|About this Abstract
||1st World Congress on High Entropy Alloys (HEA 2019)
||High Entropy Alloys 2019
||Cryogenic-temperature Deformation of Boron-doped High-entropy Alloys: Hardening by Short-range Ordering
||Jae Bok Seol, Jae Wung Bae, Zhiming Li, Won-Seok Ko, Hyoung Seop Kim
|On-Site Speaker (Planned)
||Jae Bok Seol
We report a strategy for improving the cryogenic strength of FCC-structured HEAs through short-range order (SRO), which is driven by soluble boron at the high-entropy grain interiors, not by interfacial boron. Introducing soluble boron into the FCC matrices provided the key benefits, i.e., creation of SROs and increase in SRO degree during cryogenic-temperature deformation, as proved by TEM diffraction and synchrotron XRD. With this new approach, we increased the cryogenic yield strengths of non-equiatomic Fe40Mn40Co10Cr10 (at %) and near-equiatomic NiFeMnCoCr alloys by ~32% to ~1.1 GPa compared to those of boron-free reference materials with similar grain sizes. We will present the main reason causing the advent of such deformation-induced SROs on planar dislocation band structures, which can be successfully visualized by common dark-field TEM conditions. Also, we will introduce a simple experiment to feasibly discern the SRO from the long-range order (LRO) states by use of common TEM method.