Max-Planck-Institut für Eisenforschung, Max-Planck-Straße 1, 40237 Düsseldorf, Germany.
Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
Sci Rep. 2017 Jan 12;7:40704. doi: 10.1038/srep40704.
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.
高熵合金（HEAs）由多种主要元素组成，为实现优异的机械、物理和化学性能提供了途径。我们报告了一种设计新型 HEAs 的新策略，其中包含额外的间隙元素碳。这通过调整亚稳 TRIP 辅助双相 HEA 中基体相的不稳定性，实现孪晶和相变诱发塑性（TWIP 和 TRIP）的联合激活。除了 TWIP 和 TRIP，这种合金还受益于大量的替代和间隙固溶强化，以及与其双相结构相关的复合效应。纳米颗粒形成和晶粒细化也得到了利用。新型间隙 TWIP-TRIP-HEA 将所有金属强化机制统一在一种材料中，与具有相似成分的单相 HEA 相比，其拉伸强度提高了一倍，但延展性相同。
