Enhancing the wear resistance of titanium alloys through the synthesis of layered double hydroxides combined with titanium nitride coatings

Abstract

Given the notoriously poor wear performance of Ti6Al4V (TC4) alloys, two types of MgAl layered double hydroxides (LDHs) were synthesized as lubrication additives. Systematic tribological tests were conducted to explore the performance of the TC4 alloy with these MgAl LDHs at varying concentrations in oil. It was found that, with increasing additive concentration, the wear resistance of TC4 significantly improved. Notably, MgAl LDHs with a hexagonal nanosheet structure exhibited superior lubrication performance, reducing the coefficient of friction (COF) by approximately 67.94 % compared to dry friction, and markedly enhancing the anti-wear characteristics of the TC4 alloy. Furthermore, to improve the utility of TC4 alloy in industrial applications, titanium nitride (TiN) coatings with excellent mechanical properties were deposited onto the TC4 substrate using arc ion deposition. A comprehensive analysis of the tribological behavior and wear mechanisms of TiN coating with the two MgAl LDHs additives was also conducted. Results indicated that the combination of TiN hard coatings and MgAl LDHs lubricants achieved high wear resistance for the TC4 substrate. In conclusion, a low-wear synergistic protection system integrating TiN coatings and high-performance MgAl LDHs lubricants was developed, demonstrating effective protection for TC4 alloys. This strategy not only presents a novel approach for reducing wear in TC4 alloys but also provides a reliable method for safeguarding and ensuring the long-term stability of titanium alloys mechanical components under demanding conditions.

Keywords: Friction; Layered double hydroxides; Lubrication; TiN coating; Wear.