Formation of Layered Biocomposite as a Promising Base for Metal–Ceramic Bone Implants

Abstract

The study deals with the development of a layered biocomposite as a functionally-gradient material (FGM) combining Ti–6Al–4V alloy and bioceramics based on titanium dioxide in the composition with hydroxyapatite, which is promising for the use in metal–ceramic bone implants. A method for FGM formation to overcome confinements of its components such as low mechanical strength of bioceramics and the lack of osteoinduction for titanium medical alloys has been disclosed. Spark and plasma sintering have been used to achieve strong and unsplit joint between ceramics layers and alloy. The study has shown that phase composition of both materials remains stable during their heating, while intermediate layer of β-Ti forms on the contact boundary, which increases mechanical strength of the joint. Microhardness testing has confirmed the integrity of composite with retention of strength at ceramics–alloy interface. The lack of defects and internal stress at the boundary of formed junction indicates its high mechanical stability and shows potentiality of method for possible practical application to design contemporary structurally strong implants with improved osteointegration function.