Quality Control Measures for Die Casting Production Process (Part 1)

Quality Control Measures for Die Casting Production Process (Part 1)218

Alloy smelting

  • The furnace temperature should be controlled between 630℃ and 680℃.
  • Observe the molten aluminum, suitable for the production of liquid aluminum bright white, if the liquid aluminum red, indicating that the furnace temperature is too high, such as liquid aluminum ice cream, indicating that the temperature is too low.
  • It is forbidden to mix IMPURITIES in the process of aluminum melting, and it is forbidden to put unqualified products into the furnace for smelting without permission. If there are products that need to be returned to the furnace for smelting, they must be inspected and confirmed by the group leader before they can be put into smelting.
  • To keep the liquid aluminum level stable, no scum and bubbles bubbled out, in the ladling of liquid aluminum for die casting, must be the aluminum surface oxide layer and impurities scraped off.
  • In the production process, the powder refiner and slag remover must be filled in the furnace twice in each shift, every 4 hours on average. The whole filling process must be carried out under the guidance of the group leader. After the completion of the operation, the impurities generated by refining must be cleaned up before casting production.
  • During THE PRODUCTION process, aluminum slag must be cleaned at least twice per shift, at least once every 4 hours on average.
  • All tools that come in contact with liquid aluminum must be dried first,and must be kept absolutely dry and clean. No impurities can be introduced into liquid aluminum.
  • In THE PROCESS OF aluminum melting, if excessive impurities are found in aluminum ingot or return charge, the same kind of aluminum ingot or return charge should be immediately stopped to put into the furnace, and timely report to the monitor and workshop director.


  1. First of all, the accuracy of the mold type should be determined to ensure the integrity of the mold.
  2. The assembly of molds shall be completed with the cooperation of operators, maintainers and team leaders.
  3. Mold assembly, to ensure the fastness of each strong parts, to ensure the safety of the mold in the production process.

Die debugging

After the mold assembly is completed, the machine can be tested (point moving), and the automatic low-pressure air operation can be performed once a week to ensure the flexibility of the assembled mold.

  • Check whether the screws are loose.
  • Check the equipment for oil leakage or other abnormal conditions.
  • Check whether the active parts of die casting machine and die are filled with lubricating oil.

Mold temperature (mold preheating)

  • The surface temperature of the mold is raised to 180℃-220℃.
  • Check whether the cooling water is running normally.

Try die-casting

  • The team leader sets the die casting parameters.
  • Check whether the liquid aluminum to be cast is suitable.
  • Observe whether the equipment and mold are running normally during die casting.
  • Check whether the spray pressure and water volume of the release agent are normal.
  • Check whether the size and appearance of the DIE-CAST products MEET the requirements of the drawing and inspection card, and whether there are any product defects.
  • More than 50 pieces of die casting products must be tested (20 molds must be shot at low speed and then shot at high speed)
  • The final confirmed qualified die casting can be retained as the first inspection, and fill in the “first inspection Sheet”.

Die casting production

After the die casting product is confirmed to be qualified, the parameters set shall be determined, and the operator shall not change the parameters set without authorization.
In THE process of production, if abnormal phenomena such as abnormal sound of equipment or casting is found in the mold, the machine should be stopped immediately and the maintenance personnel should be informed.

In the production process, the operator should ensure the reliability of the mold.

  • Because the parting surface is not smooth or wear, the clamping force is not enough, which leads to more flaring of the casting.
  • Liquid aluminum spatter at the injection position due to punch wear.
  • The mold cavity and slide block are damaged due to misoperation.
  • Due to the long-term use of the mold, the mold material fatigue, collapse damage, affect the quality of products.

In the production process, the operator should do the product self-inspection, stipulating that every die-casting molding 20 products, that is, a self-inspection of the product, if the product is found abnormal, should immediately stop production, find the reason.

  • Because the mold temperature is too low, the temperature of liquid aluminum is too low or the filling speed of liquid aluminum is too slow, the casting appears cold isolation.
  • Due to the insufficient time of holding pressure, the inclination of casting die drawing is too small, which leads to the casting crack or even pull crack.
  • Due to the deviation of liquid aluminum material, rough surface of mold cavity, insufficient stripping dose or failure, the casting mold is sticky.

In the production process, if the mold is found to be slightly broken, but the casting only needs to be repaired in appearance, without affecting the performance, it shall be reported to the team leader and workshop director in time. The treatment method is as follows:

  • According to the actual situation, the production may not be terminated, but all the casting products must be repaired. After the die-casting of the batch of products is completed, the mold must be repaired. This situation is applicable to the products with small batch.
  • Immediately stop production, disassemble the mold in question for maintenance, after maintenance and die casting test to confirm its integrity, can continue to put into production.

Release agent

  1. Before die casting in the production process, the mold must be sprayed with release agent.
  2. Check whether the release agent injection pressure is suitable for die casting production.
  3. Check whether the release agent flow rate is suitable for production.
  4. Check the release agent for failure.
  5. In CASE OF THE ABOVE problems, THE team leader and workshop director should be informed immediately, and the injection pressure, flow rate and release agent ratio should be adjusted in time until the production.

Production inspection

  1. Mold confirmation and assembly
  2. The leader must confirm the conformity of the mold model to be assembled and the product model must be consistent with the production order.
    2, the leader must confirm the integrity of the mold, to avoid the collapse and damage of the mold installed production.
  3. For the assembled mold, it is necessary to check its tightness and add lubricating oil to ensure the flexibility of mold operation.
  4. It is necessary to confirm the conformance of die casting products.
    Second, the first inspection of products
  5. The leader must confirm whether the first die casting produced meets the requirements of the drawing.
  6. During the first inspection of the products, the team leader must confirm whether the dimensions and appearance of the die castings meet the requirements of the drawings and inspection cards.
  7. During the first inspection of products, the leader must confirm the good operation of the die casting equipment and mold.
    Third, inspection
  8. The team leader shall inspect each operating device at least once an hour to correct the operator’s bad operation.
  9. Carry out inspection on each machine and spot check on the products under production to confirm the immediate conformity of the products.
  10. The team leader should deal with the abnormal production situation in time, and report the major quality problems to the workshop director in time.
    Four, other
  11. The team leader shall verify the shift handover procedure and record it every time he/she hands over the shift.
  12. The team leader shall fill in the work diary, record the quality problems and production situation of the shift, and give work hints for the next shift.