Enhanced Microstructure and Wear Resistance of Ti–6Al–4V Alloy with Vanadium Carbide Coating via Directed Energy Deposition

Abstract

Ti–6Al–4V alloys are known for their suboptimal tribological properties and are often challenged by durability issues under severe wear conditions. This study was conducted to enhance the alloy’s wear resistance by forming a hardened surface layer. Utilizing directed energy deposition (DED) additive manufacturing with a diode laser, vanadium carbide particles were successfully integrated onto a Ti–6Al–4V substrate. This approach deviates from traditional surface enhancement techniques like surface hardening and cladding, as it employs DED additive manufacturing under parameters akin to those used in standard Ti–6Al–4V production. The formed vanadium carbide layer achieved a remarkable thickness of over 400 µm and a Vickers hardness surpassing 1500 HV. Pin-on-disk test results further corroborated the enhanced surface wear properties of the Ti–6Al–4V alloy following the additive-manufacturing process. These findings suggest that employing vanadium carbide additive manufacturing, under conditions similar to the conventional DED process with a diode laser, significantly improves the surface wear properties of Ti–6Al–4V in metal 3D-printing applications.