【摘要】 采用低频电磁LFEC和常规DC铸造技术 ,半连续铸造了三种新的Al Zn Mg Cu Zr合金 ,考察了两种技术铸造组织、锭坯表面状况、元素晶内固溶度和力学性能的区别。结果表明 ,低频电磁铸造组织均匀细小等轴 ,呈细小的蔷薇形和球形 ,平均晶粒尺寸为 2 0～ 5 0 μm ;锭坯表面无冷隔和少偏析瘤 ;合金元素在晶粒内的含量增加 ,Zn的相对溶质固溶百分数为 75 %～ 65 % ,Mg为 72 %～ 66% ,Cu为 4 5 %～ 4 0 % ;铸态力学性能显著提高 ,拉伸强度极限为 330～ 35 0MPa ,延伸率为 0 8%～ 1 2 %。更多还原

【Abstract】 Three new Al-Zn-Mg-Cu-Zr alloys were semi-continuously cast by Low Frequency Electromagnetic Casting (LFEC) and by conventional Direct Chilling Casting (DC) without electromagnetic field. The effects of low frequency electromagnetic field on as-cast microstructures, surface quality, intracrytalline element solubility and mechanical properties were investigated. The results show that microstructures of LFEC are fine, uniform, equiaxed, rose-shaped or globular, and its average sizes are between 20～40μm; the surface of the ingots of LFEC has no cold shut and less segregation. Intracrytalline element solubility and mechanical properties of LFEC are greatly increased: the relative intracrytalline solubility of Zn, Mg and Cu are 75%～65%, 72%～66%and 45%～40% respectively. The as-cast ultimate strength is 330～350MPa and elongation is 0.8%～1.2%.更多还原