Modern metals processing: transfer of knowledge and core skills to new and emerging technologies

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Creativity and innovation in metal manufacturing is crucial for maintaining a competitive UK based metals industry. This applies to both current production methodologies such as rolling, forging etc and emerging disruptive technologies such as shaped metal deposition. Over the last ten years IMMPETUS (Institute for Microstructural and Mechanical Process Engineering: The University of Sheffield) has developed its unique systems driven approach for process and property optimisation for the latest metals process routes with significant success on the national/international stages. The ideal for predicting microstructure and properties is to use multi-scale modelling driven by well defined physically based equations. However, even where the process is well established and thought to be well understood, the reality is that there are inevitable uncertainties within such multi-scale models, and consequently most are not truly physically-based. Rather they rely on empirical parameters that allow the models to fit the data. Moreover, where the process is immature, as is the case with the projects we intend to investigate, the basic physics cannot be described accurately until the mechanisms are fully established experimentally, which can prove time-consuming. In order to cover the intractable factors not adequately and entirely described by physically based models, and to fast track the development of emerging non-traditional metal manufacturing technologies, we use hybrid models that merge (fuse) discrete data with knowledge-based and physically-based models to account for the uncertainties in the material processing route. This is a powerful approach for accurate and transparent process behaviour prediction even when data is sparse, knowledge is imprecise, but updated more often than not. All the modelling is informed and verified through the use of an impressive but parsimonious array of experimental techniques. We believe it is timely to apply such a strategy to new exciting technologies where the research is inevitably high risk, high adventure and certainly high impact. Specifically, we intend establish a novel approach to the modelling of friction stir and linear friction welding of steels and titanium alloys using a combination of our unique arbitrary strain path and thermomechanical compression machines and access to fully instrumented friction welding machines. In addition, we will bring our skills to bear on innovative metals processing with direct access to state-of-the-art equipment for e.g. shaped metal deposition. Pervasive to all of these processes is that the final microstructure is formed through transformation under dynamic conditions, with the presence of steep thermal gradients, intentional/unintentional stresses and plastic strain rates for which the current phase transformation models do not adequately predict microstructure. For all these areas, it is essential to retain highly skilled staff who have a proven track record in interdisciplinary integrated research.