Discontinuous recrystallisation as result of phase transformations

Abstract

AbstractThe evolution of the microstructure resulting (only) from the combination of diffusional phase transformations in Cu–In and Ni–Sn systems is described. For this purpose, discontinuous precipitation lamellar products in Cu–7·5In and Ni–8Sn alloys (both at.-%) have been subjected to dissolution treatments. Examination of the resulting microstructures has shown that, contrary to the precipitation transformation, the dissolution process involves volume diffusion and the grain boundaries remain stationary during dissolution. The most striking feature of the post-dissolution microstructure in these alloys is that new grains are generated in the transformation product, giving rise to a localised grain refinement. In the absence of any plastic deformation applied to the material, the role played by the (coherent) lamellar interfaces generated during the precipitation process is discussed, particularly as the energetic potential for the observed recrystallisation phenomenon.MST/1360