The occurrence of internal cracks in aluminum alloy die castings is also a headache, so if we want to solve this problem, we must first understand the causes of cracks in aluminum alloy die castings in detail!
Through the analysis, we can know that the main reasons for the cracks of die-casting aluminum parts are: (1) The content of iron in the alloy is too high or the content of silicon is too low; (2) The content of harmful impurities in the alloy is too high, which reduces the plasticity of the alloy; (3) ) Aluminum-silicon alloy: Aluminum-silicon-copper alloy contains too much zinc or copper, and aluminum-magnesium alloy contains too much magnesium. (4) The mold, especially the core temperature is too low; (5) The wall thickness of the casting has drastic changes (6) The mold staying time is too long; (7) The force is uneven during ejection.
Through the analysis of the above reasons, we have obtained the following improvement measures to avoid the occurrence of cracks in aluminum alloy die castings:
1. Correctly control the alloy composition. In some cases, pure aluminum ingots can be added to the alloy to reduce the magnesium content in the alloy or aluminum-silicon intermediate alloys can be added to the aluminum alloy to increase the silicon content;
2. In order to alleviate the mold overheating, add a cooling water circuit in the mold, reduce the mold temperature in the area through water cooling, and maintain the thermal balance of the mold; change the aluminum alloy die casting structure, increase the fillet, change the angle of the mold, and reduce the output Difficulty of mold, aluminum alloy die-casting manufacturer, reduce wall thickness difference;
3. Change or increase the ejection position to make the ejection force uniform and eliminate local excessive force.