Flow Marks And Patterns

Appearance inspection: There are stripes on the surface of the casting that are consistent with the flow direction of the molten metal, and there are obviously non-directional lines that are different from the metal matrix in color, and there is no development trend. 1. The causes of flow marks are as follows:

2. The cause of the pattern is too much paint in the cavity or poor paint quality. The solutions and prevention methods are as follows:

Netted Hairy Wings (Cracked Tortoise)

Appearance inspection: The surface of the die-casting parts has the same raised or depressed traces as net-like hair, which will expand and extend as the number of die-casting increases.

The reasons are as follows:

The solutions and prevention methods are:

Cold Barrier

Appearance inspection: The surface of the die casting has obvious, irregular, and sinking linear lines (both penetrating and non-penetrating). The shape is small and long, sometimes the junction edge is smooth, and there is a possibility of disconnection under the action of external force.

The reasons are as follows:

The solutions and prevention methods are:

Shrinkage (Dents)

Visual inspection: There are smooth dents (like discs) on the most thick surface of the die casting.

The reasons are as follows:

The solutions and prevention methods are:

Imprints

Visual inspection: the traces left by the contact between the surface of the casting and the surface of the die-casting cavity or the step marks appear on the surface of the casting.

The reasons are as follows:

1. Caused by ejector components

2. Caused by splicing or moving parts

The solutions and prevention methods are:

Traces Of Adherents

Appearance inspection: small flakes and metal or non-metallic and metal base parts are welded, and the small flakes are peeled off under the action of external force. After the peeling, the surface of the casting is bright and some are dark gray.

The reasons are as follows:

The solutions and prevention methods are:

Layering (Pinching And Peeling)

Visual inspection or damage inspection: There are obvious layers of metal in the casting part.

The reasons are as follows:

The solutions and prevention methods are:

Friction And Ablation

Visual inspection: The surface of the die-casting part has rough surfaces in some positions.

The reasons are as follows:

The solutions and prevention methods are:

Erosion

Visual inspection: There are pitting or embossing in the local position of the die casting.

The reasons are as follows:

The solutions and prevention methods are:

Cracks

Visual inspection: Put the casting in alkaline solution, the cracks are dark gray. The destruction and cracking of the metal matrix are straight or wavy, with narrow and long lines, which have a tendency to develop under the action of external forces.

Causes of cracks in aluminum alloy castings:

Solutions and prevention methods: