Abstract: Die casting production is a crucial process for manufacturing high-precision and high-quality components. However, the quality of die castings is susceptible to various external factors, including raw materials, equipment, process parameters, etc. This paper delves into the impact of external factors on die casting quality and proposes corresponding countermeasures. Practical experience has demonstrated that external factors significantly influence die casting quality. By selecting reliable raw material suppliers, regularly maintaining equipment, and optimizing process parameters, these external factors can be effectively addressed, thereby enhancing die casting quality. This study offers valuable insights for die casting enterprises to improve their product quality.
1. Introduction
With the rapid advancement of modern industry, die casting technology has been widely applied across multiple fields. As an efficient and precise production method, die casting production has become an indispensable part of the manufacturing industry. However, during the die casting process, external factors can impart different degrees of influence on the quality of die castings, which is an issue that cannot be ignored by relevant personnel. These external factors, which are uncontrollable, may originate from the environment, raw materials, equipment, operators, etc., and changes in these factors can potentially affect die casting quality. This paper focuses on studying the impact of external factors on die casting quality and presents corresponding countermeasures. Only through continuous practical research can we better address the impact of external factors on die casting quality and propel the 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 numerous external factors. Below are three common external factors in die casting production.
2.1 Temperature
In the die casting process, molten metal must maintain fluidity and plasticity within a specific temperature range. Excessively high or low temperatures can hinder the metal liquid from fully filling the mold or result in incomplete solidification. Therefore, in die casting production, it is imperative to ensure that the temperature of the metal liquid is controlled within an appropriate range to guarantee product quality and shape.
2.2 Humidity
Changes in humidity can alter the adhesion force on the mold surface, further affecting the fluidity and filling capacity of the metal liquid. In high-humidity environments, the mold surface may accumulate moisture, causing the metal liquid to fail to fill uniformly, resulting in pores or defects. Hence, in die casting production, it is necessary to closely monitor changes in environmental humidity and adopt corresponding measures to adjust mold temperature and humidity to ensure product quality.
2.3 Gas Environment
The gas environment in die casting production is also a significant external factor. During the die casting process, the gas within the mold needs to be effectively vented to avoid the formation of bubbles or pores. Additionally, harmful gases such as metal vapor or exhaust gases may be generated during the die casting process, posing potential threats to workers’ health and the environment. Therefore, in die casting production, corresponding ventilation and exhaust systems should be implemented to purify the gas environment and ensure workplace safety.
Table 1: Common External Factors in Die Casting Production
| External Factor | Description | Impact on Die Casting Quality |
|---|---|---|
| Temperature | Metal liquid needs to maintain fluidity and plasticity within a specific range. | Excessively high or low temperatures can hinder proper filling or result in incomplete solidification. |
| Humidity | Changes in humidity can alter mold surface adhesion. | High humidity can cause uneven filling, leading to pores or defects. |
| Gas Environment | Gases within the mold need to be vented to avoid bubbles or pores. | Harmful gases pose threats to worker health and the environment. |
3. Impact of External Factors on Die Casting Quality
3.1 Temperature and Humidity
External factors exert a crucial influence on die casting quality, with temperature and humidity being two key external factors. High temperatures enhance the fluidity of molten metal, which may lead to various issues. Molten metal readily absorbs gases from the air at high temperatures. When the temperature is excessively high, gases within the molten metal cannot fully escape, forming pores. These pores significantly affect the density and strength of die castings, reducing their quality. Additionally, increased fluidity at high temperatures can result in incomplete solidification of the molten metal during the mold-filling process, leading to shrinkage porosity within die castings, which同样 affects their quality. High humidity also adversely affects die casting quality. High humidity can cause pores between the molten metal and the mold contact surface. In high-humidity environments, moisture on the contact surface between the molten metal and the mold evaporates, forming gases that cannot fully escape, leading to pores during the die casting process. Pores reduce the density and strength of die castings, negatively impacting their quality. Furthermore, high humidity can cause surface defects on die castings. During the cooling process of molten metal in high-humidity environments, moisture co-occurs with metal solidification, forming surface defects that not only affect the appearance of die castings but may also impair their functionality.
3.2 Mold Design and Manufacturing
In the die casting process, the mold bears high temperatures and pressures. If the mold structure is improperly designed, it can hinder the full flow of metal liquid during the filling process, resulting in inclusions or defects within die castings. For instance, improper flow channel design in the mold can cause metal liquid flow obstructions, leading to inclusion formation. When the cooling system of the mold is improperly designed, it can result in uneven metal solidification, thereby producing defects. Therefore, during mold design, the fluidity and solidification of metal liquid should be considered to reasonably design the mold structure and avoid internal inclusions. Improper mold material selection can affect the surface finish and precision of die castings. In die casting production, the mold directly contacts the metal liquid. If the selected mold material lacks sufficient hardness, it can easily wear, affecting the surface finish of die castings. Additionally, if the thermal conductivity of the mold material is poor, it can lead to uneven metal solidification, impacting the dimensional accuracy of die castings.
Table 2: Impact of External Factors on Die Casting Quality
| External Factor | Impact on Die Casting Quality |
|---|---|
| Temperature | High temperatures can cause pores, shrinkage porosity, and reduce die casting quality. |
| Humidity | High humidity can cause pores and surface defects, negatively impacting die casting quality. |
| Mold Design and Manufacturing | Improper design can lead to inclusions or defects; inadequate material selection can affect surface finish and precision. |
3.3 Raw Material Quality
Raw material quality is the most critical factor among the external factors influencing die casting quality in die casting production.Unstable alloy composition and excessive impurity content directly affect the strength of die castings. The composition stability of alloys directly determines the mechanical properties of die castings. If the alloy composition is unstable, i.e., the content of various metallic elements cannot be maintained within the design requirements, the strength and durability of die castings cannot be guaranteed. For example, a specific 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 die castings and may even fail to meet design requirements. Various impurities, such as oxides, sulfides, and metal debris, inevitably exist during raw material production. If the impurity content is too high, they will cause problems during the die casting process. On the one hand, high levels of oxides and sulfides can reduce alloy fluidity, leading to pores in die castings, which reduces their strength and sealing performance. On the other hand, inclusions such as metal debris can cause uneven die casting structure, thereby lowering its overall performance.
4. Countermeasures
4.1 Control of Production Environment
In die casting production, the impact of external factors on the production environment cannot be overlooked. To ensure the stability of the production process and product quality, corresponding measures should be taken to address these external factors. Maintaining constant temperature and humidity is crucial. The fluidity of molten metal in die casting production is affected by temperature. Large temperature fluctuations will directly impact the flow properties of molten metal, thereby affecting product molding quality. Therefore, a constant temperature should be maintained within the die casting workshop. By installing air-conditioning systems or enhancing insulation measures, temperature fluctuations can be avoided. Humidity is also a key factor that needs to be controlled. High humidity can cause water films on the mold and die casting surfaces, affecting product surface quality. To reduce the negative impact of humidity on the mold and die casting surfaces, ventilation equipment should be strengthened. Exhaust fans or ventilation ducts can be installed to promptly remove moisture within the workshop and maintain air circulation. Additionally, consider installing dehumidification equipment within the workshop to reduce humidity to an appropriate range.
4.2 Optimization of Mold Design and Manufacturing
In die casting production, the impact of external factors on product quality cannot be ignored. To effectively address these factors, optimizing mold design and manufacturing is an important approach. Mold design directly relates to product quality and production efficiency. Staff should utilize advanced mold design software to accurately analyze mold stress distribution and deformation, thereby optimizing the mold structure to make it more reasonable and balanced, avoiding product defects and mold damage caused by improper mold structure.