The defects of aluminum castings are mainly manifested as
- The casting structural design is unreasonable, with sharp corners, and the wall thickness of the casting changes too much
- Sand mold (core) has poor yield
- Local overheating of the mold
- Pouring temperature is too high
- Premature removal of castings from the mold
- The heat treatment is overheated or overfired, and the cooling rate is excessive
Methods for preventing defects of aluminum castings
- Improve the structural design of castings, avoid sharp corners, strive for uniform wall thickness, and smooth transition
- Take measures to increase the concession of the sand mold (core)
- Ensure that all parts of the casting are solidified simultaneously or sequentially, and improve the design of the pouring system
- Properly reduce pouring temperature
- Control the mold cooling time.
- The thermal correction method is adopted when the casting is deformed.
- Correctly control the heat treatment temperature and reduce the quenching cooling rate