Hydroxyapatite and Titanium Composite Coatings on Austenitic Stainless Steel Substrates Using Direct Material Deposition

Abstract

Hydroxyapatite (HA) and titanium composite coatings, which demonstrate good biocompatibility and load bearing capacity, are important in the topical area of prosthetics. In this study, hydroxyapatite and titanium composite coatings were deposited on austenitic stainless steel (316L) substrates using the Direct Material Deposition (DMD) technique. The microstructures were characterized using optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Surface topography and roughness were assessed by SEM and profilometry, while Raman microscopy was employed to determine the nature of HA in the feedstock. The results indicate that average roughness increases with traverse speed and depends significantly on the power level. The crack orientation was found to be sensitive to traverse speed, while the number of cracks was related to the power level. Porosity decreased as the power level increased.