Precipitates effect on microstructure of as-deformed and as-annealed AZ41 magnesium alloys by adding Mn and Ca

The microstructure and precipitates effect of AZ41 alloys by adding Mn and Ca during hot compression (300 A degrees C/0.1 s(-1)) followed by annealing (300 A degrees C/1000 s) have been studied. A kind of bimodal structure consist of a large fraction of the original and deformed grains as well as a small fraction of newly formed grains is found in as-deformed alloys. Equiaxed and fine-grained microstructures occur in as-annealed samples. For Mn-free and Ca-free alloys, Zener pinning effect is minor. Particle stimulated nucleation promotes recrystallization. For Mn- and Ca-containing alloys, fine particles retard dislocation glide forming high density dislocation to inhibit recrystallization.