等径角挤压对AZ31镁合金组织及力学性能的影响

Effect of Equal Channel Angular Extrusion on the Microstructure and Mechanical Properties of AZ31 Magnesium Alloy

研究了电磁连铸AZ31镁合金沿A路径经常规等径角挤压(ECAE)和两步ECAE变形后的微观组织与力学性能。结果表明:与预挤压态相比,常规ECAE态合金随着挤压道次的增加,晶粒不断细化,伸长率不断提高,但屈服强度与抗拉强度逐渐降低;两步ECAE可以使晶粒进一步细化,伸长率、屈服强度与抗拉强度均提高。伸长率、屈服强度与抗拉强度的改变与AZ31镁合金经两步ECAE变形后位错密度增加有关。

The microstructure and mechanical properties of electromagnetic continuous cast AZ31 magnesium alloy processed by equal channel angular extrusion（ECAE） and two-step ECAE in route A were investigated.The results showed that the degree of grain refinement increased with the increasing pass number.The elongation was improved,but the yield strength and tensile strength decreased.On the contrary,after two-step ECAE much finer grain size was obtained.The elongation,the yield strength and tensile strength were enhanced compared with the sample of as-extruded.The change of the elongation,the yield strength and tensile strength is related to the increase of dislocation density.