Effect of annealing on microstructure and mechanical properties of cold rolled Al0.2CoCrFe2Ni high entropy alloy
Wang Wenwen, Tian Quanwei, Wang Yinong
2020, 45(11):
132-137.
doi:10.13251/j.issn.0254-6051.2020.11.024
Abstract
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PDF (584KB)
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Effect of annealing temperature on the microstructure and mechanical properties of Al0.2CoCrFe2Ni high entropy alloy with 80% cold rolling was studied. The crystal structure, texture type, and mechanical properties of the alloy were characterized by means of X-ray diffractometer (XRD), electron backscatter diffractometer (EBSD), and microelectronic testing machine, respectively. The results show that the alloy exhibits a stable FCC crystal structure at the as-cast, as-rolled and as-annealed states. The alloy has a typical dendritic structure at the as-cast state. After 80% rolling, significant rolling deformation bands appear, and recrystallization occurs in the subsequent annealing process. The volume fraction and grain size of recrystallized grains increase with the increase of annealing temperature. The alloy mainly exhibits (111) <112> texture after 80% rolling, and its texture intensity decreases with the increase of annealing temperature. The Al0.2CoCrFe2Ni high entropy alloy obtains greater tensile strength (1005 MPa) and lower plasticity (10%) after 80% rolling. As the annealing temperature increases, the strength of the alloy decreases and the plasticity increases, and the best comprehensive mechanical properties are obtained when annealed at 700 ℃, which mainly depends on the changes of dislocation density, recrystallization volume fraction and grain size, and the evolution of the recrystallization texture in the alloy.
