Scientific Events

Titanium is the fourth most abundant engineering material in the Earth’s crust. Although it has many beneficial properties, the cost of extraction remains a challenge and over 90% of high grade titanium is derived from the expensive and time-consuming Kroll Process. Electro-refining methods show promise but present their own special challenges. We present an overview and update of a novel molten salt process to extract and refine low-grade ores to produce high-grade powder titanium. Titanium oxycarbide produced by carbothermic reduction is electro-refined in a molten eutectic bath of NaCl:KCl salt. Anodic dissolution causes the Ti product to be plated out in the form of a dendritic product which collects on the cathode while impurities are retained in the anode. A gentle introduction to the process will be given and recent studies to apply the method to include the effect of using ilmenite and ilmenite/rutile blends as a feedstock, as well as the applicability of the process to other metals, specifically niobium (Nb) and vanadium-baring minerals presented. [more]

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). Are such “bcc superalloys” possible? Do they offer useful properties? 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 strength by over 500 MPa. This work was supported through EUROfusion 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. [more]