2008 Volume 49 Issue 5 Pages 1032-1037
Compression tests were conducted at the temperature of 573 K with the true strain rates of 10−3–1 s−1 on as-cast and homogenized Mg-6Al-2Ca-2RE (RE = rare earth) (in mass%) alloy specimens, and their dynamic recrystallization (DRX) behaviors were investigated. Strain hardening occurred after yielding, followed by strain softening. The flow stress of the as-cast specimen was higher than that of the homogenized specimen. The DRX grain size depended minimally on the Z-parameter in both of the as-cast and homogenized specimens. This is likely to be due to the particle-stimulated nucleation mechanism involving the second-phase particles. When the specimens were deformed to the true compressive strain of 1.6, non-recrystallized regions were not observed in the homogenized specimen; however, they were partially observed in the as-cast specimen. The grain size in the recrystallized region in the as-cast specimen was smaller than that in the homogenized specimen. Elemental analyses revealed Al segregation around the second-phase particles in the as-cast specimen. Therefore, it is suggested that DRX in the present Mg-Al-Ca-RE alloy is affected by not only the second-phase particles, but also the Al segregation.