Aluminum-zinc alloy die-casting die is classified as a process that is completed on special liquid aluminum-zinc alloy die-casting die forging machine. For aluminum-zinc alloy die-casting, aluminum-zinc alloy die-casting information, aluminum-zinc alloy die-casting machine and mold are all indispensable. In order to improve output power, brand quality and high economic benefits in process of production, and to allow aluminum-zinc alloy die-casting mold to have an extended life number, use and protection of aluminum-zinc alloy die-casting mold is very important.

 

Correct application and protection of aluminum-zinc alloy die-casting mold:

During aluminum-zinc alloy die casting process, aluminum-zinc alloy die-casting mold has always been in a state of reciprocating fatigue due to thermal expansion and contraction. Temperature of mold cavity part has always changed back and forth between 160 degrees and 350 degrees. Mold is quenched and heated rapidly, heat is continuously expanded and contracted, then mold is fatigued and damaged. When production starts under cold mold conditions, mold temperature starts to rise from low temperature, temperature difference increases, mold inflation increases, mold fatigue increases accordingly, which will accelerate mold damage and shorten mold life.  Therefore, in the production of aluminum-zinc alloy die casting, continuous production should be as far as possible, rapid cooling and heating of mold should be reduced as much as possible, and then life of mold should be extended.
In addition, under condition of cold mold, mold does not reach temperature at the time of normal production, gaps in various parts of mold will be relatively large. In this case, high-speed injection and pressurization are prohibited. Otherwise, various gaps of mold, including sliders, ejector holes, etc., penetrate into aluminum skin, then damage mold and affecting life of mold.

When aluminum-zinc alloy die-casting is produced, level of injection speed not only affects filling speed and injection gate speed of aluminum-zinc alloy die-casting, but injection speed is high, and impact peak will increase. Therefore, injection speed is high, injection gate speed is fast, erosion of mold will increase, impact peak will increase, impact force received by mold will increase, and mold life will be greatly reduced. Therefore, when adjusting aluminum-zinc alloy die casting process, we should reduce injection speed as much as possible while ensuring quality of product. It is very important to improve mold life and improve economic benefits of aluminum-zinc alloy die-casting enterprises. At present, advanced aluminum-zinc alloy die-casting machines are equipped with injection brake equipment, which is very beneficial to reduce peak value of impact and reduce impact force received by mold to improve life of mold.
In aluminum-zinc alloy die casting process, same injection ratio is an important parameter. Injection ratio is generally 400-900 kg/cm2 according to quality requirements and characteristics of casting. Beyond 900 kg/cm2, there is generally little effect on internal quality of casting. And injection ratio is too high, which will not only increase mold expansion force accepted, but also make mold expansion force beyond clamping force of machine tool, forming aluminum channeling. If mold has a large expansion force, same will damage mold or shorten life of mold. Therefore, in production of aluminum-zinc alloy die-casting, we should pay more attention to specific injection pressure in addition to injection speed, because injection specific pressure is not as simple as investigation of injection speed, and it is often neglected. In fact, injection specific pressure is an important parameter in aluminum-zinc alloy die casting process. It not only affects quality of casting, but also has a huge impact on life of mold. This point should particularly attract attention of aluminum-zinc alloy die-casting enterprises.

In application of molds, seals and aluminum skins often appear in molds for various reasons. At this time, it is necessary to arrange in time, otherwise continuous production will crush mold. Especially slider part, if slideway enters aluminum skin, because aluminum-zinc alloy die-casting machine has a very large clamping force, it will collapse and crush slider. Therefore, when encountering such problems, it is necessary to arrange molds in time and find out reasons to repair molds in time. Otherwise, maintenance of mold will be seriously affected if mold is damaged.

Pouring temperature of aluminum liquid during production of aluminum-zinc alloy die-casting not only affects quality of casting, but also affects service life of aluminum-zinc alloy die-casting mold. In general, when aluminum-zinc alloy die-casting, aluminum liquid pouring temperature is between 630 degrees and 720 degrees. Regarding different parts, we should choose a lower temperature when selecting pouring temperature, which not only saves power, but also extends service life of aluminum-zinc alloy die-casting mold. Because the higher temperature of molten aluminum, the greater erosion of mold, the larger scale of mold temperature field change, the greater thermal expansion and contraction, the greater fatigue of mold, the more easily damage. Therefore, properly lowering pouring temperature of aluminum liquid is conducive to extending service life of aluminum-zinc alloy die-casting mold.

Aluminum-zinc alloy die-casting mold have been continuously produced under high pressure, high speed and high temperature, operating conditions are relatively harsh. Mold may be damaged or dangerous during use. Therefore, it is very important to strengthen protection of mold, regularly maintain mold, replace damaged parts, replace wearing parts, arrange slideways, ejector holes, etc., to ensure reliability of mold when aluminum-zinc alloy die-casting is produced, extend service life of mold.

 

In addition, because aluminum-zinc alloy die-casting mold is continuously impacted, expanded and contracted during use, new internal stress will occur. If it is not eliminated in time, mold is easy to crack or crack on its surface. Therefore, regular destressing and tempering of mold cavity to eliminate stress is also an important method to extend life of mold. In general, after mold is put into use, first tempering should be performed after 3000-5000 molds. According to application situation in the future, generally about every 10,000 molds produced, mold cavity needs to be destressed and tempered, which can greatly extend service life of mold.