Development of novel grain morphology during hot extrusion of magnesium AZ21 alloy

Influence of extrusion ratio on microstructure and texture developments of high-temperature extruded AZ31 Mg alloy

“…The point-to-origin misorientation plot shows that the maximum in-grain misorientation of the large elongated grains (B and D) is greater than 15°, while that for the coarse grains (A and C) is less than 1°. The similar results have been reported by Azeem et al [6]. They concluded that the large elongated grains were pre-extruded grains which were favorably oriented to accommodate extrusion strains, and hence these grains did not have enough stored plastic energy to trigger recrystallization in spite of high-temperature extrusion.…”

“…It was seen that despite previous efforts, controversies remained about the effect of ER on the grain size of extruded alloys. Actually, there could be three types of grains in extruded magnesium alloys including the deformed grain, dynamically recrystallized (DRX) grain and abnormal growth grain [6]. Therefore, it should be more suitable to characterize the microstructure by counting volume percentage of each type of grains than to give an average grain size.…”

Effect of grain size distribution and texture on the cold extrusion behavior and mechanical properties of AZ31 Mg alloy

“…It is the classic texture system observed in Mg alloys deformed at room temperature [10,11] due to the smallest critical resolved shear stress of dislocations slipping on the basal plane along 1 12 0 direction. It was reported that the texture of hot deformed Mg alloys remained stable after moderate annealing [16,17,20]. However, texture changes are observed after annealing treatment for the extruded materials seen in Fig.…”

“…Results showed that not only mean grain size but also grain size distribution played a crucial role in the flow stress of heterogeneous materials. Recently, Azeem et al [16,17] investigated the duplex grain structure of a postextrusion annealed AZ31 Mg alloy and indicated that the abnormal grain growth resulted in the low ductility and poor fatigue performance. Similarly, texture systems have been found important in the deformation behaviors and mechanical properties of Mg alloys.…”

Influence of strain path on the microstructure evolution and mechanical properties in AM31 magnesium alloy sheets processed by differential speed rolling

“…2a and 3a). Such grains have also been reported in hot-extruded AZ31 and other magnesium alloy systems [20]. These grains have been suggested to arise from previous structures that have survived DRX.…”