The causes of shrinkage cavity and shrinkage defect are caused by die casting

The causes of shrinkage cavity and shrinkage defect of die casting are caused by the liquid shrinkage and solidification of the metal. When the sequence is solidified, where the liquid metal is not replenished at the last place, the hole is formed. The hole large and concentrated is called the shrinkage cavity, small and dispersed is called the shrinkage. There are several ways to prevent this:

1. The structure of the casting should be reasonable and well-proportioned to minimize heat.

2. Thin and uneven casting, put the thick part on top of the top, so that the mouth can be added.

3. The amount of inoculation can be increased appropriately for cast iron.

4. Correctly select the placement position and pouring system to cause solidification or sequence solidification. The sand type compactness should be suitable.

5. Ensure that the casting sequence solidifies, and the shrinkage and shrinkage are introduced into the mouth. The casting position must be correctly chosen for the casting. In each part of casting, different materials with thermal conductivity are used to place cold iron to control the cooling speed of each part of the casting, causing the conditions to solidify in the direction of the opening direction.

6. Increase the feeding effect of the riser. Place enough large and sufficient feeding at the appropriate place to ensure sufficient liquid metal to make up for the casting.

7. Select and control the composition of the metal liquid to minimize the contraction of liquid metal.

8. Correctly selecting pouring temperature and pouring speed, and reducing pouring temperature and pouring speed without adding other defects.