Clarke, AmyKaufman, Michael J.Gil Coury, Francisco2018-10-032022-02-032019-10-022022-02-032018https://hdl.handle.net/11124/172516Includes bibliographical references.2018 Summer.High Entropy Alloys (HEAs) are new and promising classes of metallic alloys for structural applications. HEA development is challenging, due to the vast compositional space that exists for these multicomponent alloys. As such, predictive modelling is paramount for the development of HEAs, so alloy design does not need to rely on time-consuming, expensive trial-and-error experimentation. Although solid solution strengthening is the main strengthening mechanism of HEAs, the fundamentals behind this mechanism are not fully understood in this context, and further consideration with respect to modeling is warranted. In this work, the solid solution strengthening mechanism of Face Centered Cubic (FCC) and Body Centered Cubic (BCC) HEAs is investigated experimentally, and the results are interpreted using a combination of different strengthening models available from the literature. Here we show the mechanical behavior of HEAs is comparable to conventional alloys. Similar temperaturedependent yield stress regimes are observed in comparison to conventional BCC alloys, and solid solution strengthening via the contribution of atomic size and elastic modulus mismatch is found to be the main strengthening mechanism. Strength models are used in high-throughput alloy design by combining solid solution strengthening and thermodynamic predictions to find strong, single-phase (e.g. FCC) HEA compositions in the multicomponent space. In addition, a high-throughput experimental methodology for characterizing a large number of HEA compositions is developed. This work contributes to fundamental understanding of solid solution strengthening and phase stability of HEAs, toward the design of promising compositions by prediction that exhibit tailored properties.born digitaldoctoral dissertationsengCopyright of the original work is retained by the author.mechanical propertieshigh entropy alloysphysical metallurgyTextEmbargo Expires: 10/02/2019