Si particle size and aspect ratio distributions in an Al–7%Si–0.6%Mg alloy during solution treatment

D357 castings were solution treated at 540 °C for 1, 4, 16 and 64 h. The size and aspect ratio data were collected using digital image analysis. The data indicate that the particles follow the LSW coarsening after a solution treatment time of 4 h. The particle size distributions are significantly wider than that suggested by the LSW distribution and the one suggested by Llorca. Among the distributions tested, two- and three-parameter lognormal distribution provided the best fits for size and aspect ratio, respectively.