基于复合变形的镁合金动态再结晶及晶粒尺寸研究

Study on Dynamic Recrystallization and Grain Size of Magnesium Alloy Based on Compound Deformation

目的研究复合变形工艺参数对镁合金动态结晶体积分数及镁合金晶粒度的影响规律。方法采用镁合金板材压痕-压平复合变形技术、扫描电子显微镜和EBSD等材料性能先进检测技术,获得经过复合变形后的镁合金材料的微观组织及动态结晶体积分数、镁合金的晶粒度等相关数据。结果当变形温度为350℃、复合变形系数为0.375时,动态再结晶体积分数达到94%。当变形温度为400℃、复合变形系数为0.375时,平均晶粒尺寸达到3.2μm。结论在镁合金压痕-压平复合变形工艺中,随着变形温度的提高及复合变形系数的增大,AZ31镁合金的动态再结晶体积分数随之提高。随着变形温度的升高和复合变形系数的增大,AZ31镁合金的晶粒尺寸随之减小,晶粒得到细化。

The objective is to study the effect of compound deformation parameters on dynamic crystallization integral and grain size of magnesium alloys.The indentation-flattening compound deformation technology(IFCDT),scanning electron mi-croscopy and EBSD advanced testing technology for material properties were adopted to abtain microstructure and relevant data of dynamic recrystallized volume fraction and grain size of magnesium alloy,which was deformed by IFCDT.When the defor-mation temperature is 350℃and the IFCDT coefficient is 0.375,the dynamic recrystallized volume fraction reaches 94%.The average grain size reaches 3.2μm when the deformation temperature is 400℃and the IFCDT coefficient is 0.375.The results show that the dynamic recrystallized volume fraction increases with the increase of deformation temperature in the process of IFCDT and the increase of IFCDT coefficient,and,with the increase of deformation temperature and IFCDT coefficient,the grain of AZ31 magnesium alloy is refined.