As one of the important components of die-casting production tools, die-casting toolings have always affected the quality of die-casting parts and the production cost of die-casting parts. However, a little carelessness in the production process of die-casting mold factories may cause the failure of die-casting molds. Today SHENZHEN KANGENSHENG TECHNOLOGY CO.,LTD. will introduce to you the three main points which might cause mold failure: mold thermal fatigue cracking, chipping, and corrosion.
① Thermal fatigue, crack, and failure of the mold
During die-casting production, the mold is repeatedly subjected to chilling and heating, and the molding surface and its interior are deformed, which are mutually involved, resulting in repeated cycles of thermal stress, resulting in damage to the structure and loss of toughness, and causing the appearance of micro-cracks and continuing growing. Once the crack expands, molten metal will squeeze in, and plus repeated mechanical stresses those will accelerate the crack propagation.
② Fragmentation failure
Under the action of the injection force, the mold will initiate cracks at the weakest part, especially when the scribe marks or electrical machining marks on the molding surface of the mold are not polished, or the clear corners of the molding appears micro cracks. When there is a brittle phase or coarse grains at the grain boundary, it is easy to break. However, the crack propagation is very fast during brittle fracture, which is a very dangerous factor for the chipping failure of the mold.
③ Dissolution failure
As mentioned above, the commonly used die-casting alloys include zinc alloy, aluminum alloy, magnesium alloy and copper alloy, as well as pure aluminum die-casting. Zn, Al, Mg are relatively active metal elements, and they have a good affinity with mold materials. Especially Al is easy to have fretting wear. When the mold hardness is high, the corrosion resistance is better. And if there are soft spots on the molding surface, it will reduce the corrosion resistance. However, in actual production, dissolution is only a part of the mold. For example, the parts (core, cavity) that are directly washed by the gate are prone to corrosion, and the aluminum alloy is prone to sticking to the mold at soft hardness.
For this reason, the die casting mold factory must pay great attention to the above three points in the die-casting production process. In the production process, it is necessary to select materials carefully, formulate a good production plan, and pay high attention to mold maintenance to ensure the die-casting life in order to help customers customize more high-quality die-casting parts.