In Vitro Wear of Titanium Reinforced Hydroxyapatite Coatings in Simulated Body Fluid

Abstract

Abstract Titanium-reinforced hydroxyapatite (Ti-HAP) coatings have been deposited over 254 SMO stainless steel using a low-velocity oxygen fuel technique. FESEM, XRD, Vickers microhardness, and shear strength tests have been performed to characterize the developed coatings. Further, in vitro wear behaviors of the coatings were evaluated using a pin-on-disc wear tester in simulated body fluid. The results reveal that 40Ti-HAP coating possesses superior wear resistance compared to 60Ti-HAP, Ti, and HAP coatings, attributed to higher surface hardness and higher shear strength values. Amongst the tested samples, the friction coefficient was lower for Ti coating, followed by 60Ti-HAP composite coating. The surface roughness was a prominent factor in reducing the friction coefficient of coating samples. Local detachment and brittle fracture were the dominant wear modes in Ti-HAP coating, whereas an additional micro-plowing wear mode was observed in pure hydroxyapatite and titanium coating.