3003铝合金扁铸锭表面花斑缺陷分析及改进措施

Analysis and improvement measures of surface speckle defect of 3003 aluminum alloy ingot

某批次3003铝合金扁铸锭铣面后表面花斑缺陷导致后续产品出现色差、亮条、性能不均等成品缺陷。因此对其宏观、微观形貌进行分析。结果表明,3003铝合金扁铸锭铣面后表面花斑缺陷本质为表面粗晶层,粗晶晶粒尺寸可达300μm以上,粗晶层深度可达30 mm以上。3003铝合金扁铸锭表层花斑缺陷的产生与铸造过程中铸造温度控制不当,下注管及分流袋没入铝液深度不合适,钛丝选择及质量控制不合理有关。采取提升铸造温度,增加下注管及分流袋没入铝液深度,选用Al-5Ti-1B丝的解决措施后,有效解决了3003铝合金扁铸锭表面花斑缺陷问题。

The surface speckle defects of a batch of 3003 aluminum alloy ingots after milling lead to color differences,bright stripes,and uneven performance in subsequent products.As a result,its macro and micro morphologies were analyzed.The analysis results indicate that the surface speckle defect of 3003 aluminum alloy ingot after milling is essentially a surface coarse grain layer,with the coarse grain size over 300μm and the depth of the coarse crystal layer over 30 mm.The occurrence of surface speckle defects in 3003 aluminum alloy ingots is related to improper control of casting temperature during the casting process,improper depth of immersion of the dipping pipe and shunt bag into the aluminum liquid,and unreasonable selection and quality control of titanium wire.The problem of speckle defects on the surface of 3003 aluminum alloy ingots was effectively solved by increasing the casting temperature,deepening the dipping pipe and shunt bag submerged in the aluminum liquid,and selecting proper Al-5Ti-1 B wire.