ABSTRACT A mould was designed to produce considerable splashing during filling, resulting in the entrainment of freshly produced double oxide film defects. Two moulds were cast to produce 60 testbars in total, suitable for four-point bend testing, to determine their Weibull moduli. Different faces of the cast test-bars, top and bottom, would have different distributions of double oxide film defects, depending on whether the defects were expected to float or to sink during casting. The faces of the test-bars placed downwards in the four-point bend-tests would experience the maximum tensile load, meaning that the test-bar faces associated with the greatest defect densities (top or bottom) would be associated with the lowest Weibull Modulus. The experiment confirmed that double oxide film defects are positively buoyant, initially, and would float towards the surface of the casting during pouring and solidification.

中文翻译：

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四点弯曲试验研究液态铝合金中双氧化膜缺陷的漂浮

摘要 模具被设计成在填充过程中产生相当大的飞溅，导致夹带新产生的双氧化膜缺陷。铸造两个模具，共生产 60 个测试棒，适用于四点弯曲测试，以确定它们的威布尔模量。浇铸试棒的不同表面（顶部和底部）将具有不同的双氧化膜缺陷分布，这取决于在铸造过程中缺陷是上浮还是下沉。在四点弯曲测试中向下放置的测试杆面将承受最大拉伸载荷，这意味着与最大缺陷密度（顶部或底部）相关的测试杆面将与最低的威布尔模量相关. 实验证实，双氧化膜缺陷是正浮力的，最初，