RAPIDLY SOLIDIFIED AL-CU ALLOYS .2. CALCULATION OF THE MICROSTRUCTURE SELECTION MAP

Calculations using current eutectic, dendritic, banding and plane front growth models have been carried out to predict the solidification microstructures of Al-Cu alloys (up to 44 wt% Cu) processed by laser rapid solidification. The predictions have been used to produce a microstructure growth map. This is then compared with the results of experimental work and can be used to test the validity of current phase diagram calculations. The calculated and experimental maps show similar regions of microstructural growth, although some important differences are also observed. In these cases, imprecision in the calculated metastable phase diagram or approximations in the solidification models can explain the lack of correlation.