Variation in dynamic deformation behavior and resultant yield asymmetry of AZ80 alloy with extrusion temperature
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2020年第11期
论文作者：Sang-Hoon Kim Sang Won Lee Byoung Gi Moon Ha Sik Kim Sung Hyuk Park
文章页码：225 - 236
摘 要：In this work, variation in the dynamic recrystallization（DRX） and dynamic precipitation behavior of AZ80 alloy during extrusion due to changes in extrusion temperature was investigated, and the resultant microstructure and yield asymmetry were analyzed. As the extrusion temperature increases from 250℃ to 350℃, the primary DRX mechanism changes from twin-induced DRX to discontinuous DRX, resulting in an increase in the DRX area fraction and un DRXed grain size. In addition, as the extrusion temperature rises, Mg17Al12 precipitation during extrusion decreases sharply throughout the extruded material. The reduction in the compressive yield strength（CYS） with increasing extrusion temperature is more pronounced than it is for the tensile yield strength（TYS）, which ultimately increases the yield asymmetry of the extruded material. The higher extrusion temperature has less of an influence on the TYS due to the promotion of certain hardening effects. On the other hand, the greater reduction in the CYS is attributed to the increased fraction and size of regions in which ■ twins predominantly form and the lower amount of precipitates, which effectively facilitates ■ twinning.
Sang-Hoon Kim1，Sang Won Lee1，Byoung Gi Moon2，Ha Sik Kim2，Sung Hyuk Park1
1. School of Materials Science and Engineering, Kyungpook National University2. Implementation Research Division, Korea Institute of Materials Science
摘 要：In this work, variation in the dynamic recrystallization（DRX） and dynamic precipitation behavior of AZ80 alloy during extrusion due to changes in extrusion temperature was investigated, and the resultant microstructure and yield asymmetry were analyzed. As the extrusion temperature increases from 250℃ to 350℃, the primary DRX mechanism changes from twin-induced DRX to discontinuous DRX, resulting in an increase in the DRX area fraction and un DRXed grain size. In addition, as the extrusion temperature rises, Mg17Al12 precipitation during extrusion decreases sharply throughout the extruded material. The reduction in the compressive yield strength（CYS） with increasing extrusion temperature is more pronounced than it is for the tensile yield strength（TYS）, which ultimately increases the yield asymmetry of the extruded material. The higher extrusion temperature has less of an influence on the TYS due to the promotion of certain hardening effects. On the other hand, the greater reduction in the CYS is attributed to the increased fraction and size of regions in which ■ twins predominantly form and the lower amount of precipitates, which effectively facilitates ■ twinning.
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