Approaches to the design and processing of novel titanium alloys

The range of commercial titanium alloys available is currently extremely restricted, with one alloy (Ti6Al-4V), and derivatives of it, accounting for a very large proportion of all applications. High performance alloys are costly to fabricate and limited to low-volume applications that can sustain the cost. With the emergence of new processing technologies that promise to reduce significantly the cost of production of titanium metal, especially in powder form, there is an emerging imperative for cost-effective near net shape powder processing techniques to permit the benefit of reduced metal cost to be passed on to higher-volume applications. Equally, there is a need for the design and development of new alloys that are intrinsically low-cost and lend themselves to fabrication by novel cost-effective net shape processing. The approaches that might be used to select, design and process both conventional alloys and novel alloy systems will be reviewed, with a focus on innovation in design of low-cost alloys amenable to new processing paths and increasingly tolerant of variability in composition.