Overheating influence on solidification - thermal variables and microstructure formation of aluminium alloy

a comparative analysis of the 5052 aluminum alloy solidification process involving different overheating ranges is presented herein. experimentally determined, the main parametersof the solidification process were affected in the overheating range and influenced the microstructure arrangement. the 5052 aluminium alloy was selected.it contains about 3% magnesium and is used for commercial purposes. the aluminium alloy was poured into a device that allows unidirectional solidification and was programmed with three different overheating ranges. temperature variation at different sample positions was monitored using a data acquisition system. from the temperature results, the other parameters of the process were determined. the dendritic spacing was determined by the micrographs. through experimental analysis, the influence of the overheating range was established at the following parameters related to the solidification process: the heat transfer coefficient at the metal/mold interface, the solidification rate, the thermal gradient at the liquidus isotherm, the cooling rate, the local solidification time and secondary arm spacing. the change between the columnar and equiaxed structure was also studied.