Effect of glass thickness on temperature gradient and stress distribution during glass tempering

• Stress change during glass quenching process is clarified.
• Thickness has influence on temperature and stress distribution during glass tempering.
• For thin glass, increase heat transfer to obtain sufficient ΔT, but Δt is very short.
• It is relatively difficult to fully temper thin glass.

The thickness of tempered glass is usually more than 3 mm. To achieve thinner tempered glass, it is necessary to clarify the stress change during its quenching process. Glass toughening involves high temperatures, which made the real-time measurement of the temperature distribution, stress distribution, and phase changes occurring difficult. However, these parameters directly affect the strength of the tempered glass. In this paper, for the purpose of evaluating and optimizing the tempering process, nonlinear finite element analysis method has been used to simulate the distribution of the temperature gradient, and the final residual stress of the glass samples with different thickness. The geometry and mathematical model to be used were established, and the boundary conditions for the simulations were set on the basis of the actual toughening conditions. It is found that the thickness has a great influence on the quenching period, temperature gradient and stress fields distribution.