Hierarchical interface regulation and tribological mechanism of MAX phase/MoS₂-reinforced PTFE/Kevlar fabric composites for self-lubricating applications

Improving the adhesion and tribological performance of fabric composite liners remains a critical challenge, particularly under varying temperature conditions. In this study, a combined strategy involving polydopamine-assisted deposition of MAX phase, shot peening of metallic substrates, and incorporation of lamellar MoS₂ was proposed to regulate interfacial structure and friction behavior. The results show that shot-peening-induced regulation of the metallic substrate topography significantly improves liner–substrate adhesion. An intermediate substrate roughness promotes resin infiltration and mechanical interlocking, increasing the peel strength to 1.41 N mm⁻¹, approximately 2.35 times that of the same MAX@fabric–MoS₂ composite bonded to an untreated substrate. The incorporation of MoS₂ produces a concentration-dependent change in tribological behavior. Among the investigated compositions, 0.5 wt.% MoS₂ yields the lowest mean coefficient of friction (COF) and wear rate, corresponding to reductions of approximately 16% and 15%, respectively, compared with the MAX@fabric composite without MoS₂. Analysis indicates that an appropriate substrate roughness facilitates resin infiltration and stable interfacial bonding, while excessive roughness induces stress concentration and reduces adhesion. The smoother and more compact worn surface obtained at 0.5 wt.% MoS₂ suggests improved stability of the sliding interface, potentially associated with the development of a lubricious interfacial tribolayer. These findings reveal that adhesion and tribological performance are governed by balanced interfacial roughness and lubricant loading, providing a hierarchical interface-design principle for fabric composite liners.