Fabrication and Wear Performance Analysis of TiN-Co-CaF2 Solid Lubricant Coatings on Ti-6Al-4V via TIG Cladding for Aerospace Applications
摘要
Titanium alloys like Ti-6Al-4V are very popular in the aerospace industry because they are stronger than other metals, do not corrode, and stay stable at high temperatures. However, their poor tribological performance under dry sliding conditions limits their application in wear-critical components. In this research article, TiN-Co-CaF2 self-lubricating composite coatings have been developed on Ti-6Al-4V substrates using TIG cladding. The aims of the self-lubricating coating are to increase the resistance to wear, reduce the coefficient of friction, and sustain high thermal environments, which are crucial for aerospace applications. XRD and SEM machines were used to evaluate phase formation and elemental distribution in coatings. The mechanical and tribological properties were evaluated through pin-on-disk wear tester and microhardness tester. The analysis of this research shows that, in comparison with the Ti-6Al-4V substrate, the coating's microhardness was enhanced seven times. Additionally, because of the combined action of the solid lubricant (CaF2), ductile metal matrix (Co), and hard ceramic reinforcement (TiN), the coating's wear rate was five times lower than that of the substrate. With an increase in the volume percentage of CaF2 and a drop in TiN, the composite coating clearly reduced the friction coefficient. The performance and lifetime of aircraft components exposed to demanding operating conditions might be greatly improved by the proposed coating.