Applying Heuristics to Multicomponent Alloy Development with the Light MetalsThursday (07.11.2019) 11:05 - 11:25 Part of:
Recently alloy development has seen interest in the reports of High Entropy Alloys; systems where there are multiple elements present in similar atomic ratios (representing compositions from the interior of complex phase diagrams, rather than alloys based on a principal element with other elements as relatively minor additions to adjust properties). Many intriguing properties for alloys of this type have been reported, such as high strength combined with ductility, and the suppression of the intermetallic phases which may otherwise be expected to form in complex compositions. Even more than this (and noting that the underlying physical metallurgy of these alloys and the scaling of some of these properties to engineering components is currently debated in the literature) such materials demonstrate the potential to find alloys with useful properties in these largely unexplored compositional ranges. However, the potential number of combinations of elements and compositions which could be selected for investigation is vast, and may involve combinations of elements for which there are few data in existence. Therefore a search cannot be realistically attempted without some theoretical guidance and systematic experimentation.
In this presentation a simple approach to identify candidate compositions, based on the Hume-Rothery rules and other heuristics is outlined, and examples of its application to alloy discovery in the light metals are given and discussed, including both a focus on alloys of interest for their own properties, and also those that can be applied in the joining of light metals by brazing.