1. Introduction
With the rapid development of modern industry, die-casting technology has been widely applied in various fields. As an efficient and precise production method, die-casting production has become an indispensable part of the manufacturing industry. However, in the process of die-casting production, external factors can have varying degrees of impact on the quality of die-casting parts, which is a problem that relevant personnel cannot ignore. The so-called external factors refer to those uncontrollable factors that may come from the environment, raw materials, equipment, operators, and other aspects. Changes in these factors may have a certain impact on the quality of die-casting parts. Based on this, this article will focus on studying the impact of external factors on the quality of die-casting parts and propose corresponding countermeasures. Only through continuous practice and research can we better address the impact of external factors on the quality of die-casting parts and promote further development of die-casting technology.
2. Common external factors in die-casting production
Die casting production is a common metal processing method, and its production process is influenced by many external factors. Here are three common external factors in die-casting production. Firstly, temperature. During the die-casting process, the metal liquid needs to maintain fluidity and plasticity within a certain temperature range. If the temperature is too high or too low, it can cause the metal liquid to not fully fill the mold or result in incomplete solidification. Therefore, in die-casting production, it is necessary to ensure that the temperature of the metal liquid is controlled within an appropriate range to ensure the quality and shape of the product; Secondly, humidity. The change in humidity can cause a change in the adhesion force on the surface of the mold, which in turn affects the fluidity and filling properties of the metal liquid. In high humidity environments, moisture may accumulate on the surface of the mold, leading to uneven filling of the metal liquid and the formation of pores or defects. Therefore, in die-casting production, it is necessary to closely monitor changes in environmental humidity and take corresponding measures to adjust mold temperature and humidity to ensure product quality; Finally, the gas environment in die-casting production is also an important external factor. During the die-casting process, the gas inside the mold needs to be effectively expelled to avoid the formation of bubbles or pores. At the same time, harmful gases such as metal vapor or exhaust gas may be generated during the die-casting process. These harmful gases pose a potential threat to the health of workers and the environment. Therefore, in die-casting production, it is necessary to adopt corresponding ventilation and exhaust systems to purify the gas environment and ensure the safety of the workplace.
3. The influence of external factors on the quality of die-casting parts
3.1 Temperature and humidity
In die-casting production, external factors have a significant impact on the quality of die-casting parts, among which temperature and humidity are two key external factors. High temperature can increase the fluidity of molten metal, which may lead to various problems. Molten metal is prone to absorbing gases from the air at high temperatures, and when the temperature is too high, the gases inside the molten metal cannot completely escape, forming pores. These pores can seriously affect the density and strength of the die-casting parts, reducing their quality. At the same time, the fluidity of molten metal increases at high temperatures, which can lead to incomplete solidification of liquid metal during the filling process, resulting in shrinkage and looseness inside the die casting, which can also affect its quality. Excessive humidity can also have a negative impact on the quality of die-casting parts, as it can cause porosity at the contact surface between the molten metal and the mold. In high humidity environments, the moisture on the contact surface between molten metal and mold will evaporate, forming gases that cannot completely escape. These gases will form pores during the die-casting process, which will reduce the density and strength of the castings and have a negative impact on their quality.
In addition, high humidity can easily lead to surface defects on die-casting parts. During the cooling process of molten metal in high humidity environments, moisture will occur simultaneously with metal solidification, forming surface defects that not only affect the appearance of die-casting parts, but may also have a negative impact on their functionality.
Management and operation are also key factors. Poor management and operation can lead to a decrease in the quality of die-casting parts. Therefore, in the production process, it is necessary to strictly follow the operating procedures to ensure the quality control of each process. At the same time, it is necessary to strengthen the training and skill improvement of employees, and enhance their understanding and operational level of die-casting technology. By studying these external factors, corresponding strategies can be developed to improve the quality of die-casting parts.
3.2 Mold Design and Manufacturing
In the process of die-casting, the mold is a tool that can withstand high temperature and high pressure. If the mold structure design is not reasonable, it is easy to cause the metal liquid to not flow sufficiently during the filling process, resulting in the formation of inclusions or defects inside the die-casting part. For example, if the flow channel design of the mold is improper, it can lead to poor flow of molten metal and the generation of inclusions; When the cooling system design of the mold is unreasonable, it can lead to uneven solidification of the metal, resulting in defects. Therefore, in mold design, the fluidity and solidification of the metal liquid should be considered, and the mold structure should be designed reasonably to avoid the formation of inclusions inside. Improper selection of mold materials can affect the surface smoothness and accuracy of die-casting parts.
In die casting production, the mold is a tool that directly contacts the molten metal. If the hardness of the selected mold material is not sufficient, it is easy to cause surface wear of the mold, which in turn affects the surface smoothness of the die casting. Meanwhile, if the thermal conductivity of the mold material is poor, it can lead to uneven solidification of the metal liquid, thereby affecting the dimensional accuracy of the die casting. Therefore, in mold manufacturing, it is necessary to choose suitable mold materials to ensure that they have sufficient hardness, wear resistance, and thermal conductivity to ensure the surface smoothness of the die-casting parts (see Figure 1).
3.3 Raw Material Quality
In the process of die-casting production, external factors have a significant impact on the quality of die-casting parts, and the quality of raw materials is the most critical factor. Unstable alloy composition and high impurity content will directly affect the strength of die-casting parts.
Alloy is a mixture composed of multiple metal elements, and the stability of its composition directly determines the mechanical properties of die castings. If the alloy composition is unstable, that is, the content of various metal elements cannot be maintained within the design requirements, then the strength and durability of die castings cannot be guaranteed. For example, a certain alloy raw material should contain a certain proportion of copper and zinc elements to meet specific strength requirements. However, if the content of these two elements cannot be stably controlled, it will affect the strength of the die casting and may even fail to meet the design requirements. In the process of raw material production, various impurities such as oxides, sulfides, and metal debris are inevitably present. If the content of these impurities is too high, they will cause problems in the die-casting process. On the one hand, high levels of oxides and sulfides can reduce the fluidity of the alloy, leading to the formation of pores in the die casting, which can lower the strength and sealing performance of the die casting; On the other hand, inclusions such as metal shavings can cause uneven microstructure in die castings, thereby reducing their overall performance.
4. Research on coping strategies
4.1 Control the production environment
In die-casting production, the impact of external factors on the production environment cannot be ignored. In order to ensure the stability of the production process and product quality, corresponding measures need to be taken to address these external factors. Maintaining a constant temperature and humidity is very important. In the process of die-casting production, the flowability of molten metal is affected by temperature. If the temperature fluctuates greatly, it will directly affect the flowability of molten metal, thereby affecting the forming quality of the product.
Therefore, a constant temperature should be maintained in the die-casting workshop to avoid severe temperature fluctuations by installing air conditioning systems or strengthening insulation measures. Humidity is also a key factor that needs to be controlled. High humidity can cause water films on the surfaces of molds and die castings, affecting the surface quality of products. In order to reduce the negative impact of humidity on the surface of molds and die castings, it is necessary to strengthen ventilation equipment. You can install exhaust fans or ventilation ducts to promptly remove moisture from the workshop and maintain air circulation. At the same time, it is also possible to consider adding dehumidification equipment in the workshop to reduce the humidity to a suitable range.
4.2 Optimizing Mold Design and Manufacturing
The impact of external factors on product quality cannot be ignored in the die-casting production process. Optimizing mold design and manufacturing is an important approach to effectively address these factors. Mold design is directly related to product quality and production efficiency. Staff should use advanced mold design software to accurately analyze the stress distribution and deformation of the mold, optimize the mold structure, make it more reasonable and balanced, and avoid product defects and mold damage caused by unreasonable mold structure.
At the same time, it is necessary to increase the importance of selecting mold materials, choose high-quality steel as much as possible, effectively improve the hardness and wear resistance of the mold, extend the service life of the mold, and better maintain the dimensional stability of the product, strengthening the surface quality of the product.
In addition to the above two aspects, there are other strategies worth considering, such as optimizing the cooling system of the mold based on the requirements of the die-casting process, in order to improve the cooling speed and uniformity of the product and reduce product defects. And by reasonably setting the spray holes and escape holes of the mold, thermal fatigue and porosity problems can be effectively avoided (see Figure 2).
4.3 Strictly control the quality of raw materials
Firstly, regularly inspect and evaluate the alloy composition and impurity content provided by the supplier. The alloy composition plays a decisive role in the performance and quality of die-casting products, while the presence of impurities may lead to a decrease in product strength or other quality issues. Therefore, establish stable cooperative relationships with suppliers and regularly test the raw materials they provide to ensure the stability of raw material quality; Secondly, introduce advanced material analysis techniques. By using advanced material analysis techniques such as spectroscopic analysis and electron microscopy, the composition and structure of raw materials are comprehensively analyzed to ensure their stability and avoid potential quality issues; Once again, establish a comprehensive supply chain management system. By closely cooperating with suppliers and establishing long-term stable cooperative relationships, we can better control the quality of raw materials.
At the same time, by jointly developing strict cooperation standards and quality control requirements with suppliers, we ensure a stable supply of raw materials. Finally, strengthen internal quality management. In the process of die-casting production, it is necessary to strengthen the control of raw material quality to ensure the inspection pass rate and usage accuracy of raw materials (see Figure 3). At the same time, establish a sound quality management system, conduct comprehensive quality monitoring, timely discover and correct quality problems, to ensure the stability of product quality.
5. Conclusion
In die-casting production, external factors have a significant impact on the quality of die-casting parts. By studying these external factors, corresponding strategies can be developed to improve the quality of die-casting parts. Therefore, in die-casting production, attention should be paid to the control of factors such as temperature, pressure, mold quality, and management and operation to ensure that the quality of die-casting parts meets the requirements.
Author of this article: Liang Zhenjin
