Practical strength of damage-resistant CaO–Al2O3–SiO2 glass-ceramic

Abstract The strength of glass depends on the size of flaws existing on its surface. Therefore, its strength considerably deteriorates once a large flaw is generated upon contact with harder materials. Such mechanical failure renders the glass unreliable, which can cause severe problems in practice. In this work, the damage resistance of CaO–Al2O3–SiO2 (CAS) glass-ceramic (GC) was evaluated through bending tests. The test was conducted using abraded samples with conventional soda–lime–silica (SLS) glass as a reference. Although the strength of the SLS glass decreased to less than 50 MPa after abrasion, CAS-GC maintained an average strength of 100 MPa with a higher Weibull distribution number. Large sharp flaws, which act as a stress concentrator, were not observed in CAS-GC. This observation was consistent with the microcrack formation instead of the radial crack around Vickers indentation in CAS-GC.