Quality Control of Raw Materials for Die-casting Aluminum Alloy Parts

For aluminum alloy die castings, in order to improve its quality, it is necessary to improve the production pass rate. Raw materials are fundamental and should therefore be a top priority for quality control. When selecting raw materials, it is necessary to strictly control the quality, adopt the method of sampling inspection, measure the chemical composition of the main elements of the alloy, and carry out corresponding acceptance.

Generally speaking, if the content of iron in the alloy structure is too large, it will greatly affect the quality of the casting, because it will cause cracks in the casting and greatly reduce the plasticity. However, if the iron content is too small, it will cause problems such as sticking of the casting and difficulty in demolding, so the iron content must be reasonably controlled. In aluminum alloy die castings, we should also attach great importance to the content of copper. Properly increasing the content of copper can improve the fluidity of the alloy and improve the strength and hardness of the casting. If the copper content is too high, the plasticity of the casting will also be reduced, the possibility of hot cracks is high, and it is not conducive to subsequent processing, so the copper content should also be controlled. In die castings, the proper amount of manganese can make the iron in the alloy into a fine crystal shape and reduce the adverse effect of iron on the alloy. It is necessary to properly control the manganese content, because if the manganese content exceeds the standard, it may cause segregation problems, so keeping it within a reasonable range can improve the plasticity of the casting. Zinc can improve the fluidity and machinability of the alloy, and the content should not be too high, otherwise it will cause cracks in the casting. Silicon can improve the molding of aluminum alloys at high temperature, and controlling the content of silicon can further improve the performance of castings, otherwise it will lead to poor processing results of castings. In addition, raw materials such as material heads and edge skins also need to be highly valued. In particular, the materials that need to be returned to the furnace should be strictly controlled and cleaned so that they can be used for the second time and will not contaminate new materials. The ratio of returned material to new material should not exceed one third, otherwise it will affect the quality of die castings.