With the development of modern machining technology, the "high-speed machining center ff" that can complete the rough and finish machining of turning, cutting, milling, and cutting can perform all-round sequential processing of parts. The plus I center can be equipped with 20 tools Automatic tool change device. The spindle speed is 15 000-40 000 r/min, which is 10-20 times that of general machine tools. This high-speed cutting can reduce the processing time by 75%. High-speed cutting tools should have high hardness and wear resistance. Performance such as damage, corrosion resistance, low friction coefficient and high resistance to high temperature.
At present, 40% of the knives in industrial production in developed countries use coated knives. New coatings are being applied to different processing fields. Due to the high cutting speed and high production efficiency of coated knives. About 80% of them Machining is done by coated knives. 80% of them are TiN coated knives. Ii originally produced 93.14 million pieces of machine clamp blades in 1995. Coated knives accounted for 70%.
Diamond film has the advantages of low friction coefficient, high hardness, wear resistance and good thermal conductivity. It can be used as a high-performance coating for knife. Diamond film cutting tools have been widely used in the processing of non-metallic and non-ferrous materials, such as car engine cylinder blocks, cylinder heads, gearboxes, and various piston parts for cutting high-silicon aluminum alloys.
Due to the difference in thermal expansion coefficient between the diamond film and the cemented carbide substrate, the thermal stress is induced. It will cause the bond strength between the film and the substrate to weaken. This is the current problem of diamond film tools. At present, there are various methods for The matrix is pretreated to increase the bonding strength. Of course, the pretreatment of the screen will have an impact on the nucleation and growth of diamond. This discussion is the pretreatment of cemented carbide. That is to eliminate the influence of Co. Because it is hard The Co in the high-quality alloy will diffuse to the surface of the swallow body during CVD. The presence of Co on the surface of the substrate will inhibit the nucleation and growth of diamond. In order to eliminate the influence of Co, one method is to remove Co and remove Co. The methods are: Xin De Co method; Co compound generation; Co replacement method. Another method is to apply an intermediate transition layer, that is, a transition layer is deposited between the substrate and the diamond film to block the diffusion of Co. This method is considered It is a method that can better eliminate the influence of Co and improve the bonding strength of the film to the substrate. Because it can eliminate the influence of Co without weakening the strength of the matrix. Some transition layers can also play the role of thermal expansion coefficient gradient transition. The transition layers used before Ii are: Ti transition layer. WC transition layer'Ti-Ni -Nb. DLC. TiC, TiN, Co or special. German Jang et al. used a diamond/Sic composite gradient film method to improve the bonding strength of the diamond film.
Chinese 
ENGLISH
