FI123716B - Method of coating a particular surface of a product with carbon nitride by laser deposition - Google Patents

Description

A method of coating a given surface of a product with carbon nitride by laser cultivation

FIELD OF THE INVENTION The invention relates generally to a method for coating large surface area products with carbon nitride by ultra short pulse laser cultivation. The invention also relates to products produced by the process. The invention has many beneficial effects such as high coating yield, excellent coating properties and low manufacturing costs.

10 Background

Carbonitride (Carbonitride)

Carbon nitride materials have been the focus of considerable experimental and theoretical attention since Cohen and colleagues suggested that β-03Ν4, 15 carbon nitride materials, corresponding to β-Si3N4, should have a hardness comparable to diamond. Subsequent calculations have shown that other crystalline C3N4 agents should have equivalent or greater stability than P-C3N4, and many of these structures should be quite hard. The C3N4 structures contain α, β, cubic lattice, pseudo cubic lattice and graphene carbon nitride. In addition, C2N2, although having a different chemical structure, is called carbon nitride.

The local structural feature that separates the potentially super-superficial and dense C3N4 structures from the lower density softer material is carbon coordination; hard materials require tetrahedral or sp-bonded carbon in the C3N4 network, while sp2 carbon leads to much softer c3 silicon materials. This requirement for sp3-bonded carbon in hard carbon ionide is fully comparable to that of amorphous diamond-like carbon (DLC), see Hu et al., Physical Rewiev B, Vol. 57,1997, number 6, pages 3185- x 3188 , Nitrogen-driven sp3 to sp2 Transformation in carbon nitride materials.

£ 30 co Like all diamond coatings, carbon nitride coatings have excellent wear and scratch resistance properties. In addition, carbon nitride materials are corrosion resistant and can act as electrical insulators, optical coatings and, most importantly, as a thermal resistor better than corresponding DLC coatings.

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Although good results can already be obtained with amorphous CNX structures, the results are over-emphasized when the nitrogen content and thus the crystallinity of carbon nitride is realized in the thin film / coating structure.

In general, the materials produced in these studies have been amorphous with nitrogen contents below 50%, i.e. no C3N4 structures.

Thanks to their easier availability, amorphous CNX materials have already found a broader application field. They are e.g. the most used material for Sulo trench coatings for hardboards, Widlow et al., Brazilian Journal of Physics, 2000, Vol. 30, No. 3, Recent Progress in Synthesis and Characterization of Amorphous and Crystalline Carbon Nitride Coatings. Such films are produced by sputtering graphite in pure nitrogen, whereby the resulting films contain amorphous carbon nitride, which has many times better wear resistance than existing coatings.

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Other attempts to produce carbon nitride coatings have been made by laser cultivation, chemical vapor cultivation of inductively coupled plasma, solvothermic process and electrical precipitation of organic liquid. Most reports mention nucleation and the generation of amorphous CNX thin films (thin solid 20 Films). In general, the materials produced in these studies have been amorphous with less than 50% nitrogen content, i.e. no C3N4 structures.

Laser Education 25 In recent years, significant advances in laser technology have provided tools for the development of ultra-high efficiency laser systems based on semiconductor fibers, thus supporting the so-called. development of cold ablation methods.

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On the priority date of the present application, a purely fibrous diode pumped g 30 semiconductor laser competes with a lamp pump, both of which have the feature of first directing the laser beam into the fiber and then transmitting it to the target. Said fiber laser systems are the only ones used in industrial scale co-laser applications.

δ o £ 3 35 Recent fiber laser fibers, as well as the resulting low radiation power, seem to limit the choice of materials to be used for vaporization / ablation. Evaporation / ablation of aluminum can be promoted through low-pulse power, whereas substances more challenging for vaporization / ablation, such as copper, tungsten, etc., require more pulse power. The same applies to the situation where new compounds were to be produced using the same traditional techniques. Notable examples include e.g. direct production of diamond from carbon (graphite) or production of alumina (alumina) directly from aluminum and oxygen through the vapor phase reaction of a suitable laser culture post-production space.

On the other hand, one of the major obstacles to transmitting advances in fiber laser technology seems to be the ability of the fiber to withstand high-power laser pulses without breaking the fiber or degrading the quality of the laser beam.

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Utilizing the new cold ablation, there were qualitative as well as production rate problems associated with the coating, with an approach to thin film production as well as cutting / grooving / grooving, etc. focusing on increasing laser power and reducing laser beam spot size in 15 destinations. However, most of the power increase was spent on noise. Quality and production rate problems still persisted, although some laser manufacturers solved the problem of laser power. Coating / thin film type samples as well as cutting / grooving / grooving etc. could only be produced at low reproduction speeds, narrow scan widths and long machining times, as such outside the 20 industrial applicability, with particular emphasis on large pieces.

If the energy content of the pulse is kept constant, the pulse power increases as the pulse duration becomes shorter, which greatly aggravates the problem. The problems are significant with pulse lasers up to 25 nanoseconds, although they are not used as such in cold ablation methods. A further reduction in pulse duration to the femto or even attosecond range makes the problem almost unsolvable. For example, in a picosecond laser system, with a pulse time of 10-15 ps, the pulse energy should be 5 µs per 10-30 µm 0 for a total laser power of 100 W and a repetition rate of 20 MHz. At the date of priority of the present g 30, the fiber that would withstand said pulse was not known to the writer.

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g The output speed is directly proportional to the playback speed or frequency. On the other hand, in known mirror film scanners (galvanic scanners or reciprocating-type scanners) that perform their duty cycle as characterized by a reciprocating motion, stopping the mirror at each end of the duty cycle is somewhat problematic, as well as stopping and turning 4 the usefulness of the mirror as a scanner and especially the scan width. If production rates are to be increased by increasing the reproduction speed, acceleration and deceleration will cause either a narrow scan interval or an uneven distribution of radiation, and thus plasma, when the radiation hits the target through an accelerating and / or 5 decelerating mirror.

If an attempt is made to increase the coating / film production rate by simply increasing the pulse repetition rate, the current above-mentioned scanners direct the pulses to the overlapping portion of the target area at low kHz pulse repetition rates in 10 uncontrolled ways. At its worst, this approach results in the release of particles from the target material instead of plasma, or at least the formation of particles in plasma. When multiple consecutive laser pulses are applied to the same target material location, the cumulative effect appears to unevenly crush the target material and may result in heating of the target material, thereby losing the benefits of cold ablation.

The same problem occurs with nanosecond lasers, while the problem is naturally even more severe because of the long-lasting, high-energy pulses. Thus, there is always a warming of the target material, with the temperature of the material rising to about 5000 K at 20, thus even a single nanosecond pulse radically erodes the target material with the above-mentioned problems.

In the prior art, not only can the target be drawn unevenly, but it can also easily fragment and impair plasma quality. Thus, the surface to be coated with said plasma also suffers from the adverse effects of plasma. The surface may contain lumps, the plasma may not be uniformly distributed to form the coating, etc., which is problematic in operation requiring precision, but may not be cm, for example in paint or pigment, assuming that defects remain below a certain limit in that application.

8 30 1 Current methods consume an object in one application, so the same target is not available for later use on the same surface. The problem has been co-solved by utilizing only the virgin surface of the object by moving the target material and / or the radius respectively.

In machining or machining applications, residual material or debris, including some pieces, may also make the cutting line uneven and thus unsuitable, such as flow-control drilling o «

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5 could happen. The surface may also have a wavy appearance due to the release of fragments, which may not be appropriate, for example, in the manufacture of certain semiconductors.

In addition, the reciprocating mirror-film scanners generate inertia forces that load the structure itself as well as the bearings to which the mirror is attached and / or cause the mirror to move. This kind of inertia may gradually quieten the attachment of the mirror, especially if the mirror is operating in the extreme range of possible operating settings, and may lead to long wandering of the settings, which can be seen in the uneven reproducibility of the product quality. Due to the stops, as well as the direction of movement and related changes in speed, this mirror-film scanner has a very limited scanning width for use in cultivation and plasma production. The effective duty cycle is relatively short compared to the full cycle, although the operation is in any case quite slow. From the viewpoint of increasing the productivity of the system using mirror-15 membrane scanners, the plasma production rate is conditionally slow, narrow scan width, operation uncertain in the long run, which also results in a very high likelihood of interfering with undesired particle emission with plasma 20 and / or coating.

Summary of the Invention

There is a great need for coating technologies for products with large surfaces.

Product life should be increased and maintenance costs reduced, starting from the point of view of sustainable development. Coatings on large product surfaces, particularly uniform coatings, should have one or more of the following properties, which remain unresolved problems: excellent optical properties, chemical and / or chemical properties. snow resistance, thermal resistance and conductivity, anti-scratch properties, excellent coating adhesion, electrical conductivity, and 3030 tribological properties.

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oo Carbon nitride materials contain many of these properties, but there are no methods of making carbon nitride coatings, especially large surface C3N4 coatings.

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Recent high-tech coating methods, as well as current coating techniques associated with laser cultivation in either the nanosecond or cold ablation (peak, femtosecond) lasers, are unable to provide any useful method for coating large surface products on an industrial scale. Current CVD and PVD coating technologies require high-vacuum conditions, making the coating process batch-like and thus unsuitable for most industrial scale coating of current products. In addition, the distance between the material being coated and the ablation coating material is long, typically over 50 cm, making the coating chambers large and vacuum pumping time consuming and energy consuming. Said high-volume vacuum chambers are also readily contaminated with the coating materials during the coating process itself, requiring continuous and time-consuming cleaning processes.

Attempts to increase the coating production rate in current laser assisted coating methods result in various defects such as micropores, increased surface roughness, reduced or lost optical properties, fine particles on the coating surface, fine particles in the surface structure, causing corrosivity, features etc.

If appropriate, the surface of the target material is eroded in such a way that only the outermost layer of the target material can be used for coating purposes, the remainder of the material is wasted or must be subjected to reprocessing before reuse. The object of the present invention is therefore to solve or at least alleviate the problems of the prior art.

It is a first object of the invention to provide a new method for solving a problem in which a specific surface of a product is coated with carbon nitride by pulsed laser cultivation £ 2 so that the uniform surface to be coated comprises at least 0.2 dm.

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A third object of the present invention is to provide at least a new method and / or g related devices for solving the problem of practically producing fine quality plasma from a carbon trix target to be used for coating various products such that the target material does not form any small particles of co , i.e., plasma is pure plasma, or fragments, where mC, if present, are rare and at least smaller in size than the cultivation depth at which plasma cultivation is created from said subject.

It is a fourth object of the present invention to provide at least a novel method and / or related means for solving how a uniform surface of a product can be coated with fine quality plasma without fine particle size larger than the growth depth into which plasma is created by cultivation from said subject, i.e. substrates with pure plasma derived from a virtually carbon nitride material.

A fifth object of the present invention is to provide a good adhesion of the coating to the uniform surface of the product by means of said clean plasma such that the waste of kinetic energy on the fine particle particles is reduced by limiting their existence or size below the growth depth. At the same time, the presence of only small particles of fine particles does not form cool surfaces which could affect the homogeneity of the plasma cloud through crystallization and condensation-related phenomena.

It is a sixth object of the invention to provide at least a novel method and / or means for solving the problem of providing a wide scanning width simultaneously with finely divided plasma quality and of providing a wide coating width even for large product bodies in an industrial manner.

A seventh object of the invention is to provide at least a new method and / or means related thereto to solve the problem of providing high repetition rate in industrial scale applications for use in accordance with the aforementioned objects of the invention.

It is an eighth object of the invention to provide at least a novel method and / or related means for solving the problem of providing fine plasma for coating uniform product surfaces and for producing products according to Objectives 1-7, while still retaining target material for use in coating steps. similar coatings / thin films when required.

It is another object of the invention to use such a method and means in accordance with the foregoing objectives to solve the problem of cold working and / or coating surfaces for coated products.

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The present invention is based on the surprising finding that the surfaces of various products comprising large surfaces can be coated at industrial production speeds and with excellent properties, generally related to several common technicalities of carbon nitrides, using carbon nitride. C3N4Hx target material is preferably used as the carbon nitride material, but other carbon nitride or carbon based target materials are not to be ignored.

In addition, the present process achieves a cost-effective utilization rate for carbon nitride target materials by ablating them in a manner that provides reuse of the material already in use while maintaining good coating results. The present invention further achieves coating of different products under low vacuum conditions while providing good coating properties. In addition, the coating chamber volumes required are dramatically smaller than in competing methods. These features dramatically reduce the cost of overall hardware and increase coating production speed. In many advantageous cases, the coating hardware can be installed on a production line in an online style.

Coating growth rates on a 20W USPLD are 2 mmVmin. When the power of the laser 15 is increased to 80 W, the growth rate of the USPLD coating accordingly increases to 8mm3 / min. According to the invention, the increase in growth rate can now be fully utilized for high quality coating production.

In this patent application, the term "coating" refers to the formation of any material of 20 thickness on a substrate. Thus, coating may also involve producing thin films, e.g., with a thickness of <1 µm.

The various embodiments of the invention may be conveniently combined.

Those skilled in the art, having read and understood the invention, will know many different ways of modifying embodiments of the invention without departing from the scope of the invention, which is not limited to the embodiments disclosed, which are:

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g is exemplified by embodiments of the invention.

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The described and other advantages of the invention will be apparent from the following detailed description with reference to the figures, in which:

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Figure 1 shows an exemplary galvanic scanner assembly utilized

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prior art cold-ablation coating / thin-film production as well as machining and other machining applications. The number of galvanic scanners in laser beam control varies, but typically one gal van scanner is used,

Figure 2 illustrates an ITO coating on a polycarbonate sheet (-100 mm x 5 30 mm) using a prior art oscillating mirror (head scanner) produced at various ITO thin film thicknesses (30 nm, 60 nm and 90 nm),

Figure 3 illustrates a situation where a prior art galvanometric scanner is used to scan a laser beam at a scan rate of about 1 m / s, resulting in highly overlapping pulses at a repetition frequency of 2 MHz,

Figure 4 shows a possible product coated according to the invention,

Figure 5 shows one possible turbine scanner mirror used in the method of the invention, 15

Figure 6 shows the movement of the magnifying beam achieved by each mirror of Figure 5;

Figure 7 illustrates beam guidance through one possible rotary scanner used in accordance with the invention,

Figure 8 shows beam control through one possible rotary scanner used in accordance with the invention, Figure 9 shows beam control through one possible rotary scanner used in accordance with the invention, δ

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isL Figure 10 shows a sample tube coated according to the invention,

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Figure 11 shows a possible file or rasp, coated according to the invention,

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Fig. 12 shows a possible car cylinder, coated according to the invention,

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Figure 13a. illustrates an exemplary scanning and ablation of a target material according to the invention by means of a rotary scanner (turbine scanner),

Figure 13b. shows an exemplary portion of the target material of Figure 13a, 10

Figure 13c. shows an exemplary grown area of the target material of Figure 13b, Figure 14a. illustrates an example of target material scanning and ablation using a turbine scanner (rotary scanner) according to the invention,

Figure 15a. illustrates problems with prior art plasma-related techniques, Figure 15b. illustrates problems with prior art plasma technologies.

Detailed Description of Embodiments of the Invention

According to the invention there is provided a method of coating a given surface of a product with carbon nitride 15 by laser culturing, wherein the uniform surface area to be coated comprises at least 0.2 dm and is applied by targeting laser pulses short enough to cause cold ablation at the target characterized in that the pulsed laser beam is scanned by means of a rotating optical scanner, each scanner including at least one mirror for reflecting said laser beam, wherein the scanning speed of the pulsed laser beam at the target surface is greater than 10 m / s.

According to one embodiment of the invention, the carbon nitride material herein refers to all CNX materials, preferably C3N4 or C2N2 materials, and most preferably 25 minutes to C3N4 materials. The coating may contain small amounts of hydrogen, thus having a nitrogen to carbon ratio of about 4: 3.

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Preferably, the target material contains C3N4 material, e.g. in graphite form, o Such graphite material always contains a variable but small amount of g 30 hydrogen. Thus, here too, the nitrogen-carbon ratio is not exactly but approximately 4: 3.

According to an embodiment of the invention, the coating test electrometry is controlled by carrying out the coating in a nitrogen atmosphere.

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rC Products are to be understood, without limitation, to be used in, for example, construction, as a whole, 35 interior, decoration, machinery, vehicle parts such as cars, trucks, motorcycles and tractors, aircraft such as aircraft propulsion, ships, boats, trains, rails , tools, medical products, electronic devices and their cases, various stone and ceramic products, fiber-based products, glass-based products, plastic-based products, lighting, computer hard drives, profiles, frames, component parts, insulating materials, process equipments, tanks in various industrial sectors such as the chemical industry, 5 electric power and energy industries, solar cells, leds, spacecraft, pure metals, plastics and plates, military applications, ventilation, mining, screws, water pipes, Pori and their parts, etc.

Ultra Short Laser Pulsed 10 Deposition is often abbreviated as USPLD. Said cultivation is also referred to as cold ablation, where one of the features is that, unlike competing nanosecond lasers, for example, heat transfer from the exposed target area to this environment does not occur, with laser pulse energies still high enough to exceed the target material ablation threshold. Pulse lengths are typically less than 50 ps, e.g., 5-30 ps, i.e., ultralight, with cold ablation at picosecond, femtosecond, and attosecond pulse lasers. The material vaporized from the subject by laser cultivation is grown on a substrate held near room temperature. Still, the plasma temperature reaches 1,000,000 K in the exposed target area. Plasma velocity is overwhelming, even reaching 100,000 m / s, thereby achieving a better prediction of sufficient adhesion of the produced coating / thin film.

In another embodiment of the invention, said uniform surface area comprises at least 0.5 dm. In yet another embodiment, said uniform surface area comprises at least 1.0 dm. The invention is also readily accomplished by coating products with uniform coated surfaces greater than 0.5 m, such as those of 1 m and larger. Because the process is particularly advantageous for coating large £ 2 surfaces with high-quality plasma, it faces an under-served or completely unserved market for a wide variety of glass products.

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cp g 30 In industrial applications, it is important to achieve high efficiency in laser processing, x In cold ablation, the intensity of laser pulses must exceed a predetermined threshold to promote the phenomenon of cold ablation. This limit depends on the target material. In order to achieve high processing efficiency and thus industrial productivity, the playback speed of wood should be high, e.g., 1 MHz, preferably above 2 MHz, and preferably

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^ 35 over 5 MHz. As previously mentioned, it is preferable not to direct multiple pulses to the same location of the target material, since this causes a cumulative effect in the target material, with particle growth leading to poor quality plasma and thus poor quality and high heat treatment of the target material. in order to achieve this, it is also necessary to provide a high scanning speed for the laser beam. In accordance with the invention, the beam velocity at the target surface should generally be greater than 10 m / s for effective processing, and preferably greater than 50 m / s, and more preferably greater than 100 m / s, even at speeds such as 2000 m / s. However, in optical scanners based on a vibrating mirror, the moment of inertia prevents the mirror from reaching a sufficiently high angular velocity. The received laser beam on the target surface is thus only a few m / s in speed, illustrating in Figure 1 an example of such a vibrating mirror, also called a galvanic scanner.

While current plating methods utilizing galvanic scanners can produce scanning widths of up to 10 cm, preferably less, the present invention also achieves much wider scanning widths such as 30 cm and even more than 1 15 meters with excellent coating properties and production speeds.

According to one embodiment of the invention, a rotating optical scanner here refers to scanners comprising at least one mirror for reflecting a laser beam. A Tä-20 scanner and its applications are described in patent application FI20065867. According to another embodiment of the invention, the rotating optical scanner comprises at least three mirrors for reflecting the laser beam. In one embodiment of the invention, the polygonal prism shown in Figure 5 is utilized. Here, the polygonal prism has surfaces 21, 22, 23, 24, 25, 26, 27 and 28. The arrow 20 indicates that the 25 prism can be rotated about its axis 19 which the axis is the prism axis of symmetry. When the prismatic surfaces of Fig. 5 are mirror surfaces, preferably oblique, to provide a scanning line of θ2, arranged so that each surface alternates, with respect to reflection, the direction of radiation incident on the mirror surface as the prism rotates about its axis. , its radiation transmission line, as part of a rotating scanner such as a turbine scanner. Figure 5 shows 8 surfaces, but there may be considerably more surfaces, even dozens or hundreds. Figure 5 also shows that the mirrors are at the same angle vi-co with respect to the axis, but especially with more mirrors containing? in an embodiment, said angle may vary step by step so that within a certain gear range, a certain stepped transition at the working point is achieved at the target, as illustrated in Figure 6, among other things. Various embodiments of the invention are not limited to various turbine scanner mirror arrangements regarding, for example, the size, shape and number of mirrors reflecting a laser beam.

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The structure of the turbine scanner, Fig. 5, includes at least 2 mirrors, preferably more than 6 mirrors, e.g. 8 mirrors (21-28) disposed symmetrically about the central axis 19. As the prism 21 in the turbine scanner rotates 20 about the central axis 19, the mirrors 5 direct the radiation reflected from the point 29, e.g., a laser beam, precisely to the line pattern, always starting from the same direction (Figure 6). The mirror structure of the turbine scanner may be inclined (Fig. 7) or inclined at a certain angle, e.g. Figs. 8 and 9. The dimensions of the turbine scanner may be freely selected. In one preferred embodiment of the coating method, it has a circumference of 30 cm, a diameter of 12 cm and a height of 5 cm.

In one embodiment of the invention, it is preferable that the turbine mirrors 21-28 are preferably angled with respect to the central axis 19, since the laser beam 15 is then easily guided to the scanner system.

In the turbine scanner used according to an embodiment of the invention (Fig. 5), the mirrors 21-29 may differ from each other in such a way that as many lines in the form of a line (Fig. 6) are scanned during one revolution of rotation as there are mirrors 21-28.

According to the invention, the surface to be coated may comprise all or part of the surface of the product.

In a preferred embodiment of the invention, laser cultivation is performed in a vacuum of 10'1 to 10'12 atmospheres. High vacuum conditions require fairly long pumping times of £ 2 and thus longer coating production times. This is not a big problem with certain higher end products, but it is definitely the case, for example, with consumer products with larger surfaces.

ig 30 If, for example, new abrasion and scratch resistant coatings, chemically inert coatings, tribological coatings, heat-resistant and / or heat-conductive coatings, electrically conductive coatings, and possibly simultaneously excellent c8 coatings are considered, these products simply do not rC mass of coating methods, not from a technological or economic point of view, when wet.

Thus, in a particularly preferred embodiment of the invention, laser cultivation is performed in a vacuum of 10 to 1 to 10 to 4 atmospheres. According to the invention, excellent coatings of 14 te / thin film can be achieved even in low atmospheres, with dramatically reduced processing times and improved industrial usability.

According to the invention, it is possible to carry out the coating in such a way that the distance between the target material and said uniform surface area to be coated is less than 25 cm, preferably less than 15 cm, and most preferably less than 10 cm. Thereby, the development of radially reduced volume coating chambers is achieved, reducing the total cost of coating production lines and further reducing the time required for vacuum pumping.

In a preferred embodiment of the invention, the ablated surface of the target material can be repeatedly ablated to produce a defect-free coating. For most current coating technologies, the target material is unevenly consumed in a manner where the exposed area cannot be reused for cultivation and thus must be rejected or sent for regeneration after a given use. An attempt has been made to solve the problem by continuously developing various techniques for feeding new non-ablated target material for coating purposes, e.g. by moving the target material relative to the x / y axes or by rotating the cylindrical target material. The present invention simultaneously provides excellent coating properties and production rates as well as the use of a target material in a manner in which good quality plasma retains its properties through the use of substantially all of the target target material. Preferably, more than 50% by weight of the single target material is consumed to produce good quality plasma according to the invention. Good quality plasma herein refers to plasma directed to producing defect-free coatings and thin films, while maintaining the good quality of the plasma cloud at high pulse rates and growth rates. Some of these features are described below.

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While the present invention favors the use of carbon nitride materials as g 30 target material, in another embodiment, the invention is also applicable to the production of certain carbon linitride coatings by ablation of graphite or pyrocarbon in various nitrogen-containing atmospheres.

The coating produced in accordance with one embodiment of the invention has an average surface roughness of less than 100 nm when scanned from 1pm2 on an AFM microscope. More preferably, the average surface roughness is less than 30 nm. Mean surface roughness herein is defined as the mean deviation from the centerline curve fitted by a suitable method, such as that obtainable in an AFM or profile meter. The surface roughness affects e.g. abrasion and scratch resistance properties, the tribological properties as well as the translucency of the coatings of the products coated according to the invention.

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Still, in a preferred embodiment of the invention, the coating produced has an optical transmittance of at least 88%, preferably not less than 90%, and most preferably not less than 92% of said uniform surface area. It can even be higher than 98%.

In another embodiment of the invention, the coating produced in said one-shaped surface area contains less than one pinhole per 1 mm, preferably less than one micro-hole per 1 cm, and preferably no micro-holes in said uniform surface area. A micro-hole is a hole that passes through or substantially through the coating. The tiny holes provide a platform for the erosion of the originally coated material, for example through chemical and environmental factors. A single micro-hole, e.g., in a chemical reactor or tube, a medical implant, a spacecraft, various parts of vehicles and their mechanical parts, or further in a metal structure or interior, can easily lead to a dramatically reduced service life of said product.

Thus, in another preferred embodiment, said uniform surface is coated in a manner wherein the first 50% of said coating in said uniform surface does not contain any particles having a diameter greater than 1000 nm, preferably 100 nm and most preferably 30 nm. If the early stages of the coating manufacturing process produce micrometer-sized particles, said particles may open up corrosion passages in subsequent layers of the produced coating. Li-

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Because of the irregular shape of the particles, it is very difficult to seal the surface below the particles. Furthermore, said particles substantially increase the roughness of the surface 9. Even in this context, the current method allows for increased

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0 life expectancy and reduced maintenance costs for various products.

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According to one embodiment of the invention, said uniform surface co of the fibrous product is coated with only one coating. According to another embodiment of the invention, said uniform surface of the article is coated with a multilayer coating. Several coatings can be produced for various reasons. One of the reasons may be to improve the adhesion of certain coatings to the product to be coated by preparing a first batch of coating which adheres better to the surface and has properties that facilitate the next coating layer to adhere to said 16 layers better than the surface itself. In addition, a multilayer coating may contain multiple functions that are not possible without such a structure. The present invention provides the production of multiple coatings in a single coating chamber or in adjacent chambers.

The present invention further provides the production of composite coatings on a product surface by simultaneously ablating one composite material target containing carbon nitride or one or more target materials in addition to the carbon nitride target comprising one or more agents. A preferred additional material includes a metal such as titanium. In some cases, it is preferred according to the invention to add a small amount of nucleating agents such as Ni, Pt, Re, Rh or Cr. Composites may also contain polymers such as Teflon or silicone.

According to the invention, the thickness of said coating on the uniform surface of the product is between 20 nm and 20 µm, preferably between 100 nm and 5 µm. The coating thicknesses should not be limited to these, since the present invention provides for the production of Mole-15 waxy coatings on the one hand and very thick coatings such as 100 µm and more on the other hand.

The present invention further provides the fabrication of 3D structures by utilizing a product component as a scaffold to increase said 3D structure.

According to the invention there is also provided a carbon nitride coated product comprising a surface coated with 20 specific laser cultures, wherein the uniform coated surface area is at least 0.2 dm and the coating is performed by ultra short pulsed laser scattering such that a pulsed laser beam is scanned by a rotating optical scanner at least one mirror to reflect said laser beam. The advantages of these products have been described in more detail in the 25 minutes earlier description of the process.

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In a more preferred embodiment of the invention, said uniform surface area comprises at least 0.5 dm. In a more preferred embodiment, said uniform surface area comprises at least 1.0 dm. The invention also facilitates the coating of products having uniform coated surfaces of greater than 0.5 m2, such as those of 1 m and larger.

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According to one embodiment of the invention, the coating produced has an average surface roughness of less than 100 nm at a scanning area of about 1 pm2 in a uniform surface area under an AFM (Atomic Force Microscope) microscope. More preferably, the uniform surface roughness is less than 30 nm. Mean surface roughness is herein defined as the mean deviation from a fitted centerline mean curve by a suitable method, e.g., A F M or by a profile gauge. The surface roughness affects e.g. wear and female-5 conversion properties, tribological properties as well as the translucency of coatings of the metal products coated according to the invention.

Still, in a preferred embodiment of the invention, the coating produced has an optical permeability of at least 88%, preferably not less than 90%, and most preferably not less than 92% of said uniform surface area. It can even be higher than 98%.

In another embodiment of the invention, the coating produced in said uniform surface area contains less than one pinhole per 1 mm, preferably less than one micropore per 1 cm, and preferably no micro holes in said uniform surface area.

In yet another embodiment, said uniform surface area is coated in such a way that the first 50% of said coating area in said uniform surface area does not contain any particles having a diameter greater than 1000 nm, preferably 100 nm and most preferably 30 nm.

The coating of the carbon nitride coated product of the invention may contain almost any type of carbon nitride. Preferably, the carbon nitride contains C2N2 or C3N4, most preferably C3N4. In this case, it may be advantageous to use a graphite coating for certain solutions and a crystalline solution for some other solutions. C3N4 graphite usually contains small amounts of hydrogen. The crystalline carbon nitride may contain one crystalline form or mixtures thereof. Said forms include the α-, β-, o-cube lattice and pseudocube lattice forms. Carbon nitride, as used herein, may also mean various mixtures of x and metal composites of all crystalline and graphitic forms.

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Particularly preferred embodiments of the invention include carbon nitride in an α and / or β crystalline form, either in pure form or as a composite with respect to each other or to different metals.

According to another preferred embodiment of the invention, said uniform surface of the product is coated with a multilayer coating. According to another preferred embodiment, said uniform surface of the product is coated with a single coating layer.

According to a preferred embodiment of the invention, the thickness of said coating on the uniform surface of the product is between 20 nm and 20 µm, preferably between 100 nm and 5 µm. The invention also provides carbon nitride-coated products containing one or more atomic-level coatings and thick coatings in excess of 100 µm, e.g. 1 mm. The present invention further provides the fabrication of 3D structures by utilizing a coated component as a scaffold to increase the 3D structure.

examples

Example of Demonstrating Problems of the Prior Art - Laser Technology

Figure 2 illustrates an ITO coating on a polycarbonate sheet (-100 mm x 30 mm) using a prior art optical scanner, namely a vibrating mirror (head scanner) 20, produced at various ITO thin film thicknesses (30 nm, 60 nm and 90 nm). Although the ITO coating is not applied to the metal substrate, the pattern clearly demonstrates some of the problems associated with the use of a vibrating mirror as an optical scanner, especially in ultra short pulse laser (USPLD) but also in c3 laser assisted coatings in general. Because the oscillating mirror changes its direction of rotation 25 in its end positions and due to the moment of inertia, the angular velocity of the mirror is not constant g near the extreme positions. Because of the oscillatory motion, the mirror is constantly braking and x stops before being re-accelerated, thereby causing irregular treatment of the target material at the edges of the scanned area. As can be seen in Figure 2, this ω converts to poor quality plasma comprising particles, particularly at the edges of the scanned rC 30 region, and ultimately to poor quality and apparently uneven coating results.

The coating parameters are chosen to demonstrate the uneven distribution of the grown material due to the nature of the scanner used. If parameters are appropriately selected, the quality of the 19 films can be improved, whereby problems become invisible but non-existent.

Example of Demonstrating Problems of the Prior Art - Laser Technology 5 Traditionally, galvanic scanners are typically used to scan a laser beam at a maximum speed of about 2-3 m / s, in practice about 1 m / s. This means that up to 40 to 60 pulses overlap at a repetition rate of 2 MHz (Figure 3).

Example of Demonstration of Prior Art Problems - Laser Technology 10

Plasma quality problems are demonstrated in Figures 15a and 15b, which illustrate the creation of plasma according to prior art. The laser pulse 1114 hits the target surface 1111. It has a long pulse, the depth h and the beam diameter d are of the same order, while the heat of the pulse 1114 also heats the surface in the hit point area 15a, but also below the surface 1111 deeper than the depth h. , which, when disassembled, produce pieces marked with an F. Because plasma in this example may be of relatively poor quality, the molecules as well as their clusters appear to be indicated by small dots 1115, such as with reference to numeral 1115 having nuclei 20 or clusters of similar structures formed from gases 1116 shown in Figure 15b. The letters "o" show particles that can be formed and grown by condensation and / or agglomeration. The liberated pieces may also increase due to condensation and / or accumulation, indicated by curved arrows from dots to F and from o to F. Curved arrows 25 also indicate phase shifts from plasma 1113 to gas 1116 and further to particles

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g 1115 as well as particles of size 1117. Because the growth cloud in Fig. 15b may contain fragments F as well as particles formed by vapors and gases due to poor plasma production, plasma is not a continuous area of plasma and hence its quality.

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o Variation can be observed within a single pulse cloud. Composition and structural streams 30b below and also due to the resulting depth variations (Fig. 15a), the target surface 1111 of Fig. 15b is no longer available for multiple increments, "and the target is thus wasted, even if some material remains, o Such problems are common in the nanosecond class. lasers in general, as well as current picosecond lasers if they utilize state-of-the-art scanners.

35 Example -1 20 of the Invention

Figure 13a demonstrates a target material ablated by a picosecond pulse laser utilizing a rotary scanner whose speed causes the target material to be ablated with a slight overlap of adjacent pulses, avoiding the problems of prior art galvanic scanners. Figure 13b shows an enlarged view of one portion of the Ablated material, clearly showing the smooth and controlled ablation of the material on both the x and y axes, thereby generating high quality, particle-free plasma as well as high quality thin films and coatings. Figure 13c demonstrates one example of the possible x and y dimensions of 10 individual ablation points achieved with one or a few pulses. It can be clearly seen here that the invention results in the ablation of the material in such a way that the width of the ablated dot is always much greater than the depth of the ablated dot region. Theoretically, any particles (if any) could now be of maximum point size. The rotary scanner now provides good quality, particle-15 free plasma production at an excellent production rate, at the same time a wide scan rate, being particularly advantageous for substrates comprising large surface areas to be coated. In addition, Figures 13a, 13b and 13c clearly show that, unlike current techniques, an already ablated target material region can be ablated for a new generation of high-quality plasma, thereby radically reducing the total cost of production of a pin-20 film / thin film.

Example of the Invention - 2

Figure 14 illustrates an example of plating utilizing a picosecond ti-USPLD laser and scanning laser pulses with a turbine scanner. Here, the scanning speed is 30 m / s with a laser spot width of 30 µm. In this example, there is 1/3 overlap between the pulses of adjacent £ 2.

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Examples of the Invention - Coated Products

The following samples were grown on various metal substrates using ultra-short pulse laser cultivation (USPLD) with a picosecond laser at 1064 nm δ (X-glass, 20-80 W). The substrate temperature was varied between room temperature and 400 ° C and the target temperature from room temperature to 700 ° C. C3N4Hx sintered graphite (Carbodeon Ltd Oy) target material was used for coating applications. When utilizing a nitrogen atmosphere, the nitrogen pressure ranged from 10'4 to 10'1 mbar. As a scanner, a rotating mirror scanner was used, which was able to adjust the speed of the beam 10 at the target surface from 1 to 350 m / s. Utilized reproduction rates ranged from 1-30 MHz, clearly demonstrating the importance of both scanner and high reproduction speeds for producing high quality coatings in an industrial manner. The grown slides were imaged by confocal microscopy, FTIR and Raman spectroscopy, AFM, optical transmission measurements, ESEM and in some cases by electronic measurements (University of Kuopio, Finland; ORC, Tampere, Finland and Corelase Oy, Tampere, Finland). . Spot sizes used ranged from 20 to 45 µm. The wear tests were performed using the pin-on-disk method (University of Kuopio, Finland); tests were conducted at room temperature at 22 ° C and 50% (AD coatings) or 25% (others) relative humidity (without lubrication) with loads between 10-125 g using hardened steel ball (AISI 420), 6 mm diameter, as a pin (PIN). For AD coatings the rotation speed was 300-600 rpm and for lenses 1 rpm. All coatings have excellent abrasion and adhesion properties.

Example 1 “A stainless steel bone screw was coated by ablating hot-pressed C3N4Hx at a pulse repetition rate of 20 MHz, a pulse energy of 5 µs, a pulse hold of 20 ps, and a distance of g 30 to 10 mm from the target material. The vacuum level was 10'5 atmospheres during the coating process. The thickness of the coating was measured at 1 µm and the average surface roughness was determined to be less than 3 nm in the 1 µm area as scanned by the AFM microscope. No micro-holes were found in any of the measured areas of the carbon nitride co-binder.

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Example 2

The chromium metal-coated rasp was coated by ablating the C3N4HX sintered material at a pulse repetition rate of 6 MHz, a pulse energy of 5 µm, a pulse length of 22 to 24 ps, and a distance of 5 cm between the target material and the surface to be coated. The vacuum level was 10'4 atmospheres during the coating process. The process resulted in a uniform coating. The thickness of the carbon nitride coating was measured at 390 nm and the average surface roughness was determined to be less than 2 nm in the 1 pm2 area as scanned by AFM-5 microscope. No micro-holes were found in any measured area of carbon nitride coating (C3N4).

Example 3 A metal motor valve as shown in Figure 12 was coated with carbon nitride on C3N4Hx material sintered with Abla at a pulse repetition rate of 4 MHz, a pulse energy of 5 µm, a pulse length of 24 ps, and a distance of 3 cm between the target material and the surface to be coated. Nitrogen pressure ranged from 10'4 to 10'1 mbar. The process resulted in a uniform C3N4 coating. The thickness of the carbon nitride coating was measured at 500 nm and the average surface roughness was determined to be less than 2 nm in the 1 pm2 area as scanned by the AFM microscope. No micro-holes were found in any measured area of carbon nitride coating (C3N4).

Example 4 20

The laboratory glass tube of Figure 10 was coated by ablating sintered graphite carbon nitride (C3N4Hx, Carbodeon Ltd Oy) target material at a pulse repetition rate of 2 MHz, a pulse energy of 5 µm, a pulse length of 15 mm and a distance between the target material and the surface to be coated. The glass material was preheated to about 120 ° C. The vacuum level was 10'5 atmospheres during the coating process. The process resulted in a uniform C3N4 coating having a thickness of 19 nm. No micro-holes were found in any measured coating area.

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c5 Example 5 8 30 i A polycarbonate sheet of 10 mm x 25 mm was plated by ablating C3N4HX, hot extruded, at a pulse repetition rate of Mhz, a pulse energy of 5 cp, a pulse length of 20 ps, and the target material and surface to be coated? with a distance of 65 mm. Nitrogen pressure ranged from 10'4 to 10'1 mbar.

The coating thickness was measured at 100 nm. The average surface roughness of the coating was determined to be less than 3 nm when scanned by the 1 µM microscope. No micropores were observed in any of the measured areas of the carbon nitride coating.

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Example 6

The polished granite slab of Figure 4 comprising 100 mm x 100 mm was plated by ablating graphite carbon nitride at a repetition rate of 4 Mhz in a nitrogen atmosphere with nitrogen pressure ranging from 10'4 to 10'1 mbar. The pulse energy used was 5 µs, the pulse length was 20 ps, and the distance between the target material and the surface to be coated was 40 mm. The vacuum level was maintained in a vacuum of 10-5 atmospheres prior to the coating process. The coating thickness was about 1 µm and the mean surface roughness λ 10 was determined to be less than 10 nm when scanned from the 1 µm region using an AFM microscope.

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Claims (7)

A method of coating a given surface of a product with carbon nitride by laser culturing, wherein the uniform surface to be coated comprises at least 0.2 dm 2 and is applied by targeting laser pulses 5 short enough to cause cold ablation at the target and having a pulse rate of at least 1 MHz. characterized in that the pulsed laser beam is scanned by means of a rotating optical scanner comprising at least one mirror for reflecting said laser beam, wherein the scanning speed of the pulsed laser beam at the target surface is greater than 10 m / s. A method according to claim 1, characterized in that said uniform surface area comprises at least 0.5 dm 2. A method according to claims 1-2, characterized in that said uniform surface area comprises at least 1.0 dm 2. Method according to one of the preceding claims, characterized in that said laser cultivation is carried out at a pressure of 10 to 7 kPa. Method according to claim 4, characterized in that said laser cultivation is carried out at a pressure of 10 Pa to 10 kPa. Method according to one of the preceding claims, characterized in that the distance between the target material and said uniform surface to be coated is less than 25 cm, preferably less than 15 cm, and most preferably less than 10 cm. Method according to one of the preceding claims, characterized in that the thickness of said coating on the uniform surface of the product is between 20 nm and 20 ° μηι, preferably between 100 nm and 5 µm. i ^. cp CO o X X Q. CO CO LO 1 ^ o o C \ J