The investigation on properties of Ti- 5Si and Ti- 5Nb implant alloys coated by bioactive based composite coating

Abstract

Titanium (Ti) alloys are widely utilized in orthopedics owing to their excellent mechanical properties and biocompatibility. To improve their resistance to corrosion and ion release properties, substrates of Ti alloy have been produced employing powder metallurgy by adding alloying elements (Si and Nb) at 5wt.% along with CP-Ti. Two torch flame sprays have been utilized for coating the Ti-5Nb and Ti-5Si alloys with two kinds of nanocoating: HAp+25%SiC (type-A) and ZSM5+25%ZrO2 (type-B). These nanocoating combinations represented bioactive and bioinert to combine the biological and mechanical properties of the implant surface. Different tests and characterization techniques have been carried out, including SEM, XRD, AFM, AAS, hardness, adhesion strength, and corrosion resistance. The results manifested that the coatings (types A and B) improved the properties of Ti alloys; however, ZSM5+25%ZrO2 has better properties than type-A in terms of less porosity, higher crystallinity%, higher hardness, higher adhesion strength, lower corrosion rate, and less Ti ions release. Comparing the results of the two Ti alloys, Ti-5Si has higher hardness, corrosion resistance, and less ionic release than the Ti-5Nb alloy. Hence, the Ti-5Si coated by ZSM5+25%ZrO2 (B coated Ti-5Si) is the best sample in this study.