预处理对高应变速率轧制镁合金板材组织均匀性和力学性能的影响

Effect of Pre-treatment on the Microstructural Homogeneity and Mechanical Properties of Magnesium Alloy Sheets Produced by High Strain Rate Rolling

传统的镁合金板材加工技术存在生产效率低、成本偏高和成形性能不够理想等局限.本论文采用高应变速率轧制对AZ31镁合金进行轧制,对比研究了两种预处理方法对板材组织性能的影响.结果表明,高应变速率轧制是获得具有细小晶粒组织和良好综合力学性能的镁合金板材的有效手段.经过预变形+均匀化的预处理,高应变速率轧制板材的组织均匀性得到很大的提高,终轧板材内分布着极均匀的细小晶粒组织,其平均晶粒尺寸为2.3μm.由于组织均匀性的提高,板材塑性得到进一步提高,其室温伸长率可达28%.

Magnesium sheets prepared by traditional plastic processing technologies always exhibit undesirable mechanical properties,which is inefficient and costly for commercial application.High strain rate rolling（HSRR） was operated on AZ31 magnesium alloy.The microstructure and mechanical properties of the HSRRed sheets pre-treated in two different ways were investigated.The results indicated that HSRR was an effective method to produce magnesium alloy sheets characteristic of fine grains and high comprehensive mechanical properties.The pre-strain plus homogenization pre-treatment could significantly improve the microstructural homogeneity of the high strain rate rolled sheet,in which the fine grains were distributed very homogeneously and the average grain size was 2.3 μm.The ductility of the sheet was enhanced due to the improved microstructural homogeneity,and the elongation at room temperature was up to 28%.