Three-dimensional visualization and quantitative characterization of primary silicon particles in an Al–Si base alloy

 The three-dimensional (3-D) microstructure of an Al–Si base alloy is reconstructed to visualize and characterize the 3-D geometry of primary Si. Octahedral, plate-like and other 3-D morphologies of primary Si are observed and quantitatively characterized. The octahedral morphology is predicted to occur when the ratio of the crystal growth velocities along [0 0 1] and [1 1 1] directions is equal to √3 (and not 1.5 as previously reported by other researchers). A digital library of 3-D primary Si particles is created for realistic microstructure simulations.