Laser cladding of Ti-6Al-4V alloy with vanadium carbide particles

Abstract

The tribological properties of Ti-6Al-4V alloy are generally poor. This study was an attempt to produce a hardened surface layer on this alloy for longer service life during severe wear conditions. For this purpose, laser surface cladding of this alloy with vanadium carbide (VC) powder was performed using a YAG Fiber laser at power strengths of 1000 W, 1500 W, and 2000 W and a travelling speed of 4 mm/s. Surface cladded layers of Ti-6Al-4V alloy metal matrix composite reinforced with VC particles were produced on the substrate under all processing conditions. The size of the cladding layer was increased by increasing the processing power. The cladding layer was well bonded to the substrate, especially at higher processing powers. The VC particles were homogenously distributed within the cladding layer at processing powers of 2000 W and 1500 W, whilst it showed some clusters at a power of 1000 W. Some of the VC particles were melted and re-solidified as fine long dendritic structures during the laser treatment. The cladding layer produced under all processing conditions exhibits remarkable improvement of hardness and wear resistance (almost twice). As the processing powers decreased, the surface of the cladding layers showed higher hardness. The cladding layer also showed improved corrosion resistance.