快速凝固制备Mg-Al-Zn合金薄带

Research on Mg-Al-Zn Alloy Strips by Rapid Solidification

镁合金的力学性能、抗腐蚀性能及室温塑性都较差,至今它的应用仍受到限制。快速凝固通过改善合金的微观结构,是克服上述局限的有效方法之一。采用双辊旋铸技术快淬制备AZ31镁合金薄带。对双辊转速对薄带厚度及其微观硬度的影响进行了分析。微观硬度随双辊转速的提高而提高。然而,由于AZ31镁合金的Al、Zn含量过少,固溶有限,所以由热处理引起的析出相强化有限,这也是由热处理所引起的微观硬度增幅不大的原因。所以,对AZ31镁合金进行强化处理,应该采用快速凝固细化晶粒的方法较为有效。

Applications of magnesium alloys are limited because of their poor mechanical properties,corrosion resistance and workability.Refinement of microstructure through rapid solidification processing is one of the highly potential approaches to overcome these limitations.In the present study,the technology of processing of rapidly solidified ribbons in Mg-3%Al-1%Zn alloy has been established using twin-roll technique.The effect of wheel speed on thickness and microhardness of the ribbons is presented.Microhardness is found to increase with the wheel speed.However,the Al and Zn contents in Mg-3%Al-1%Zn alloy are so small that their solid solubility are limited and the precipitation hardening leaded by heat treatment is not obvious, it is the reason that the amplitude of microhardness leaded by heat treatment is low.As a result, one of the effective methods of improving the properties of Mg-3%Al-1%Zn alloy is rapid solidification processing.