Determination of heating or cooling schedule of brittle materials from the stand point of thermal failure

Thermal stress and failure of ceramic materials during thermal processes are the important factors for selecting heating or cooling schedules of their uses and manufacturingIn this paper, the authors propose the method for calculating transient thermal stresses in elastic bodies during thermal processes with the schedules of the following type.(Constant initial temperatures θi)→(Heating or cooling at constant rates k)→(Final constant temperatures θf)The bodies were assumed to be spheres, infinite cylinders and infinite plates in shape, respectively. Newton's law was applied for the heat transfer between the surfaces of the bodies and the surrounding mediums.The calculations were performed with the computer and the maximum thermal stresses at surfaces or at centers of the bodies were shown graphically in dimensionless form. Refering tensile strength and some other physical properties of a brittle material to the figures, one can determine the maximum rate kmax for faultless heating or cooling of the material.