APPLICATION OF HIGH MAGNETIC FIELD TO TEXTURE MODIFICATION IN ZINC ALLOY

摘要

Highly textured Zn-1.1%Al alloy with fine-grained microstructure was annealed in a high magnetic field of 32 T. The texture of the samples was characterized by the two 0002 components tilted at 15-20° from the normal to the rolling direction of the sheet. The annealing of samples parallel to the field preserved the maximum intensity of texture components and redistributed the intensity between original orientation of 0002 components and the normal direction. Annealing of samples at ～20° to the field resulted in the increase or retention of texture components with higher magnetic susceptibility and in the complete disappearance of the components with lower susceptibility. It has been shown that the difference in magnetic susceptibility creates an additional magnetic driving force for boundary migration. The magnetically induced boundary migration was studied using Zn bicrystals. Bicrystals with symmetric 90°< 1010 > tilt boundaries were annealed in a high magnetic field of 25 T. The grains in the bicrystal had asymmetrical orientation with respect to the field. For the Zn polycrystalline alloy, the driving forces of magnetically induced and capillary driven boundary migration were found comparable at the average grain size of ?0.1 mm. This allowed interpreting the observed texture modification in terms of selective grain growth exerted by magnetic driving force for boundary migration.