Die casting process of aluminum alloy die casting
Aluminum alloy die casting production process is simple, easy to operate, high efficiency, easy to achieve automatic production, aluminum alloy die casting machine metal liquid directly from the pressure chamber into the hollow, metal consumption is small, temperature fluctuation range is small, die casting process is stable. Die casting metal liquid from the sealed channel into the hollow, impurities are not easy to bring people, die casting quality is good.
The aluminum alloy die-casting production process is simple, easy to operate, high efficiency, and easy to realize automatic production. The metal liquid of the aluminum alloy die-casting machine directly enters the hollow from the pressure chamber, with small metal consumption, small temperature fluctuation range, and stable die-casting process. The metal liquid of the die-casting machine enters the hollow from the closed channel, so impurities are not easy to carry, and the die-casting quality is good. At the same time, due to the low die-casting ratio, it is immersed in the pressure chamber, stamping, nozzle and other metal liquids for a long time It is easy to erode, affecting the service life and increasing the iron content in the alloy. For low melting point alloy die-casting (such as magnesium alloy) that is easy to burn, tungsten can be sealed to protect the alloy liquid through inert gas to prevent oxidation or combustion. At present, hot chamber casting machines are mostly used for low melting point alloy castings such as zinc alloy, but also for small aluminum and magnesium alloy castings p>
Structural process elements of aluminum alloy die castings:
The basic structural process elements of die-casting include wall thickness, rib, casting hole, casting fillet, peeling slope, thread, gear, slot gap, rivet head, bump, grid, text, symbol, array and die-casting. The reasonable wall thickness of die casting depends on many factors, such as the specific structure of the casting, alloy properties, and die casting technology. It is generally proved that the mechanical properties of die castings decrease with the increase of wall thickness. The tensile strength and density of thin wall castings are higher than those of thick wall castings, and the wear resistance of thin wall castings is also good. As the wall thickness of die casting increases, the porosity and porosity defects shown in internal B) will also increase. Therefore, in order to fully ensure the strength and stiffness of die casting, the reasonable wall thickness must be designed as thin wall and uniform wall thickness. Otherwise, the internal structure of the die casting is uneven, which increases the difficulty of the implementation of the die casting process. Under normal process conditions, the wall thickness of the die casting shall not exceed 4.5mm, and the ratio between the larger wall thickness and the smaller wall thickness shall not be greater than 3 * 1. For the thick wall of the casting, in order to avoid defects such as looseness, the thin wall thickness must be reduced and added p>
Aluminum alloy die casting for automobile parts:
Dimensional accuracy of die-casting: dimensional accuracy is one of the key features of die-casting structure process that affect die-casting design and die-casting process. The dimensional accuracy that can be achieved by die casting is relatively high, and its stability is also very good. Basically depends on the precision of die casting. The dimensional deviation of die casting is caused by many reasons, including the deviation of the chemical composition of the alloy itself, the high and low temperature of the working environment, the fluctuation of the shrinkage rate of the alloy metal, the stability of the moving state of the die opening and core pulling and release mechanisms, the error caused by the wear amount during the use of the die, the deviation of the die casting process parameters, the error caused by the precision and stiffness of the die casting machinery, the number of die maintenance, the service life, etc. Mutual influence. For example, the alloy shrinkage depends on the die casting shape, die casting process parameters, alloy type and die casting wall thickness. Therefore, the relationship between these conditions and shrinkage must be studied to determine the shrinkage that conforms to the actual situation. For the selection of linear dimension tolerance grade of die castings, the tolerance zone must have a nominal distribution. That is, half of the tolerance is positive and the other half is negative. For asymmetric settings, the size of the unmachined, the hole is positive, and the axis is negative. The dimension to be machined, the hole is negative, and the axis is positive p>