The effect of thermal conditioning on high frequency ceramic dielectric insulation

One of the objectives of the Signal Corps sponsored research program on ceramic dielectrics is to improve the impact resistance of high frequency ceramic dielectric insulation. The fundamentals involved indicated that increasing physical strength and decreasing modulus of elasticity should increase impact resistance, however, an analysis of the available data for these properties indicated that both vary directly. A consideration of the effect of tempering on the strength of glass, and the work of Hummel and Lowery(1) in which they realized an appreciable increase in transverse strength by thermally conditioning a ceramic containing 75% glass and 25% alumina, indicated the possibility that highly crystalline bodies might be effected by thermal conditioning.