Dissolution of beta particles in an Al-Mg-Si alloy during DSC runs

A DSC experimental study of the dissolution kinetics of beta precipitates i n an Al-Mg-Si alloy has been carried out in order to test the validity of a recent particle dissolution model [F.J. Vermolen, K. Vuik, S. van der Zwaa g, Mater. Sci. Eng. A246 (1998) 93-103; F.J. Vermolen, K. Vuik, S. van der Zwaag, Mater. Sci. Eng. A254 (1998) 13-32; F.J. Vermolen, Ph.D Thesis, Delf t University, Press, The Netherlands]. The results demonstrate that the mod el is successful in simulating particle dissolution during linear heating. The concentrations of both alloying elements at the particle-matrix interfa ce during particle dissolution are decided by both the solubility product a nd the diffusion coefficients. The existence of a size distribution of part icles was found to have a significant effect on the dissolution kinetics an d therefore should be included in any model if an accurate prediction of th e dissolution kinetics is to be achieved. (C) 1999 Elsevier Science S.A. Al l rights reserved.