Mechanical properties and precipitate behavior of Mg-9Al-1Zn alloy processed by equal-channel angular pressing and aging

Magnesium alloy processed by equal channel angular processing (ECAP) usually had a good ductility, but often inadequate strength. Herein, an approach was developed to simultaneously achieve high strength and good ductility in the Mg-9Al-1Zn alloy. This approach involved pre-solution treatment, ECAP and subsequent aging. The pre-solution accelerated the grain refinement and increased the strain hardening during the ECAP that improved the strength of the alloy. The spherical big precipitates and dispersed nanosized fine precipitates generated separately during the ECAP and the following aging process. As increasing the ECAP passes from 4 to 12, the strain hardening decreased but the fine structure became more equilibrium. Moreover, the aging hardening became more effective that resulted in a good ductility and a high strength in the Mg-9Al-1Zn alloy.