Iranian Journal of Materials Science and Engineering

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In this research, variant selection of martensite transformed from ultrafine-grained (UFG) austenite fabricated by accumulative roll bonding (ARB) process and subsequent annealing was investigated with respect tomorphology of parentaustenitic phase. The results show that the original shape of austenite grain is very effective factor in determiningthe preferred variants of martensite transformed from the elongated ultrafine-grained austenite fabricated by 6-cycles via the ARB process. Annealing treatment of the austenitic samples subjected to the 6-cycle ARB processed at 873 K for 1.8 ks suppressed the variant selection by changing the morphology of austenite grains from elongated ultrafine-grains to fully-recrystallized and equiaxed fine-grains

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In the present work, accumulative roll bonding (ARB) was used as an effective method for processed of nano/ultrafine grained AA6063 alloy. Microstructural characteristics indicate considerable grain refinement leading to an average grain size of less than 200 nm after 7 ARB cycles. Texture analysis showed that 1-cycle ARB formed a strong texture near Copper component ({112}<111>). However, texture transition appeared by increasing the number of ARB cycles and after 7-cycle of ARB, the texture was mainly developed close to Rotated Cube component ({100}<110>). The results originated from mechanical properties indicated a substantial increment in strength and microhardness besides a meaningful drop of ductility after 7 ARB cycles.