Analysis of alloy-porcelain compatibility using a multi-component material strip equation.

Abstract

An analytical model has been developed to calculate residual stresses and curvature changes due to thermal contraction differences in metal-porcelain strips consisting of any number (n) of component materials. This model was also used to analyze transient and residual stresses due to solidification of a semicircular arch casting. Results obtained from this model were in close agreement with those obtained from finite element calculations for the cases studied. Some experimental evidence exists to suggest that thermal contraction coefficients of certain body porcelains progressively increase with the number of firing cycles. Therefore, a parametric study was conducted to determine the effects of variations in the thermal contraction coefficient of each porcelain layer on residual stresses and gap changes produced in porcelainized semicircular arch specimens. Based on the analytical model developed in this study, we found that calculated residual stresses near interfacial areas of adjacent layers of porcelain are most sensitive to variations in thermal contraction coefficients of the material layers.