Current development trend of cutting tool coating technology

- Jan 22, 2018-

Modern manufacturing development cannot leave the cutting tool, cutting tool has become one of the key factors enhance the level of manufacturing technology, increasingly improve machining requirements, high speed, high precision, high efficiency, intelligent and environmental protection become machining the pursuit of the goal; The energy level of the processed materials is continuously improved; High strength and ultra-high strength materials, high toughness, hard cutting and other materials are not poor; Under the new situation, the special requirements for cutting processing, such as hard machining, micro-lubrication and non-lubricated dry cutting, which are more than 50HRC, are constantly emerging. In a word, the personalized characteristics of cutting processing are visible.

In the face of these changes, if you want the tool design and the overall performance of the manufacturing process or cutting tool materials up to adapt to these requirements, the technical difficulty is very big, especially for cutting tool material, not only highly economy on the resource utilization, and required materials meet the cutting performance of increasingly complex, is often hard to do.

And throughout the cutting tool failure of a large number of examples can be seen, the failure of most often with physics, chemistry, mechanics, etc on the surface of the material condition of surface performance, that is, modern machining is higher and higher requirements on the properties of cutting tool material surface, it will effectively promote the surface engineering technology such as vapor deposition technology research. The experimental results show that, by the method of material surface modification technology to give the surface of the cutting tool cutting performance, one of the cutting tool material surface modification technology of chemical vapor deposition (CVD) and physical vapor deposition (PVD) technology, has been applied to modern cutting tools has achieved ideal effect.

Currently, as a cutting tool in the mainstream of carbide cutting tools, coated carbide cutting tools has accounted for more than 80%, the PVD technology, because of its low processing temperature, and will not affect the tool base material performance, variety and processing plan, make its application has become increasingly widespread. Coating technology has become one of the three core technologies that make up modern cutting tools.

In recent years, the development of modern cutting tool coating technology has been greatly promoted by the continuous improvement of machining requirements and the energy level of the processed materials, as well as the reduction of cutting processing to environmental pollution. Membrane material multiple alloying, coating process in the diversification of TiAIN, TiAICN, CrSiN multivariate composite coating and multi-layer coating tools won the high wear resistance, low friction, good thermal stability and antioxidant power good comprehensive performance, greatly improve the performance of modern cutting tools; The microstructure of nano-component and nano-film coating has resulted in a new solution for the cutting of refractory materials. Diamond coating and diamond-like coating (DLC) have achieved good results in processing graphite parts and fiber reinforced non-metallic materials and non-ferrous alloy materials. In order to adapt to the development of coating process, the process equipment of coating has realized integration, modularization and intellectualization, making coating technology more and more individualized.

The diversity of membrane materials.

At present, the development trend of modern cutting tool coating technology is the diversification of film materials. Membrane materials multiple alloying is still the main research direction, it is using the binary transition metal nitride, carbide can often each other mutually soluble properties, adding alloying elements in Ti - N membrane forming composite nitride coating.

For example, at present, the most applied TiAIN ternary coating in the carbide coating tool can obtain different film layer performance by adjusting the composition ratio of AI elements. As in Ti - N join carbon element, by carbon atoms in solid solution and precipitation, can form Ti (C, N) ternary coating, compared with the single coating Ti - N, these multiple coating has excellent comprehensive performance, improves the oxidation temperature and wear resistance, and low coefficient of friction. Adding AI and C elements in ti-n can make up the quaternary film layer of TiAICN (see figure 1). The film has good thermal stability, high wear resistance and low friction, and has been widely used in the field of hard machining. As for hardening processing module, not only improves the machining efficiency, obtained good processing surface and solves the processing after the heat treatment deformation problem first, to improve the manufacturing precision of the mould.