Laser ternary Hf-Nb-Zr composites coatings on Ti6Al4V alloy for biomedical application

Abstract

Ti6Al4V alloy has been found to be the leading material for hip replacement due to its biocompatibility and good yield strength; however poor corrosion and wear properties are experienced in human tissue surroundings. Laser metal deposition was accomplished on Ti6Al4V alloy using: 25Hafnium, 50Niobium, and 25Zirconium reinforcements with the aid of Nd:YAG Rofin Sinar laser. Characterization of the produced deposits was carried out by optical microscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy and X-ray diffraction. Hardness, corrosion and wear analyses were also done. Microstructure of 25Hf-50Nb-25Zr coatings indicated homogeneous microstructures of both α and β phases. More α acicular phases were formed than β phases. The 25Hf-50Nb-25Zr coating on Ti6Al4V reduced the content of aluminium and vanadium on the substrate. Maximum hardness value and lowest volume wear rate were obtained at laser power of 1250 W with hardness values of 599.18 HV and 0.6 m3 volume wear loss. Improvement in corrosion resistance of 99.98% was obtained. It was established that improved properties were obtained after laser surface cladding of 25Hf-50Nb-25Zr on Ti6Al4V alloy.