Fatigue behavior of additively manufactured Ti3Al2V alloy

Abstract

In this study, we measured the tensile, compression, and fatigue behavior of additively manufactured Ti3Al2V as a function of build orientation. Ti3Al2V alloy was prepared by mixing commercially pure titanium and Ti6Al4V in 1:1 wt. ratio. Laser powder bed fusion-based additive manufacturing technique was used to fabricate the samples. Tensile tests resulted in an ultimate strength of 989 ± 8 MPa for Ti3Al2V. Ti6Al4V 90° orientation samples showed a compressive yield strength of 1178 ± 33 MPa and that for Ti3Al2V 90° orientation samples were 968 ± 24 MPa. By varying the build orientation to account for anisotropy, Ti32 45° and Ti32 0° samples displayed almost similar compressive yield strength values of 1071 ± 16 and 1051 ± 18 MPa, respectively, which were higher than that of Ti32 90° sample. Fatigue loading revealed an endurance limit (10 million cycles) of 250 MPa for Ti6Al4V and of 219 MPa for Ti3Al2V built at 90° orientation. The effect of the build orientation was significant under fatigue loading; Ti3Al2V built at 45° and 0° orientations displayed endurance limits of 387.5 MPa and 512 MPa, respectively; more than two-fold increment in endurance limit was observed. In conclusion, the superior attributes of Ti3Al2V alloy over Ti6Al4V alloy, as demonstrated in this study, justify its potential in load-bearing applications, particularly for use in orthopedic devices.