Relationship between hot workability and texture evolution in an Al-Zn-Mg-Cu alloy under hot compressive stress mode

초록

Al-Zn-Mg-Cu alloys exhibit the best mechanical properties among aluminum alloys, though they suffer from poor formability during metalworking processes. Thus, utilizing Al-Zn-Mg-Cu alloy for a broad spectrum of applications necessitates a deep understanding of their plastic deformation behaviors at elevated temperatures. Specifically, pinpointing microstructural evolutions in Al-Zn-Mg-Cu alloys post high-temperature deformations is important. In this study, we investigated the high-temperature deformation behavior and mechanisms of an Al-Zn-Mg-Cu alloy using a hot compression tester. Compression tests were carried out at strain rates ranging from 10-3 s-1 to 1.0 s-1 and temperatures between 300 degrees C and 500 degrees C. A processing map, constructed from flow curves, highlighted flow instabilities at higher strain rates and cooler temperatures. In flow instability regions, microstructure and texture analyses using EBSD demonstrated reduced recrystallization, diminished power dissipation efficiencies, and a notable alpha-fiber generation. Taylor factor maps revealed that (100) grains had elevated Taylor factors, suggesting strong deformation resistance in (100)-oriented grains.

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