An investigation into the effect of die temperature and heat treatment on A360 properties produced by the semi-solid forming and cooling slope method

Abstract

Forming Al alloys using the semi-solid method could largely overcome major problems of the die casting process. The cooling slope method is applied by pouring the melt on to the cooling slope to refine and spherodize it. Applying the cooling slope method in casting is relatively simple, yet financially beneficial in terms of required equipment, not to mention the fact that it is capable of producing semi-solid slurries. Parameters to be considered in this method include die temperature and heat treatment; both affecting microstructure and mechanical properties of the work piece. In this study, pouring conditions were 60° slope angle and 400mm length. Under these conditions, the highest obtained hardness was 77HB. Three different temperatures (25°C, 300°C, and 600°C) were compared in order to obtain the most suitable microstructure. The 300°C die temperature was found to result in the optimum microstructure. Thereafter, samples produced under the optimum die temperature were reheated in 580°C for 5, 10, and 15min and then immediately quenched in 25°C water. Results indicate that samples obtained from 10min heating had finer and more proportional microstructure, and under this condition hardness was increased from 80.6HB to 87.1HB.