Composite materials; Production techniques; Sliding wear; Solid lubricants; Surface analysis
• ISSN: 0043-1648; 1873-2577
• DOI: 10.1016/j.wear.2013.12.014

Investigations in graphene of controlling friction and wear of Ni3Al matrix self-lubricating composites (NMSC) are needed for moving mechanical assemblies. The friction and wear behaviors of NMSC with graphene nanoplatelets (GNPs) against Si3N4 ball are tested using a constant load of 10N and a constant speed of 0.2m/s from room temperature (RT) to 600°C. Tribological test results have revealed that small amounts of GNPs in the NMSC are able to drastically reduce the friction coefficients and wear rates over the effective operating range (RT-400°C). A possible explanation for these results is that the refinement of grains accompanying the slippage of laminated sheets between GNPs could provide a source of the stress dissipation and form the GNP protective layer during sliding process, leading to the reduction of wear rates as well as the friction coefficients. It is concluded that GNPs hold great potential applications as an effective solid lubricant for moderate loads and stress, and can be easily used for the preparation of the self-lubricating composites in the future. [Display omitted] •Tribological properties of NMSC and NMSC/GNPs are tested.•NMSC/GNPs exhibit excellent tribological properties.•A significant decrease in friction and wear has been obtained from NMSC/GNPs.•Grain refinement plays the major role in the excellent tribological performances.