Microstructure behavior of brass alloy billet solidified by progressively controlled casting

摘要

Progressively controlled casting is a new casting method by which solid liquid interface can be progressively moved to the uppermost section through balancing solidification rate and pouring rate. Thus, since the shrinkage can be minimized by this new casting method, casting design such as riser, runner and gate can be minimized. In this study, in order to minimize shrinkage, we fabricated 65-35 brass alloy billets with O.D. of 60 mm and length of 300 mm by progressively controlled casting and the casting process was performed at temperature of 1323 K with pouring rate of 1 kg/s, interval time of 0.5-2 s and pouring cycle of 1, 5 and 10, respectively. The microstructure and compositional change of 65-35 brass alloy billets were observed by means of investigating the dendrite arm spacing, phase segregation and Zn content of billets over the whole section by SEM, EDS and XRF. With increasing pouring cycle, secondary dendrite arm spacing was more uniform and deviation of phase segregation decreased.