8 Die Casting Defects and Their Solutions

By Cherry / July 17th, 2024 

The die-casting process is widely used in the manufacturing industry due to its high efficiency and precision.

However, the die-casting process also produces various defects that affect product quality and performance. Understanding these defects and their solutions is 

crucial to improving product quality.

This article will introduce 8 common die-casting defects and their solutions in detail.

1. Porosity

Defect description: Porosity is caused by the failure of gas to escape when the metal solidifies, resulting in small holes inside or on the surface of the casting.

Solution:

Control the pouring speed: Avoid pouring speeds that are too fast or too slow to reduce gas entrainment.

Use vacuum die casting: Use a vacuum system in the mold cavity to reduce gas residue.

Optimize the exhaust system: Ensure that the exhaust holes of the mold are reasonably located and the exhaust is smooth.

2. Cold Shut

Defect description: The two metal streams fail to fully merge, forming obvious seams or cracks.

Solution:

Increase the pouring temperature: Ensure the fluidity of the molten metal to prevent a cold shut.

Design a reasonable runner system: Optimize the runner and gate position to ensure a uniform flow of molten metal.

Appropriate mold temperature: Keep the mold temperature in an appropriate range to avoid excessive cooling of the molten metal.

3. Oxide inclusions

Defect Description: The molten metal carries oxides during the pouring process, forming impurity inclusions.

Solution:

Purify the molten metal: Purify the molten metal before pouring it to remove oxides.

Improve the pouring system: Use ceramic filters or filter elements to prevent oxides from entering the mold cavity.

Reduce air contact during pouring: Control the pouring environment to reduce the contact between the molten metal and the air.

4. Shrinkage

Defect description: The volume of the metal shrinks during solidification, resulting in holes or depressions on the surface or inside of the casting.

Solution:

Optimize the cooling system: Control the cooling rate of the mold to avoid excessive local cooling.

Use shrinkage measures: Design reasonable risers to provide sufficient metal replenishment.

Adjust the pouring temperature: Ensure that the molten metal is poured at an appropriate temperature to reduce shrinkage.

5. Hot Tear

Defect description: The casting cracks due to thermal stress during the cooling process.

Solution:

Optimize mold design: Reduce uneven thickness and evenly distribute cooling channels.

Control cooling speed: Avoid too fast cooling and reduce thermal stress.

Use suitable alloys: Select alloy materials with good crack resistance.

6. Sticking

Defect Description: The casting is partially or completely adhered to the mold and is difficult to de-mold.

Solution:

Use mold release agent: Apply an appropriate amount of mold release agent on the mold surface to reduce adhesion.

Improve mold surface treatment: Polish or plate the mold surface to reduce friction.

Adjust mold temperature: Control the mold temperature within an appropriate range to avoid being too high or too low.

7. Surface Defects

Defect Description: Sand holes, pits, wrinkles, and other undesirable phenomena appear on the surface of the casting.

Solution:

Optimize mold surface: Ensure that the mold surface is smooth and reduce surface defects.

Control the pouring speed and pressure: Avoid splashing of molten metal and the formation of surface defects.

Use appropriate coatings: Coat the mold to improve the surface quality of the casting.

8. Slag Inclusion

Defect description: Impurities in the molten metal are not effectively removed, forming slag inclusions.

Solution:

Purify the molten metal: Use efficient purification equipment to remove impurities in the molten metal.

Optimize the pouring system: Design a reasonable pouring and runner system to reduce the chance of slag inclusion.

Control the pouring environment: Keep the pouring environment clean to avoid impurities from entering the molten metal.

Conclusion

By understanding and solving common defects in the die-casting process, the quality of castings can be significantly improved and production costs can be reduced.

The above 8 defects and their solutions provide a comprehensive reference for the die-casting process, helping manufacturers to achieve a more efficient and stable 

production process in actual production.

For more info, you can refer to: https://www.youtube.com/shorts/JLX410QV_kw

Contact LK Egypt to learn more info about the die-casting machine

LKAGENT OFFICE DCM

Address: Industry Zone, South of Port Said Kebly, Egypt

https://www.zazdiecasting.com/

Phone/WhatsApp/Wechat: +86 13598704163

Mobile: +20 101 304 3317      +20 150 181 8310

Email: jack@zazmae.com      ahmedmahmoud@zazmae.com

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