Effect of hydroxyapatite/SiO2 hybride coatings on surface morphology and corrosion resistance of REX-734 alloy
By Say, Yakup; Aksakal, Bunyamin; Dikici, Burak
Published in Ceramics International
2016
Abstract
Abstract REX-734 stainless steel alloy was coated with hydroxyapatite (HA)-silicon dioxide (SiO2) composite (hybride) coatings by using the sol-gel method. Surface morphologies, adhesion resistances and corrosion behaviors of the coatings were examined and the characterization of the coatings was performed by using XRD, SEM, and EDS. It was observed that porous and crack-free surface morphology enhanced adhesion strength of the coatings. Through the shear tests, it was found that the adhesion resistance was 25.14 {MPa} in {HA} coatings and 25.47 {MPa} in HA-SiO2 coatings. Corrosion analyses of the coatings were performed by using potentiodynamic polarization (PDS) tests. It was determined that corrosion dimples formed on the coating surface and the corrosion resistance in HA+SiO2 coatings increased with decreasing porosity; however, in the further steps of corrosion, it reached to the base material by causing a pitting effect on the coated surface.