086-757-25500218
Die-casting die belongs to a kind of casting liquid die forging and special die-casting die forging machine to complete the process. For die-casting, the three elements of die-casting material, die-casting machine and die are indispensable. In order to improve production efficiency, brand quality and high economic benefits, and to extend the life of die casting die, the use and maintenance of die casting die is very important.
Correct use and maintenance of die casting die:
1. Minimize the quench and heat of the die, and make continuous production as far as possible. High-speed injection is strictly prohibited under the condition of cold die.
In the process of die-casting, the die-casting die is always in the state of reciprocating fatigue of thermal expansion and cold contraction. The temperature of the die cavity is basically changing from 160 degrees to 350 degrees. The die is rapidly cold and hot, and the hot expansion and cold contraction are not stopped, which results in the fatigue damage of the die. When the cold die is produced, the temperature of the die starts to rise from low temperature, the temperature difference increases, the expansion and contraction of the die increases, and the fatigue of the die increases correspondingly, which will accelerate the damage of the die and shorten the life of the die. Therefore, in die casting production, continuous production should be made as far as possible to minimize the quench and heat of the die, thereby prolonging the life of the die.
In addition, in the cold mold state, the mold does not reach the normal production temperature, the gap between the parts of the mold is relatively large, in this case, high-speed injection and pressurization are strictly prohibited. Otherwise, the clearance parts of the die, including slider and ejector hole, easily penetrate into the aluminium sheet, thus damaging the die and affecting the life of the die.
2. Reduce the injection speed as much as possible, reduce the specific pressure as much as possible, and reduce the impact of the die.
In die casting production, the injection speed not only affects the filling speed and the injection gate speed of die casting, but also increases the impact peak value when the injection speed is high. Therefore, the injection speed is high, the injection gate speed is fast, the erosion of the die will intensify, the peak impact will increase, the impact force of the die will increase, and the life of the die will be greatly reduced. Therefore, when we adjust the die casting process, in order to ensure product quality, it is very important to reduce the injection speed as far as possible for improving die life and economic benefits of die casting enterprises. At present, the advanced die-casting machine is equipped with pressure shooting brake device, which is very helpful to reduce the impact peak value, reduce the impact force of the die and improve the life of the die.
The injection specific pressure is also an important parameter in the die casting process. The injection specific pressure is generally 400-900 kg/cm2 according to the quality requirements and characteristics of the castings. Over 900 kg/cm2 has little effect on the internal quality of castings. The high injection pressure not only increases the expanding force of the die, but also makes the expanding force exceed the clamping force of the machine tool, resulting in aluminum channeling. At the same time, if the expanding force of the die is large, the die will be damaged or the life of the die will be shortened. Therefore, in die casting production, we should pay more attention to the specific pressure of injection besides the injection speed, because the specific pressure of injection is not as easy to observe as the injection speed, which is often neglected. In fact, injection specific pressure is an important parameter in die casting process, which not only affects the quality of castings, but also has a great impact on the life of dies. In particular, this should attract the attention of die-casting enterprises.
3. The cover and aluminium skin should be cleaned up in time to prevent the extrusion of the die.
In the use of moulds, there are always caps and aluminium sheets on the moulds for various reasons, which must be cleaned up in time, otherwise the moulds will be extruded and damaged by continued production. Especially in the slider part, if the slideway enters the aluminium sheet and so on, the slider will collapse and extrude because of the very large clamping force of the die casting machine. Therefore, in the face of such problems, it is necessary to clean the mould in time and find out the reasons for timely repair of the mould. Otherwise, the service life of the die will be seriously affected when the die is damaged.
4. Reduce the pouring temperature of molten aluminium as far as possible and improve the service life of the die.
The pouring temperature of molten aluminium during die casting production not only affects the quality of castings, but also affects the service life of die casting dies. In general, the pouring temperature of molten aluminium is 630 - 720 degrees. For different parts, we should choose the pouring temperature as low as possible, which not only saves energy, but also prolongs the service life of the die casting die. Because the higher the temperature of molten aluminium, the greater the erosion of the die, the larger the range of the temperature field of the die, the bigger the thermal expansion and contraction, the bigger the fatigue of the die, the easier the damage. Therefore, proper reduction of pouring temperature of molten aluminium is beneficial to prolong the service life of die casting die.
5. Strengthen the maintenance of the die, regularly maintain, regularly temper the die cavity to remove stress.
Die-casting die has been continuously produced under high pressure, high speed and high temperature, and the use conditions are poor. In the process of using, the die will cause damage or hidden trouble. Therefore, it is very important to strengthen the maintenance of the die, regularly maintain the die, replace the damaged parts, replace the vulnerable parts, clean the slideway, ejector hole, etc. It is also very important to ensure the reliability of the die casting production, as well as to extend the service life of the die.
At the same time, because the die-casting die is constantly impacted in use, continuously hot expansion and cold contraction, new internal stress will be generated. If not eliminated in time, the die surface will easily crack or crack. Therefore, regular stress relief and tempering of the die cavity is also an important means to prolong the life of the die. Generally speaking, the first tempering should be carried out after 3000-5000 moulds are put into use. In the future, according to the use of the situation, generally every production of about 10,000 moulds, it is necessary to stress relief temper the die cavity, which can greatly prolong the service life of the die.
This article is organized by Foshan Jinju Qiwei Die Casting Co., Ltd., a die-casting manufacturer. The service hotline of aluminium alloy die-casting is 0757-25500218! Website：http://www.jjqw.com/。