Anelastic relaxation due to hydrogen in Ti–35Nb–7Zr–5Ta alloy

► Mechanical spectroscopy measurements in Ti–35Nb–7Zr–5Ta alloys with hydrogen. ► Two relaxation structures: low temperature associated with hydrogen; high temperature associated with oxygen. ► Stress induced ordering of hydrogen atoms around oxygen interstitial trapping atoms. Titanium and its alloys are frequently used in the production of prostheses and dental implants due to their properties, such as high corrosion resistance, low elasticity modulus, and high mechanical strength/density relation. Among the Ti-based alloys, Ti–35Nb–7Zr–5Ta (TNZT) is one that presents the smallest elasticity modulus (around 45GPa), making it an excellent alternative to be used as a biomaterial. In this paper, mechanical spectroscopy measurements were made of TNZT alloys containing several quantities of hydrogen in solid solution. Mechanical spectroscopy measurements were made by using a torsion pendulum, operating at an oscillation frequency in the interval 2–20Hz, temperature in the range 100–300K, heating rate of about 1K/min, and vacuum lower than 10−5Torr. A relaxation structure and a reduction in the elasticity modulus were observed for the heat-treated and doped samples. The observed peak was associated with the interaction of hydrogen trapped by oxygen atoms around the titanium atom of the metallic matrix.