Significant Contribution to Strength Enhancement from Deformation Twins in Thermomechanically Processed Al0.1CoCrFeNi Microstructures
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Strengthening mechanisms from thermomechanical processing treatments were explored in single-phase FCC high-entropy alloy Al0.1CoCrFeNi. Cold work offers substantial strengthening in this low stacking fault energy material owing to the resultant high work hardening rates. An enormous increase in yield strength of ~ 275% was obtained in 40% rolled material, but was accompanied by a steep drop in ductility. Recovery and recrystallization annealing treatments were investigated for improving elongation and obtaining better balance of strength–ductility combinations. Formation of novel microstructures from the different processing routes was examined. X-ray diffraction peak broadening and mechanical test results were coupled to estimate micro-strain in the different conditions and understand micro-strain’s correlation to strength. Retention of large-scale deformation twins formed during cold rolling is shown to play a key role in elevation of yield strength after heat treatments.
KeywordsAl0.1CoCrFeNi dislocation hardening high-entropy alloy mechanical properties partial recrystallization recovery thermomechanical processing
The work was performed under a cooperative agreement between the Army Research Laboratory and the University of North Texas (W911NF-16-2-0189). We also acknowledge the Materials Research Facility at UNT for microscopy facilities.
The raw data and the processing required to reproduce these findings are available to download and will be uploaded along with the manuscript.
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