Texture and Structure Study of AZ41 Alloy after ECAP and Annealing

Abstract

Equal channel angular pressing (ECAP) of magnesium alloys dramatically effects the texture and structure of the alloys due to processes of severe plastic deformation and dynamic recrystallization. Changes in texture, structure and tensile properties of AZ41 alloy after ECAP by Bc regime with 4 passes at a temperature of 245° C and subsequent annealing were studied. Evaluation of texture and structure was performed using the orientation distribution function (ODF) restore from the X-ray direct pole figures and the large number of individual orientations measured by the EBSD method. After ECAP the structure of the dynamically recrystallized fine grains with an average size of about 2,9 μm was revealed. The ratio of the volume fraction of low angle grain boundaries (LAGBs) to the high angle grain boundaries (HAGBs) constituted as 1:3. The formation of few basal texture, tilted by 45 ÷ 55 ° to the pressing direction was also found. Subsequent annealing increases the grain size to 10 μm, the fraction of HAGBs - up to 85% and practically does not change the texture type. These changes in structural parameters improve considerably the low-temperature ductility of AZ41 alloy.