In the Nizny Novgorod region, researchers have developed the first vacuum nano-plating technique in the world that can also be used in mass production

An old technical adage says that the performance characteristics of any product largely depend on the quality of its surface treatment. To extend the life of metal products, their surface can be coated with a rust-protective layer of a substance more resistant to corrosion. The galvanic method of applying such coatings, the most widely used nowadays, was invented back in the late 1830s by Boris Yakobi. Tens of thousands of modern manufacturing methods--from removing concomitant mixtures from metals to various molded products--cannot work without it. Car bodies, watchcases, and eyeglass frames as well as diverse accessories and jewelry need corrosion-proof and reinforcing coatings. The trouble is that hexavalent chromium, the mostly frequently used anti-corrosive coating in galvanism, is an officially recognized carcinogen. Nickel, often used to protect surfaces, is on the black list of substances that cannot be in long-term contact with the skin. And in the process of galvanic plating, objects are plunged into a tub filled with cyanides dissolved in a strong acid.
The fight against galvanic methods began in earnest in the late 1960s, when so-called vacuum PVD technologies were developed (PVD – Physical Vapor Deposition). PVD-coatings can be obtained by different methods, for example, via thermal evaporation at high temperatures. However, the film is applied very slowly. Furthermore, due to the low voltage it comes out porous, and its atomic structure still has some hollows that quickly bring reinforcing and anti-corrosive advantages to naught. Because of its high cost, electron-beam evaporation is confined to optical instruments and devices.
In the seventies, scientists from the Kharkov Polytechnic Institute were the first to develop another vacuum method –arc evaporation– and created Bulat machine tools. They were designed to obtain super-hard reinforced coatings for a variety of tools, dies, and molds. US-based Multiarch, the largest modern producer of vacuum equipment, began by purchasing the license for Bulat and is currently producing the fifth generation of units based on the Khavkov discovery. But this method, too, turned out to be too expensive for mass production. The most capital-intensive sectors of the global coating application industry have failed to find a replacement for the galvanic method. Meanwhile, an alternative technology based on another vacuum device – an unbalanced magnetron constructed by skilled craftsmen from Elan-Praktika – has already been introduced at several Russian enterprises.

Rastyapino (the present name for Dzerzhinsk) shot ahead into the world leaders in vacuum technologies, first of all, because the town harbors a Scientific Research Institute of Engineering. In the eighties, this super-secret institute held the monopoly in non-nuclear combat parts for missiles. Thin-film heat flow probes were needed to analyze test results. Yuri Agabekov, the head of the combustion and explosion physics laboratory at the Institute, was given a task absolutely new to him. To increase efficiency of the probe’s surface layer, he had to throw himself into PVD technologies and become an expert in this field.
By the early 1990s, the government defense industry had finally collapsed. A group of seven people from all areas of the Institute’s research talked it over and decided to continue their already successful research activity into new coatings application technologies. Later, they formed the core of the future company.
They managed quite quickly to find a market niche. “We were saved by teeth. Prosthetic dentistry is an ever-present industry and an ever-present source of income,” notes Agabekov. “I know from experience that the titanium nitride on dentures came to the aid of more than one vacuum specialist in the nineties.”
By 1994, Elan-Praktika had driven their rivals off the market. The dental business and tinted glass allowed them to make a decent living but the former defense establishment’s specialists either through habit or devotion decided to develop a new area. “You know, we simply got bored,” Agabekov admits. “And after a short debate we decided to invest part of our revenue in what had begun to fascinate us: coating application using an unbalanced magnetron.”

The principle of all magnetrons is the crossing of magnetic and electric fields. Electrons, first, are accelerated by the electric field and then slowed by a perpendicular magnetic one. In balanced magnetrons, the electrons’ energy ionizes plasma-forming gas. Positive ions gather speed due to the field and begin to bombard negatively charged targets, tanks filled with a substance that used to coat a product. The atoms, which were pulled out from the target as a result of this bombardment, hit the product’s surface and form a protective layer.
The problem with balanced magnetrons is that the energy of atoms extracted from the target is very low. They fly at a thermalized speed and land “lazily” and haphazardly on a surface. As a result, the surface has a loose structure with multitude of pores and its characteristics are not very attractive from the consumer’s point of view – it has no strength whatsoever, nor does it have corrosion resistance.
An unbalanced magnetron is quite another matter. Thanks to its field configuration, ions not only kick atoms out from a target but also continue to attack them after they have already reached the product’s surface. The ion bombardment forces the target’s “lazy” atoms to rush around the surface in search of the most appropriate places in terms of energy. The resulting surface structure is dense. Moreover, by controlling the field and adding more gas into the chamber, researchers can apply diverse substances layer-by-layer to the substrate, thus forming composite coatings. With the unbalanced magnetron, researchers are able to apply virtually any materials to a great variety of products ranging from optical frames to machine tools.
Gradual work on the new spraying device turned into a rush job after Elan met with a leading executive from a Chistopol-based watchmaker at a conversion exhibition. At their own risk and expense, Elan debugged and tested the first machine, which had been sitting around the company’s shop for a year. Almost immediately afterwards, they received an order for three more machines, and two years later, the watchmakers completely dismantled the galvanic chromium-plating lines at their plant.

The watch-makers were followed by the producers of eyewear, who quickly realized that Elan-Praktik’s vacuum plating would considerably reduce the costs of metal frames in the medium-priced and expensive market segments. In a shop at Elan-Praktik, they are still creating decorative coatings for expensive frames by the Filos Group, the third company in Italy in terms of output. Currently, talks are under way to sell the entire line.
However, the Dzerzhinsk specialists themselves consider a victory in another marker as their most significant achievement. In 2000, they began cooperation with the Kovrov Electromechanical Plant, a well-preserved giant of the Soviet defense establishment that produces hydraulic systems for both military and civilian purposes. When the plant began to produce, according to Agabekov, “world-class” locks made of zinc-aluminium-copper (ZAC) alloy, they had problems with coating quality. After struggling with other vacuum specialists, they turned to Elan-Praktik. “Of course, we were attracted by the opportunity to work with the large and successful enterprise, but the most important thing was that they gave us a really interesting task from the scientific and engineering point of view,” Yury Agabekov recalls with enthusiasm. “It involved not just the complex geometry of the product to be plated, but also the new material. ZAC alloy that is very complicated in terms of corrosion protection. No one else in the world has ever tried to solve this problem.”
ZAC alloy products are a huge potential market for magnetron equipment. For example, 90% of cheap Hong Kong and Chinese watches are made of this highly available alloy. Its use is growing by leaps and bounds. It took Elan-Praktik nearly six months to develop a new non-galvanic technique for ZAC alloy, but they reached a real nanotechnology breakthrough. The coating, which Elan specialists taught the Chistopol watchmakers to apply, consisted of two layers of 0.8 micromicrons each. For the Kovrov’ machine builders, they created a composite, 4-component coating, in which layers go one after another with a thickness of just 5 nanometers (10^-9m)!
The Kovrov Electromechanical Plant immediately latched on to the new technology and now intends to use the nano-composite coatings not only on locks but also on important hydraulic units. The Moscow mint has already tested the technique on dies, which usually lasted for only 100,000 coins. With Elan-Praktik’s nano-composite coating 750 thousand coins could be minted without difficulty.
However, the demand for the super-technology in the domestic market won’t be great: one can count on one hand the enterprises that both need and can execute precision treatment of a metal product’s surface that would then make is possibly to apply nano-coatings. On the other hand, there are thousands of such enterprises in the West, and their interest in the development from Rastyapino is great. The Design Engineering Show in Birmingham will most likely confirm this.

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