Study of the non-linear stress-strain behavior in Ti-Nb-Zr alloys

Abstract

The aim of this work is to study the elastic behavior of some Ti-Nb-Zr alloys (Ti-8Nb-13Zr, Ti-13Nb-13Zr, Ti-18Nb-13Zr and Ti-41.1Nb-7.1Zr) developed to biomedical applications. These alloys were produced by arc melting under argon atmosphere. Uniaxial tensile tests, carried out in a MST servo-hydraulic machine, were employed in their mechanical characterization. The occurrence of non-linear stress-strain behavior in the conventional elastic region (total strain values up to 0.2%) lead to the Ramberg-Osgood relationship, modified by Hill, in order to analyze that portion of the obtained curves. The present study involves the following properties: initial elastic modulus, tangent modulus, secant modulus, proof stress and the Ramberg-Osgood parameter (n). The results demonstrate that these alloys are not similar with respect to the mechanical behavior. Furthermore, it is shown that the degree of non-linearity in the stress-strain behavior is quantified by the parameter (n). © 2005.