The die-casting mold fittings belong to a process method for casting a liquid die forging and a dedicated die-casting die forging machine. For die-casting, die-casting materials, a die-casting machine and a die are indispensable. In order to increase the production efficiency, brand quality, and high economic efficiency during the production process, and to make the die-casting mold fittings use for prolonged life, the use and maintenance of the die-casting mold fittings is very important.
Correct use and maintenance methods of die-casting mould parts:
1. Minimize the hot and cold heat of the mold and try to produce it continuously. In the cold mold state, it is forbidden to shoot at high speed.
During the die casting process, the die-casting mold fittings have been in a hot and cold shrinkage reciprocating fatigue state. The temperature of the mold cavity has basically been changed from 160 to 350 degrees. The mold is quenched and hot, and the heat is kept hot and cold, resulting in molds. Fatigue damage. When starting production in the cold mold state, the temperature of the mold starts to rise from a low temperature, the temperature difference increases, the expansion and contraction of the mold increase, and the mold fatigue increases accordingly, which accelerates the mold damage and shortens the life of the mold. Therefore, in the production of die-casting, continuous production should be carried out as far as possible to minimize the quenching and heating of the die, thereby prolonging the life of the die.
In addition, in the cold mold state, the mold does not reach the temperature during normal production, and the gap between the mold parts is relatively large. In this case, it is prohibited to open the high-speed injection and pressurization. Otherwise, parts of the mold gap, including the slider, the top hole, etc., can easily break 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, reduce the impact of the mold.
In die-casting production, the level of injection speed not only affects the filling speed of die-casting, the velocity of the injected in-gate, but also has a high shot rate and an increased impact peak. Therefore, the shot speed is high, and the injection gate speed is high, the mold flushing will be intensified, the impact peak will be increased, the impact force of the mold will be increased, and the mold life will be greatly reduced. Therefore, when adjusting the die-casting process, we will try to reduce the shot rate while ensuring the quality of the product. It is very important to improve the life of the die and improve the economic efficiency of die-casting enterprises. At present, the advanced die casting machine is equipped with a shot-blasting brake device, which is very beneficial for reducing the impact peak, reducing the impact force of the die, and improving the die life.
The injection specific pressure in the die casting process is also an important parameter, and the injection specific pressure is generally 400-900 kg/cm2 depending on the quality requirements and characteristics of the casting. More than 900 kg/cm2 has little effect on the internal quality of the casting. The injection pressure is too high, not only to increase the mold to withstand the increase in force, and even will increase the force exceeds the clamping force of the machine, resulting in aluminum. At the same time, if the mold is subjected to 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 the shot speed, we should pay more attention to the shot specific pressure. Since the shot-to-specific pressure is not as easy to observe as the shot speed, it is often overlooked. In fact, the injection pressure ratio is an important parameter in the die casting process. It not only affects the quality of the casting, but also has a huge impact on the life of the die. This should in particular cause concern for die-casting companies.
3, mold parts appear in the use of drapery, aluminum skin to clean up in a timely manner to prevent squeezing die.
In the use of the mold, the mold will often appear capped and aluminum skin due to various reasons. At this time, it must be cleaned up in time. Otherwise, if the production is continued, the mold will be crushed. In particular, in the case of a slide block, if the slideway enters into an aluminum skin or the like, the mold clamping force of the die-casting machine is very large, and the slide block is collapsed and collapsed. Therefore, in the face of such problems, it is necessary to clean the mold in time and find out the reasons for timely repair of the mold. Otherwise, if the mold is damaged and repaired, it will seriously affect the life of the mold.
4. Minimize the casting temperature of aluminum liquid and increase the service life of the mold.
The casting temperature of aluminum liquid during die casting production not only affects the quality of the casting, but also affects the service life of the die casting mold parts. In general die casting, the casting temperature of aluminum liquid is between 630 and 720. For different parts, we should choose the lower one when choosing the casting temperature. This will not only save energy, but also extend the service life of die casting mould parts. Because the higher the temperature of aluminum liquid, the greater the erosion of the mold, the greater the range of the mold temperature field changes, the greater the thermal expansion and contraction, the greater the fatigue of the mold, the more easily damaged. Therefore, appropriately reducing the casting temperature of the aluminum liquid is beneficial to extending the service life of the die casting mold parts.
5, to strengthen the maintenance of the mold, regular maintenance, regular mold cavity tempered to stress treatment.
Die-casting mold fittings have been continuously produced under high pressure, high speed and high temperature, and the conditions for use have been relatively poor. During use, the mold will be damaged or have hidden troubles. Therefore, it is very important to strengthen the maintenance of molds, regular maintenance of the molds, replacement of damaged parts, replacement of wearing parts, cleaning of slides, jack holes, etc., to ensure the reliability of the mold in die-casting production. Extend the life of the mold.
At the same time, because the die-casting mold parts are constantly subjected to impact during use, continuous thermal expansion and contraction will generate new internal stress. If they are not eliminated in time, the mold will easily crack or crack. Therefore, the stress relief and tempering of the mold cavity on a regular basis to eliminate stress is also an important means to extend the life of the mold. Under normal circumstances, after the mold is put into use, it should be tempered for the first time after 3000-5000 molds. In the future, according to the use conditions, in general, about 10,000 molds are to be produced, and the mold cavity needs to be destressed and tempered, which can greatly extend the service life of the mold.