Reinforcement with ordered intermetallic precipitates is a potent strategy for the development of strength alongside damage tolerance and is central to the success of fcc nickel-based superalloys. Such a strategy is equally of interest within bcc-based systems for their increased melting point and acceptable cost. However, only limited studies have been made on refractory metal (RM) or titanium based alloys strengthened by ordered-bcc precipitates (e.g. B2 or L21).
In this talk, opportunities for refractory-metal-based superalloys systems will be discussed, including a review of Cr-Ni2AlTi, Mo-NiAl, Ta-(Ti,Zr)2Al(Mo,Nb) and Nb-Pd2HfAl systems together with newly developed alloys. These alloys exploit an extensive two-phase field that exists between A2 (RM,Ti) and B2 TiFe to produce nanoscale precipitate reinforced microstructures that increase the proof strength by over 500 MPa.
This work was supported through EURO-Fusion Researcher Grant & EPSRC Doctoral Prize Fellowships, EPSRC ‘DARE’ (darealloys.org) EP/L025213/1 and Rolls-Royce/EPSRC Strategic Partnership EP/H022309/1 and EP/H500375/1.