Interstitial atoms enable joint twinning and transformation induced plasticity in strong and ductile high-entropy alloys

作者：Zhiming Li, Cemal Cem Taşan, Hauke Springer, Baptiste Gault, Dierk Raabe · 发表于：Scientific Reports · 年份：2017 · DOI：10.1038/srep40704 · 被引用次数：487 · 研究领域：High Entropy Alloys Studies、High-Temperature Coating Behaviors、Advanced materials and composites

High-entropy alloys (HEAs) consisting of multiple principle elements provide an avenue for realizing exceptional mechanical, physical and chemical properties. We report a novel strategy for designing a new class of HEAs incorporating the additional interstitial element carbon. This results in joint activation of twinning- and transformation-induced plasticity (TWIP and TRIP) by tuning the matrix phase's instability in a metastable TRIP-assisted dual-phase HEA. Besides TWIP and TRIP, such alloys benefit from massive substitutional and interstitial solid solution strengthening as well as from the composite effect associated with its dual-phase structure. Nanosize particle formation and grain size reduction are also utilized. The new interstitial TWIP-TRIP-HEA thus unifies all metallic strengthening mechanisms in one material, leading to twice the tensile strength compared to a single-phase HEA with similar composition, yet, at identical ductility.