Abstract The high oxidation of aluminum alloy would result in abundant oxidation defects. In recent years, bifilm has been increasingly recognized as a source of the metallurgical defects. The crack defects in aluminum alloy casting was investigated in the present work from the viewpoint of bifilm. Computed tomography has been used to image the defects in three dimensions which demonstrated the complexity of the bifilm defect. Detailed energy spectrum analysis showed that the bifilm has different compositions at different thickness. Simulations suggested that the defect is affected by flow field, thus could be eliminated by process optimization. These results would shed new lights on the understanding of the formation of bifilm defects and improve the defects control engineering of castings.

中文翻译：

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铝合金铸件中的氧化双膜缺陷

摘要 铝合金的高度氧化会导致大量的氧化缺陷。近年来，双膜越来越多地被认为是冶金缺陷的来源。本工作从双膜的角度对铝合金铸件中的裂纹缺陷进行了研究。计算机断层扫描已被用于在三个维度上对缺陷进行成像，这证明了双膜缺陷的复杂性。详细的能谱分析表明，双膜在不同厚度下具有不同的成分。模拟表明，该缺陷受流场的影响，因此可以通过工艺优化消除。这些结果将为理解双膜缺陷的形成提供新的思路，并改进铸件的缺陷控制工程。