Ceramic bilayer structures are formed by coating a green alumina substrate with an aqueous magnesia slurry and then heating the composite body. At high temperature, diffusion and reaction to a spinel can occur, and the body deforms. The deformation of the bilayer structure is attributed to the phase change accompanying spinel formation and to differential sintering between layers. As compared to other bilayer structures obtained by deposition methods, relatively thick top layers are obtained and large strain mismatches occur. At small ratios of the thickness of the top to bottom layer for bilayer plates, equal curvature is observed in two directions whereas at larger thickness ratios, a bifurcation in the deformation behavior is observed with unequal curvature in two directions.

Keywords: ceramic material, layered materials, bifurcation.