Our latest research publication is now available online (here). In this publication a new twinning mechanism – transformation twinning – is investigated in an additively-manufactured Ti-6Al-4V alloy. We propose that the cyclic thermal loading during additive manufacturing introduces large thermal stresses at high temperature, enabling grain reorientation that transforms the 60°/<12̅10> variant boundaries into the more energetically stable 57.42°/<12̅10> twin boundaries. This transformation twinning phenomenon follows a strain accommodation mechanism and the resulting boundary structure benefits the mechanical properties and thermal stability of titanium alloys.