The understanding of the mechanisms and processes taking place during the production of metal matrix composites, especially of in situ produced composites, is of crucial importance for the properties of the composite. An analytical solution of the equations governing the kinetics of diffusion-controlled precipitation of TiB2 is proposed. The solution allows to predict the concentration profiles and the volume fraction distribution of the reinforcements that are in situ formed along the specimen. The influence of the physicochemical parameters is also taken into account in the proposed solution. (C) 2001 American Institute of Physics.