摘要：由于镁合金具有密度低、耐冲击、比强度低等其他材料不具备的优点，使其在电子器件和汽车行业扮演了越来越重要的角色，需求量逐渐增大。但是镁合金的室温加工性能较差，易产生边裂、板型难控制、表面不光洁等问题，导致需要对轧制后的镁合金进行切边等处理，提高了镁合金板材制备的成本，限制了镁合金的发展。因此研究镁合金室温加工技术、提高镁合金室温成型能力迫在眉睫。

本实验以商用AZ31镁合金为研究对象，研究了差温叠轧和异步叠轧轧制工艺下，镁合金的组织、力学性能的变化。重点研究了板材在差温叠轧复合轧制方式下组织及织构的变形。得出以下结论：

（1）叠轧过程中上下板材容易产生侧弯，导致上下轧件错开，板材开裂，需要增加接触面的摩擦力，甚至在接触面之间引入一定的作用力。

（2）齿面板材容易在轧制过程中发生折叠现象，在板材表面形成一定的皱褶，并在后续的变形过程中渗入芯部，从而降低板材的力学性能。

（3）差温叠轧可以细化板材晶粒组织，同时变形过程中引入一定的剪切应力，能够激活非基面滑移，弱化基面织构，提高板材的室温力学性能。

（4）镁合金在低温下主要依靠{0001}基面滑移产生塑性变形，变形后形成较强的{0001}面织构。

（5）轧件在高温轧制变形过程中更易变形，容易发生动态再结晶，且非基面滑移数量增加，{0001}基面织构弱化效果更好，形成具有一定取向的{0001}织构，力学性能更好。

关键词：剪应变；非对称轧制；镁合金；织构

Effect of shear strain on the texture of Mg alloy

Abstract: Because magnesium alloy have the advantages of low density, impact resistance, low specific strength, it have played an increasingly important role in electronic devices and the automotive industry, and their demand has gradually increased. However, the room temperature processing performance of magnesium alloys is poor, and it is easy to cause problems such as edge cracks, difficult to control the plate shape, and the surface is not smooth, resulting in the necessity of trimming and other processing of the magnesium alloy after rolling, thereby increasing the cost of magnesium alloy sheet preparation. Limits the development of magnesium alloys. Therefore, it is imminent to study room temperature processing technology of magnesium alloy and improve the room temperature forming ability of magnesium alloy.

In this experiment, commercial AZ31 magnesium alloys were used as the research object, and the microstructure and mechanical properties of magnesium alloys under differential temperature and superposition rolling processes were studied. The paper focuses on the deformation of the microstructure and texture of the sheet under the differential temperature rolling. Concluded as follow:

(1) In the process of stack rolling, the upper and lower plates are prone to side bends, resulting in misalignment of the upper and lower rolling pieces and cracking of the plates. It is necessary to increase the frictional force of the contact surface and even introduce a certain force between the contact surfaces.

(2) The tooth plate material is easy to fold during the rolling process, forming a certain wrinkle on the surface of the plate, and infiltrating into the core during the subsequent deformation, thereby reducing the mechanical properties of the plate.

(3) Differential temperature rolling can refine the grain structure of the plate, and at the same time introduce a certain shear stress during the deformation process, can activate the non-basal slip, weaken the base texture, and improve the room temperature mechanical properties of the plate.

(4) Magnesium alloys mainly rely on {0001} basal plane slipping to generate plastic deformation at low temperature, and a strong {0001} surface texture is formed after deformation.