摘要
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 degrees slope angle and 400 mm length. Under these conditions, the highest obtained hardness was 77 HB. Three different temperatures (25 degrees C, 300 degrees C, and 600 degrees C) were compared in order to obtain the most suitable microstructure. The 300 degrees C die temperature was found to result in the optimum microstructure. Thereafter, samples produced under the optimum die temperature were reheated in 580 degrees C for 5, 10, and 15 min and then immediately quenched in 25 degrees C water. Results indicate that samples obtained from 10 min heating had finer and more proportional microstructure, and under this condition hardness was increased from 80.6 HB to 87.1 HB.
- 出版日期2011