Combined Effect of Cryogenic and Aging Treatments on Wear Behavior of Ti-6Al-4V α/β Alloy for Biomedical Applications

Abstract

Ti-6Al-4V α/β titanium alloy is used in the biomedical industry to produce artificial joints due to its excellent osseointegration property, low density, and low Elasticity modulus compatible with bone structure. Ti-6Al-4V alloy is expected to have high wear resistance to prevent toxic elements such as Al, V from being released into the body environment during joint movement. In this study, aging treatment and a combination of aging and cryogenic treatment were applied to the alloy to obtain advanced tensile properties and wear resistance. Cryogenic treatments were conducted at deep (-196°C) and shallow (-140°C) cryogenic treatment temperatures. After that, single-step and duplex aging treatment were conducted to the one group of samples after the cryogenic treatment, while another group was single-step and duplex aged without cryo treatment. The heat treatments' influence on the alloy's tensile, wear, and microstructural properties were determined by tensile, wear tests, XRD phase analysis, and microstructural investigations. After applying the duplex aging treatment amount of the β phases decreased, a good balance between tensile strength and the elongation was obtained, and the wear resistance of the alloy increased compare to the single-step aging. In addition, the decrease of the cryogenic treatment temperature slowed down the phase transformation kinetics, and it caused a decrease in precipitation of α phases at both single-step and duplex aged samples. Superior wear resistance was obtained with the decreasing of β phases in the microstructure of the samples that were duplex aged after cryogenic treatment.