Enhancing tribological performance of laser-textured Ti–Al–C composite coatings fabricated by SLM

Ti6Al4V (TC4) is widely used in aerospace, but its low surface hardness and poor wear resistance limit tribological applications. To improve performance, Ti-Al-C composite coatings have been applied to TC4 substrates via laser cladding, yet these still show high coefficients of friction (COF) and wear rates at room temperature. In this work, a Ti-Al-C composite coating with surface texture was fabricated on TC4 using laser cladding combined with selective laser melting (SLM), aiming to further enhance anti-friction and anti-wear properties. The morphology, hardness, and wear mechanisms of textures formed under varying laser energy densities were systematically studied. Results showed texture height increased with energy density up to a threshold of ≤5.13 J/mm 3 . Dry and oil-lubricated friction tests confirmed texture as a key factor. Under dry sliding, textures with optimal dimensions (height: 2.45 μm; width: 40.45 μm) reduced COF by 67.57–72.09%. Under oil lubrication, reductions were more pronounced, reaching 99.12% compared to untreated TC4. These benefits stem from grain refinement during texture formation, which improved hardness, decreased contact area, and trapped wear debris, significantly enhancing tribological performance. Moreover, under lubrication, textures acted as reservoirs, promoting hydrodynamic effects and secondary lubrication. Importantly, this method avoids the drawbacks of subtractive manufacturing by employing material remelting for texture fabrication, achieving both improved tribological function and environmental sustainability.