Recent Development in Beta Titanium Alloys for Biomedical Applications

Abstract

β-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 β-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 β-type Ti alloys from the perspective of the molybdenum equivalency (Moeq) method and DV-Xα molecular orbital method. Based on these methods, a considerable number of β-type Ti alloys are developed. Although β-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 β-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, β-type Ti alloys have comparable or even better mechanical properties, corrosion behavior, and biocompatibility compared with other types of Ti alloys. Hence, β-type Ti alloys are the more suitable materials used as implant materials. However, there are still some problems with β-type Ti alloys, such as biological inertness. As such, summarizing the findings from the current literature, suggestions forβ-type Ti alloys with bioactive coatings are proposed for the future development.

Phase Transformation-Induced Improvement in Hardness and High-Temperature Wear Resistance of Plasma-Sprayed and Remelted NiCrBSi/WC Coatings

“…Under a synergistic effect of the dispersion strengthening and the change in the microstructure, the hardness of RE-NW35 coating is therefore significantly enhanced. Such a phenomenon is frequently observed in the metallic materials [66][67][68][69][70][71]. Furthermore, it is interesting that the hardness of the substrate increases from 240 ± 10 to 560 ± 11 HV after remelting.…”

Structural and Material Determinants Influencing the Behavior of Porous Ti and Its Alloys Made by Additive Manufacturing Techniques for Biomedical Applications

“…Other research groups [179] proposed the fabrication of Ti-10Mo-xFe scaffolds using a powder metallurgy process as the potentially low-cost process to manufacture porous structure. The addition of Fe and Mo to Ti alloys enhanced their mechanical strength and reduced their elastic modulus [158,165]. The studies indicated that Ti-10Mo-5Fe revealed the highest compressive strength (2392 MPa) and strain (43%), and elastic modulus (91 GPa) low as compared to CP-Ti and some other Tibased alloys.…”

“…However, to lower elastic modulus and minimal contents of toxic elements such as aluminum and vanadium, new biocompatible β-Ti alloys with β stabilizing alloying elements (Mo, Si, Ta, Sn, Zr) were recently developed. According to the literature, β-type Ti alloys demonstrate better mechanical properties, due to the moduli closer to those of human bone in comparison to α-type Ti alloys and α + β-type Ti alloys, as well as better biocompatibility due to the non-toxic nature of β-stabilizers [158]. For example, the elastic modulus of human cortical bone is about 30 GPa, while those of Ti-6Al-7Nb and Ti-6Al-4V are about 110 GPa and 112 GPa, and that of Ti-24Nb-4Zr-8Sn is below 50 GPa.…”

Powder Bed Fusion Additive Manufacturing Using Critical Raw Materials: A Review

“…The promising application of zirconium (Zr) is related to titanium-based alloys. Binary and ternary Ti-based alloys with zirconium, niobium, and tantalum are regarded as the most promising substitution of Ti64 for biomedical applications [ 84 ], showing significantly better biocompatibility and having mechanical properties much closer to those of human bones [ 16 , 17 , 85 , 86 , 87 , 88 ]. Growing demand for prostheses and implants and the ability of additive manufacturing to functionalize them will determine the demand for Zr as an alloying element rather than an individual material.…”