Since the advent of alloy die casting at the beginning of the last century, it has been adopted by many industrial sectors because of its advantages of fast casting speed, low temperature, low energy consumption and long mold life. And its varieties gradually increased, the dosage continued to expand, thus forming a series of alloy products. In addition, these alloys can be processed by hot pressing chamber die casting machine, which is much faster than the high aluminum-zinc alloy and aluminum alloy cast in the cold press chamber. In addition, these alloys can be easily machined into economical thin-walled die castings, and the surface of the castings can be easily machined, painted and plated. Because of this, the alloy die casting market has been prosperous for a long time.

Quality problems and analysis of common alloy die casting on the market: Although the quality standards of zinc die casting alloys have tended to be unified and the composition requirements are generally the same, the reflection of die casting alloys produced by different manufacturers in the market is different; Some alloys are of good quality and satisfied with users; Some alloys are not well applied, which usually reflect the following problems: (1) too much zinc slag, and the die castings are fragile; (2) When the alloy is in a liquid state, the fluidity is poor and the water for die casting is insufficient; (3) Poor surface condition of die-casting parts leads to black spots, bubbles and other defects during baking and electroplating. The reasons for these problems are complex, in general, in addition to the raw materials of the zinc die-casting alloy itself, the influence of the manufacturer's process is not excluded.

Countermeasures to improve the quality of alloy die casting: 1. Strictly control the chemical composition of raw materials. The iron content in aluminum ingots has a great influence on the quality of die-casting zinc alloys. According to the actual iron content analysis of similar die-casting alloy products abroad, the iron content of the raw material aluminum ingot should actually be 0. 05% or less. Therefore, in order to meet the high-quality requirements of some domestic consumers for alloy die-casting, our alloy factory can consider importing aluminum ingots with low iron content from abroad as raw materials for alloy production. 2. Use melting tools correctly. When conditions permit, non-ferrous metal materials or 314, 3I6 stainless steel should be used as operating tools and crucibles in the zinc die-casting alloy melting process to prevent the iron in the tools or crucibles from entering the alloy; When using iron tools and crucibles in factories without conditions, a protective layer should be pre-coated on the surface of the zinc alloy melt. 3. Strengthen the management of returning materials. In order to ensure the quality of zinc die-casting alloys and die-casting parts, in addition to selecting high-purity raw materials. In the process of alloy production and die casting manufacturing, the composition of recycled materials should be strictly controlled, and the harmful impurities in them should be inspected and analyzed, and their content should be determined before being used together. 4. Choose advanced smelting equipment. There are many kinds of smelting equipment for the production of die-casting zinc alloy in China, and from the perspective of ensuring product quality, the power-frequency coreless furnace is undoubtedly the ideal melting equipment for the production of die-cast zinc alloy.

In summary, the quality of alloy die casting can be improved from the following aspects: (1) Strictly control the chemical composition of raw materials in the smelting furnace. (2) Select advanced smelting equipment and suitable slagging agent. (3) Adjust the temperature and atmosphere of the melting process; Strictly control some of the elements added to the alloy. (4) Use non-ferrous metal operating tools as much as possible in the alloy melting process. Of course, iron tools coated with a protective layer can also be used.