As an efficient and precise metal forming process, die casting is widely used in automotive, electronics, communication and other fields. However, in the process of die casting production, environmental factors such as humidity and temperature have a significant impact on casting quality. Improper environmental conditions may lead to defects such as pores, shrinkage holes and cracks in castings, thereby reducing product performance and service life. Therefore, effective control of humidity and temperature in the production environment is of great significance for improving casting quality and reducing defects. Let’s discuss the key technologies and methods of environmental control of die casting machine.

1、The influence of humidity on die casting production and control methods

【1】Influence of humidity on die casting production

Humidity is an important parameter in the die casting production environment, and its impact on casting quality is mainly reflected in the following aspects:

(1) Mold surface state: in a high humidity environment, water vapor is easy to condense into water droplets on the mold surface, resulting in a decrease in mold surface lubricity, increasing the difficulty of casting release, and even causing casting strains or sticking molds.

(2) Gas solubility: the water in the air will be dissolved in the liquid metal, when the metal solidifies, these water will be precipitated in the form of gas, forming pores, affecting the density and mechanical properties of the casting.

(3) Cooling speed: The specific heat capacity of the air with higher humidity is larger, which will slow down the cooling speed of the casting, resulting in coarse grains and decreased mechanical properties.

【2】Humidity control method

In view of the influence of humidity on die casting production, the following measures can be taken to effectively control:

(1) The use of dehumidification equipment: an industrial dehumidifier is installed in the die-casting workshop to reduce the moisture content in the air by physical or chemical means and maintain the appropriate relative humidity.

(2) Strengthen ventilation: regularly open Windows for ventilation or use exhaust fans and other equipment to promote air circulation and reduce the humidity in the workshop. Also, avoid keeping doors and Windows closed for long periods in wet weather.

(3) Control the water source: reduce the water source in the workshop, such as avoiding the use of a large amount of water to clean the ground and equipment, and repair the leakage point in time. In addition, hygroscopic materials or desiccant can be used to absorb moisture from the air.

(4) Staff training: strengthen employees’ awareness of the importance of humidity control and improve their operational skills and responsibility. Ensure that employees follow the operating procedures to avoid humidity problems caused by human factors.

2、 The influence of temperature on die casting production and control methods

【1】Effect of temperature on die casting production

Temperature is another key parameter in the die casting production process, and its influence on the quality of the casting can not be ignored. Specifically, the impact of temperature on die casting production is mainly reflected in the following aspects:

(1) Mold preheating: too low mold temperature will lead to poor metal filling, cold insulation and other defects; The mold temperature is too high, may cause the sticking mold, thimble marks too deep and other problems. Therefore, a reasonable preheating temperature of the mold is very important to ensure the quality of the casting.

(2) Alloy melting: the melting temperature of the alloy directly affects its fluidity and fillability. Too low temperature will make the alloy flow poor, difficult to fill the cavity; Too high a temperature may lead to serious suction of the alloy, increasing the risk of porosity in the casting.

(3) Cooling system: the temperature of the cooling system of the die casting machine will also affect the solidification process and mechanical properties of the casting. Too fast cooling speed may lead to the increase of internal stress and crack; If the cooling rate is too slow, the casting grain may be coarse and the mechanical properties will decrease.

【2】Temperature control method

In order to effectively control the temperature parameters in the die casting process, the following measures can be taken:

(1) Mold temperature control: Use mold temperature control equipment to heat and hold the mold to ensure that the mold temperature is stable within a reasonable range. At the same time, the mold temperature curve is adjusted according to the requirements of different alloys and castings to meet the production needs.

(2) Alloy melting monitoring: Use the melting furnace temperature control system to monitor the melting temperature of the alloy in real time, and maintain a stable melting temperature by automatically adjusting the heating power and time. In addition, advanced temperature measuring instruments can be used to accurately measure the temperature of the alloy liquid to ensure that it meets the process requirements.

(3) Cooling system optimization: rationally design the layout of the cooling system and the direction of the pipeline to ensure that the cooling water can flow evenly through all parts of the mold. At the same time, the flow rate and temperature of cooling water are adjusted according to the actual production to achieve the best cooling effect. In addition, regular cleaning of impurities and scale in the cooling system is also one of the important measures to ensure the cooling effect.

3、 Comprehensive environmental control strategy

In the process of die casting, the control of humidity and temperature is often interrelated. Therefore, it is important to develop a comprehensive environmental control strategy to improve the quality of castings. Here are some suggestions:

Establish an environmental monitoring system: Install temperature and humidity sensors and data acquisition systems in the die-casting workshop to monitor changes in environmental parameters in real time. Through the data analysis software to process and analyze the collected data, timely find the abnormal situation and take measures to adjust.

Formulate environmental control standards: Formulate corresponding environmental control standards according to the requirements of different alloys, castings and production processes. These standards should include the range of key parameters such as humidity and temperature and the allowable fluctuation range. At the same time, the selection, installation and maintenance requirements of environmental control equipment should also be clearly defined.

Regular maintenance and maintenance: Regular maintenance and maintenance of key equipment such as dehumidification equipment, temperature control equipment and cooling system. Check whether the running status of the device is normal and whether there are hidden faults. Clean the dust and debris inside the equipment; Replace aging or damaged parts, etc. Through regular maintenance and maintenance can extend the service life of the equipment and ensure its normal operation effect.

Training and education: to enhance employees’ awareness and understanding of the importance of environmental control; Improve their operational skills and responsibility; It is very important to cultivate their good habits of following operating procedures and safety regulations. Only through training and education can employees truly realize the important role of environmental control in die casting production and put it into practice to achieve this goal.

4、Conclusion

Environmental control of die casting machine is one of the key links to improve casting quality and reduce defects. By scientifically and reasonably controlling the humidity and temperature parameters in the production environment, the internal quality and appearance quality of castings can be effectively improved. It has significant advantages and functions in reducing production costs and improving production efficiency. Therefore, we should pay attention to the environmental control work of die casting machine and take effective measures to implement and manage to ensure the improvement and development of product quality and enterprise competitiveness.