Titanium perovskite (CaTiO3) formation in Ti6Al4V alloy using the electrical discharge machining process for biomedical applications

Abstract The use of the energy generated in machining processes by electrical discharge (EDM) to enrich metal surfaces with nitrogen is already well known, and following on from this research focus, the aim of this study is to evaluate the possibility of enrichment through this process, for the surface of Ti6Al4V alloy with titanium perovskite. The resulting surface shows high biocompatibility with human bone and teeth and becomes essential as a biomedical material. Tests were performed using a sink EDM process and as a dielectric fluid, an aqueous solution of calcium chloride was used. The samples characterizations were made using the scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), optical microscopy and Knoop microhardness. The results showed the formation of an uneven surface enriched with calcium, in the form of titanium perovskite. On the lateral section of the sample one notes the formation of a porous layer. Beneath this, a uniform hardened layer was formed, extending to a depth of approximately 200 μm below the surface. Calcium insertion into the Ti6Al4V surface was attributed to the occurrence of re-solidification and ion implantation. It can be concluded that it is feasible to enrich, by EDM, the surface of a Ti6Al4V alloy with titanium perovskite.