Interfacial characterization of plasma-spray coated calcium phosphate on Ti-6Al-4V

Microstructural characterization was performed on plasma-spray coated calci um phosphate and its interface with Ti-6Al-4V using scanning and transmissi on electron microscopy. The amorphous calcium phosphate phase was found nea r the coating/substrate interface, usually in between the crystalline hydro xyapatite grains and the Ti-6Al-4V substrate. The presence of the amorphous calcium phosphate and the channels extending from the interface to the coa ting surface was attributed to the low interfacial bond strength in a physi ological environment. There was an indication of titanium diffusing into th e amorphous regions. However, no reaction phases were found between the coa ting and the Ti-6Al-4V substrate. In the coating area remote from the inter face, no intergranular amorphous calcium phosphate phase was observed. The microstructure of the Ti-6Al-4V substrate near the interface was observed t o be affected by heat generated during plasma spraying. (C) 1998 Kluwer Aca demic Publishers.