Wear Characterization of Biomedical Porous Alloy (Ni50–xTi50Cux) at Elevated Temperature

Abstract

In today’s scenario a small amount of wear can change the dimensions of devices, especially in micro-devices. Equiatomic NiTi alloy has its applications in engineering and medical due to shape memory, pseudoelasticity, biocompatibility and corrosion resistance. In the present research copper is mixed at different proportion from 0 to 10% in NiTi alloy to study the wear behavior and its mechanism at different loads and temperature environments (37 to 250°C). The wear results (WC/Ni50–xTi50Cux couple) show that the wear rate increases with increasing load and temperature. After a certain temperature the wear rate decreases due to formation of mechanically mixed layer. Microhardness of NiTi alloy also increases after increasing copper contents. X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) techniques were used to check the phases of wear pins and WC disk. Ni40Ti50Cu10 pin was suggested for the biomedical application due to its low wear rate; the same surface was evaluated at different load to study the wear mechanisms. Defragmented particles were studied to investigate the morphology of debris at different loads. XRD analysis reveals that with the addition of copper content in NiTi alloy, the wear resistance increases due to intermediate phase TiNi0.8Cu0.2 matrix