What are the common defects in valve die casting?

In the valve die casting production process, common defects mainly fall into the following categories. Leveraging the technological advantages and quality control system of Ningbo Jieda Molding & Machine Co., Ltd. in the field of valve die casting, these defects can be effectively prevented and their occurrence rate reduced.

1. Porosity and Shrinkage Cavities

Causes: Gases are not completely expelled during the filling or solidification process of molten aluminum, or uneven cooling rates lead to localized shrinkage.
Impact: Porosity weakens the structural strength of the valve and affects its sealing performance.
Jieda's Advantage: The company uses advanced CAE simulation software for flow analysis, optimizing the gating system and cooling circuit, significantly reducing porosity.

2. Cold Shut

Causes: The molten metal does not flow smoothly within the mold, resulting in two metal streams not fully fusing at the contact surface.
Impact: Cold shuts can cause cracks or leaks on the valve body surface, affecting its service life.
Jieda's Advantages: With over 80 high-precision CNC machine tools and automated die-casting equipment, we ensure precise control of metal filling speed and temperature, minimizing cold shuts.

3. Hot Cracks

Causes: Excessive temperature gradients during cooling cause internal stress and cracks in the metal.
Impact: Hot cracks can lead to valve failure under high pressure.
Jieda's Advantages: Our company implements a closed-loop risk prevention system through IATF 16949 quality management, systematically monitoring and regulating the cooling system to significantly reduce the incidence of hot cracks.

4. Surface Defects (e.g., burrs, dents, oxide scale)

Causes: Improper mold surface treatment, poor venting, or substandard secondary processing.
Impact: Surface defects affect valve assembly accuracy and appearance quality.
Jieda's Advantages: We have a professional surface treatment workshop equipped with precision polishing, sandblasting, and rust prevention processes to ensure smooth, burr-free valve surfaces.