Solution of Shrinkage Prevention in Aluminum Die Casting Processing

The reason of shrinkage and shrinkage defects in Dalian aluminum die casting processing is that the liquid shrinkage and solidification shrinkage of metal are larger than the solid shrinkage. When performing sequential solidification, the liquid metal cannot be replenished in the solidified area, and holes will be formed. Large and concentrated holes are called shrinkage holes, and small and dispersed holes are called shrinkage holes. Prevention methods are:

1. The processing structure of aluminum die castings shall be reasonably designed and the thickness shall be uniform to reduce hot spots.

2. For aluminum die castings with uneven thickness, please place the thicker part at a higher place to increase the riser.

3. For Dalian aluminum die casting, the inoculation amount can be appropriately increased.

4. Correctly select the pouring position and pouring system to cause simultaneous curing or sequential curing. The compactness of the sand mold should be appropriate.

5. Ensure that the treatment sequence is cured, and bring the shrinkage cavity and shrinkage to the riser. Therefore, the position of aluminum die casting must be correctly selected during casting. Materials with different thermal conductivity are used for each part of the mold, and cold iron is placed to control the cooling rate of each part, which leads to the solidification in the direction of the riser.

6. Improve the feeding effect of riser. Place the risers of sufficient size and quantity in proper positions to ensure that there is enough liquid metal to feed the nearby aluminum die castings.

7. Select and control the composition of molten metal to greatly reduce the shrinkage of liquid metal.

8. Correctly select the pouring temperature and pouring speed, and properly reduce the pouring temperature and pouring speed without adding other defects.