Mechanical Performance and Biocompatibility of Biomedical Beta-Type Titanium Alloy Subjected to Micro-Shot Peening

Abstract:

Beta-type Ti-29Nb-13Ta-4.6Zr (TNTZ) was recently developed as a representative biomedical Ti alloy. As-solutionized TNTZ has a low Young’s modulus less than 60 GPa close to that of cortical bone along with very low cytotoxicity and good bone biocompatibility. Solution treatment and aging (STA) is a typical heat treatment for improving the mechanical properties of beta-type titanium alloys. However, STA also drastically increases the Young’s modulus. Therefore, this study investigated the effects of surface modification, micro-shot peening, on the mechanical properties of TNTZ subjected to severe thermomechanical treatment in order to maintain a relatively low Young’s modulus. The bone contact characteristics of TNTZ samples subjected to surface modification and cancellous bone were also compared. The Vickers hardness of cold-swaged TNTZ (TNTZ_SW) subjected to micro-shot peening was significantly increased within 20 mm from the very edge of the specimen surface. The fatigue strength of TNTZ_SW subjected to micro-shot peening increased especially in the high cycle fatigue life region. The fatigue limit was around 400 MPa. The bone formations on TNTZ_SW subjected to micro-shot peening and TNTZ_SW with the mirror surface as comparison material were almost identical to each other. However, the relative bone contact ratio of TNTZ_SW subjected to micro-shot peening was better than that of TNTZ_SW with the mirror surface.

• Periodical: Materials Science Forum (Volumes 783-786)
• Pages: 1215-1220
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.783-786.1215
• Online since: May 2014
• Authors: Toshikazu Akahori, Yurie Oguchi, Tomokazu Hattori, Hisao Fukui, Mitsuo Niinomi
• Keywords: Biocompatibility, Mechanical Property, Metallic Biomaterial, Microstructure, Surface Modification

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