超疏水和RTV涂层表面覆冰剪切强度及其影响因素的对比分析

Comparative Analysis of the Variation of Icing Shear Strength of Superhydrophobic and RTV Coatings

超疏水涂层和RTV涂层都具有防冰性能,但关于两者防冰性能的对比研究较少。文中使用覆冰剪切强度降低系数λ对比两种涂层防冰性能的差异,并通过理论模型计算了λ的理论值。在低温试验箱内对涂敷了两种涂层的4种材质基板进行覆冰剪切力实验,并在实验中设置了不同的冻冰时间、覆冰环境温度。实验结果表明,RTV涂层表面覆冰剪切强度是超疏水涂层的13~86倍,覆冰剪切强度降低系数λ理论值和实验值相符合;随冻冰时间的延长,覆冰剪切强度逐渐增大或基本不变;随覆冰环境温度的降低,覆冰剪切强度呈先增大后减小再增大的趋势;不同基板材质表面的覆冰剪切强度均是超疏水绝缘涂层小于RTV涂层。冻冰时间和覆冰环境温度对两种涂层表面覆冰剪切强度的影响规律并不完全相同。

Both superhydrophobic coating and RTV coating have anti icing properties, but there are few comparative studies on their anti-icing properties. In this paper, icing shear strength reduction factor λ was used to compare the difference of the anti-icing performance between the two coatings, and the theoretical value was calculated by theoretical models. Icing shear force tests were performed on four substrates coated with two kinds of coatings in a low temperature test box, in addition different freezing time and ice-coating ambient temperature were set as experimental variables. The experimental results show that the icing shear strength of RTV coating is 13~86 times that of superhydrophobic coating, and the theoretical value of icing shear strength reduction factor λ is consistent with the experimental value. With the prolongation of freezing time, the icing shear strength gradually increases or basically remains unchanged. With the decrease of the ice-coating ambient temperature, the icing shear strength increases first followed by decreasing and then a increasing again. The icing shear strength of superhydrophobic insulating coating is smaller than that of RTV coating on different substrates. The effects of freezing time and icing ambient temperature on the icing shear strength of the two coatings are not exactly the same.