Effects of Rolling Temperature and Annealing Temperature on Mechanical Properties of Mg–8％Al–1％Zn–1％Ca Alloy Medium Plates

The mechanical properties and microstructure of rolled and annealed Mg–8 mass％Al–1 mass％Zn–1 mass％Ca (AZX811) alloy plates were investigated. To investigate the effect of rolling temperature, samples were prepared by rolling at 623 K and 723 K, following which annealing was performed at 473 K. The size of the Al–Ca compound was finer in the 723 K rolled sample than in the 623 K rolled sample. The higher tensile strength and elongation of the 723 K rolled sample compared to the 623 K rolled sample were attributed to the finer Al–Ca compounds in the former. In addition, the effect of annealing temperature on the mechanical properties and microstructure of the 723 K rolled AZX811 alloys were investigated. As a result of these investigations, a decrease in proof stress and an increase in failure elongation were observed when the annealing temperature was set to 573 K. This was mainly ascribed to a decrease in the fraction of grains below 10 µm in size, a decrease in the basal texture intensity, and a solid solution of fine Mg17Al12 precipitates.