通过对 6 块玻璃自爆残片的电镜观察和成分分析,发现并证明了引起钢化玻璃自爆的主要原因不仅仅是传统认识中的硫化镍(NiS)微粒,很多情况是由单质硅微粒引起的。进一步对单质硅微粒引起自爆的力学机理进行了分析和有限元模拟。结果显示:由于单质硅微粒周边玻璃的切向应力过大从而引起局部拉伸破坏并导致整体破裂,降温过程可以使这种应力增加并加大破裂危险。
It has been discovered and demonstrated, via scanning electron microscope examination on 6 samples of broken glasses, that one important cause for the spontaneous breakage in tempered glass occurs as a result of the single-phase polycrystalline silicon particles, rather than simply the nickel sulfide (NiS) particles that are commonly recognized to be the main cause for the spontaneous breakage. The mechanism of the spontaneous breakage resulting from these silicon particles was analyzed by using the finite element method. The calculation indicates that the crack initiation and extension on a whole glass sample is imputed to the tensile tangent stress in the glass near the silicon particle. The risk of spontaneous breakage, as caused by silicon particles in a heat-treated glass, might increase with a decreasing temperature.