Evaluation of Microstructure and Mechanical Properties of Thermomechanically Processed β Ti‐۳۵Nb‐۷Zr‐۵Ta Alloy

It has long been thought-provoking and challenging as well for researchers to design and produce a special low-modulus β titanium alloy such as Ti‐۳۵Nb‐۷Zr‐۵Ta, representing optimal mechanical properties that is needed to successfully simulate bone tissue. In order to identify the key effects of processing pathways on the development of microstructure, Young’s modulus, and strength, a nominal Ti-۳۵Nb-۷Zr-۵Ta alloy was made via casting, hot forging, homogenizing, cold rolling and finally annealing. Results from tensile test alongside microscopic and XRD analysis confirm the importance influence of processing method on fully β phase microstructure, low elastic modulus and high strength of the alloy. The specimen with post-deformation annealing at ۵۰۰ °C demonstrated the Young’s modulus of ۴۹.۸ GPa, yield strength of ۷۸۰ MPa and ultimate tensile strength of ۸۹۰ MPa, all of which are incredibly close to that of bone, hence suitable for orthopedic implants. At temperature above ۵۰۰ °C, a sharp fall was observed in the mechanical properties.

Keywords:

TiNbZrTa alloy , Thermomechanical processing , microstructure , Phase transformation , Young’s modulus