连续挤压工艺生产AZ31镁合金板材的实验研究

本文利用连续挤压技术的单、双杆进料方法试验生产了尺寸为160mm×8mm, 170mm×4mm和160mm×3mm的AZ31镁合金板材。分析了单、双杆进料方式,不同宽厚比和不同挤压速度等条件对镁合金板材横截面微观组织及力学性能的影响。讨论了应用双杆进料连续挤压工艺生产AZ31镁合金宽薄板的工艺可行性。结果表明：与单杆进料相比,双杆进料方式的连续挤压AZ31镁合金板材横截面微观组织均匀性较好,板材平均抗拉强度可达到239MPa,平均延伸率为15%。宽厚比由20增加到53,可获得5μm细化晶粒的镁合金板材。随挤压轮转速提高，板材抗拉强度降低，是由于温度升高会导致晶粒尺寸变大。

Experimental studies on AZ31 magnesium sheets processed by continuous extrusion

In this study, the magnesium sheets in size of 160mm×8mm, 170mm×4mm and 160mm×3mm were processed experimentally by using continuous extrusion method with single and double rod modes. The influence of the process conditions, including feeding modes (single and double rod), width thickness radio and extrusion speed on the forming abilities, the microstructure distributions and the mechanical properties of the AZ31 magnesium sheets were examined. As a result, the microstructure distributions in cross-section of the sheets processed by the double rod mode show more homogeneous, comparing with the sheets processed by the single rod mode. The average tensile strength was up to 239MPa and the average elongation was 15%.The magnesium sheets with refined grains were obtained when the width thickness radio was improved to be 53.The tensile strength of AZ31 sheets decreased with increasing the wheel speed. This is because higher temperature generally leads to larger grain size.