Aging behavior of Al-10%Si-0.3%Mg alloy castings rolled after casting

The aging behavior after solutionization in Al-10 mass%Si-0.3 mass%Mg alloy cast into permanent mold and then rolled up to 68% was investigated by OM, TEM and micro-vickers hardness measurement. The eutectic silicon particles are partial diffusion and coarsening with spheroidal after solution heat treatment, Mg₂Si crystallized phase was approximately dissolution into the Al matrix. The alloy aged at 423 K was found to produced needle shaped precipitates parallel to [100] in Al matrix, while streaks along the [100] and [010] directions were observed between diffraction spots of the matrix in each SADP. When the alloy aged at 473 K, β″ phase, parallelogram-type and granular precipitates were observed. These precipitates were very similar to observed in 6000 families alloy wrought material. It was estimated another fine precipitates affected precipitation strengthening in the alloy.