Microsegregation in Al-Cu Alloys

A comparison has been made between the amount of microsegregation predicted by a numerical model and that found experimentally in Al-Cu alloys varying in composition between 1 and 8 wt pct Cu. A depleted region was predicted and observed experimentally near the Al[subscript 2]Cu. The depleted region was formed below the eutectic temperature and had a significant effect on the ordered composition-fraction plots, particularly for high alloy compositions. Although the fit between experiment and theory was reasonably good, it was concluded that it was necessary to propose that local equilibrium was not maintained between the phases in the solid-state reactions.