How to prevent shrinkage of aluminum alloy die-casting parts, with solutions attached

Aluminum alloy die castings are one of the important components widely used in modern mechanical, automotive, electronic and other fields, with many advantages such as low cost, high manufacturing accuracy, convenient processing, and good surface quality.

With the continuous improvement of performance requirements for aluminum alloy die castings, the problem of shrinkage is becoming increasingly serious, seriously affecting the quality and service life of aluminum alloy die castings.

This article will introduce several common methods to prevent shrinkage problems in aluminum alloy die castings.

1、 Change the design of die-casting process

1. Improve mold closing speed

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In the process of aluminum alloy die-casting, the clamping speed has a significant impact on the formation of shrinkage cavities in die-casting parts.

Increasing the clamping speed can shorten the injection time, increase the pressure on the solution before entering the mold, and make it easier for the gas to be discharged.

However, the speed of mold closing cannot be blindly increased, and adjustments should be made according to specific circumstances.

2. Increase the thickness of the die casting

Increasing the thickness of the die casting can reduce the formation of internal shrinkage cavities. In the design of die castings, attention should be paid to making the wall thickness as uniform as possible to avoid shrinkage problems caused by uneven wall thickness.

3. Reduce compression ratio

Excessive compression ratio can also lead to the formation of shrinkage cavities. Reducing the compression ratio can reduce the shrinkage of the internal material liquid, thereby reducing the shrinkage problem of aluminum alloy die castings.

The specific compression ratio needs to be optimized according to the specific situation.

2、 Optimize the performance of aluminum alloy materials

1. Choose appropriate aluminum alloy materials

Choosing appropriate aluminum alloy materials can effectively reduce the occurrence of shrinkage problems in aluminum alloy die castings. Some high-purity and low gas content aluminum alloy materials are relatively stable during the die-casting process, with fewer shrinkage problems.

When selecting aluminum alloy materials, specific analysis should be conducted on a case by case basis.

2. Optimize aluminum alloy composition

Optimizing the composition of aluminum alloy can improve the physical and chemical properties of aluminum alloy materials, reduce the shrinkage rate of the solution, and thus reduce the occurrence of shrinkage problems in aluminum alloy die castings.

The specific optimization plan needs to be targeted based on the composition characteristics of aluminum alloy materials.

3、 Improving surface treatment technology

1. Increase cooling speed

The correct control of the cooling rate of aluminum alloy die castings is the key to ensuring that the castings achieve the required quality. The cooling rate of aluminum alloy die castings can have an impact on their quality. The cooling process is caused by the Thermal expansion of aluminum alloy die castings. If the cooling speed of different parts is inconsistent, it will lead to the effect of internal stress, which will cause casting deformation and Casting defect.

The speed of cooling can also affect the internal crystal structure of aluminum alloy die castings.

A faster cooling rate means that the actual crystallization temperature is lower and the undercooling is higher;

A slower cooling rate means a lower undercooling, and the actual crystallization temperature is close to the theoretical crystallization temperature. A faster cooling rate can lead to the formation of finer grains.

Improving the cooling rate of aluminum alloy die castings can effectively reduce the occurrence of shrinkage problems in aluminum alloy die castings. In surface treatment technology, spraying cold water and increasing cooling time can both increase cooling speed to achieve the effect of reducing shrinkage problems.

Shunjingyuan Precision Casting Company is a professional enterprise engaged in the manufacturing and processing of aluminum alloy precision parts. Its main products involve automotive parts, electric tools, general machinery, automation robots, optoelectronic communication and other industries.

The company has integrated years of data and advanced technological means in mold development and design, and has numerous patented inventions with independent intellectual property rights. Its technical level is at the forefront of the industry and has been widely praised by domestic and foreign customers.

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Prepared by: Zhao Xiao

Reviewed by: Wang Kunpeng