At present, aluminum die-casting mold is a widely used mold type. It has the characteristics of long production cycle, large investment and high precision, so the production cost of this mold is relatively high. However, due to a series of internal and external factors such as materials and machining, the mold may fail prematurely and be scrapped. Let's take you to analyze what is the reason that affects the service life of aluminum die-casting molds.
The choice of mold material has a great influence on the service life of the mold. Studies have shown that improper material selection and heat treatment will cause early failure of the mold, and aluminum die-casting molds are hot work molds, and their manufacturing conditions are relatively poor. The personnel should control the temperature of the molten aluminum between 650-720 °C and preheat it. If it is not preheated, the temperature of the surface of the mold cavity will increase from room temperature to the liquid temperature, and the surface of the cavity will be subjected to a large amount of pressure. tensile stress. In the process of opening the top part of the mold, the surface of the cavity will also bear great compressive stress, and after thousands of times of die casting, defects such as cracks will appear on the surface of the mold.
Aluminum die-casting molds have relatively high quality requirements for materials. At the current stage, the material of aluminum die-casting mold is steel, which is a widely used hot work die steel. This kind of steel has good cold and heat fatigue resistance, fracture toughness and thermal stability. Before manufacturing aluminum die-casting molds, manufacturers need to analyze and inspect the materials to prevent early scrapping of molds and waste of processing costs.
When designing an aluminum die-casting mold, it should be avoided that the fillet is too sharp and the cross-section change is too large, because the stress concentration caused by the sharp fillet is 10 times the average stress of the mold, which may easily lead to early failure of the mold. In addition, the designer should also pay attention to the deformation and cracking of the mold in the subsequent heat treatment. In order to prevent the formation of the above defects, the cross-sectional size of the mold should be uniform and symmetrical, and the blind holes should be opened as through holes as much as possible, and process holes can be opened if necessary. In the design of the mold structure, the appearance of geometric gaps, including knife marks, included angles, grooves, holes and sudden changes in cross-section, should also be avoided.
Improper machining can easily lead to stress concentration and insufficient finish, which can lead to defects in aluminum die-casting molds and affect service life. Therefore, in the process of mold processing, the surface of the cooling control system should be smooth without any traces of machining.
The above are the three major factors that affect the service life of aluminum die-casting molds. With the advancement of science and technology, manufacturers need to learn advanced machining techniques, pay attention to production precautions, and try their best to improve the machining accuracy of aluminum die-casting molds, so as to prolong the use of molds life.
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