The kinetics of interface-diffusion-controlled reaction in lamellar eutectoids and reactive multilayers

We consider the solid state reactions alpha + beta --> omega and omega --> alpha + beta at sufficiently low temperatures so that volume diffusion is n egligible and interphase boundary diffusion is rate controlling. The partic ipating phases are assumed to have fixed compositions. The existence of a s teady stale reaction front (one which propagates with constant velocity and shape) is possible only for certain imposed conditions (e.g. for a range o f driving forces). An analytical solution of the problem is given for the s mall slope approximation, and numerical solutions are investigated for the general case. Multiple solutions and re-entrant shapes are found for certai n conditions. Possible applications of the present treatment include interm ediate phase formation in multilayers, pearlite reversion and "pearlite-lik e" reactions. (C) 1998 Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.