Measures to prevent pinholes:
(1) It is strictly forbidden to use contaminated cast aluminum alloy materials, organic compounds and materials that are severely oxidized and corroded.
(2) Control the smelting process and strengthen the degassing refining.
(3) Control the thickness of the metal coating, too thick and easy to produce pinholes.
(4) The mold temperature should not be too high, and chilling measures such as copper block or watering should be applied to the thick-walled parts of the casting.
(5) Strictly control the moisture when using the sand type, and use the dry core as much as possible.
Measures to prevent stomata production:
(1) Modify the unreasonable pouring riser system to make the liquid flow stable and avoid gas entrapment.
(2) The mold and core should be preheated beforehand, and then applied to the coating. After the end, it must be dried before use.
(3) Designing molds and cores should consider adequate exhaust measures.
Measures to prevent looseness:
(1) Reasonable riser setting to ensure its solidification and ability to supplement.
(2) Appropriately reduce the working temperature of the metal mold.
(3) Control the thickness of the coating and thin the thick wall.
(4) Adjust the cooling speed of each part of the metal type so that the casting has a large chilling capacity at the thick wall.
Properly reduce the metal casting temperature.