The fracture resistance of domestic and foreign nanolaminate ceramics was studied by the EF (edge fracture) method. This method provides for indentor chipping of rectangular specimen edges, which permits evaluating such fracture resistance characteristics, as chipping resistance and edge toughness. There is no way of experimental determining the stress intensity factor effected as the penetration of a Vickers indentor into the polished specimen surface and measurement of crack sizes that are formed near the angles of its imprint. The influence of stress concentrations in the indentor–specimen surface contact zone on the fracture resistance of ceramics was assessed. Different test stress concentrations were produced with conical diamond indentors of different tip radii. Studies on domestic titanoaluminous carbide Ti₃AlC₂ specimens demonstrated that with a reduction in stress concentration levels (indentors with increasingly larger tip radii), its edge toughness grew to a smaller extent than that of Y₂O₃ and TS Mg-PSZ ceramics. It is indicative of the limited sensitivity of an examined material to stress concentrations on local fracture. The ratio of edge toughness determined with the indentors of maximum and minimum tip radii (in this case, 400 and 11 μm) can serve as a measure of its sensitivity (in comparison to this characteristic for examined materials). Note that the edge toughness of Ti₃AlC₂ ceramics is almost one-third as large than, e.g., that of Y₂O₃ ceramics and 1.6 times smaller than that of TS nonlinearly elastic zirconia Mg-PSZ.

中文翻译：

---

纳米层压板的局部断裂：边缘碎裂测试

采用EF（边缘断裂）方法研究了国内外纳米层压陶瓷的耐断裂性能。该方法提供了矩形试样边缘的压头崩裂，其允许评估诸如抗崩裂性和边缘韧性的抗断裂特性。没有实验来确定应力强度因子的方法，该应力强度因子是维氏压头穿透到抛光试样表面中的结果，也不是测量在其压印角度附近形成的裂纹尺寸的方法。评估了在压头-试样表面接触区中的应力集中对陶瓷抗断裂性的影响。用不同尖端半径的锥形金刚石压头产生不同的测试应力集中。国产钛铝碳化物Ti _3的研究AlC ₂样品表明，随着应力集中水平的降低（尖端半径逐渐增大的压头），其边缘韧性的增长幅度小于Y ₂ O ₃和TS Mg-PSZ陶瓷。这表明受检材料对局部断裂应力集中的敏感性有限。边缘韧性的比率与最大和最小的尖端半径（在此情况下，400和11的压头确定μ米）可以作为它的灵敏度的量度（相比于该特性用于检查材料）。注意，Ti ₃ AlC ₂陶瓷的边缘韧性几乎是例如Y ₂ O的三分之一。_3种陶瓷，比TS非线性弹性氧化锆Mg-PSZ小1.6倍。