How to control the Auto Part Die Casting defect?

Auto Part Die Casting Defect Control Measures

During die casting, defects often arise from imbalances in metal flow, heat conduction, and mold design. Precise control of key process parameters can effectively reduce the defect rate.

Molten Metal Quality Control

Liquid Phase Temperature Control: Strictly control the pouring temperature of the molten aluminum to avoid incomplete solidification and cold shut defects caused by excessively low temperatures.

Gas Removal: During the smelting process, use nitrogen or helium blowing technology to remove dissolved gases such as hydrogen from the molten aluminum, preventing gas porosity and shrinkage porosity.

Impurity Filtration: Use metal mesh or ceramic filters to remove slag and oxide scale from the molten aluminum, ensuring its purity.

Mold Design and Temperature Management

Cooling System Design: Optimize the flow rate and temperature of the cooling water channels to ensure uniform temperature distribution in the mold, avoiding warping or thermal cracking caused by excessive local temperature differences.

Gateway Design: Computational fluid dynamics (CFD) analysis is used to optimize the gateway, runner, and distribution system, ensuring sufficient fluidity of the molten metal during flow and preventing cold shavings.

Mold Maintenance: Regularly inspect the polish and wear of the mold surface, promptly replacing damaged parts to ensure the surface quality of the die-cast parts.

Injection Parameter Optimization:

Injection Speed Control: Injection speed is precisely controlled based on the fluidity of the molten aluminum and the complexity of the parts to avoid porosity due to insufficient flow.

Holding Time Setting: The holding time and pressure are set appropriately to ensure the molten aluminum fully fills the mold and compensates for shrinkage, reducing the risk of porosity and shrinkage cavities.

Injection Point Layout: The optimal injection point location is determined through finite element analysis to avoid temperature drops and defects caused by excessively long molten metal flow paths.

Inspection and Quality Traceability:

Non-destructive Testing: X-ray inspection or ultrasonic flaw detectors are used to perform non-destructive testing on internal defects to ensure finished product quality.

Process Monitoring: Real-time monitoring of the injection curve of the injection molding machine, recording the injection parameters of each machine to provide a basis for quality traceability.

Continuous Improvement: Establishing a closed-loop quality management system (such as IATF 16949), statistically analyzing discovered defects, and continuously optimizing process parameters.