Solid Lubrication Performance of Few‐ and Multilayer Ti₃C₂Tₓ Coatings

Abstract

Multilayer Ti3C2TX nanosheets (MXenes) have gained notable attention in the tribological community due to their outstanding wear resistance induced by their ability to form beneficial tribolayers. Regarding delaminated, few-layer Ti3C2Tx nanosheets, much less knowledge about their tribological performance is available. Therefore, this study aims at comparing the solid lubrication ability of spray-coated few- or multilayer Ti3C2Tx coatings (dispersion concentrations of 2 and 5 mg mL−1). Linear-reciprocating ball-on-disk tests are conducted using normal loads of 100 and 200 mN. The results clearly demonstrate the superior tribological performance of multilayer Ti3C2Tx nanosheets, inducing a low, stable, and reproducible evolution of the coefficient of friction. This holds particularly true for coatings fabricated with the lower concentrated dispersion, which are characterized by a reduced coating thickness and less lubricious material. In contrast, few-layer MXenes, irrespective of the coating thickness and available amount of lubricious material (dispersion concentration), demonstrate continuously rising frictional values, which can be traced back to the nanosheets’ degradation.