High-resolution transmission electron microscopy investigations of a highly adhesive hydroxyapatite coating/titanium interface fabricated by ion-beam-assisted deposition

An atomic intermixing layer, 25 nm in width, has been identified by high-re solution transmission electron microscopy (HRTEM) and energy-dispersive X-r ay spectroscopy (EDS) analysis at the ceramic/metal interface of a hydroxya patite (HA) coating/titanium implant prepared by an ion-beam-assisted depos ition (IBAD) technique and post-heat-treatment process. The detailed interf acial microstructure revealed a gradient evolution of both the structure an d composition of the interfacial phases from the titanium substrate to HA c oatings. An enhancement of the tensile bond strength was found and was attr ibuted to the possible chemical bonding at the ceramic/metal interface. (C) 2000 John Wiley & Sons, Inc.