Finite Element Analysis of Thermal Stress of the Metal/Ceramic Multi-Layer Composites with Controlled Compositional Gradients

Abstract

The effect of interlayers having controlled compositional gradients on the residual thermal stress distributions of stainless steel/silicon nitride and tungsten/zirconia bondings was studied by the finite element method. A cylindrical model for the sample geometry and stepwise compositional variations in the interlayers were employed for the calculation. The thermal stress distributions were determined under the condition of a temperature difference of 1400 degrees using the elastic constants and the thermal expansion coefficients of the materials involved, assuming their linear dependence on the composition of the interlayer. Marked effect of reducing the thermal stress of the metal/ceramic bonding has been expected by inserting the interlayers with stepwise compositional profiles. The effect of width and compositional graduation fineness, as well as the composition profile, of the interlayers on thermal stress reduction has been demonstrated.