1 College of Materials Science and Engineering, Fuzhou University, Fuzhou 350116, China 2 School of Aerospace, Mechanical and Mechatronic Engineering, the University of Sydney, Sydney NSW2006, Australia 3 School of Materials Science and Engineering, Fujian University of Technology, Fuzhou 350116, China
An as-cast Al0.3CoCrFeNi high entropy alloy with face-centered cubic (FCC) structure was processed by high-pressure torsion (HPT) to different strain values. This deformation-induced microstructure evolution was investigated by using Vickers hardness, electron backscatter diffraction, X-ray diffraction and transmission electron microscopy. The results show that, during HPT processing,the crystal structure is not changed, remaining FCC structure, while nanocrystallization of grains is induced by HPT to 30nm of average grain size; grain refinement is achieved through twinning (including primary and secondary twinning), de-twinning (including primary and secondary de-twinning) and twin boundary subdivision; competition between twinning and de-twinning processes contributes to the decrease and subsequent increase in twin boundary spacing, while the minimum spacing of primary and secondary twins reach 2.7nm and 0.9nm, respectively.
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2015, Vol. 43 
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