- SURFACE & COATINGS TECHNOLOGY Journal
- March 2022
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- Low wear resistance and the relative high Young's modulus reduce the lifetime of the current biomedical Ti alloys for orthopaedic applications. In this study, two novel low-cost beta-Ti alloys (Ti-5Fe-25Nb and Tisingle bond40Nb in wt%), with reduced elastic modulus, are produced by powder metallurgy route, starting from TiH2 powder. In order to increase their wear resistance, two strategies are proposed: 1) addition of 5 vol% of TiN reinforcement particles and 2) gas nitriding surface treatment to produce a TiN coating. Wear resistance was evaluated by dry sliding reciprocating wear tests against alumina as counter material. Dry sliding tests were performed under unlubricated conditions, applying 10 N and 20 N load. Gas nitrided samples exhibit higher hardness than base alloys, while maintaining low elastic modulus. Both modification techniques improve wear resistance. The highest wear reduction was obtained for gas nitrided samples, reaching a wear rate reduction between 86% and 43%, compared to untreated alloys at 10 N, and between 4% to 15% at 20 N.
- wear resistance; titanium matrix composite; gas nitriding; low-cost β-ti alloys; titanium hydride; biomaterials