The Latest Technology Various new technologies for surf […]
The Latest Technology
Various new technologies for surface treatment of die-casting molds are emerging, but in general they can be divided into the following three categories:
(1) Improvement techniques of conventional heat treatment processes;
(2) Surface modification technology, including surface thermal diffusion treatment, surface phase transformation strengthening, and electric spark strengthening technology;
(3) Coating technology, including electroless plating.
Die casting molds are a large class in the mold. With the rapid development of China's automobile and motorcycle industry, the die-casting industry has ushered in a new era of development. At the same time, it also puts forward higher requirements on the comprehensive mechanical properties and life of die-casting molds. Luo Baihui, secretary-general of the International Model Association, believes that it is still difficult to meet the ever-increasing use performance requirements by relying only on new mold materials. Various surface treatment techniques must be applied to the surface treatment of die-casting molds to achieve high efficiency in die-casting molds. High precision and long life requirements. In various molds, the working conditions of the die-casting mold are more demanding. Pressure casting is to make the molten metal fill the mold cavity under high pressure and high speed and die-casting. It is repeatedly in contact with the hot metal during the working process. Therefore, the die-casting mold is required to have high heat fatigue resistance, thermal conductivity wear resistance and corrosion resistance. , impact toughness, red hardness, good release properties, etc. Therefore, the surface treatment technology for the die-casting mold is highly demanded.
Improved technology of traditional heat treatment process
The traditional heat treatment process for die-casting molds is quenching-tempering, and surface treatment techniques have been developed in the future. Because of the variety of materials that can be used as die-casting molds, the same surface treatment techniques and process applications can have different effects on different materials. Schkov proposes a substrate pretreatment technology for mold substrate and surface treatment technology. Based on the traditional process, a suitable processing technology is proposed for different mold materials to improve mold performance and improve mold life. Another development direction of heat treatment technology improvement is to combine the traditional heat treatment process with advanced surface treatment technology to improve the service life of the die casting mold. For example, carbonitriding by chemical heat treatment, combined with conventional quenching and tempering processes, NQN (ie carbonitriding-quenching-carbonitriding composite strengthening, not only obtains high surface hardness, but also effectively hardens the layer). The depth is increased, the hardness gradient distribution of the layer is reasonable, the tempering stability and the corrosion resistance are improved, so that the surface quality and performance of the die-casting mold are greatly improved while obtaining good core performance.