Torsion modulus as a tool to evaluate the role of thermo-mechanical treatment and composition of dental Ti-Zr alloys

In this study, the mechanical spectroscopy technique was applied to measure the torsion modulus of Ti-xZr (where x = 0, 5, 10 and 15 wt%) alloys for dental applications. The technique makes it possible to measure the torsion or shear modulus (G) of the samples without the use of Poisson’s ratio, which is an advantage when compared with other dynamic methods. The G value of the Ti-Zr samples was compared with titanium samples of equal size in terms of their thermo-mechanical treatment and composition. In order to perform this comparison, an equation that expresses G as a function of the diameter and length of the commercially pure titanium (CP-Ti) samples was determined. This equation was used to evaluate the values for G of the CP-Ti so that it was possible to compare them with those for the Ti-Zr alloys. The results showed that there was a relationship between the G values of the Ti-Zr and the CP-Ti samples and that they depended on the microstructural characteristics (after undergoing thermo-mechanical treatment) and the Zr content.