Analysis die casting defects

7.Layering (peeling and peeling)
Appearance inspection:

There is a distinct layer of metal in the casting.

The reasons are as follows:
(1) the mold rigidity is not enough in the process of filling the metal liquid, the template generates jitter;
(2) during the injection process, a crawling phenomenon occurs;
(3) improper design of runner system.

8. Friction ablation.
Appearance inspection:
The surface of the die casting is roughened in some positions.

The reasons are as follows:
(1) the position direction and shape of the inner sprue caused by die casting (die) are improper;
(2) it is not enough to cool down the hard part of the molten metal solution caused by casting conditions.

9. Erosion

Appearance inspection:
The parts of the die casting are pitted or embossed.

The reasons are as follows:
(1) improper placement of the sprue gate;
(2) the cooling condition is not good.


10.Crack

Appearance inspection:
The casting is placed in an alkaline solution and the crack is dark gray.
The damage and fracture of metal matrix are linear or wavy, and the lines are narrow and long, and there is a trend of development under the action of external forces.


The reasons are as follows:

(1) high iron content or low silicon content in alloy;
The content of harmful impurities in alloy is too high and the plasticity of alloy is reduced.
Aluminum silicon alloy, aluminum silicon copper alloy containing zinc or high copper content;
There is too much magnesium in aluminum magnesium alloy;
(2) the retention time is too short and the holding time is short;
The thickness of the casting wall varies greatly;
(3) the local package is too tight, and the force is not equal when the top is out.

?

?