At present, aluminum die casting has a wide range of applications in communication products, auto parts and industrial applications. Most of the die-casting products produced by precision die casting manufacturers are mainly dominated by experience. The quality of die casting is difficult to reach the standard, and there are always various quality problems, such as deformation of die casting. Through the analysis of the causes of die casting deformation of aluminum die casting products in the production process, the main factors affecting product quality were found out, so as to improve the quality of die casting products and reduce production cost.

Analysis and solution for various deformation reasons of die casting parts

 

1. Poor molding

Appearance features: the metal liquid is filled with cavity, the casting surface has irregular holes, sag or uneven edges, and the surface shape is similar to natural liquid flow or liquid surface.

 

Cause:

1)insufficient width of inner runner or poor exhaust of die casting

2)poor fluidity of alloy.

3)low casting temperature or pressure casting mold temperature and low injection rate.

4)insufficient injection pressure.

5)the dimension of die casting cavity is unreasonable and difficult to fill.6) too much or not dry.

 

Method 

1)improve the inner runner and exhaust conditions, and appropriately increase the temperature of the die casting and casting

2)increase injection rate and injection rate.

3)pay attention to proper amount of water spraying and dry.

 

2, the deformation

Appearance features: the casting is deviated (curved) beyond the tolerance of the drawing.

(1) unreasonable casting structure and uneven contraction of each part.

(2) the opening time is too short.

(3) the casting during the ejection process is inclined and the force is not uniform.

(4) it can be adjusted (adjusted) if necessary.

(5) unreasonable piling or improper removal of gate.

 

Method of prevention: 

(1) improve the casting structure to make the casting wall thickness uniform.

(2) do not stack, especially large and thin castings.

(3) strengthen rigidity. Note the die opening time and the ejection time and ejection speed adjustment.

(4) the casting is not rigid enough.

 

3. Convex and concave thimble

Appearance features: convex and concave ejection of thimble.

 

Cause:

(1) unreasonable configuration of thimble length.

(2) repair the mold difficulty.

(3) local temperature of the mold is too high, and the ejector pin is easy to get stuck.

 

Prevention method:

(1) the length of thimble should be reasonable.

(2) spray more water to lower the mold temperature when local temperature is high.

(3) local difficulties in mold release.

 

4, cold,

Appearance features: the surface of the casting has irregular and obvious subsidence lines, which often appear in the far area from the gate, and occur in a certain place for various parts.

 

Causes: 

(1) the two metal flows are connected with each other, but they are not completely fused and without interpenetration. The binding force of the two layers of metal is weak.

(2) incorrect gate position and long flow path.

(3) the position of overflow groove is not consistent with or insufficient capacity at the metal flow collection point.

(4) the exhaust groove is blocked and the exhaust is insufficient.

(5) the gate speed is too low.

(6) material temperature and mold temperature are too low.

 

Prevention method:

(1) modify the gate to improve the metal flow direction, so that the two metal flows are closely connected.

(2) add or increase overflow groove near the occurrence of cold lattice.

(3) when die-casting, first remove the aluminum from the exhaust tank or increase the exhaust tank.

(4) increase gate thickness and gate cross-section area while increasing injection rate.

(5) properly increase material temperature and mold temperature.