Thermal Shock Fracture Testing for Float Glass by Infrared Radiation Technique

Abstract

An infrared radiation heating method was proposed previously as a new technique for estimating thermal shock resistance of ceramics, and a concept of thermal shock fracture toughness and stress intensity factors for a disk-shaped specimen with an edge crack was expressed. The method uses a thin circular disk which is heated by infrared ray at the central area with a constant heat flux. The technique makes it possible to evaluate the thermal shock strength, R1c, and thermal shock fracture toughness, R2c, directly from the electric power charged and the time to fracture, despite the fact that R1c and R2c consist of the thermal properties of the material tested. In this report, the thermal shock strength and the thermal shock fracture toughness for float glass at room and high temperature are evaluated by the infrared radiation heating technique, and shown as a function of temperature when the specimen failures. The thermal shock parameters obtained experimentally are also compared with the estimated values which are calculated by combining the temperature-dependent mechanical properties of float glass.