Fatigue behavior of additively manufactured Ti3Al2V alloy.

Abstract

This study 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 (CpTi) and Ti6Al4V in 1:1 wt. ratio. Laser powder bed fusion (L-PBF) based additive manufacturing (AM) 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 was 968 ± 24 MPa. Varying the build orientation to account for anisotropy, Ti32-45° and Ti32-0° displayed similar compressive yield strength values of 1071 ± 16 and 1051± 18 MPa, respectively, higher than Ti32-90°. Fatigue loading revealed an endurance limit (10 million cycles) of 250 MPa for Ti6Al4V and 219 MPa for Ti3Al2V built at 90° orientations. The effect of the build orientation was significant under fatigue loading; Ti3Al2V built at 45° displayed an endurance limit of 387.5 MPa, and 0° showed 512 MPa; more than two-fold increment in endurance limit was observed. Our results show the potential of Ti3Al2V alloy for orthopedic devices, replacing Ti6Al4V alloy, particularly in load-bearing applications.