Analysis die casting defects

4. Depression (dent)

Appearance inspection:
There are smooth grooves (like disks) on most of the surface of the die cast.

The reasons are as follows:
(1) caused by contraction.

• The design of the die casting is too large;

• Improper placement of sprue;

• Low pressure ratio, short time of holding pressure;

• The local temperature of the die casting mould is too high.

(2) unreasonable design of cooling system;
(3) premature opening of mold;
(4) the casting temperature is too high.

5. The impressions

Appearance inspection:
The surface of the castings and the surface of the mold cavity surface contact with the marks or the surface of the castings.


The reasons are as follows:

(1) caused by ejection element.

• The end face of the roof is worn;

• The adjustment of the top lever is inconsistent;

? The cavity splicing part of the die casting model is not well matched with other parts.

(2) caused by splicing or activity.

• The mounting part is loose;

• Loose or worn parts of the activity;

The side wall surface of the casting is formed by the inserts which are interspersed with the moving and fixed modes.

6. Traces of adhesive.

Appearance inspection:
The small flake and metal or non-metal and metal matrix are fused together, peeling off the small pieces under the action of external forces. The surface of the castings after peeling is shiny, and some are dark gray.


The reasons are as follows:
(1) there are metal or non-metallic residues on the surface of the die casting mold cavity;
(2) when pouring, the impurities are attached to the surface of the cavity.