First, in a variety of materials being processed, Vosten stainless steel, high manganese steel, hardened steel, composite materials and wear-resistant cast iron and other materials are very difficult to process, but with the development of the industry, the use of these materials continues to increase. At the same time, in the future, as various industries continue to improve the requirements of the material, more new materials will appear, such as in the aerospace industry, titanium alloys, nickel-based alloys, and super heat-resistant alloys, ceramics and other difficult to process materials, each of which is a new type of material for the cutting process presents a new challenge.


The emergence of coated tools is a revolution in the development of cutting tool materials, the use of coating technology can effectively improve the service life of cutting tools, so that the tool to obtain excellent overall mechanical properties, thereby significantly improving machining efficiency. Therefore, the industrial advanced countries use the coating tool in the cutting tool accounted for an increasing proportion of about 70% to 80% of the proportion. Shown for the development of tool coating history, from the first generation of a single film layer gradually developed to multiple multi-layer film layer to meet the different materials and cutting environment of the cutting process.

pvd vacuum coating

Second, the trend of technological development

(A) film diversification and customisation of services

Into the 21st century PVD technology compared with the 1990s, has changed greatly, from a single TiN, TiCN, TiAlN development to dozens of coating type, for different cutting application conditions, the film composition, structure can be selected, through the appropriate preparation technology, in order to obtain satisfactory cutting results. For example, in gear processing, in addition to zz coating tool life has strict requirements, how to ensure the accuracy of the gear and surface quality is also critical, so the current common use of composite film layer, that is, hard coating + soft coating, of course, for different coating manufacturers, to achieve the purpose of the process method is not the same; and in the high-speed milling process, often only use hard coating. In addition, the concept of customised service is initially formed, for example, Platit's coating equipment adopts an open working mode, which can be used for different customers to develop more suitable coating technology at any time.


(ii) Development of coating technology for high-speed and dry cutting

In the high-speed processing or dry cutting process, the temperature becomes the main reason affecting the service life of the tool, so improve the high temperature performance of the film, to ensure the red hardness of the coated tool has become the focus of the development of PVD technology in recent years. To improve the Aluminium-Titanium Nitride film layer, increasing the content of Al in the film is one of the effective methods, so the so-called AlTiN coating (Al content greater than 50%) has appeared, and it should be said that with the increase of the Al content (within a certain range), the overall effectiveness of the film has been improved, but there are still some key technologies to be solved: for example, how to complete this kind of coating during the production process, especially when the Al content is more than 65%, how to control the crystal structure of AlN in this film layer, etc. From the latest development, the coating industry has solved the problem of high-speed, high-temperature cutting and processing through other thin film technology, such as Balzers' AlCrN coating, Platit's (nc-Ti1-xAlxN)/(αSi3N4) coating, CemeCon's TINALOX coating, Metaplas' AlTiN-saturn coating. All of them have excellent high temperature performance and have been successfully applied in the field of high speed and dry cutting machining.

Hardware Coating

(III) Improvement of film structure

Currently in the PVD market, cathodic arc ion plating technology is still dominant, but unlike before, whichever company adopts cathodic arc ion plating technology tries to improve the organisation of the film layer through the development of hardware and the adjustment of the production process to avoid the generation of "liquid droplets" and columnar crystals. Especially with the emergence of the nano-concept, resulting in cathodic arc thin film coating organisation to obtain a fundamental improvement in the use of the technology to obtain the surface roughness of the film layer Ra value has been less than 0.15 μm, thus making the cathodic arc coating of the overall efficiency can be improved, and accepted by the market.


(D) New concepts in the field of PVD coating

As we all know, the counterpart of PVD technology is CVD technology, which has high bonding strength, thick film layer and can be coated with α-Al2O3 film layer, so it is more suitable for high-speed, dry roughing and semi-finishing machining field of medium and heavy cutting. How to use PVD technology to develop Al2O3 coating technology, realise thick film coating, and extend PVD coating technology to roughing and semi-finishing fields has been a pressing problem for the industry. And CemeCon's research in this field has made breakthrough progress and heralds the arrival of a new era of PVD technology.