RU2425907C2 - Procedure for modification of metal surfaces and device - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: procedure for modification consists in forming flow of working gas containing carrying gas, and also chemically active reagents and/or alloying additives and in directing flow of working gas on modified surface. Also, surface is effected with laser pulse periodic radiation generating laser plasma on surface and/or near surface region. The device for realisation of the procedure consists of reaction chamber 24 equipped with element of positioning 17 of treated object 14, of input for flow of working gas and input 23 for laser radiation, of source of working gas, of facility for forming flow of working gas 28 in the reaction chamber, of pulse-periodic laser 20 and of unit for transmitting laser radiation into the reaction chamber and beam focusing designed for direction of laser beam on modified surface of an object.

EFFECT: improved functional properties of surface layer.

10 cl, 3 dwg

Description

The invention relates to technologies for changing the structure or chemical composition of the surface layer of objects made of metals or alloys, for example, nitriding, cementation, alloying, etc., in order to significantly improve the functional properties of the surface layer, such as: wear resistance, impact resistance, chemical and corrosion resistance, and can be used for surface treatment of machine parts and mechanisms, pipelines and pumps, housing elements, functional and supporting metal structures, the answer guides for basic characteristics, and complete overhaul life of the final product or a technical system.

Metal surfaces, resistant to wear and tear, chemical and oxidative effects, are necessary for various uses, for example, in mechanical engineering, automation, agriculture, railway industry, aircraft manufacturing, chemical, oil and other industries. The cost of restoring worn surfaces of machine parts and mechanisms, pipelines, their elements is very significant. To reduce wear of surfaces during friction and to prevent corrosion, lubricating oil is traditionally used. Also, to harden the surface, nitriding is commonly used, during which baths with cyanide salts are used. However, all these technologies are not only expensive in themselves, but also dangerous for the environment.

To prevent damage from corrosion and impacts of the main surfaces, an alternative solution is to cover them with a protective layer, while they remain intact. However, such coatings can significantly increase the weight of nodes and mechanisms. Although the cost of protecting the surface from mechanical wear is high, the cost of protecting against corrosion and chemical attack is even higher. The German company AUDI has proposed a laser system that uses an ultraviolet excimer laser to modify the surface structure and / or chemical composition to create a protective coating on the surface of the engine. Such a system rotates the engine block, and the laser remains stationary. It is inefficient in terms of processing curved surfaces and has a high cost. For these reasons, the use of such a method and system is limited.

A known method of surface modification of objects made of structural steel, including cleaning the surface by mechanical means, coating with silicon nitride gel, drying the surface and surface treatment with a CO ₂ laser [US Patent No. 5411770, IPC С23С 10/00]. As a result, the gel reacts with the surface to form a hardened silicon enriched alloy. This method is adopted as a prototype of the invention.

The disadvantages of the prototype include its limited creation of only one type of coating on a metal surface.

The invention solves the problem of creating a method of surface modification, which allows to obtain a variety of coatings on metal surfaces.

The problem is solved in that a method is proposed for modifying the surface of an object made of metal or alloy, in accordance with which a working gas stream containing carrier gas and chemically active reagents and / or alloying additives is formed, and the said working gas stream is directed to the surface to be modified, wherein the said modified surface is affected by laser pulse-periodic radiation with the formation on the named modified surface and / or in its near-surface region of la grain plasma.

The best results are obtained if the working gas flow is formed with a pressure of at least 0.5 atm.

When implementing the method, as a rule, the impact on the surface to be modified by laser pulse-periodic radiation is carried out repeatedly.

The carrier gas may be an inert gas or a mixture of inert gases.

Also, a reactive gas or a mixture of reactive gases can be used as a carrier gas.

When implementing the method, the surface to be modified can be moved.

Multiple, not less than 3-5, and mainly 10-100, one-time exposure to periodic periodic pulsed laser radiation on the surface is carried out by a series of laser pulses with a stationary object or constantly repeating laser pulses with relative movement of the irradiation area and the surface of the object.

The intensity of the action of laser radiation and near-surface plasma preferably provides heating of the surface of the object above the melting point already in the initial part of the pulse series (mainly up to 0.2 of the total number of pulses), and the pulse repetition rate ensures that the surface temperature is maintained at the moments in the main part of the series (after the initial) before the start of the next pulse in the range from a slightly lower (30-100 degrees) melting point to about half the melting temperature (for example For cast iron and steels preferably above the austenitizing temperature).

The area of influence of laser radiation on the surface is formed close in shape to the area of influence of the working gas stream. The radiation intensity is preferably formed constant over the area of irradiation of the surface.

The carrier gas can be used as inert gases: argon, helium, neon, which do not participate in chemical reactions in the plasma, and chemically active gases: nitrogen, carbon monoxide, ammonia, propane, etc., or mixtures thereof, which can participate in chemical reactions taking place in plasma and to be sources of alloying elements.

The pressure in the gas stream is preferably maintained above atmospheric pressure, but in some cases it may be lower, for example, when working with toxic gases with the need for evacuation and disposal of harmful emissions.

The working gas flow rate provides a change in the initial reacting / doping components and, depending on the laser pulse repetition rate, is maintained in the range of 1-100 m / s.

Alloying additives and / or chemically active reagents can be contained in the working gas in the form of gases, vapors, micro- and / or nanoaerosols, including in the form of a stoichiometric mixture of various aerosols, including refractory ones.

The treated surface during the laser-plasma modification process can move, if necessary.

The method is based on the ignition of a laser plasma near the surface of the treated object, which is also affected by a carrier gas stream containing dopants and / or chemically active reagents, its maintenance and management, as well as the implementation of plasma-chemical reactions, both directly in the named plasma, and the surface of the treated object with simultaneous thermochemical treatment of the metal surface in order to obtain a modified surface layer of the object with high operational and properties.

For example, the method is applicable for nitriding and / or cementing the surface of cast irons and steels, for alloying with pure metals or alloys with the formation of supersaturated solid solutions and the formation of intermetallic compounds, for alloying with carbides of refractory metals (TiC, VC, TaC, WC, etc.).

In particular, the method is applicable for high-performance laser-plasma modification of the cylinder liner surface of internal combustion engines with the formation of a high-hard nanostructured surface layer (tens to hundreds of nanometers thick) containing iron carbides and nitrides, as well as a sublayer up to tens of microns thick with a predominantly martensitic structure.

This method can be carried out using the proposed device.

A device for modifying the metal surface of an object comprises a reaction chamber equipped with a means for positioning the object to be processed, an input for a working gas flow and an input for laser radiation, a working gas source, means for generating a working gas flow in the reaction chamber, a pulse-periodic laser, and a laser radiation delivery means in a reaction chamber and beam focusing, configured to direct the beam to the surface of the object to be modified.

It is advisable to equip the device with a control tool in the form of a control processor.

The positioning tool of the processed object can be made with the possibility of its movement.

The means for delivering laser radiation to the reaction chamber and focusing the beam is designed so that the laser beam acts on the surface to be modified.

The first embodiment of a device for surface modification is shown in FIG.

Scheme of laser-plasma exposure to the surface of the object is shown in figa.

The second variant of the device for surface modification in the manner described is shown in figure 2.

The sequence of stages of the method of surface modification is shown in Fig.3.

In figure 1, 1A and 2, the following positions mean:

10 - a device for implementing the method of modifying external surfaces or internal open cavities with a radius of curvature of the surface of at least 0.1 m;

12 - modified surface layer;

12a is a surface zone, mainly consisting of target compounds or a layer of alloying elements / compounds synthesized in plasma or on the surface;

12b - zone, the properties and characteristics of which are mainly determined by the diffusion of alloying elements;

12c - zone, the properties and structure of which are mainly determined by thermal phase transformations;

14 - the processed object;

15 - thermostat - means for heating or cooling the processed object;

16 - laser plasma;

17 - means for positioning / moving the workpiece and / or the reaction chamber;

18 - flow of working gas;

20 - pulse-periodic laser;

22 - an optical system for transporting and forming an irradiation zone on a modifiable surface of an object;

23 is an optical window for entering the laser radiation reaction chamber;

24 - reaction chamber;

26 - laser radiation;

27 - element for channeling the beam and protective gas;

28 - means for forming a working gas stream;

29 - a stream of protective gas;

30 - management tool;

32 - a system for measuring and monitoring the characteristics of laser radiation;

34 - a system for measuring and monitoring the characteristics of laser plasma radiation and the temperature of the treated surface;

36 - adjustable valve;

37 - adjustable valve / s;

38 - adjustable valve / s;

40 - preparation / mixing means with alloying additives and working gas chemicals;

42 - carrier gas supply means;

44 - gas source (gas sources) - carrier and / or active gas (gases);

46 - element of the reaction chamber, providing a small gap with the surface of the processed object 14;

48 - flow of exhaust working gas;

50 - a device for implementing the method of modifying the inner cylindrical surfaces with a rotating reaction chamber;

52 - movable platform;

54 - means for rotating the reaction chamber;

56 - clip, which also serves as a collector for supplying gas to the reaction chamber and cooling;

58 - inner annular grooves;

59 - through holes;

60 - gaskets;

62 - means for supplying a working gas;

64 - a mirror;

65 - the end face of the tool 28 from the side of the surface of the object 14;

66 - spring.

Using the device 10 shown in FIG. 1, a method for modifying external surfaces or internal open cavities with a surface curvature radius of at least 0.1 m is as follows.

The radiation 26 of a repetitively pulsed laser 20 by an optical system 22 for transporting and forming a laser beam is directed into the reaction chamber 24 and is combined with a high-speed working gas stream 18 consisting of a carrier gas and alloying elements, chemically active reagents. In the area of the laser beam on the surface, an intensity above the threshold for ignition of the near-surface laser plasma 16 should be provided (Fig. 3). For example, for a CO ₂ laser, the level of radiation intensity depends on the type of carrier gas (argon, helium, neon, nitrogen, oxygen, etc.), the type of reagents and dopants (vapors, aerosols), the duration and frequency of laser pulses usually is in the range of 0.1-100 MW / cm ² , but this range may be wider. Without going into details of the physical and physicochemical mechanisms, the formation process (80 of Fig. 3) of the modified layer 12 can be divided into four main stages, which we will consider for the main part (after the initial) series of pulses, when the process becomes stably repeating.

Stage 1 (82 figure 3): - the formation of a laser plasma. In the first phase of stage 1, at the leading edge of the laser pulse, a rapid heating of the surface layer occurs (12a of Fig. 1a), accompanied by thermal / photoemission of electrons. These electrons, together with the electrons left from the previous laser plasma, are the initiators of the avalanche-like development of the optical discharge. To reduce the ablation of layer 12a, it is preferable to carry out this phase in a short (less than 50 ns, preferably 10-20 ns) time. In the second phase, during the action of the main part of the laser pulse, the surface laser plasma 16 forms and develops with its rapid heating to a temperature of 10-20 thousand degrees Celsius, ionization and dissociation (if the carrier gas is molecular, or the initial chemical reagents are present in the working gas in the form molecular gases, vapors, etc.), heating and at least partial melting and evaporation (including ablation) of microparticles of alloying additives, if they are in the working gas in the form of aerosols. In the second phase, a dense laser plasma almost completely absorbs laser radiation, and surface heating is predominantly carried out by radiation and heat transfer of the plasma.

Stage 2 (84 figure 3) - this stage partially coincides in time with the first stage: there is a supersonic (shock-wave) expansion of the laser plasma, which is accompanied by heating of additional areas of the working gas bordering the plasma, including their dissociation, ionization and activation, by equalizing the plasma pressure with the pressure of the surrounding gas and general cooling of the plasma to a temperature 2-3 times lower than the temperature of the plasma at the stage of formation.

In the first and second stages, the surface is most intensively heated to high temperatures (usually above the melting point), as well as the surface layer (12a) is saturated with alloying elements. Conditions are created for the formation of thermal and diffusion (alloying elements) flows into the material of the object.

Stage 3 (86 figure 3): the transfer of laser plasma energy to the surface of the object (and dopant microparticles, if present) continues, accompanied by cooling of the plasma and some stabilization of the surface temperature (usually above the melting point). Plasma-chemical reactions proceed intensively at this stage, which lead to the formation of highly activated compounds and nanoparticle nuclei if the starting reagents are used in the form of gases or vapors. In the presence of dopants in the form of microparticles, their at least partial melting occurs. The products of plasma-chemical reactions and / or the molten (at least partially) microparticles of the dopants are carried by the stream to the surface of the object, synthesizing / forming a layer 12a (figa), and diffusion and thermal waves propagate in the material of the object, forming zones 12b and 12c ( figa), respectively.

Stage 4 (88 figure 3): a cooled, almost completely recombined plasma is blown away by the flow of the working gas, which brings a "fresh" portion of chemically active and alloying additives. Due to the removal of heat deeper into the metal, the temperature of the treated surface decreases, preferably below the melting point, in order to eliminate the hydrodynamic effects of surface shape distortion, in particular, the melt splash by the pressure of the laser plasma from the next radiation pulse.

The final formation of zones 12b and 12c (figa) occurs after the completion of a series of laser pulses and phase-structural transformations in the metal of the object. Note that the designation of zones 12b and 12c is relatively arbitrary, since they do not have clear boundaries. The concentration of diffusing alloying additives (and / or compounds with their participation), as well as their effect on the structure and properties of the material in zone 12b, gradually decrease with increasing distance from the surface. The same applies to the zone of thermal phase transformations of 12 s, which in some cases may be absent.

For the effective use of dopants and / or chemicals, the preferred cross-section of the working gas stream formed by the element 28 of the reaction chamber 24 practically coincides with the shape of the area of action of the laser beam 26b on the surface of the object, and the preferred flow rate is set no more than the product of the laser pulse repetition rate by the size laser plasma in the direction of flow after completion of stage 2.

For example, for a CO ₂ laser providing a laser pulse repetition rate in the range of 5-100 kHz, the preferred working gas flow rate with an increase in the aforementioned frequency can be in the range from 10 to 100 m / s.

However, these ranges are optional and may be extended. For example, when using dopants in the form of sufficiently large (more than 10–20 μm) microaerosols, the preferred flow rate of the working gas can be significantly and even many times reduced to increase the duration of laser radiation and plasma.

For a cost-effective, high-performance implementation of the laser-plasma method of surface modification of metals, a laser or a laser system 20 is preferred with a high repetition rate of laser pulses — more than 5000 Hz (in some cases, this frequency may be lower) having such a laser pulse power that a laser pulse is generated plasma 16. For example, in one of the successful embodiments, a CO ₂ laser was used with a pulse repetition rate from hundreds of hertz to 100 kHz and a pulse power of tens and hundreds yen kilowatt. Other types of lasers, both gas and solid state, with other power ranges, can also be used.

The optical system 22 is designed to transport and generate laser radiation, as well as to direct part of the radiation (usually insignificant) to the systems for measuring and monitoring the characteristics of laser radiation 32, as well as laser plasma radiation and the temperature of the treated surface 34. For example, system 22 may consist from several mirrors, including movable ones, that provide movement of the laser beam, including a reaction chamber moving at the surface of the object being processed, beam formation in working gas stream 18 on the surface of the object, and for alternately directing the laser beam in different reaction chambers, if the device has a plurality of reaction chambers. In another embodiment of the invention, a system for transporting and focusing laser radiation 22 may include an optical fiber for transporting laser radiation in one or more sections of the optical path.

In preferred embodiments, the system 22 comprises at least one diffraction mirror for forming a laser beam exposure region in a form preferred for a particular technology (for example, close to a rectangular or round shape) with a close to uniform (uniform) illumination intensity.

In preferred embodiments, the system 22 comprises one or more translucent partially reflective elements, for example optical wedges with flat surfaces through which the laser beam passes, to reflect part of the radiation into the systems 32, 34, as well as at least one lens for focusing the beam or coordination of sections of the optical path.

The optical system 22 directs the laser radiation to the input window 23 of the reaction chamber 24, which can be made in the form of a lens. A converging laser beam 26b passes inside the protective cavity 27 (Fig. 1), in which to significantly reduce, until completely eliminating, the absorption of laser energy by the flow of the working gas 18 in the beam section in front of the plasma, as well as to protect the entrance window 23 from undesirable exposure to the mixture 18 and plasma, in particular ablation products, shielding gas 29 is supplied, typically a carrier gas under static pressure, slightly 0.1-1 kPa higher than the pressure in the flow forming means 28.

The design of the reaction chamber 24, in addition to the window 23 for introducing a laser beam, may include windows for diagnosing the laser plasma 16 and the resulting coating 12, for example, for video monitoring or optical pyrometry.

To form a cross-section of the working gas stream 18 close to the dimensions of the laser plasma 16, the outlet or nozzle of the working gas stream forming means 28 of the reaction chamber 24 is preferably made close to the shape of the laser beam.

The body of the reaction chamber 24 and the heat-stressed structural elements 27, 28 of a number of units of the means 17 and the system 22 and others can be forced to cool with water or other refrigerant.

The chemical preparation system 40 may consist of one or more subsystems (not shown) with different versions and different types of reagents (gases, vapors, aerosols).

For example, in one embodiment of a device for supplying reagents in the form of hexamethyldisilazane vapors, evaporation is carried out in a carrier gas medium, which is supplied through an adjustable valve 38 from a common gas line 42, and the flow rate and impurity concentration are controlled by the temperature of the evaporator and the flow rate of the carrier gas through the adjustable valve 38. in one successful embodiment, other chemical reagents for supplying a carbon mikroaerozoley and Si ₃ N ₄ used adjustable dosing micropowder to form a slurry with the carrier m gas.

The temperature of the treated object, along with other process parameters, has a decisive influence on the diffusion rate of alloying elements, the structure and phase composition, as well as the properties of the formed near-surface zones 12b and 12c. For example, to increase the martensitic structural component during the processing of high-carbon steels and cast irons, additional cooling of the object is desirable. Therefore, it is advisable to place the processed object 14 on special tools - supporting tables, etc., which are connected by good thermal contact with the node 15, providing thermostat functions - heating or cooling, i.e. maintaining the temperature of the object within predetermined limits controlled by the control processor 30.

The control processor 30, receiving and processing signals of measuring systems 32, 34, etc., as well as nodes 15, 17 through actuators and mechanisms (not shown), controls the operation of the laser 20, nodes 15, 17, means 40, 54, etc. as well as adjustable valves 36, 37, 38 (possibly some others) and ensures that the process is performed in accordance with the steps shown in FIG. 3.

The node / nodes of the means 17 provide positioning and / or relative movement of the processed object and, accordingly, the area of influence of the laser plasma on the surface of the object, which can be translational, rotational, combined.

In more detail, the claimed method for the synthesis of coatings, the main stages of which are shown in figure 3, is as follows.

As the processed objects used to modify the surface of this method, there may be parts of various geometric shapes, consisting of metals or alloys.

The surface preparation of the treated object 70 (Fig. 3) for coating may in some cases be mechanical (turning, milling, sandblasting, honing, grinding, etc.), in other cases, chemical, using detergents and / or chemical means, including using ultrasonic devices, etc., as well as combined. It is important to note that in many cases surface pretreatment is not required, since the laser plasma in conjunction with laser radiation have a strong cleaning effect on the surface of the object being processed. Installation and fixing of the treated object 14 in some cases should provide good (with a small temperature difference) thermal contact with the thermostat 15. In some other cases, when the heat transferred to the processed object during laser-plasma processing heats the surface of the object to a temperature in some specified optimal limits, thermal contact may be poor or thermostat 15 may not be required.

The preparation of the reaction chamber (72, FIG. 3), in addition to the obvious preventive cleanings or cleanings when replacing the composition of the dopants and the starting reagents, consists in some cases (FIG. 1) in purging the reaction chamber with carrier gas, preferably with multiple (3-10 times) replacement initial air to the carrier gas.

The beginning of the laser-plasma process 74 consists in igniting and maintaining for some (small) time the laser plasma 16 in the carrier gas stream (usually without dopants and chemicals) to clean, activate and establish a certain preferred surface temperature of the treated object.

The supply of a mixture of dopants and / or starting chemicals 76, and the formation of a working gas stream occur almost simultaneously after the completion of the laser-plasma process of preparing the surface of the object 74 and continue until the completion of the entire process of modifying the surface of the object.

As constituent mixtures of alloying additives and starting reagents, various chemical elements and compounds in various states of aggregation can be used.

For example, in some successful embodiments of this method, it is sufficient to use nitrogen gas (N ₂ ) to modify (nitrize) the surface of cast iron, without any other additives.

Laser-plasma modification of the surface 80 (including the stages 82, 84, 86, 88 described above) is carried out almost simultaneously (with a shift by the time required to modify the initial region) with a relative movement of 90 of the surface of the treated object and the area of influence of the laser plasma stream.

In some other cases, when it is required to obtain an area of modification of the surface of an object with smaller dimensions relative to the size of the area of influence of the laser plasma, aperture masks (not shown) with holes / slots of the required shape that are superimposed on the surface of the object and limit the processing area of the object can be used.

At the end of some predetermined surface modification process, the supply of chemical reagents ceases, and the laser beam can be blocked or directed to another reaction chamber 94 if the laser-plasma modification device contains several reaction chambers.

In some cases, the change of the processed object 96 is carried out after a sufficient time of the presence of the treated object in an inert atmosphere (usually in a carrier gas medium to lower the temperature of the coating 12a and the surface of the object below a certain one, exceeding which may cause undesirable exposure to the air atmosphere.

Compared with a variant of the device 10 (FIG. 1), the device 50 (FIG. 2) is designed to implement a method for modifying the inner cylindrical surfaces with the possibility of rotation of the reaction chamber when the workpiece is bulky (for example, a cylinder block of an internal combustion engine) or the diameter of the work cylinder no more than ~ 0.2 m.

The body of the reaction chamber 24 is placed in a ferrule 56, which is mounted on the platform 52 with the ability to move the means 17. The means 54, which can also be located on the platform 52, allows the means controlled 30 (not shown in FIG. 2) to rotate the reaction chamber around the axis cylindrical body. The holder 56 also serves as a collector for supplying gases (carrier and / or working) to the reaction chamber through the inner annular grooves 58 and holes (at least one) 59. If necessary, at least one groove 58 can be used to cool the reaction vessel chambers with water or other refrigerant. To seal, separate the volumes of the grooves 58 and to ensure the sliding of the cylindrical body of the reaction chamber 24 in the holder 56, sliding seals 60 (for example, of graphitized fluoroplastic) can be used. The mirror 64 is used to direct the laser beam 26b through the means of forming a stream 28 of the working gas 18 to the surface of the processed object 14 to form a laser plasma 16. If necessary, to separate the flows of carrier gas and working gas, the latter can be supplied by means 62 from the annular groove 58 in the clip 56 in a similar groove 58 and through the openings 59 in the flow forming means 28. In a similar way, cooling of the means 28 can be ensured. In order to maintain a close to constant, small (~ 0.1-0.3 mm) clearance between the machining the surface of the object 14 and the end face 65 of the tool 28 facing the surface to be treated, the tool 28 can axially slide in the housing of the reaction chamber 24. To stabilize the gap, a spring 66 is used, which compensates for the vector sum of the centrifugal force and the force arising from the pressure difference in chamber 24 and in the gap, taking into account the Bernoulli effect. The design of the element 46 of the reaction chamber should provide a small gap with the surface of the treated object 14, so that the flow of exhaust gas 48 prevents the flow of atmospheric air into the zone of surface modification 12.

The positioning and relative movement of the area of influence of the laser plasma flow and the surface of the object 14 can be carried out both by moving the processed object, and by moving the reaction chamber or a combination of these movements.

The described method and device allow nitriding, cementing of surfaces of parts made of cast iron and steel, alloying with pure metals or alloys with the formation of supersaturated solid solutions and the formation of intermetallic compounds, alloying with carbides of refractory metals (TiC, VC, TaC, WC, etc.).

Claims (10)

1. A method of modifying the surface of an object made of metal or alloy, comprising exposing the surface to be modified by laser radiation, characterized in that a flow of a working gas containing a carrier gas is formed, as well as chemically active reagents and / or alloying additives, and the said working stream is directed gas on the surface to be modified, wherein the said surface to be modified is affected by laser pulse-periodic radiation with the formation on the named surface to be modified and / or e the surface region of the laser plasma. 2. The method according to claim 1, characterized in that the working gas stream is formed with a pressure of at least 0.5 atm. 3. The method according to claim 1, characterized in that the exposure to laser radiation is carried out repeatedly. 4. The method according to claim 1, characterized in that inert gas or a mixture of inert gases is used as a carrier gas. 5. The method according to claim 1, characterized in that a chemically active gas or a mixture of reactive gases is used as a carrier gas. 6. The method according to claim 1, characterized in that the surface to be modified is moved. 7. A device for modifying the metal surface of an object, comprising a reaction chamber equipped with positioning tool for the object to be treated, an input for a working gas stream and an input for laser radiation, a working gas source, means for generating a working gas stream in the reaction chamber, a periodic pulsed laser, and a delivery means laser radiation into the reaction chamber and focusing the beam, made with the possibility of directing the laser beam on the modified surface of the object. 8. The device according to claim 7, characterized in that it comprises control means in the form of a control processor. 9. The device according to claim 7, characterized in that the positioning means of the processed object is arranged to move it. 10. The device according to claim 8, characterized in that the means for delivering laser radiation to the reaction chamber and focusing the beam is made in such a way that the laser beam acts on the surface to be modified.

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