电磁铸造铝合金锭的力学性能

MECHANICA1 PROPERTY OF ALUMINUM ALLOY INGOT BY ELECTROMAGNETIC CASTING

分析了电磁铸造铝合金铸坯的表面和内部质量,并与普通连续铸造铸坯进行了对比.结果表明,电磁铸造铸坯表面光滑如镜,其表面粗糙度仅为Ra O.65μm,消除了普通连续铸造铸坯表面存在的振痕和偏析瘤等铸造缺陷;定量金相测定的EMC铸锭的晶粒尺寸是DC锭的一半.细小、均匀的等轴晶使电磁铸造铸锭具有良好的力学性能,其抗拉强度比连铸坯提高3.7％～19.6％,延伸率提高7.1％～200％.另外,合金元素含量越高,电磁铸造铸坯的性能提高的幅度越大.

The surface and inner qualities of aluminum alloy ingot by electromagnetic casting (EMC) have been investigated and compared with those of the direct casting (DC) one. The results show that the surface of EMC slab is very smooth, its roughness is Ra 0.65 μm. The surface imperfections, such as oscillation and subsurface segregation etc. caused by a mold of direct casting, are avoided. It is also found that the macrostructure of EMC slab is composed of fine, uniform equiaxed grains. The result of quantitative analysis shows that the grain size of EMC ingot is half of DC one. The EMC ingot consists of fine and uniform grains, it has an excellent mechanical properties. Its tensile intensity increases by 3.7%~19.6% and elongation increases by 7.1%~200 % than the DC ingot. And the higher the content of alloy elements, the better the mechanical properties of EMC ingot.