Flame–retardant magnesium alloys prepared by adding calcium have been used as lightweight structural material. Thermomechanical treatments using hot
rolling or hot extrusion are effective to improve the mechanical properties of flame–retardant magnesium alloys. This study focuses on the uniaxial hot pressing
process for improving the mechanical properties of cast Mg–9Al–1Zn–2Ca alloy. The hot pressing tests were carried out with different temperatures up to 673 K and
maximum compression strains of 65ÿ. Microstructural characterization was carried out using a field–emission scanning electron microscope equipped with an electron
back scattered diffraction system. 0.2ÿ proof stress, tensile strength and elongation to fracture were measured by a universal testing machine at room temperature.
The Mg–9Al–1Zn–2Ca alloy showed the highest strength after the 65ÿ compression at 573 K, and the highest ductility after the 65ÿ compression at 673 K. The
enhanced mechanical properties are attributed to grain refinement caused by dynamic recrystallization and reduced cavities due to the high compression strain.