Metallic Silicon Spheres In Container Glass

Metallic silicon spheres are a group of glass flaws. These inclusions not only reduce the mechanical strength of the glass product but also reduce the temperature shock resistance of containers.The reason for reduced temperature stability is the difference in the coefficients of expansion between the metallic silicon and the glass. The coefficient of thermal expansion of the silicon is clearly lower than that of the glass. Hence, the silicon spheres do not shrink much during the annealing process. Compression and tension forces finally lead to characteristical cracks around the spheres.