Microstructure and bendabiltiy of AM60 and AZ61 magnesium alloy tubes

Microstructure and bendability of AM60 and AZ61 magnesium alloy tubes have been investigated. The AM60 tubes were successfully extruded at a temperature of 420°C and an average strain rate of 0.14 s^-1, while the AZ61 tubes were extruded at 410°C and 0.1 s^-1. The bendability of AM60 alloy was better than that of AZ61 alloy at room temperature due to its finer grain size and more favorable crystal orientation for plasticity. For AM60 alloy tubes, a moderate temperature range (100-200°C) was sufficient for bending since twinning and possible non-basal slip enhanced the formability. Higher bending temperatures (200-250°C) were needed for bending AZ61 alloy tubes where extensive non-basal slip was facilitated by the CDRX (continuous dynamic recrystallization) mechanism.