Effect of heating rate on structure of HA coating prepared by sol–gel

Abstract

HA coatings were deposited on Ti–6Al–4V alloy substrate using the sol–gel technique. Various heat treatments were carried out and the subsequent effect of heating rate on the resulting coatings was also investigated. The sol–gel derived coatings were studied by X-ray diffraction, electronic probe microanalysis and scratch tester. The results show that the heating rate greatly influences the morphologies, the composition and the adhesion strength of resulting coatings. Under the slow heating rate, the coatings are characterised by high phase purity, compact lamellar structure and less cracks on the surface. Moreover, the scratch test results indicate that the adhesion strength of coatings with slow heating rate is higher than that of coatings with rapid heating rate.