Abstract Magnesium alloy sheets usually has to be processed by warm forming, and change of strain path and evolution of microstructure can significantly influence their warm formability. Forming limit test for an AZ31B alloy sheet under strain path changes was configured and implemented, and the effects of strain paths and microstructure evolution on the forming limit diagram are investigated. The sheet was pre-strained under in-plane uniaxial, plane strain and biaxial tension loading paths at 150 °C, 200 °C and 300 °C, followed by hemispherical punch stretching experiments at the three temperatures using specimens extracted from the pre-strained samples. A crystal plasticity model that incorporates dynamic recrystallization (DRX) and annealing recovery was combined with the Marciniak-Kuczynski (M-K) approach to calculate the FLDs. The evolution of dislocation density during annealing in the pre-strained FLD test at 200 °C was evaluated, through which the predictions of pre-strained FLDs were considerably improved. The present work provides experimental as well as crystal plasticity based methods for evaluating warm formability of magnesium alloys influenced by temperature, pre-straining, DRX and recovery.

中文翻译：

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镁合金AZ31B板高温成形极限

摘要 镁合金板材通常需要进行温成形加工，应变路径的变化和显微组织的演变会对其温成形性能产生显着影响。配置并实施了应变路径变化下 AZ31B 合金薄板的成形极限测试，研究了应变路径和组织演变对成形极限图的影响。板材在 150 °C、200 °C 和 300 °C 下在面内单轴、平面应变和双轴拉伸加载路径下进行预应变，然后使用从预应变中提取的试样在三个温度下进行半球冲头拉伸实验。样品。结合动态再结晶 (DRX) 和退火恢复的晶体塑性模型与 Marciniak-Kuczynski (MK) 方法相结合来计算 FLD。评估了在 200 °C 下预应变 FLD 测试中退火过程中位错密度的演变，从而大大提高了预应变 FLD 的预测。目前的工作为评估受温度、预应变、DRX 和恢复影响的镁合金的温成形性提供了基于实验和晶体塑性的方法。