Die casting mold is one of the three major elements in die casting production. A mold with a correct and reasonable structure is a prerequisite for the smooth progress of die casting production, and plays an important role in ensuring the quality of die castings (lower machine qualification rate).
Due to the characteristics of die-casting technology, the correct selection of various process parameters is the determining factor for obtaining high-quality castings, and molds are the prerequisite for correctly selecting and adjusting various process parameters. Mold design is essentially a comprehensive reflection of various factors that may occur in die-casting production. If the mold design is reasonable, there will be fewer problems encountered in actual production, and the qualification rate of castings will be high. On the contrary, if the mold design is unreasonable, the wrapping force of the dynamic fixed mold is basically the same during the design of the die-casting parts, and the pouring system is mostly in the fixed mold and produced on the Guannan die-casting machine where the punch cannot be fed after injection, it cannot be produced normally, and the castings are stuck to the fixed mold all the time.
Although the surface finish of the fixed mold cavity is very smooth, there is still a phenomenon of sticking to the fixed mold due to the deep cavity. Therefore, in mold design, it is necessary to comprehensively analyze the structure of the casting, familiarize oneself with the operation process of the die-casting machine, have the possibility of adjusting the die-casting machine and process parameters, master the filling characteristics in different situations, and consider the methods of mold processing, drilling and fixing forms before designing a mold that is practical and meets production requirements.
Due to the extremely short filling time of the metal liquid, the specific pressure and flow rate of the metal liquid are very high, which makes the working conditions of the die-casting mold extremely harsh. In addition, the impact of alternating stress caused by rapid cooling and heating has a significant impact on the service life of the mold.
The service life of a mold usually refers to the natural damage that occurs through careful design and manufacturing, combined with good maintenance and upkeep, under normal use conditions, and before it can be repaired and scrapped, the modulus of the die cast (including the number of waste products in die casting production).
In actual production, there are three main forms of mold failure: ① thermal fatigue cracking damage failure; ② Fragmentation failure; ③ Corrosion failure.