For the practical problems of poor stability of the 7055 aluminum in the mass production process,the comparison about the microstructure of both the semi-continuous casting ingot and the low frequency electromagnetic casting of this alloy was made by microscope SEM and TEM in the paper.Then the research result showed that the low frequency electromagnetic casting can refine the microstructure of the semi-continuous casting of the 7055 aluminum perspicuously,and made the size of the non-equilibrium crystal phase reduce significantly,and also caused the contents of both the lamellar eutectic crystals and the A17Cu2Fe phase in alloy to reduce.At the same time,the low melting point eutectic products in the low frequency electromagnetic casting alloy were less than those in semi-continuous casting ones but also the dissolution rate was more.So,it is good for improving production efficiency to use the low frequency electromagnetic casting alloy,as which need less time to be homogenized under the conditions of the same homogenization temperature.%针对7055铝合金在批量生产时存在稳定性差的实际问题,利用金相显微镜、扫描电镜和透射电镜等对该合金普通半连续铸造铸锭和低频电磁铸造铸锭组织进行对比分析,研究结果表明:低频电磁铸造可显著细化7055铝合金普通半连续铸造组织,并使非平衡结晶相的尺寸明显减小且使合金中片层状共晶体和A17Cu2Fe相的含量减少.同时,低频电磁铸造比普通半连续铸造合金中所含低熔点共晶产物少且溶解较快,故采用低频电磁铸造的合金在相同均匀化温度下均匀化所用的时间较少,对提高生产效率极为有利.
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