The role of low-angle grain boundaries in multi-temperature equal channel angular pressing of Mg–3Al–1Zn alloy
- 246 Downloads
Equal channel angular pressing was used to process an AZ31B magnesium alloy (nominally Mg–3Al–1Zn in wt%) at temperatures decreasing from 200 to 150 °C. The resulting microstructure was characterized by electron backscattered diffraction to reveal the role of low-angle grain boundaries in grain refinement. It was found that low-angle grain boundaries with misorientation angles lower than 5° are surrounded by regions of increased strain gradients, which can stimulate the generation of non-basal slip dislocations during the equal channel angular pressing at temperatures of approximately 150 °C. The strain gradients in the vicinity of the grain boundaries with misorientation angles in the range of 5°–10° were less frequent or were completely absent for high-angle grain boundaries with misorientation angles higher than 10°. This article also discusses the importance of low-angle grain boundaries for the generation of non-basal 〈c+a〉 dislocations needed for successful equal channel angular pressing of AZ31B at temperature of 150 °C.
KeywordsSlip System Strain Gradient Equal Channel Angular Pressing Misorientation Angle Critical Resolve Shear Stress
The authors acknowledge financial support from the Academy of Sciences of the Czech Republic (Grant KAN300100801).
- 11.Stoica GM, Fielden DE, McDaniels R, Liu Y, Huang B, Liaw PK, Xu C, Langdon TG (2005) Mater Sci Eng A 410–411:239Google Scholar
- 16.Wright SL, Field DP, Dingley DJ (2000) In: Kumar M, Adams BL, Schwartz AJ (eds) Electron backscatter diffraction in materials science. Kluwer Academic/Plenum Publisher, New York, p 141Google Scholar
- 21.Kelly A, Groves GW, Kidd P (2000) Crystallography and crystal defects. Wiley, New YorkGoogle Scholar
- 23.Agnew SR, Horton JA, Yoo MH (2002) Met Trans A 33:851Google Scholar
- 27.Sutton AP, Balluffi RW (1995) Interfaces in Crystalline Materials. Clarendon Press, OxfordGoogle Scholar