Solid Lubrication Performance of Multi-Layer Ti3cnt X Carbonitrides

Abstract

2D MXene nanosheets have received notable attention in tribological research due to their excellent wear resistance and durability under solid lubrication. Although MXenes include carbides, nitrides, and carbonitrides, only MXene carbides have been tribologically assessed. This study assesses the mechanical and tribological properties of multilayer Ti3CNTx carbonitride MXene coatings by linear-reciprocating ball-on-disk tribometry to elucidate their performance and tribo-film formation capabilities under different load conditions. Coupling advanced mechanical testing and materials characterization, our work highlights the dual role of tribochemically-formed oxides regarding the wear behavior of these coatings. At low loads, the formation of compact and aligned tribo-layers effectively reduced friction and wear, demonstrating an excellent solid lubrication performance. Under higher loads, the coatings, however, transitioned to severe wear, driven by the formation of rutile TiO2, which notably increased abrasion and plastic deformation. Our findings illustrate that the present chemistry in the X site in MXenes majorly affects the tribochemical-induced oxidation of MXenes, hence affecting their long-term performance in solid lubrication applications.

Keywords: 2D materials, MXenes, Ti3CNTx, Solid Lubrication, Mechanical Properties, Tribo-layer formation