Microstructure and mechanical properties of an extruded Mg-8Bi-1Al-1Zn (wt%) alloy

Enhancing the Mechanical Properties of AZ80 Alloy by Combining Extrusion and Three Pass Calibre Rolling

“…It should be noted that more randomized texture is generated with the ultra-fine DRXed grains than that of the deformed grains in the CRed sample, as indicated in Figure 6g,h. The result is consistent with previous research on the texture components transition during DRX [23]. And the basal texture (e,f) EDS data of (e) particle A and (f) particle B in (c).…”

“…It should be noted that more randomized texture is generated with the ultra-fine DRXed grains than that of the deformed grains in the CRed sample, as indicated in Figure 6g,h. The result is consistent with previous research on the texture components transition during DRX [23]. And the basal texture weakening effect of caliber rolling processing on extruded Mg alloy is also revealed in the research on AZ31 by Mukai et al [17], which is mainly caused by the shear deformation.…”

“…The fully DRXed microstructure of the as-extruded AZ80 is most likely because of the relatively high extrusion temperature (300 • C) and high extrusion speed (6 m/min) adopted in this study, which are known to increase the DRX fraction [21]. In addition, the present of micro-scale Mg 17 Al 12 and Al 8 Mn 5 phase particles with the size of~10 µm can also contribute to the DRX via generating local inhomogeneity of the strain energy during hot deformation, which is known as particle-simulated nucleation [22,23].…”

“…Besides, the dimples in the CRed sample there are much smaller and shallower than those of the as-extruded sample, as compared in Figure 10b,d. As the strain hardening ability of ultra-fine grain area is lower than that of the micro-scale grain area [23], the inhomogeneous deformation between ultra-fine grains and microscale deformed grains in CRed sample will cause the initiation of fracture, thus decrease the ductility of the CRed AZ80 alloy.…”

“…Based on the indexed result of the selected area electron diffraction pattern, these nano-scale precipitation particles are confirmed as Mg 17 Al 12 (bcc, a = b = c = 1.056 nm). These spherical Mg 17 Al 12 particles are mainly formed during extrusion as a result of dynamic precipitation [23]. During caliber rolling at 300 • C, these pre-existing phases are believed to restrict the grain growth of the DRXed grains after nucleation by pinning effect, which will contribute to the formation of ultra-fine DRXed grain structure [25][26][27].…”