BIOCOMPATIBLE AND MECHANICAL-PROPERTIES OF LOW-TEMPERATURE DEPOSITED QUATERNARY (TI,AL,V)N COATINGS ON TI6AL4V TITANIUM-ALLOY SUBSTRATES

A series of quaternary (Ti, Al, V) N coating layers were obtained by l ow temperature reactive plasma sputtering in differing deposition cond itions to improve the wear resistance and the biocompatibility of a ti tanium surgical alloy, specifically Ti-6Al-4V. Characterization of the mechanical properties, structure and the chemical composition of the coating layer was explored by microhardness test, ball against flat we ar test, scanning electron microscopy and X-ray diffraction. The bioco mpatibility of the optimum coating layer (as determined by mechanical performance) was examined by a modified MTT toxicity test and by monit oring cell growth assessed by quantitative stereological analysis. The experimental results are encouraging, indicating that this low temper ature deposited, dense, quaternary (Ti,Al,V) N coating layer exhibits improved mechanical properties such as high hardness and excellent adh esion to a Ti alloy substrate and is highly biocompatible.