Dissolution of particles in binary alloys: part II. experimental investigation on an Al-Si alloy

Abstract

A detailed experimental study of the dissolution kinetics of Si particles in an Al-Si alloy has been carried out in order to test the validity of the two models presented in the accompanying article.[1] In these models, the dissolution kinetics are dependent on the particle size distribution of the alloy. An alloy with composition Co = 0.77 at. pct Si was heat-treated in order to obtain rather coarse spherical particles (1 to 10 μn). The size distribution of the particles was found to be close to the log-normal distribution. At high temperatures, when the solvus concentration was well above Co, the experimental values were very close to the values of the model which predicted the highest dissolution rates. At lower temperatures, when the solvus concentration was closer toC o, the experimental values lay in between the values predicted by the two models. The results clearly demonstrate that a size distribution of particles must be included in the model if an accurate prediction of the dissolution kinetics is to be achieved.