High temperature deformation of Ti alloy superplastically embedded with HA

This study is focused on the feasibility of forming titanium (Ti) alloy superplastically embedded with hydroxyapatite (HA) nanolayer. The superplastically embedded sample having a layer thickness of approximately 249 nm and a surface hardness of 661 HV is deformed under compression mode at 1200 K for 10, 20 and 30% deformation degree. The HA layer thickness decreases to approximately 241, 223 and 206 nm with increasing deformation degree. Surface morphology reveals microcracks and delaminations of HA at certain areas as deformation degree is increased. Comparison using non-superplastic embedment sample shows that a significant degree of surface deterioration occurs even at 10% deformation. Based from the results, it can be concluded that the superplastically embedded HA layer is still strongly intact to the substrate surface even after deformation process without deteriorating the HA structure.