等通道挤压AZ80镁合金的析出行为和性能

研究了AZ80镁合金经300℃等通道挤压(ECAP)后的组织、织构与力学性能的演变规律以及第二相析出行为的影响。结果表明:ECAP显著促进了粒状连续析出,可有效节省后续热处理时间。A路径多道次挤压最终获得基面织构;Bc路径挤压后形成基面近似平行于剪切面的织构;第二相析出对ECAP织构特征的形成没有显著影响。用该工艺可获得较高的延伸率(13%-19%),但是抗拉强度过低(300 MPa),综合机械性能不理想。可通过抑制挤压前的未溶粗大粒子的析出、减少挤压道次和降低挤压温度等措施优化AZ80的析出控制。

Precipitation Behavior,Texture and Mechanical Properties of AZ80 Magnesium Alloy Produced by Equal Channel Angular Extrusion

AZ80 magnesium alloy was subjected to ECAP (equal channel angular extrusion) processing at 300 . The evolution of microstructure, texture and mechanical properties influenced by the precipitation was investigated. The results show that ECAP processing significantly favored granular–like Mg₁₇Al₁₂ continuous precipitation in accompany with reducing time effectively during subsequent aging treatment; basal texture can be obtained via route A after ECAP with multi passes, whereas typical shear texture with most basal planes parallel to the shear plane of mode in route Bc; however the precipitation has not remarkable effect on the texture development during ECAP. A relative low ultimate tensile strength of 300 MPa and an improved elongation of 19% were obtained in the processed samples due to strong texture and coarse precipitates. Further optimization should be made by means of impeding the precipitation of the coarse particles before ECAP and decreasing the number of pass and pressing temperature.