On the formation of hierarchical microstructure in a Mo-doped NiCoCr medium-entropy alloy with enhanced strength-ductility synergy. (15th January 2020)

• Record Type: Journal Article
• Authors: He, Junyang; Makineni, Surendra Kumar; Lu, Wenjun; Shang, Yuanyuan; Lu, Zhaoping; Li, Zhiming; Gault, Baptiste
• Is Part Of: Scripta materialia. Number 175(2020)
• Page Start: 1
• Page End: 6
• Publication Date: 2020-01-15
• Subjects: Medium entropy alloys -- Hierarchical microstructure -- Partial recrystallization -- Yield strength -- Deformation twinning; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2019.08.036
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: We demonstrate the formation of a hierarchical microstructure by optimized combination of Mo-doping and thermo-mechanical processing in a NiCoCr medium-entropy-alloy (MEA) that results in a significant improvement in yield-strength (~775 MPa) and ultimate-tensile-strength (~1200 MPa) with an elongation to fracture up to 35%. Addition of Mo slows down the recrystallization kinetics of the cold-rolled alloy at 700 °C. After 4 h annealing, the microstructure comprises soft recrystallized and hard non-recrystallized zones, dispersed σ precipitates, annealing twins and retained stacking faults/nanotwins that are shown to contribute to the overall mechanical behavior. Graphical abstract: Unlabelled Image