In the process of zinc alloy die-casting, to ensure the dimensional accuracy and surface quality of the product, it is necessary to start from multiple aspects such as raw material selection, mold design and manufacturing, die-casting process control, post-treatment process, and quality inspection. The following is a detailed analysis and recommendations:

1、 Raw material selection

Choose high-quality zinc alloy raw materials:

The composition of zinc alloy has a direct impact on the performance and quality of die-casting parts. High purity and low impurity content zinc alloy raw materials should be selected. Zinc alloy materials with aluminum content of about 4% usually have good electroplating and mechanical properties

Strictly control the alloy composition to avoid excessive impurities such as iron, lead, and cadmium, which can affect the intergranular corrosion sensitivity and mechanical properties of zinc alloys

2、 Mold design and manufacturing

Reasonably design molds:

The design of molds directly affects the shape, size, and surface quality of die-casting parts. The cavity size of the mold should be accurately calculated, taking into account the shrinkage rate of the alloy, to ensure the dimensional accuracy of the die casting

The design of the runner, gate, and exhaust system of the mold should be reasonable to avoid defects such as eddy currents, gas entrapment, and slag inclusion, which can affect the surface quality of the die casting

Select high-quality mold materials:

Mold materials should have good heat resistance, wear resistance, and toughness to extend the service life of the mold and reduce the problem of decreased part accuracy caused by mold wear

Regular maintenance and upkeep of molds:

Regularly clean, polish, and repair molds to ensure their surface smoothness and dimensional accuracy

3、 Die casting process control

Accurate control of die-casting parameters:

Temperature control: The melting temperature and die-casting temperature should be strictly controlled within a reasonable range. Excessive temperature can lead to poor fluidity of the alloy liquid, which can easily result in defects such as shrinkage and porosity; If the temperature is too low, it will affect the filling performance of the alloy liquid, resulting in defects such as cold shut and under casting

Pressure control: The die-casting pressure should be precisely adjusted to ensure that the alloy liquid can fully fill the mold cavity, while avoiding excessive pressure that may cause mold damage or product deformation

Speed control: The injection speed should be moderate, as being too fast or too slow can affect the dimensional accuracy and surface quality of the die casting

Optimize the pouring system:

Design a reasonable pouring system to ensure that the alloy liquid enters the mold cavity smoothly and evenly, avoiding the generation of eddy currents and gas entrapment, and reducing defects such as porosity and slag inclusion

Control the cooling and solidification process:

Adopting a reasonable cooling system and cooling time to ensure uniform solidification of die castings, prevent defects such as shrinkage and porosity, and improve the strength and surface quality of castings

4、 Post processing technology

Remove burrs and burrs:

After demolding the die-casting parts, the burrs and burrs on the surface should be removed in a timely manner to avoid affecting the dimensional accuracy and appearance quality of the product

Surface treatment:

According to the usage requirements and aesthetics of the product, surface treatment methods such as electroplating, spraying, and spray painting can be selected to improve the corrosion resistance and aesthetics of the product

Before surface treatment, die-casting parts should be cleaned, polished, and polished to ensure surface smoothness and flatness

5、 Quality inspection

Adopting advanced detection equipment:

Use high-precision measuring tools such as coordinate measuring instruments, projectors, etc. to accurately measure the dimensions of die-casting parts, ensuring that dimensional deviations meet tolerance requirements

Conduct a comprehensive visual inspection:

Carefully inspect the surface of the die-casting parts for defects such as cracks, sand holes, bubbles, and cold shuts to ensure that the surface quality meets the requirements

Adopting non-destructive testing technology:

For some products that require high internal quality, non-destructive testing techniques such as X-ray inspection and ultrasonic testing can be used to ensure that there are no defects inside the product

6、 Continuous improvement and optimization

Regularly evaluate the production process:

Regularly evaluate and analyze the production process, identify key factors affecting product dimensional accuracy and surface quality, and develop improvement measures

Introducing advanced technology and processes:

Pay attention to industry trends and new technological developments, timely introduce advanced die-casting technology and processes, and improve production efficiency and product quality

Strengthen employee training:

Provide necessary training for production personnel to enhance their professional skills and quality control awareness, ensuring that they are proficient in operating procedures and quality standards

In summary, by strictly controlling the quality of raw materials, designing molds reasonably, accurately controlling die-casting process parameters, strengthening post-treatment processes and quality inspections, and continuously improving and optimizing production processes, the dimensional accuracy and surface quality of zinc alloy die-casting products can be effectively ensured