In the production process of gravity castings, air holes often appear due to improper operation or unskilled technology. Once air holes appear, the castings will be scrapped due to quality problems and increase the production cost. There are many reasons for pore defects. Many enterprises always feel at a loss when they encounter problems. Next, starting with the causes of air holes in castings, the solutions to air hole defects are analyzed.
1. To ensure the refining degassing quality of aluminum alloy smelting, select good refining agent and degassing agent to reduce the gas content in aluminum liquid, and timely remove oxides such as liquid level scum and bubble to prevent gas from entering the die casting again.
2. Ensure that the mold exhaust is unobstructed and unblocked, and ensure that the gas in the mold is completely discharged, especially at the polymerization of liquid aluminum, the exhaust channel must be unobstructed.
3. Adjust the parameters of gravity casting, the mold filling speed shall not be too fast to prevent air entrainment, and the casting temperature shall be well controlled.
4. Attention should be paid to the use of core pulling and cooling in product design and die design to minimize excessive wall thickness difference.
5. For the pores that often appear in the fixed parts, we should improve the mold and design.
In gravity casting production, there are many reasons for pores in products. The fundamental problem can be solved only by finding out the reasons and applying the medicine to the case.
Editing: xyq