High strength heat-treatable β-titanium alloy for additive manufacturing

Metastable β-titanium alloys offer the highest strength of any class of titanium alloy due to their ability to be precipitation hardened. In this work, Ti–3Al–8V–6Cr–4Mo–4Zr was produced through wire arc additive manufacturing and the mechanical properties and microstructural response to heat treatments were investigated. In the solution treated condition, the alloy was primarily composed of the body-centre cubic β phase with very high ductility and moderate strength (σyield ≈ 860MPa). However, with post-build age hardening it was possible to control the size and spacing of hexagonal close-packed α-precipitates allowing highly customisable properties and very high strengths (σyield > 1600MPa).