Development of the Conform Process to Recycle Titanium Alloy Swarf into Wire for Sustainable Additive Manufacturing Feedstock

Compared to metal powder, wire feedstock has significant advantages in terms of ease of handling for additive manufacturing processes. In addition, powder specifications on morphology and size mean that large volumes of powder can be surplus to requirements. In wire fed additive manufacturing (AM) pro-cesses, 100% of the material is used. This makes solid state processes such as continuous extrusion or Conform even more important in the future. Such severe plastic deformation processes can convert sur-plus powder, particulate or waste product, such as machining swarf, into a rod/wire form. This can then be further cold drawn into <5 mm diameter wire for direct energy deposition (DED) processes. Conform has been used since the 1970s for copper and aluminium rod feedstocks. However, over recent years at the University of Sheffield and BWE Ltd, it has been demonstrated that Conform can be adapted to con-vert CP-Ti powder and Ti-6Al-4V swarf into fully consolidated wire with a fine, equiaxed grain struc-ture. The figure below shows a schematic of the Conform process used for the the production of CP-Ti wire from powder.
In this EngD project a key aim will be to (1) design, make (using field-assisted sintering technology) and test high temperature, wear resistant tooling from aerospace nickel superalloy waste in order to enable titanium alloy swarf to be continuous extruded at prolonged rates that are deemed affordable for the aer-ospace manufacturing industry. (2) determine the effect of swarf/particulate characteristics on wire mi-crostructure and properties, including downstream cold drawability. The aim will be to design tooling optimised for titanium swarf and powder feedstocks - which will require finite element modelling. The long term ambition is to develop and de-risk the Conform process as a disruptive, sustainable manufac-turing technology to recycle machining waste.
During your EngD you will develop core skills in process metallurgy, materials science such as micro-structural characterisation, FE modelling and data analytical approaches. You will work collaboratively with our Engineering Leads and technical staff and will have access to high performance manufacturing and characterisation facilities in the Henry Royce Institute. You will develop an insight into the technical advanced manufacturing challenges in the aerospace sector and work closely with metallurgists at DSTL