Analysis of Common Defects in Zinc Alloy Die Castings

Release Date:

2026-03-12

I. Surface patterns and metal flow marks on zinc alloy die-cast parts: Causes include: 1. The runner leading to the casting gate is too shallow. 2. Excessive injection pressure results in excessively high metal flow velocity, causing splashing of the molten metal.

I. Surface patterns and metal flow marks on zinc alloy die-cast parts: Causes:

1. The runner leading to the casting inlet is too shallow.

2. Excessive injection pressure results in excessively high metal flow velocity, leading to spattering of the molten metal.

Adjustment method:

1. Deepen the gate runner.

2. Reduce the injection pressure.

II. Causes of the formation of small protrusions on the surface of zinc alloy die-cast parts:

1. Rough surface.

2. Scratches, pits, or cracks appear on the inner surface of the mold cavity.

Adjustment method:

1. Polished cavity.

2. Replace the cavity or perform repairs.

3. The casting surface exhibits ejector pin marks, resulting in an uneven and rough finish. Causes:

1. The push rod (ejector pin) is too long;

2. The cavity surface is rough or contains foreign matter.

Adjustment method:

1. Adjust the length of the push rod.

2. Polish the cavity and remove debris and oil contamination.

IV. Causes of Cracks or Local Deformation on the Surface of Zinc Alloy Die Castings:

1. Uneven distribution or insufficient quantity of the top-loading rods, resulting in uneven stress:

2. The material-advancing rod fixing plate becomes skewed during operation, resulting in uneven force distribution—one side bearing a greater load than the other—which leads to product deformation and cracking.

3. The casting wall is too thin, leading to deformation after shrinkage.

Adjustment method:

1. Increase the number of ejector pins and adjust their distribution to ensure uniform ejection forces on the casting.

2. Adjust and reinstall the pushrod mounting plate.

Keywords: Chengyu Forging, Heat Treatment

Classification, Characteristics, and Equipment Used in Forging

None

Classification, Characteristics, and Equipment Used in Forging

None