For aluminum alloy die castings, in order to improve its quality, it is necessary to increase the yield of production. Raw materials are fundamental, so it should be the top priority of the quality control. When selecting raw materials, we must strictly control the quality, using sampling inspection to determine the chemical composition of the main elements of the alloy, and carrying out corresponding acceptance.
Generally speaking, if the iron content is too much in the alloy structure, it will greatly affect the quality of the casting. The reason is that it will cause cracks in the casting and greatly reduce the plasticity. However, if the content of the iron is too low, it will cause problems such as mucous film and difficult demoulding of the casting. Therefore, the iron content must be controlled reasonably. In pressure die casting process, the content of copper should also be attached great importance. Appropriately increasing the content of copper can improve the fluidity of the alloy and increase the strength and hardness of the casting. If the copper content is too high, the plasticity of the casting will also decrease and the possibility of appearing hot cracking will be higher. It is not conducive to subsequent processing, so the copper content should also be controlled. In die casting, the appropriate content of manganese can make the iron in the alloy into a fine crystal shape, reducing the adverse effect of iron on the alloy. It is necessary to appropriately control the manganese content. Because if the manganese content exceeds the standard, it may cause segregation problems. Therefore, keeping it within a reasonable range can improve the plasticity of the casting. Zinc can improve alloy fluidity and machinability. The content should not be too high, otherwise it will cause cracks in the casting. Silicon can improve the shape of aluminum alloy at high temperatures, and controlling the content of silicon can further improve the performance of the casting. If not, it will lead to poor processing effects of the casting. In addition, raw materials such as material ends and edgings also need to be highly valued. In particular, the materials that need to be returned to the furnace must be strictly controlled and cleaned so that they can be reused and will not contaminate new materials. The ratio of recycled materials to new materials cannot exceed one third, otherwise the quality of die casting will be affected.
