Strengthening is a huge challenge of ultrathin cover glass in mobile electronic devices. In this paper, a transparent sol‐gel silica coating has been sprayed on the surface of chemically strengthened cover glass, and three different coatings (identified as thickness/curing temperature: 3 μm/80°C, 5 μm/80°C, and 3 μm/180°C) have been prepared. Characterized by four‐point bending experiment, the strengthening effects of three coatings, representing by the increases of strength of the coated glass, are 47 MPa, 98 MPa, and 58 MPa for 3 μm/80°C, 5 μm/80°C, and 3 μm/180°C, respectively. Based on finite element simulation and experimental data of four‐point bending, the influence of four parameters of surface coating (elastic modulus, residual stress, filling ratio, and thickness) on glass strengthening has been investigated. Simulation analysis shows that the increase of elastic modulus, residual stress, and filling ratio of the SiO₂ coating facilitates the increase of bending strength of cover glass, and the coating thickness has less influence on the glass strength. However, the experimental results demonstrate that the coating thickness has a significant impact on the strength of glass: when the layer thickness of sample cured at 80°C increases from 3μm to 5μm, the bending strength of glass can improve by 51MPa. Since greater coating thickness induces greater filling ratio, which is the main contributor to the strengthening effect of increased coating thickness, so, elastic modulus, residual stress, and filling ratio of the coating are the three key factors of the cover glass strengthening.

中文翻译：

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Sol-Gel SiO2涂层对防护玻璃的强化机理

加强是移动电子设备中超薄覆盖玻璃的巨大挑战。在本文中，已在化学增强的防护玻璃表面上喷涂了透明的溶胶-凝胶二氧化硅涂层，并喷涂了三种不同的涂层（标识为厚度/固化温度：3μm/ 80°C，5μm/ 80°C和已经准备好3μm/ 180°C）。通过四点弯曲实验表征，在3μm/ 80°C，5μm/ 80°C下，以镀膜玻璃强度的增加表示的三种涂层的强化效果分别为47 MPa，98 MPa和58 MPa。和3μm/ 180°C。基于有限元模拟和四点弯曲的实验数据，研究了表面涂层的四个参数（弹性模量，残余应力，填充率和厚度）对玻璃强化的影响。₂涂层有利于覆盖玻璃的弯曲强度的增加，并且涂层厚度对玻璃强度的影响较小。然而，实验结果表明，涂​​层厚度对玻璃强度有显着影响：当在80°C固化的样品的层厚度从3μm增加到5μm时，玻璃的弯曲强度可以提高51MPa。由于更大的涂层厚度会导致更大的填充率，这是增加涂层厚度的增强作用的主要因素，因此，涂层的弹性模量，残余应力和填充率是覆盖玻璃增强的三个关键因素。