A Design Study in Metal Matrix Composite Castings
- AAAV Transmission Case
Casting
Flow and Wall Fill
When
gravity casting SiC-aluminum MMC alloys, the foundry engineer cannot rely on excess
superheat or high metal velocity to fill thin walls and extended features.
Excess superheat will result in aluminum carbide
formation in the melt which will reduce mechanical properties.
High metal velocities result in high levels of casting
defects.
The
casting engineer should review the casting design for thin wall sections and long
runs and consider where and how to thicken critical wall features to eliminate
misruns.