Density and solidification shrinkage of hypoeutectic aluminum-silicon alloys

The density of liquid and solid hypoeutectic aluminum-silicon alloys has be en measured with high accuracy in the temperature range 400 degreesC to 800 degreesC by using the indirect Archimedian method. A eutectic mixture of K CI and LiCl salts was used as reference liquid. This method allowed measure ments of density for both liquid and solid in the same experiment and thus reduced the systematic error in estimating the solidification shrinkage. Th e results show that the density of liquid aluminum-silicon alloy increases with increasing silicon content, while silicon reduces the density in the s olid state. Silicon content reduces the solidification shrinkage from 6.6 p ct for pure aluminum to 4.4 pct for Al-11.6 pct Si.