Removal of the α-Case layer from precision-cast cellular TiAl6Nb7 to be used for biomedical applications

A study was conducted to demonstrate the removal of α-case layer from precision-cast cellular TiAl6Nb7 alloy and use it in biomedical applications. A precision-casting process was developed to produce metallic sponges based on the Ti alloy, Ti67 and conduct investigations. MgO + Al₂O₃ + CaO-based investments were used as mold material in a centrifugal casting machine to perform the precision-casting process. Casting of Ti67 specimens were carried out under inert argon atmosphere along with high centrifugal forces allowing for proper filling of the fine-structured mold. The samples were ultrasonically cleaned in ethanol for 10 minutes to remove any residues of the investment material from the surface before pickling. The material's microstructure and any change in the surface topography and the removal of the α-case layer during the pickling process was analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS).