Abstract This paper examines the relationship between rheology and the qualitative appearance of dried, mica-based paint coatings used in the aerospace industry. The goal is to identify key rheological characteristics indicative of poor coating visual appearance, providing a screening tool to identify unsatisfactory paint formulations. Four mica paints were studied, having coating visual appearances ranging from very poor to very good. Strain sweeps indicated that the poor-quality paints have a smaller % strain midpoint in the linear visco-elastic range; while the good-quality paints have a lower G’/G” cross-over point in frequency sweeps. Thixotropy experiments utilizing single and multiple-loop hysteresis cycles plotting shear stress as a function of shear rate showed that the base mica paints with good appearance had nearly constant, reversible profiles in the forward and the backward directions; while the mica paints with poor appearance were irreversible with a noticeable gradual change in shear stress as more loops are run. The difference in area between the forward and the reverse curves was determined, leading to a quantifiable criterion that can differentiate good paints from poor paints with significance testing. This work would establish the first rheology model using hysteresis loops to predict the visual properties of mica-based paints.

中文翻译：

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将涂层质量与云母基涂料的流变学相关联

摘要 本文研究了流变学与航空航天工业中使用的干燥云母基涂料的定性外观之间的关系。目标是确定表明涂层视觉外观不佳的关键流变学特征，提供一种筛选工具来识别不令人满意的涂料配方。研究了四种云母涂料，其涂层视觉外观从非常差到非常好。应变扫描表明，劣质涂料在线性粘弹性范围内的应变中点百分比较小；而优质涂料在频率扫描中具有较低的 G'/G” 交叉点。使用单环和多环滞后循环绘制剪切应力与剪切速率的函数的触变实验表明，具有良好外观的基础云母涂料几乎恒定，在向前和向后方向的可逆轮廓；而外观差的云母涂料是不可逆的，随着运行更多的循环，剪切应力会发生明显的逐渐变化。确定了正向曲线和反向曲线之间的面积差异，从而形成了一个可量化的标准，可以通过显着性测试区分优质涂料和劣质涂料。这项工作将建立第一个使用滞后回线来预测云母基涂料视觉特性的流变学模型。得出一个可量化的标准，可以通过显着性测试区分好油漆和差油漆。这项工作将建立第一个使用滞后回线来预测云母基涂料视觉特性的流变学模型。得出一个可量化的标准，可以通过显着性测试区分好油漆和差油漆。这项工作将建立第一个使用滞后回线来预测云母基涂料视觉特性的流变学模型。