双辊快淬制备镁合金薄带的工艺研究

采用双辊快淬熔体旋铸法制备了AZ31镁合金薄带, 介绍了其基本原理、工艺参数的确定、熔体喷射速度的计算以及界面传热系数的估算。分析了薄带厚度和宽度与两辊线速度、喷嘴孔径的关系, 以及热处理对薄带力学性能的影响。结果表明, 薄带的厚度随辊面线速度V_r的增大而减小, 随喷嘴孔径的增大而增大, 薄带的宽度随辊面线速度增大而减小, 随金属熔体喷射流量的增大而增大。薄带的微观组织为过饱和的单相α-Mg固溶体组织, 其晶粒细小, 力学性能显著提高。

Study on Processing for Fabrication of Magnesium Alloy Ribbons by Twin-roll Rapidly Solidification

The AZ31 Magnesium alloy ribbons is prepared by twin-roll rapid solidification technique. The principle of the twin-roll method and the calculation of melt ejection speed and the estimation of interface heat-transfer coefficient are introduced. The effect of wheel speed and nozzle diameter on thickness and width of the strips and the effect of heat treatment on mechanical property are analyzed. Results show that thickness and width decrease with the wheel speed, and increase with the nozzle diameter. Microstructure of the ribbons is supersaturated solid solution of α-Mg with fine grains. Their mechanical properties are obviously improved compared with the casting alloy.