Die at work in addition to require sufficiently high strength and toughness, and its surface properties are essential to performance and service life of the mould. These surface properties: abrasion resistance, corrosion resistance, coefficient of friction, fatigue, etc. These performance improvements, relying solely on improvement and enhancement of substrate material is very limited, but not economic, and by surface treatment technology, do have a multiplier effect, which is the reason why prompt development of surface treatment technology.
Mold surface treatment technology, is through the surface treatment technology of coating, surface modification, or complex, changing the mold surface morphology, chemical composition, organizational structure and stress state in order to obtain the required surface properties of systems engineering. On the way from surface treatment, can be divided into: Chemistry, physics, physical chemistry, and mechanical methods. Is designed to improve the performance of new surface treatment technology to flourish, but mainly with more applications in mould manufacture nitriding, carburizing and hardening film deposition.
Gas nitriding and nitriding process ion nitriding, liquid nitriding and other means, in each nitriding method, there are several types of nitriding technology can be adapted to different requirements of different types of steel. Due to nitriding technology can form the surface of superior performance, and nitriding process and mold steel quenching process of well coordinated, simultaneous nitriding temperature is low, without intense cooling after nitriding, minimal deformation of the mold, mold surface strengthening is the use of nitriding technology earlier, is also the most widely used.
Die carburizing purposes, primarily to improve overall strength and toughness of the precision mould, mould work surfaces with high strength and wear resistance, technical ideas were introduced, with lower material, instead of a higher level of material by carburizing and quenching, resulting in reduced manufacturing costs. Hardened film deposition technology is more mature is CVD, PVD. In order to increase the bond strength of coating surface, now developing a variety of enhanced CVD, PVD technology.
Hardened film deposition technology as early as tools (cutting tools, cutting tools, measuring tools, and so on) applied with excellent results, a variety of tools have been coated with hardened film as a standard process. Die since the beginning of the last century 80 's-coated hardened membrane technology. Current technical conditions, the hardened film deposition (mainly equipment) costs more, still only applied on the moulds that require precision, long life, if we adopt the way of building heat treatment center, the coating hardened film costs can be significantly reduced, more die if you take this technology, overall improvement of mold manufacturing technology in China.