Recent Development in Beta Titanium Alloys for Biomedical Applications

beta-type titanium (Ti) alloys have attracted a lot of attention as novel biomedical materials in the past decades due to their low elastic moduli and good biocompatibility. This article provides a broad and extensive review of beta-type Ti alloys in terms of alloy design, preparation methods, mechanical properties, corrosion behavior, and biocompatibility. After briefly introducing the development of Ti and Ti alloys for biomedical applications, this article reviews the design of beta-type Ti alloys from the perspective of the molybdenum equivalency (Mo-eq) method andDV-X alpha molecular orbital method. Based on these methods, a considerable number of beta-type Ti alloys are developed. Although beta-type Ti alloys have lower elastic moduli compared with other types of Ti alloys, they still possess higher elastic moduli than human bones. Therefore, porous beta-type Ti alloys with declined elastic modulus have been developed by some preparation methods, such as powder metallurgy, additive manufacture and so on. As reviewed, beta-type Ti alloys have comparable or even better mechanical properties, corrosion behavior, and biocompatibility compared with other types of Ti alloys. Hence, beta-type Ti alloys are the more suitable materials used as implant materials. However, there are still some problems with beta-type Ti alloys, such as biological inertness. As such, summarizing the findings from the current literature, suggestions for beta-type Ti alloys with bioactive coatings are proposed for the future development.