The paper presents the experimental results of investigations using different types of glass by the Rockwell indenter scratching of the specimen surface till its edge chipping (S+EF method). The peculiar features of the materials’ fracture are determined as a result of fractography analysis of the empirical data. It is proposed to classify chips under two different groups. The first group is characterized by the edge fracture that is accompanied by the fully developed shell-like chip with typical zones of the fracture crack propagation (traces of axisymmetric quasi-cone crack propagation). The second group of chips involves the edge fracture without smoothly outlined borders of the fracture crack propagation on the lateral surface of the specimen with a set of branched and randomly oriented cracks having the reflecting zone of comparatively small dimensions. The mechanisms of variation in the shape of chip scars (fracture crack propagation trajectory) are implied with the increase of the fracture load on the indenter or fracture distance. It is established that the fracture resistance is invariant to the fracture load and does not depend on the asymmetry of chip scars according to their side views. The authors demonstrate the correlation dependence between the test results (the S+EF and SEVNB methods) on the different glass types, which reveals the effect on the specified cracking and chipping of the material in the zone of its contact with indenter for fracture resistance of glass under local edge loading. The authors propose to use the methods of indenter scratching of the specimen surface till its edge chipping as the rapid assessment of damage and fracture resistance of glass in the solution to the optimization tasks, certification procedure or materials’ selection.

中文翻译：

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在试样表面的洛氏压头刮擦直至边缘出现缺口的情况下，玻璃的损伤和抗断裂性能

本文介绍了使用不同类型的玻璃进行研究的实验结果，通过洛氏压头刮擦样品表面直至其边缘崩裂（S + EF方法）。材料断裂的特殊特征是通过对经验数据进行分形分析而确定的。建议将芯片分类为两个不同的组。第一组的特征是边缘断裂，伴随着完全发达的壳状切屑，具有典型的裂缝裂纹扩展区域（轴对称准圆锥裂纹扩展轨迹）。第二组切屑涉及边缘裂纹，而裂纹裂纹在试样的侧面上没有平滑轮廓的边界扩展，而裂纹分支则具有一组分支和随机取向的裂纹，这些裂纹的反射区尺寸较小。切屑疤痕形状的变化（断裂裂纹扩展轨迹）的变化机理暗示着压头上的断裂载荷或断裂距离的增加。已经确定，根据其侧视图，抗断裂性对于断裂载荷是不变的，并且不取决于切屑疤痕的不对称性。作者展示了不同玻璃类型的测试结果（S + EF和SEVNB方法）之间的相关性，这揭示了在与压头接触的区域中材料在指定的开裂和碎裂方面的影响，以防止玻璃在局部边缘载荷下的耐断裂性。作者建议使用压头划伤试样表面直至其边缘崩裂的方法，作为对优化任务，认证程序或材料选择的解决方案中玻璃损伤和耐断裂性的快速评估。