中文摘要：

镁(Mg ) 合金 AZ31 被连续可变剖面图直接生产挤出(CVCDE ) 到学习它的变丑行为。Metallographic 显微镜学(OM ) ，传播电子显微镜学(TEM ) ，和扫描电子显微镜学(SEM ) 被用来作为处理方法的功能在微观结构和 Mg 合金 AZ31 的破裂形态学观察变化。结果表明 Mg 合金 AZ31 的谷物被精制，他们的微观结构被 CVCDE 一致。在 CVCDE 与 2 过渡期间生产的 Mg 合金 AZ31 的再结晶死比与 1 过渡期间由常规挤出(CE ) 和 CVCDE 生产了的是更完全的死，并且谷物更好、更一致。AZ31 合金的粘性被改进。破裂模式从韧性和易碎物的联合被发展到一种唯一的可锻的形式。在摘要，有 2 过渡期间的 CVCDE 模子结构死能改进 Mg 合金 AZ31 的微观结构，粘性，和坚韧。

英文摘要：

Magnesium（Mg） alloy AZ31 was produced by continuous variable cross-section direct extrusion（CVCDE）to study its deformation behavior. Metallographic microscopy（OM）, transmission electron microscopy（TEM）, and scanning electron microscopy（SEM） were used to observe the variations in microstructure and fracture morphology of Mg alloy AZ31 as a function of processing methods. The results reveal that grains of Mg alloy AZ31 were refined and their microstructure was homogenized by CVCDE. The recrystallization in Mg alloy AZ31 produced by CVCDE with 2 interim dies was more complete than that produced by conventional extrusion（CE） and CVCDE with 1 interim die, and the grains were finer and more uniform.Plasticity of the AZ31 alloy was improved. Fracture mode was evolved from a combination of ductility and brittleness to a sole ductile form. In summary, a CVCDE mold structure with 2 interim dies can improve microstructure, plasticity, and toughness of Mg alloy AZ31.