Characteristics of dynamic softening during high temperature deformation of CoCrFeMnNi high-entropy alloy and its correlation with the evolving microstructure and micro-texture
| Autor: | Madan Patnamsetty, Mahesh C. Somani, Pasi Peura, Sumit Ghosh |
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| Přispěvatelé: | Tampere University, Materials Science and Environmental Engineering, Research group: Metals Technology |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Mining engineering. Metallurgy
Materials science Deformation (mechanics) Micro–texture TN1-997 Metals and Alloys Recrystallization (metallurgy) Dynamic recrystallization Kinetic model Plastic flow Microstructure High Entropy Alloys Surfaces Coatings and Films Biomaterials Stress (mechanics) Critical stress/strain 216 Materials engineering Volume fraction Ceramics and Composites High entropy alloys Texture (crystalline) Composite material Softening |
| Zdroj: | Journal of Materials Research and Technology, Vol 15, Iss, Pp 6608-6623 (2021) |
| Popis: | The characteristics of dynamic recrystallization (DRX) of a CoCrFeMnNi high–entropy alloy (HEA) was investigated via hot compression testing in the temperature range 950–1100 °C and at true strain rates of 10-2 and 10-1 s-1. The discontinuous DRX was found to be the dominant mechanism corroborating the microstructural evolution. The progress of the initiation of DRX was investigated in terms of critical strain/stress required using the Poliak–Jonas analytical criterion. Consequently, a new kinetic model based on Avrami–type function was established for the HEA to predict the DRX fractional recrystallization. It was revealed that the volume fraction of DRX grains increased with increasing strain. In the case of 10-2 s-1, steady–state flow was achieved after the completion of one DRX process cycle resulting in further straining, leading to the occurrence of dynamic restoration processes involving formation of substructures and generation and annihilation of dislocations inside the DRX grains which effectively increased the fraction of partially deformed DRX (substructured) grains. A good agreement between the proposed DRX kinetics model and microstructure observation results validated the accuracy of DRX kinetics model for CoCrFeMnNi HEA. The preferred orientation of the non–recrystallized grains was towards the formation of fiber texture, whereas a random micro–texture is revealed in the recrystallized grains. publishedVersion |
| Databáze: | OpenAIRE |
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