A new scheme was suggested for the prediction of interface reaction products at metal/ceramic interfaces. This was based upon thermodynamic calculations and diffusion simulations. Diffusion-controlled reaction and local equilibrium were assumed to exist at the interface. The thermodynamic state of the interface, before the formation of reaction products, was assumed to correspond to metastable equilibrium between the 2 initial phases. In order to determine the boundary compositions, multi-component diffusion simulation of Al2O3/Ti was performed. The driving forces for the formation of all of the other phases could be calculated under the assumed metastable equilibrium conditions. By selecting the phase with the highest driving force for formation to be the first-formed interface reaction product, the order of formation as well as the interface layer sequence could be predicted. The present scheme was applied to interface reaction between pure Ti and alumina at 1100C. It was predicted that TiAl would always form first at the onset of the interface reaction, but the stability of the TiAl depended upon the O potential in the Ti matrix.

B.J.Lee: Acta Materialia, 1997, 45[10], 3993-9