HAADF-STEM and Super-XTM XEDS Tomography of Complex Nano-scale Precipitates in a High Entropy Alloy, AlMo0.5NbTa0.5TiZr

High entropy alloys (HEAs) are a relatively new class of materials garnering a great deal of attention due to their remarkable balance of properties, including high strength, toughness, ductility, and corrosion resistance. In contrast to conventional alloy systems, HEAs are based on 4 or more principal elements with near equimolar concentrations and tend to have simple microstructures due to the preferential formation of solid solution phases attributed to the high configurational entropy of mixing [1]. HEAs appear to offer new pathways to lightweighting in structural applications, new alloys for intermediate and elevated temperature components, and new magnetic materials. However, to realize this potential requires considerable alloy development that will rely on application of integrated computational materials (science and) engineering (ICME). The development of accurate computational models to predict alloy performance requires a detailed knowledge of the morphology and interconnectedness of microstructural features. Due to spinodal decomposition, these alloys often consist of a mixture of ordered and disordered phases on the nano-scale, and because of the compositional and structural complexity, it is desirable to characterize the morphology as well as the chemical nature of the precipitates for inclusion in ICME models.