Aluminum die-casting mold belongs to a process of casting liquid die forging and special die-casting forging machine. For die-casting, die-casting materials, die-casting machines and molds are indispensable. In order to improve production efficiency, brand quality and high economic efficiency in the production process, and to make the die-casting mold use extended life, the use and maintenance of the die-casting mold is very important.
Correct use and maintenance of die-casting molds:
1. Minimize the rapid cooling of the mold and try to produce it continuously. In the cold mold state, high-speed injection is strictly prohibited.
During the die-casting process, the die-casting mold has been in the reciprocating fatigue state of heat expansion and contraction. The temperature of the mold cavity part has been changing back and forth at 160-350 degrees. The mold is quenching and hot, and the heat is constantly rising and contracting, resulting in mold fatigue. damage. When the production starts in the cold mold state, the mold temperature starts to rise from the low temperature, the temperature difference increases, the mold expands and shrinks, and the mold fatigue increases accordingly, which will accelerate the mold damage and shorten the mold life. Therefore, in the die casting production should be as continuous as possible, to minimize the rapid cooling of the mold, thereby extending the life of the mold.
In addition, in the cold mold state, the mold does not reach the temperature at the normal production, and the gap between the mold parts is relatively large. In this case, it is strictly prohibited to turn on the high-speed injection and pressurization. Otherwise, the gap parts of the mold, including the slider, the ejector hole, etc., are easily broken into the aluminum skin, thereby damaging the mold and affecting the life of the mold.
2, try to reduce the injection speed, try to reduce the specific pressure and reduce the impact of the mold.
In the die casting production, the injection speed not only affects the filling speed of the die casting, but also the injection gate speed, and the injection speed is high, and the impact peak value is also increased. Therefore, the injection speed is high, the injection gate speed is fast, the scouring of the mold is intensified, the impact peak is increased, the impact force of the mold is increased, and the life of the mold is greatly reduced. Therefore, when adjusting the die-casting process, we can reduce the injection speed as much as possible while ensuring the quality of the product. It is very important to improve the life of the die and improve the economic benefits of the die-casting enterprise. At present, the advanced die casting machine is equipped with a compression brake device, which is very beneficial for reducing the impact peak, reducing the impact force of the mold and improving the life of the mold.
The injection specific pressure in the die casting process is also an important parameter. The injection specific pressure is generally 400-900 kg/cm 2 according to the quality requirements and characteristics of the casting. More than 900 kg / cm 2, generally does not have a significant effect on the internal quality of the casting. However, the pressure ratio of the injection is too high, which not only increases the force of the mold, but even increases the force of the mold beyond the clamping force of the machine tool, resulting in bismuth aluminum. At the same time, if the mold is subjected to a large force, it will also damage the mold or shorten the life of the mold. Therefore, in the production of die-casting, in addition to focusing on the injection speed, we should pay more attention to the injection specific pressure. Since the injection specific pressure is not as easy to observe as the injection speed, it is often ignored. In fact, the injection specific pressure is an important parameter in the die-casting process, which not only affects the quality of the casting, but also has a huge impact on the life of the mold. This should especially be of concern to die casting companies.
3, the mold appears in the use of the seal, aluminum skin should be cleaned in time to prevent the mold from being squeezed.
In the use of the mold, the mold will often appear to be covered, aluminum skin for various reasons, then it must be cleaned up in time, otherwise continue to produce will mold the mold. Especially in the slider part, if the slideway enters the aluminum skin, etc., the clamping force of the die casting machine is very large, and the slider will be collapsed and squeezed. Therefore, in the face of such problems, it is necessary to clean the mold in time and find out the reason for timely repair of the mold. Otherwise, if the mold is damaged before repairing, it will seriously affect the life of the mold.
4. Try to reduce the pouring temperature of aluminum liquid and improve the service life of the mold.
The casting temperature of the aluminum liquid during die casting production not only affects the quality of the casting but also the service life of the die casting mold. In general die casting, the pouring temperature of aluminum liquid is between 630 ° and 720 °. For different parts, we should choose lower when choosing the pouring temperature, which not only saves energy, but also prolongs the service life of die casting mold. Because the higher the temperature of the aluminum liquid, the greater the erosion of the mold, the larger the range of the temperature field change of the mold, the larger the thermal expansion and contraction, the greater the fatigue of the mold, and the easier it is to damage. Therefore, properly reducing the pouring temperature of the aluminum liquid is beneficial to prolong the service life of the die casting mold.