Accumulative roll bonding

Accumulative roll bonding (ARB) is a severe plastic deformation (SPD) process. It is a method of rolling a stack of metal sheets, which are repeatedly rolled to a severe reduction ratio, sectioned into two halves, piled again and rolled. It has been often proposed as a method for the production of metal materials with ultrafine grain microstructure. ARB is a modification of repeated forging and folding method which has been in use since the end of Bronze Age or the beginning of Iron for sword making.^[1] The earliest works on modern ARB were by N. Tsuji, Y. Saito and co-workers.^[2][3] To obtain a single slab of a solid material, the rolling involves not only deformation, but also roll bonding.^[4]