摘要
采用异相位电磁连铸技术,制备d290 mm×35 mm的铝合金空心管坯,研究异相位电磁场对铸锭凝固组织及表面质量的影响。结果表明:异相位电磁场通过改变金属熔体的流动状态,减少原子团簇上角隅的形成,降低熔体及凝固前沿的温度梯度等机制,可使Al熔体内产生爆发式形核,增加晶核数量,抑制枝晶生长,从而可细化、球化晶粒,改善铸锭凝固组织,避免裂纹的产生;同时,异相位电磁场通过作用于初凝壳内液态金属熔体以及初凝壳本身的电磁力,降低了结晶器与初凝壳的接触压力、减小了铸锭表面的摩擦并抑制了偏析瘤的形成,从而提高铝合金空心管坯的内外表面质量。
Under the out-phase electromagnetic field, AI alloy hollow billet of d290 mm× 35 mm was semi-continuously cast, the effect of out-phase electromagnetic on as-cast microstructures and surface quality were investigated. The results show that the out-phase magnetic field changes the flow of metal melt, reduces the corner, reduces the temperature gradient of melt and solidification front, which gives rise to fulminic nucleation, increases the magnitude of crystal nucleus, restraines the growth of dendritic crystal in melt aluminium, the refines crystal grain, improves solidification structure, and eliminates phenomenon of crack. Simultaneously, Lorentz force that acts on the metal melt and initial skull reduces the contact pressure between the crystallizer and the initial skull, decreases the friction of ingot surface, restrains the form of segregation burl, and improves the surfaee quality of AI alloy hollow billet.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2006年第3期500-504,共5页
The Chinese Journal of Nonferrous Metals
基金
国家高技术研究发展计划资助项目(2001AA332030)
关键词
铝合金
电磁铸造
凝固组织
表面质量
aluminum alloy
electromagnetic casting
solidification structure
surface quality
作者简介
王哲峰（1970-），男，博士研究生
通讯作者：崔建忠，教授；电话：13514286803；E-mail：zhefeng_w@126．com
