Many alloys strengthened by coherent superlattice precipitates exhibit excellent mechanical properties. These benefits have inspired the investigation of a range of analogous systems in both FCC and BCC metals, though few of the latter have achieved commercial success. In this work, the concept of superlattice precipitate reinforcement has been explored within a beta titanium alloy. Compositional selection was achieved using computational thermodynamics. This ensured that the high temperature beta phase could be retained to lower temperatures, and that a suitable volume fraction of reinforcing superlattice precipitates could be attained during subsequent heat treatment. During the design process, priority was given to more abundant elements to minimise alloy cost and to address sustainability concerns. The alloy demonstrated a complex microstructure, with precipitates that had an internal substructure comprising regular arrays of intermetallic phases. This microstructure was associated with exceptional hardness. The prospect for further improvement to balance mechanical properties will be discussed.

Funding is acknowledged from the EPSRC and Rolls-Royce plc.