|About this Abstract
||2020 TMS Annual Meeting & Exhibition
||High Entropy Alloys VIII
||J-25: Concurrent TWIP-TRIP, Short-range Order and Strain Localization in Single-crystal NiCrCo Medium Entropy Alloy Drives Exceptional Mechanical Behavior
||Sezer Picak, Prashant Singh, Aayush Sharma, Yuri I. Chumlyakov, Duane D. Johnson, Raymundo Arroyave, Ibrahim Karaman
|On-Site Speaker (Planned)
High entropy alloys are new class of multi-component systems that form solid-solution phases with unique mechanical behavior. We report that exceptional mechanical properties of a face-centered-cubic NiCoCr medium entropy alloy are driven by interplay of deformation twinning, stress/strain-induced martensitic transformation, short-range ordering and strain-localization. Our molecular dynamics simulations suggest simultaneous twinning and martensitic transformation under uniaxial tensile deformation. We also predict favorable short-range order wave-vector [W = (1 ½ 0)] (usually) responsible for planar slip and anomalous work hardening in f.c.c. based alloys using first-principles thermodynamic linear-response. Ex-situ transmission electron microscopy and diffraction experiments confirm our predictions and establish that the simultaneous activation of twinning, martensitic transformation, short-range ordering and deformation-induced strain localization in NiCoCr alloys maintain high-strength, ductility and toughness. These concurrent strengthening mechanisms provide strategies to further improve such properties in this new class of alloys.
||Planned: Supplemental Proceedings volume; Planned: Supplemental Proceedings volume