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为了研究机械伺服压力机变速加载模式对AZ31镁合金镦粗成形过程微观组织和硬度的影响,采用在机械伺服压力机上匀速加载模式和单向减速加载模式对镁合金镦粗成形过程进行了有限元分析,并进行了AZ31镁合金试样的金相分析和硬度测量。结果表明:在压缩变形初始阶段,采用单向减速模式的试样发生了动态再结晶,而采用匀速加载模式的试样未发生再结晶。在变形量达到70%时,采用两种速度模式镦粗试样的微观组织趋向一致。与匀速加载模式相比,单向减速加载模式有利于减小试样温差变化,也有助于镁合金完全动态再结晶,且试样的晶粒细小、组织分布均匀,通过单向减速加载模式的AZ31镁合金试样的硬度比匀速加载模式试样的硬度提高了49%。
In order to study the effect of variable speed loading mode of mechanical servo press on the microstructure and hardness of upsetting process of AZ31 magnesium alloy, the finite element method of upsetting forming process of magnesium alloy was carried out by using uniform loading mode and unidirectional loading mode in mechanical servo press. Analysis, and carried out the AZ31 magnesium alloy sample metallographic analysis and hardness measurement. The results show that during the initial stage of compressive deformation, dynamic recrystallization occurs in the specimen with unidirectional deceleration mode, while no recrystallization occurs in the specimen with uniform loading mode. When the deformation reaches 70%, the microstructure of upsetting specimen with two velocity patterns tends to be consistent. Compared with the uniform loading mode, the unidirectional deceleration loading mode is conducive to reducing the temperature variation of the sample, but also to the complete dynamic recrystallization of the magnesium alloy, and the grain size of the sample is fine and the tissue distribution is uniform. Through the unidirectional deceleration loading mode The hardness of the AZ31 magnesium alloy specimen was increased by 49% compared with the uniform loading specimen.