Solder Defect

Aluminum or magnesium can combine with die steel, causing cast metal to stick to the die surface. In zinc, the zinc forms a layer on top of the steel.

1. Aluminum:
• Reduce the temperature in the solder area, if possible. This is the best solution.
• Add a fountain (bubbler) in the solder area. Even a small fountain can be effective.
• Use a high heat transfer material in the solder area, such as TZM, ANVILLOY, or MITECH.
• Make sure the water lines are functioning and clean.
• Increase the spray on the solder area.
• Reduce the speed and increase the cycle time.
• Reduce the fill time.
• Reduce the length of time the metal impacts on the solder area.
• Check the metal velocity. Is it too high? The velocity should be above atomization but not much higher (about 1000 to 1400 ips).
• Check the PQ2 settings to find the best plunger size, speed, pressure, etc.
• Verify that the actual plunger size and speed are meeting the desired conditions.
• Check the draft angle at the solder point.
• Check for undercuts or a rough surface on the die at the solder point.
• Check the iron content of the alloy. If it is above 0.75%, use lower pressure if possible.
2. Zinc (build-up):
• Lower the die temperature, if possible. This is the best action.
• Improve the die surface finish by reducing the surface roughness.
• Increase the draft angle.
• Apply a coating with a smooth surface, such as tin or crc.
• Polish the die using an inhibited acid to keep die damage to a minimum. Use 600 grit sandpaper.