A mechanical comparison of alpha and beta phase biomedical TiTa lattice structures

Recent orthopaedic implant alloy design has focused on beta-type Ti alloys, as the body centred cubic (BCC) crystal structure has the tendency to be characterised by a low elastic modulus. Nevertheless, the currently most used metal is Ti-6Al-4V, which mainly retains a hexagonal closed packed (HCP) crystal structure when produced by additive manufacturing. The benefits and disadvantages of the mechanical response of each crystal structure for implant applications is yet to be explored. Utilising the TiTa alloy system, low modulus Ti25Ta and Ti65Ta lattices were additively manufactured with opposing crystal structures of alpha' martensite (HCP) and beta grains (BCC). The lattices showed similar tensile, compressive and high cycle fatigue behaviour, indicating that the alpha' alloy was mechanically equal to the beta alloy for implant applications. The mechanical properties of both the TiTa lattices were also superior to identically manufactured lattices in Ti-6Al-4V in both as-built and heat treated conditions. (C) 2021 The Author(s). Published by Elsevier Ltd.

Automated summary

Recent focus in orthopaedic implant alloy design has been on beta-type Ti alloys with low elastic modulus, particularly Ti-6Al-4V produced through additive manufacturing. However, utilizing the TiTa alloy system can result in lattice structures with superior mechanical properties compared to Ti-6Al-4V.