Aluminum alloy castings need to be preheated before use. The aluminum mold needs to be preheated to a certain temperature before use. Preheating can extend the service life of the mold. Preheating is commonly used with electrical appliances or induction heating. The preheating temperature should be controlled between 250 ℃ and 300 ℃, and the insulation time should be around 0.5 hours. It is prohibited to use molten metal (aluminum water) to directly preheat the mold, because the cold mold is directly in contact with the hot liquid metal, which will inevitably be subjected to thermal shock, resulting in thermal erosion and accelerating cracking and peeling caused by thermal fatigue.
During the production process of aluminum die castings, the surface machining quality of their mold cavity can be effectively improved. The surface of the mold cavity should not have obvious deep machining tool marks to prevent cracking caused by stress concentration during mold operation. When precision machining of the mold, effective polishing and grinding should be carried out on the surface of the mold cavity to control the roughness value of the mold cavity surface to 0.8 μ Below m.
Cooling of aluminum die castings during use. In continuous production, the temperature of the aluminum mold often rises. If the temperature is too high, it not only causes the liquid metal to form a mold, but also slows down the cooling of the casting, resulting in coarse grains and a decrease in the quality of the aluminum castings. Therefore, when the temperature of the aluminum mold is too high, cooling measures should be taken. Generally, compressed air or water should be used for cooling. The aluminum mold is designed with a cooling system to ensure the thermal balance of the mold. It is strictly prohibited to use cold water to cool the mold to avoid rapid cooling and shrinkage of the mold, which can cause cracks and premature failure of the mold and shorten its lifespan. Of course, spraying paint appropriately during the use of the mold can not only prevent mold sticking but also have a certain cooling effect, which is beneficial for improving the mold's lifespan.
After use, the maintenance and management of aluminum die castings should be carried out. After the use of the aluminum mold, the mold cavity should be cleaned in a timely manner to effectively remove residual aluminum. After cooling, rust prevention treatment should be carried out and stored flat for centralized management, for reuse. Aluminum casting molds are important fixtures in motor manufacturing, accounting for a significant proportion of motor manufacturing costs. Practice has proven that the use of new mold materials, reasonable forging, and correct heat treatment are key steps in improving the service life of aluminum casting molds; At the same time, by mastering various related links such as mold design, manufacturing, use, and maintenance management, the service life of aluminum casting molds can be effectively extended, and the manufacturing cost of motors can be correspondingly reduced.
When aluminum die castings are manufactured with electric discharge perforated electrodes in wind blade slots, the sharp edges around the electrodes are rounded to d1.5mm-2mm to ensure that there is no sharp transition in the mold cavity after electrical machining, and to avoid cracking and failure at the sharp corners of the mold. The correct and standardized use of aluminum molds, accompanied by careful maintenance and management, will prolong their service life.