Dr. Ben Thomas

Position:
Research Associate

Research Area:
Continuous Rotary Extrusion

I started my research career after graduating with an degree in Physics and Astrophysics from the University of Sheffield in 2006.

In 2010 I started a PhD in Metallurgy as part of the Advanced Metallic Systems Centre for doctoral training (www.metallicscdt.co.uk). My thesis was entitled ‘The continuous extrusion processing of titanium particulates’, which was supervised by Dr. Martin Jackson. I am now a post-doctoral researcher in the STAR group, continuing development of the Conform and CRE processes with a range of titanium alloy powders.

Current Research

My research projects closely follow the work conducted for my PhD thesis into the continuous extrusion of titanium powders.

By using conventional Conform™, Continuous Rotary Extrusion (CRE) machines and commercially available titanium powders we developed an understanding of the process window required to fully consolidate powders into wire in a single step. When coupled with new `cost-effective' powders and novel titanium alloy compositions it becomes possible to completely bypass conventional titanium processing routes. This provides the technological basis for a true step change in the cost reduction of small section titanium extruded profiles.

Potential applications for the extruded wire range from high performance engine valve spring wire, to automotive suspension springs, wire additive manufacturing feedstock (3D printing with wire). The technology also has the potential to consolidate machine turnings or swarf from conventional machining operations negating the need for remelting for recycling.

Other research

Experimental trials on Conform and CRE machines forms the basis of the STAR groups research into continuous extrusion processing. However, we also employ a range of lab based experiments and large-scale finite and discrete element simulations to support these trials.

The group has developed `small-scale' powder rheology/mechanical behaviour experiments using a combination of uniaxial compression and annular shear cell equipment, modified for use with metal powders. Data from these experiments have fed into both finite (DEFORM™) and discrete element (EDEM™) simulations for validation. The `virtual' materials and models are then used to investigate the effects of tooling geometry, temperature and friction changes on the continuous extrusion machine and the extruded product.

I am also heavily involved in the Manufacturing with Advanced Powder Processes EPSRC Future Manufacturing Hub as a lead researcher in Theme P2.2. Within this theme MAPP aims to further develop the Field Assisted Sintering Technology with a range of metallic and ceramic powder materials for industrial applications. Utilising this `high-tech' rapid sintering an applying more traditional metal-forming techniques to the resultant parts opens up possibilities for cost and performance improvements in a range of typically conservative industries such as automotive.