Aging behavior of the Ti-29Nb-13Ta-4.6Zr new beta alloy for medical implants

Abstract

MASAHIKO IKEDA, SHIN-YA KOMATSU, ISAO SOWA, and MITSUO NIINOMI The aging behavior of the Ti-29Nb-13Ta-4.6Zr alloy quenched from 1033 K was investigated by employing electrical resistivity () and Vickers hardness (HV) measurements, optical microscopy (OM), and X-ray diffraction (XRD). Upon aging at 573 K, the value at room-and liquid-nitrogen temperatures initially increased to 120 and 30 ks, respectively, and decreased with continued aging time. The HV value started to increase from 0.06 ks and the isothermal phase was identified at 300 ks of aging by XRD. On aging at 773 K, an incubation period of 6 ks was observed for the change at both temperatures, following which decreased. An incubation period for the HV change was extended up to 12 ks, and then HV increased. Precipitated ␣ was observed and identified by OM and XRD, respectively, whereas no reflections of isothermal phase were identified during the whole aging time at 773 K. The upper-limit temperature of isothermal precipitation is situated at around 673 K.

XRD and nanoindentation testing of thermo-mechanical processed Ti-29Nb-9Ta-10Zr alloy

“…8b,c) because of the strain softening heat treatment. The cold-rolling-induced elastic modulus decreasing had already been reported [24,26] due to the proper mechanisms of cold rolling, such as: 1. dislocations slipping; 2. deformation twins, and most important 3. α -martensite phase transformation induced by cold rolling [27][28][29]. The decrease of the elastic modulus caused by deformation is in agreement with the alloy structural evolution observed by XRD measurements and above discussed, allotted to the formation of a (200) α /[010] α texture of the α phase and to the crystallographic anisotropy of the α phase, but also to the formation of the strong rolling texture {001} β 110 β for the β phase.…”

Wear and Electrochemical Corrosion Behavior of Biomedical Ti–25Nb–3Mo–3Zr–2Sn Alloy in Simulated Physiological Solutions

“…Among titanium alloys for medical implants, Ti-6Al-4V alloy is the most frequently used [4,5]. But in the case of Ti-6Al-4V alloy, there is another problem-aluminum and vanadium may cause long-term health problems [2,[5][6][7][8]]-e.g., aluminum, it is possible relation to Alzheimer's disease [5,8]. In early stage, the titanium alloys composed of nontoxic elements that have been developed are mainly a?b type ones.…”

Effect of Oxide Particles Formed through Addition of Rare-Earth Metal on Mechanical Properties of Biomedical β-Type Titanium Alloy

“…8) Although an aging treatment improves the mechanical properties of TNTZ, Young's modulus also increases by precipitation of an ¡ phase. 9,10) Therefore, strengthening methods without causing a simultaneous increase in Young's modulus are required for producing improved TNTZ applicable in bone prostheses. Dispersion strengthening is a method, which improves the mechanical properties without increasing Young's modulus.…”