Strain Mismatch in Ceramic Multilayers: Determination by Strength Measurements

In asymmetrical 3-layer laminates with constant overall and inner layer thickness, the residual compressive stresses in the two outer layers are not longer the same: compression is higher in the thinner layer.Therefore, it can be expected that the strength also depends on the outer layer thickness. Experimental evidence of this behavior was found by measuring the bending strength of asymmetrical tri-layers. A value of the thermal expansion mismatch was determined by fitting the theoretical expression to the experimental data.