Mechanical properties of an AM20 magnesium alloy processed by accumulative roll-bonding

This work investigates the influence of up to three cycles of accumulative roll-bonding (ARB) on the microstructure and the mechanical behavior of the magnesium alloy AM20. Two initial material states are studied: an initial twin-roll cast (TRC) state and an initial TRC and subsequently heat-treated (HT) state (400°C/24h). The ARB process leads to a reduction of grain size in both material states. Both the TRC and the TRC+HT materials exhibit a stabilized basal texture after ARB, which causes the formation of 101¯21¯011 extension twins under compressive loading in the direction of rolling at quasi-static and dynamic strain rates at room temperature. An increase of 0.2% yield strength and compression strength is the result of texture evolution and microstructure refinement through the ARB process. Strain at failure remains constant in the TRC material states and decreases in the TRC+HT states after roll-bonding. Yield strength and strain at failure exhibit marginal dependencies on the strain rate, whereas the compression strength exhibits a greater dependency on the strain rate. •Twin roll cast AM20 was processed up to three cycles of accumulative roll-bonding (ARB).•The ARB process leads to a significant reduction of grain size.•No complete homogenization of initial twin roll cast sheets (without heat treatment) is achieved by ARB.•ARB sheets show high amount of extension twins under compressive loading at room temperature.•Increasing yield strength and compression strength are achieved by ARB.