Preheating Requirements and Continuous Production of Aluminum Die Casting

I. The preheating requirements of aluminum die casting

Aluminum die casting need to be preheated to the specified temperature before use. Preheating can prolong the service life of the mold. Preheating mostly adopts electrical appliances or induction heating, and the preheating temperature is controlled at 250℃ to 300℃. The mold can be used after 0.5h heat preservation. It is forbidden to use molten metal (aluminum water) to preheat the mold directly, because the cold aluminium die casting mold is in direct contact with the hot liquid metal, which is bound to be subjected to thermal impact, thus producing thermal erosion and accelerating the cracking and peeling caused by thermal fatigue.

Aluminium die casting parts can effectively improve the surface machining quality of the mold cavity during the production process. There should be no obvious deep machining marks on the surface of the mold cavity to prevent cracking of the mold due to stress concentration during operation. In the finishing process of mold, the surface of aluminium die casting mold cavity should be effectively polished and ground, so that the roughness value of the cavity surface can be controlled below 0.8 μm.

II. The continuous production of aluminum die casting

Aluminum die castings need cooling in production. In the continuous production, the temperature of the aluminum die casting mold often increases, in addition to making liquid metals form extruding shape, too high temperature also makes the casting cool slowly, resulting in coarse grain and quality decline of aluminium die casting. Therefore, when the temperature of aluminum die casting mold is too high, cooling measures should be taken, and compressed air or water is usually used for cooling. Aluminum die casting mold is generally designed with a cooling system to ensure the heat balance of the mold. It is forbidden to chill the mold with cold water, so as to avoid cracks caused by rapid cooling and shrinkage of the mold, which will lead to premature failure of the mold and shorten the life of the mold. Of course, in the use of the mold, the appropriate spray coating can not only prevent the mold sticking but also play a certain cooling role, which is beneficial to improve the life of the mold.

III. The maintenance and management of aluminum die casting mold

After the use of aluminium die casting mold, the mold cavity should be cleaned in time to a certain extent to effectively remove the residual aluminum. Rust prevention treatment should be carried out after cooling, and then put it into storage, place it flatly and make centralized management for reuse. Aluminum die casting mould is an important tool in motor manufacturing, which occupies a large proportion in motor manufacturing cost. Practice has proved that using new materials, reasonable forging and correct heat treatment are the key links to improve the service life of aluminum die castings. At the same time, the service life of aluminum die casting mold can be effectively extended with good grasp of mold design, manufacturing, use and maintenance management and other related links, and the motor manufacturing cost can be reduced accordingly.