Dynamical coarsening processes of microstructures in non-dendritic AlSi7Mg alloy remelted in semi-solid state①
(School of Materials Science and Engineering, University of Science and Technology Beijing,
Beijing100083, P.R.China)
Beijing100083, P.R.China)
Abstract: The microstructural variation in the non-dendritic AlSi7Mg samples remelted in the semi-solid state has been investigated. It is proposed that the primaryα-Al phases are mainly coarsened by connecting the secondary arms or fine primaryα-Al phases together at the stage of a small quantity of liquid and slowly coarsened through diffusion at the stage of a great quantity of liquid. The dynamical coarsening equation controlled by diffusion is in good agreement with the
equation ofd3-d30=ktand the effect of the starting microstructures on the coarsening of primaryα-Al phases is gradually decreased when the soaking time is long enough.
equation ofd3-d30=ktand the effect of the starting microstructures on the coarsening of primaryα-Al phases is gradually decreased when the soaking time is long enough.
Key words: aluminium alloy; semi-solid; isothermal remelting; microstructure