Understanding the Formation Mechanism of Residual Stress during Precision Glass Moulding
Precision glass moulding is a technique that enables the production of optical lenses of complex geometries in a single step. However, it has been reported that the product quality highly depends on the properties of a raw material, the design of a die, and the selection of a processing program. This paper aims to reveal the formation mechanism of the residual stresses by optical lens moulding. To this end, a modulus-based constitutive model was developed to integrate with the deformation and stress analyses by the finite element method. The investigation showed that the residual stresses are caused by the variability and heterogeneity of thermal expansion in a lens, but that they can be reduced effectively by decreasing the rate of cooling within the stage from the molding temperature to the glass transition temperature.
Yeong-Maw Hwang and Cho-Pei Jiang
W. D. Liu and L. C. Zhang, "Understanding the Formation Mechanism of Residual Stress during Precision Glass Moulding", Key Engineering Materials, Vol. 626, pp. 182-186, 2015