Heat transfer at the mold-metal interface in permanent mold casting of aluminum alloys project. Quarterly project status report, October 1--December 31, 1998 (Technical Report) | OSTI.GOV

摘要

The first series of experiments at the CMI-Tech Center was successfully conducted on October 14 and 15 with the participation of the University of Michigan team. The preliminary experimental results indicate that the die surface temperatures (or near the surface) have a close correlation with the metal pressure profiles. Considering the difference in timing of the peak die temperatures, the high melt temperature and hotter die temperature for Inter 54 might cause a longer solidification time, and the pressure would decrease more slowly than for Inter 12. The slopes of the metal pressure profiles at the low pressure setting are almost linear. This may mean that the low metal pressure couldn`t effectively keep a pressure channel opened. In other words, as temperature decreased, the solid fraction increased and the solidified shell strengthened, and the pressure, which couldn`t overcome the resistance, would drop linearly. However, at the high pressure, there are inflection points in the pressure profiles. The inflection points are at about 8,500 psi for both the low and the high melt temperature settings. This suggests that the metal pressure was sufficient enough to overcome the resistance of the solidified shell before the inflection point was reached. A preliminary microstructure