Investigation of the synergetic effect of oleophilic textured surfaces and MoS 2 at different loads on the tribological performance of Ti64 alloy

Abstract

In this research study, surface modification of Ti64 alloy was carried out using laser surface texturing (LST). The investigation aims to explore the effects of loads, oleophilic textured surfaces, and MoS₂ as a solid lubricant on the friction and wear reduction of Ti64 alloy and AISI 52100 steel tribo-pairs. Three types of LST textures (Circular, triangular, and square textures) were created on the Ti64 alloy. Subsequently, tribological experiments were performed using a ball-on-disc universal tribometer at loads of 5, 10, and 15N with a 15 Hz frequency. The worn surface was analyzed using various methods, including optical microscopy, 3D-profilometer, FESEM, EDAX analysis, and Raman spectroscopy. The study compared the coefficient of friction (COF) and wear behavior of non-textured surfaces (N_TS) with those of textured surfaces (T_S) under both dry sliding conditions (D_SC) and lubricated sliding conditions (L_SC). The results demonstrated a significant reduction in the COF and wear coefficients on the T_S. Specifically, the circular texture (C_iT) exhibited a remarkable reduction of 39.3%, 63.83%, and 83.6% in wear coefficients compared to the N_TS tested under D_SC and L_SC (using pure PAO-4 and PAO-4 + 1% wt MoS₂) with sliding load of 15N. D_SC showed abrasion, adhesion, and delamination wear, while L_SC displayed mild adhesion, delamination, and tribo-layer formation on N_TS and T_S. The analysis indicated that the use of L_ST and solid lubricant nanoparticles on a Ti64 alloy would result in improved service life and better endurance in cutting tools and tribo-mating parts.