Effect of solidification cooling rate and phosphorus inoculation on number per unit volume of primary silicon particles in hypereutectic aluminium—silicon alloys

Collected data on derived number per unit volume ¯N V of primary silicon particles in hypereutectic Al-Si alloys show a power relationship with solidification cooling rate ˙T of the form ¯N V = A˙Tn where typically n ∼ 1 and A 130 mm−3 (K/s)−1 in the absence of phosphorus and A 720 mm−3 (K/s)−1 in its prescence. Significantly lower apparent values of ¯N V from one set of results appear to stem from measurement of a mean long dimension rather than diameter of particle sections as well as lower measured undercoolings than in Bridgman experiments at similar ˙T. C 2005 Springer Science + Business Media, Inc.