Mathematical analysis and its experimental comparisons for the accumulative roll bonding (ARB) process with different superimposed layers

Abstract

Based on the traditional two-layer accumulative roll bonding (TARB), the geometrical variations and mathematical relationship during the four-layer accumulative roll bonding (FARB) were derived and summarized. Furthermore, the multi-layer accumulative roll bonding (MARB) technology was proposed and the geometrical variations and mathematical relationship of MARB were simultaneously derived and summarized. Experimentally, Mg-14Li-3Al-2Gd (LAGd1432) sheets were fabricated by TARB and FARB, respectively. Compared with the TARB, the FARB has a higher accumulative efficiency in terms of accumulative layers, total number of interfaces, interface spacing, total deformation and equivalent strain. Therefore, the FARB-processed sheets in lower cycles have the similar microstructure and mechanical properties of the TARB-processed sheets in higher cycles. In addition, FARB process can further break through the deformation limit of TARB process in a single cycle through adopting two-step rolling in one cycle with 50% deformation in one pass and 75% accumulative deformation in one cycle, which can effectively solve the problem of poor interface bonding of the latest interface brought by the last cycle, and thus significantly improve the phenomenon of unstable performance of the ARB-processed sheets.

Keywords

• ARB
• Mathematical relationship
• Equivalent strain
• Strengthening mechanism