The Relationship Between U-Shaped Glass's Strength and Temperature

Low and high temperatures have different effects on glass strength. It's generally believed that as the temperature increases, defects accumulate more strain energy, increasing the probability of breakage. At temperatures above 200°C, the glass's viscous flow increases, blunting microcracks and alleviating stress.

This, in turn, increases the glass's strength. Glass has a wide operating temperature range, and the mechanism by which temperature affects its strength is still unclear. According to tests from zero degrees Celsius (-273°C) to 500°C, the lowest strength point is around 200°C.

This also requires consideration of glass's thermal stability, which refers to the extreme temperature differences it can withstand without breaking, or its resistance to rapid heating and cooling. The smaller the significant coefficient of expansion, the better its thermal stability. The Δt for U-shaped glass is approximately 110°C. In other words, glass heated to 350°C will break if its temperature is suddenly lowered to 240°C.

Glass-ceramics, due to their high coefficient of expansion, also have high thermal stability. Generally, when hot, the pressure on the glass surface is not easy to damage, and when cold, the tension on the glass surface is easy to damage. The thermal stability of glass is also related to the glass composition, product thickness, and whether it is quenched, etc.