WO1993009260A1

WO1993009260A1 - Coating for metallic or non-metallic substrates, process and device for producing the same

Info

Publication number: WO1993009260A1
Application number: PCT/AT1992/000139
Authority: WO
Inventors: Helmut Strauss
Original assignee: Helmut Strauss
Priority date: 1991-11-05
Filing date: 1992-11-04
Publication date: 1993-05-13
Also published as: ATA218991A; DE4293695D2; AU2896892A; AT398580B

Abstract

A coating is disclosed for metallic or non-metallic substrates. The surface of the substrate is at least partially provided with a heat-, thermal shock-, wear-, impact- and/or corrosion-resistant coat applied by a thermal process, having several layers based on at least one coating component from at least one of the groups of thermally stratifying substances. The coat has at least two mutually bonded layers. The substrate itself is bonded to a substantially compact, at least unilayer basis layer ('first layer'), applied by a thermal coating process, bonded in turn to at least one at least unilayer additional or covering layer ('second layer') applied by a thermal spraying process and containing finely or ultra-finely dispersed particles of at least one of the abovementioned stratifying agents, compounds, metals and/or alloys having a specific surface area of at least 6 m2/g, in particular at least 8 m2/g (according to Blaine). Said particles from an intermediate layer formed before the additional layer is sprayed on the basis layer are applied into and distributed in the additional layer. A process and equipment for producing this coating are also disclosed.

Description

Coating for metallic or non-metallic

Substrates, method and device for their production

The invention relates to a coating for metallic or non-metallic substrates accessible by thermal material application, wherein at least parts of the surface of the substrate are covered with a heat, thermal shock, wear, impact and / or corrosion-resistant, multi-layer coating applied by means of a thermal process are provided on the basis of at least one coating component from at least one of the groups of the thermal layer-forming substances, “cermets”, oxides, carbides, nitrides, borides, suicides, fluorides, phosphates, silicates, metals, intermetallic compounds and metal alloys, Process for forming the above-mentioned coatings and a device for carrying out the process.

From the multitude of coating methods that have become known, surface treatment, coating with galvanic, CVD and PVD processes, melt and powder dipping, plating and the most varied spraying techniques are by no means fully mentioned. Objects equipped with the surface protection mentioned at the outset are likewise only examples of internal combustion engine components, piston rings, turbochargers, gas turbine blades, engines, rocket nozzles, furnace and mold linings, casting vessels, pouring openings, blow lances, forging dies, crusher jaws, grinder components and rolling mill coatings and rolling mill rolls and coatings of components of metallurgical, energy and chemical plants called.

The thermal spraying on which the method according to the invention is based is a well-known method for the surface coating of metallic and non-metallic materials. For this purpose, gas-heated sprayers for powder, wire, rod-shaped materials, plasma sprayers for powder and wire-shaped materials and arc sprayers for wire-shaped materials, as well as detonation spraying are used.

The most common materials for thermal spraying are in the DIN regulations DIN 8566, Part 1 = solid wires for the

Flame spraying, DIN 8566, part 2 = solid wires for arc spraying, DIN

8566, part 3 = cored wires and rods for flame spraying, DIN 32529 = powder for thermal spraying, DIN 65097 = aerospace, powder for thermal spraying and DIN 55928. Up to the present time, powdery additional materials have only been used for grain spraying with powders of substantially more than 1 μm. As a result of the development of new technologies, which require the highest temperature, corrosion and also thermal and mechanical shock resistance, the disadvantage of coatings and coatings obtainable by known methods is that they are applied only in relatively thin layers can. At higher layer thicknesses, phenomena occur, which are due to various "stress factors", which can lead to crack formation, flattening and mechanical stresses within the layer itself and ultimately also between the respective coating and substrate.

It is known from FR-PS 853 144 to reduce the susceptibility to corrosion of metallic substrates on their surface, particles of poorly soluble chromates or dichromates together with or e.g. to be applied in an overlapping application just before the thermal spraying of metal layers.

Furthermore, e.g. EP-AI 275 083 describes a pretreatment agent for metal syringes which is applied to a metallic substrate, e.g. Steel applied with a spray coating based on a material that is supposed to be less noble than the substrate. This agent contains particles with sizes of e.g. 5-200 μm, based on oxides or carbides of Si, Al or Fe and supports the anchoring of the covering metal spray layer on the substrate.

Based on detailed investigations, a method has now been found which tries to get the described problems under control by avoiding the build-up of the above-mentioned stress factors within a layer which, according to previous terms, is "much too thick" during manufacture or within the layer of stress already built up is reduced again.

The present invention accordingly relates to a method of the type mentioned at the outset, which is characterized in that the coating essentially comprises at least two layers bonded to one another, an essentially compact, at least single-layer base layer applied to the substrate itself by means of a thermal coating method ("1st layer"), which in turn is bonded with at least one further particle, which is itself very fine or ultra-disperse The above-mentioned layer formers, compounds, metals and / or alloys

2 with a specific surface area of at least 6 m / g, in particular

2 at least 8 m / g, distributed (according to Blaine) containing, applied by means of thermal spraying, at least single-layer second or top layer ("second layer"), into which second layer the particles mentioned are connected with them in front spraying the

Second layer ^{1 are entered} on the intermediate layer formed intermediate layer.

The above-mentioned "-ids" in the individual layers of the coating are primarily those of subgroup elements, in particular the 2nd to 6th subgroup, including those with magnet and / or electret properties, as well as "mixed oxides", silicates or. the like like spinels. As layering agents are enamels, glazes, glasses or the like. called.

A characteristic and, as has been found, a very significant feature of the coatings according to the invention and the technology on which their manufacture and application are based is the use of so-called ultradispersive powders, i.e. of particles with dimensions which, from a mechanical point of view, practically no longer cause them to be inhomogeneities, but rather as the homogeneity of multilayer, that is to say thick, coating layers and their integration into one another which promote components thereof appear.

The new coatings receive the described characteristics in a simplified way in the following way: Thermal spraying devices apply metallic or non-metallic material to metallic or non-metallic surfaces of a workpiece. With a separate apparatus, either ultradispersive powder dispersed in a liquid, with or without the addition of surface-activating salts, or salts which contain starting components of the thermal spray layer, are dissolved or suspended in a liquid, e.g. conveyed with a carrier gas, applied to a thermal spray coating. The process of layer formation and in particular the introduction of disperse particles into a subsequent thermal spray layer is carried out by overmolding of ultradispersive particles applied to the base layer covering the workpiece with a further thermally sprayed layer.

When spraying the "2." and each subsequent layer of the coating is a kind of mechanical "whirl" from the outset ultradisperse or as a solution or as a chemical compound monomolecularly present, ie "latent ultradispersive" particles, this whirling is further supported by "flash evaporation" of the solvent, for example, as a result of shock-like heating when the "next" thermal spray layer is sprayed on. Control of the resuspension is carried out by a "hold-down" effect of ^'by the straight contained in the order - the sprayed particles is achieved, so that- a resuspension of ultradispersiven particles in areas outside the coating practically does not occur. Ultimately, therefore, there is a further thermal spray layer on a previously applied thermal spray layer, in which, starting from a respective boundary layer with the previous layer, where there may be a higher concentration of ultradispersive particles, the finely dispersed particles of a previously applied disperse coating are fine distributed. When a next layer is sprayed, these particles are partly pressed into the surface of the previous layer due to the pressure and temperature conditions, which may melt slightly, and in their quasi-homogeneous distribution form a kind of mediator between the individual layers of the coating . With these particles, a reduction of the stress that occurs solely as a result of the temperature difference between the previously applied and freshly sprayed layer, but also as a result of the high mechanical stress during the spraying process itself, and an integral adhesion of the individual layers to one another is ensured. The invention is thus capable of practically eliminating or reducing problems which have previously occurred in the case of thermally sprayed, multi-layer layers of greater thickness, such as microcracks, microcracks, flaking and the like, in such a way that disturbances such as have hitherto occurred with such layers, are no longer to be expected. When applying a multi-layer coating, the process is such that after a thermal base coating, the application of the ultradisperse or latent ultradisperse particles is carried out, and then a spray layer, again an intermediate layer of ultradisperse particles, then a conventional spray layer, etc. are applied sequentially . A particular advantage of this procedure is that an additional device that can be produced with little effort is sufficient to apply the ultradisperse layer in order to supplement a spraying process that would otherwise be carried out conventionally and on existing systems. The invention thus brings about a substantial improvement in the properties of the layers, which can be produced by known thermal spray processes, with respect to layer thickness, porosity and pore distribution, heat protection, wear resistance, heat resistance, long-term fatigue stress, etc.

The main characteristic of the invention is that components exist and are distributed in the ultradispersed state in the spray layer formed or in its individual layers.

The insertion of particles with a specific surface area of more

2 as 6 / g is therefore in addition to the application of a known thermal

Spray layer made and changes the previously known layer properties advantageous. The presence of components in an ultra-dispersive state in the thermal spray layer improves the wear and heat resistance properties while at the same time maintaining the known good thermal protection properties. The incorporation, formation and distribution of components in the ultra-dispersive state in the coating layer to be formed ensures and increases the active development of the physico-chemical interaction processes in the mass of the material to be formed; furthermore, if desired, the uniformity of the distribution of the pores in the coating composition is ensured and increased, whereby an improvement in wear resistance, heat resistance and heat protection properties is achieved.

A very important basis of the invention is that when particles with a specific surface area of less than 6 are introduced

2 m / g, the described effects of the ultradisperse state of the particles do not occur, the coating which then forms has pores which are distributed non-uniformly in the coating mass and in size, with the result that the wear resistance and the heat resistance are never longer than 100 hours are guaranteed. With the enlargement of the specific

The surface (over 6 / g) of the particles introduced into the coating formation zone improve the high temperature and

Wear properties, as found, abruptly.

A particularly favorable matching of the thicknesses of the layers of the thermal spray and ultra-dispersive components to one another can be achieved with a preferred coating, which has the properties described in claim

2 features mentioned.

Will special coatings immunity to thermal and Aiming for mechanical "shocks", a variant of the coating according to claim 3 has proven to be particularly favorable. As a result, negative phenomena resulting so far have been practically eliminated due to layers of different thermal expansion arranged one on top of the other. Coatings with the particularly preferred components according to

A n s r u c h 4 are characterized by particularly favorable properties with regard to thermal, chemical and mechano-stress, whereby the stabilization mentioned further extends these positive effects. If intermediate layers or particles built into and integrated into the spray layer are provided with the preferred dimensions specified in A n s r u c h 5, in addition to practically complete stress reduction within the layer, a decrease in their brittleness can be observed while maintaining their hardness. Particularly preferred due to their high effectiveness and availability are the particulate materials comprised by A n s pr r u c h 6.

A multi-layer coating, as according to the advantageous

Embodiment according to claim 7 is provided, is particularly to be preferred if objects which are exposed to high abrasive, corrosion or hot exhaust gas loads are to be provided with thick layers for increased protection of a substrate.

In the preferred configuration of the individual layers of the coating according to the invention in accordance with A n s r u c h 8, a particularly stress-resistant shape for binding the individual layers to one another is achieved.

Another essential object of the invention are methods for forming a coating of coatings, as described above, the basic method being characterized in its essential features by the characterizing part of claim 9. The particles as such can be ultra-dispersive as such, e.g. be present in a carrier fluid, which can be a gas or a liquid, but furthermore also as practically monomolecular units dissolved in a solvent, or else e.g. released as such from an organometallic compound or its solution in situ when the next thermal spray layer is sprayed on.

It is essential that by applying heated particles of the or a "second layer", a whirling up of the particles of the ultradispersive intermediate layer is mechanically pulse-induced and by shock evaporation of the solvent or a decomposition product of organic-organic compounds, etc., and that either the already present as ultradisperse particles or in situ as such, for example, ultradispersive particles formed from a solvent are genuinely introduced into the next layer. This ensures an optimal distribution of the stress reduction components integrated into the layer, which form these fine particles.

There is an intimate integration in the layer formation process, which connects the ultradisperse component with the thermal spray layer by means of physico-chemical alternating processes that have not yet been fully understood, whereby ultimately the superficially "roughened, sintered, corroded or / and melted" component in the ultradispersive state into the thermal Spray layer is integrated. According to the invention, the components can be applied to the thermal spray layers in one layer, in multiple layers or in a sandwich process. A thermally applied base layer and a final top layer, which is always a thermal spray layer, are mandatory. The components of the ultradispers intermediate layer must always be overlaid by a thermal spray layer to form the novel character of the spray layer.

The particularly preferred multi-layer coating provided in accordance with A n s r u c h 10 enables, for the first time, the production of “high-thickness” layers with unexpectedly favorable properties, which are often quite in the centimeter range, as have already been described above. When using intermediate layer components with the previously defined particle sizes according to claim 11, a layer structure designed specifically for specific later stresses can be achieved, the polyvinyl alcohol provided as a dispersing agent having a particularly homogeneous and low height gradient distribution of the finely dispersed powder in the the person to be applied himself and when the intermediate layer is overmolded, this ensures controlled shock evaporation and entrainment of the particles into the newly applied layer in a particularly advantageous manner.

In a procedure according to claim 12, particularly fine distribution and homogeneity of the particles of the intermediate layer can be achieved in the thermal spray layer sprayed onto them. For example, it can decompose an organometallic compound to form ultra-dispersive Metal particles, but also metal oxide particles. The formation of hydroxides, for example titanium hydroxide or aluminum hydroxide, by precipitation, whereby a desired oxide particle and an evaporation of the water released which promotes its entry into the spray layer, can be achieved by shock heating during overmolding.

A use of compounds as sForm the preferred ^embodiments' provides the on s pru c hes 13, on the one hand a particularly high homogeneity of the distribution can be achieved even on the other hand a specific gas of the particles of the intermediary layer in the carrier fluid and Steam development of the organic acid component on contact with the hot, newly applied, thermal spray layer; the homogeneity of the dispersion is also improved.

If the quantity ratios according to A n s ru c h 14 are observed, coatings with a particularly favorable overall property profile can be obtained.

A procedure according to A n s r u c h 15 can advantageously contribute to the prevention of coagulation and a lack of homogeneity when applying the intermediate layer. In an advantageous mode of operation according to claim 16, particularly high fine dispersity of the particles built into the next thermal spray layer can be achieved.

A combined process is achieved by an intermediate layer application process according to claim 17. The ultradisperse solid particles are not suspended in an inert carrier liquid or in a binder and applied as such a suspension. Rather, the liquid phase provided for suspending the particles itself forms one or at least one output component for the formation of additional, in many cases even more highly dispersed particles, for example by evaporation of the solvent in the previously practically monomolecular distribution of the particles, for example by decay or decomposition , particle-forming salts or compounds was present. When the solid particles are suspended in a liquid element-organic particle-forming compound as the starting component for the further ultradisperse particles, very similar effects can be achieved, the advantage of which is the particularly tension-free homogeneity of the second layer (s) ultimately present. This probably arises from the fact that the solids already present in such suspensions lying ultradisperse particles of ultra-ultradisperse, only by decomposition or the like. the particle particles formed in the liquid phase are encased. This should result in an advantageous ultradisperse surface roughness of the ultradisperse particles. Sometimes the energy impact of the hot material of the second layer is achieved in this höchstdispers coated ultra fine particles ^• a removal of the höchstdispersen particles and -whose entry as such in the second layer, which both Phäno¬ mene to reduce stress seems to be particularly promote. Another object of the invention is a particularly preferred embodiment of a device for preparing the fine particle dispersions provided for the application of the intermediate layer. Their essential features are summarized in claim 18. With the new device, which is specifically targeted to the coating according to the invention and its method for producing it, optimum homogeneity can be achieved in a simple manner, in particular in the particle size and possibly also subsequent breakup of particle agglomerations in individual particles.

Finally, a further object of the present invention is the use of the intermediate layer-forming components with the characteristics mentioned in A n s r u c h 19 for the purposes mentioned there.

The preferred spraying device according to the invention to be used is explained with the aid of the drawing. In the device shown, the essential components described below and the method of operation specified there are provided.

The ultra-dispersive powder and / or the further components are dispersed in liquid and filled into the spraying device. The device 100 comprises a pressure vessel 4. The prepared components are filled into the pressure vessel via the filling funnel 14. The fill level in the pressure vessel is indicated by the fill level indicator 11. Via pressure connection 5 and pressure control 6, the pressure vessel is kept continuously under 3 to 10 bar overpressure, depending on the spray layer to be formed. The excess pressure in the pressure vessel is recorded by means of the pressure indicator 13. A pressure relief valve 7 protects the system against impermissibly high pressure and ensures occupational safety. The components filled in the pressure vessel rise over the riser pipe 12 under the pressure conditions of the prevailing in the pressure vessel Pressure for delivery control 8 and fine metering 9 to the spray gun. The flow rate measurement 15 regulates reproducible amounts of the dispersed components.

The dispersed components are prevented from segregating as described below: According to the invention, the mixture of the ultradispersive powders, with or without addition, is to be kept in a dispersed state in liquid with a uniform mixture distribution. This is achieved in that the pressure vessel in the arrangement shown is placed in a tub 20 filled with liquid 2. The fill level of the medium transmitting the vibration is displayed on a measuring scale 10.

Under this tub (vibration container) is the necessary vibration

(Vibration) either by ultrasound, or by conventional

Vibration 1 is generated and transferred to the vibration medium. The

Vibrating fluid 2 can be refilled through the filler neck 3. The withdrawal quantity of the dispersed liquid is determined either by the difference in the quantity scale display in the pressure vessel, or by a special balance, which is integrated in the spraying system

(Delivery counter).

The conveying and spraying of the dispersed components is carried out as follows: from the fine metering unit 9, the pressure vessel content (the dispersed components) is conveyed via a conveying line from the excess pressure prevailing in the pressure vessel to an atomizer gun 16 (not shown) and from a controllable atomizer nozzle provided with a pressure indicator , applied to the workpiece. According to the invention, the application is carried out either pulsating or continuously atomizing, depending on the layer property promoted.

The invention is explained in detail on the basis of the following examples and comparative examples:

In the examples, the conventional base layer (not described in more detail) and the cover layer (= second layer), which are thermal spray layers, each have the same basic composition. The total layer thickness was between 0.35 and 0.8 mm.

Example 1: The spraying was carried out on an "Aurora" system. ZrO ^ powder stabilized with Y "0" or MgO was used as the material for the coating, and in addition Zr0 ₂ particles with a specific surface area of 2 15 to 35 m / g introduced into the coating formation zone. The was

Arc current strength 800 to 950 A, the voltage 40 to 50 V, the consumption of the plasma-forming gases Ar and H "46 to 75 1 / min or 0.12 to 0.21 1 / min. The characteristics of the coatings produced were evaluated according to the following criteria: open porosity (0P), heat resistance (T), heat resistance (Sh) and wear resistance (I).

The value of the open porosity was determined by hydrostatic weighing, the heat resistance value according to the number of heat changes between 20 and 800 ° C until the moment the coating was destroyed, the heat resistance according to the time (h) until the appearance of cracks when holding the samples with the Coatings in air at 1500 ° C and the wear resistance determined on the basis of the diameter (mm) of the wear spot of a steel ball when rubbed on the sprayed surface for five hours. The coating produced had the following characteristics: 0P: 0.08 to 0.15; T: 847, Sh: 426, I: 0.56.

Example 2:

The procedure was carried out as in Example 1. As a coating material, 25 to 50 μm stabilized ZrO "powder with additional fraction of Al ₉ 0" particles with a specific

2 •• surface of 28 to 30 m / g used in the coating formation zone. A coating with the following characteristics was obtained:

OP: 0.07 to 0.09; T: 956, Sh: 394; I: 0.54.

Example 3:

The procedure was carried out as in Example 1. As a coating material Al O _n the powder fraction was 24 microns to 45 with the additional introduction of Al ₉ 0 particles with a specific

2 surface of 28 to 30 m / g used in the coating formation zone, the arc current was 800 to 850 A. The coating obtained had the following characteristics:

OP: 0.09 to 0.11, T: 821, Sh: 400, 1: 0.75.

Example 4:

The procedure was carried out as in Example 3. Al _^ O ^ powder of the fraction 24 to 45 μm was used as the coating material with the additional introduction of SiO ₂ particles _with a specific Surface from 10 to 15 / g used in the coating formation zone. A coating with the following characteristics was obtained:

OP: 0.07 to 0.09; T: 701; Sh: 365; I: 0.7.

Example 5:

The procedure was carried out as in Example 1. ZrOp powder stabilized with Y D of the fraction 25 to 50 μm was used as the coating material with the additional introduction of an aqueous CrOg solution in the concentration of 1000 g / l into the coating formation zone. The coating obtained had the following characteristics: 0P: 0.08 to 0.09; T: 694; Sh: 492; I: 0.46.

Example 6:

The procedure was carried out as in Example 1. ZrOp powder stabilized with MgO of the fraction 25 to 45 μm was used as the coating material with the additional introduction of an aqueous CrOg solution in the concentration of 1200 g / 1 into the coating formation zone. A coating was obtained with the following characteristics: 0P: 0.08 to 0.12; T: 700; Sh: 456; I: 0.37.

Example 7:

The procedure was carried out as in Example 1. ZrOp powder stabilized with MgO fraction 25 to 45 μm was used as the coating material with additional introduction of tetraethoxysilane into the coating formation zone. The coating obtained had the following characteristics: 0P: 0.1 to 0.15; T: 652; Sh: 496; I: 0.40.

Example 8: The process was carried out as in Example 1. ZrOp powder stabilized with Y 0 _{3 of} the fraction 25 to 50 μm was used as the coating material with the additional introduction of aluminum tri-sec-butoxide into the coating formation zone. A coating was obtained with the following characteristics: 0P: 0.1 to 0.3; T: 587; Sh: 362, I: 0.83.

Example 9:

The procedure was carried out as in Example 1. As The coating material was stabilized with Y "0" of the fraction 25 to 50 μm ZrOp powder with additional simultaneous introduction of a CrC solution in the concentration of 1000 g / 1 and of Zr0_ particles with a

2nd .. specific surface of 15 to 35 m / g used in the coating formation zone. The coating obtained had the following characteristics:

0P: 0.09 to 0.13; T: 607; Sh: 349; I: 0.64.

Example 10:

The procedure was carried out as in Example 1. ZrOp powder stabilized with YO "of the fraction 25 to 50 μm was used as the coating material with the additional simultaneous introduction of a CrO" solution in the concentration of 1200 g / 1 and AlpO "particles with a specific surface area of 28 to 30 m / g used in the coating formation zone. A coating was obtained with the following characteristics: OP: 0.07 to 0.09; T: 767; Sh: 521; I: 0.46.

Example 11:

The procedure was carried out as in Example 1. As

Coating material was stabilized with YO ,, the fraction 25 to 50 μm stabilized ZrOp powder with additional simultaneous introduction of a CrO.-.- solution in the concentration of 1200 g / 1 and of SiO _p particles with a

2 •• specific surface area of 10 to 15 / g used in the coating formation zone. The coating obtained had the following characteristics:

OP: 0.08 to 0.1; T: 756; Sh: 508, I: 0.51.

Example 12:

The procedure was carried out as in Example 1. As a coating material, YpO ,, the fraction was stabilized 25 to 50 μm ZrOp powder with the additional simultaneous introduction of

Aluminum tri-sec-butoxide and Al »0" particles with a specific

2 •• surface of 28 to 30 m / g used in the coating formation zone.

A coating with the following characteristics was obtained:

OP: 0.09 to 0.16; T: 801; sH: 632, I: 045.

Example 13:

The procedure was carried out as in Example 1. Zrθ2 powder stabilized with MgO fraction 25 to 45 μm as coating material with simultaneous separate introduction of a CrO solution in the concentration of 1000 g / 1 and Al ₉ 0 "particles with a

2 - Specific surface area of 28 to 30 m / g used in the coating formation zone. The coating obtained had the following characteristics:

OP: 0.09 to 0.18; T: 844; sH: 462; 1: 0.49.

Example 14:

The procedure was carried out as in Example 1. ^* YpO.-. the fraction 25 to 50 μm stabilized ZrOp powder with additional separate introduction of the CrO _^ solution in the concentration of 1200 g / 1 and of SiO _p particles with a specific

2 -

Surface from 10 to 15 / g used in the coating formation zone. A coating was obtained with the following characteristics: OP: 0.12 to 0.15; T: 736; Sh: 501; I: 0.52.

Example 15:

The procedure was carried out as in Example 1. The coating material used was YpO., The fraction 25 to 50 μm stabilized ZrOp powder with the additional separate introduction of aluminum tri-sec-butoxide and of Al ₉ 0 "particles with a specific

2 - surface of 28 to 30 m / g used in the coating formation zone.

The coating obtained had the following characteristics:

OP: 0.09 to 0.12; Z: 797; Sh: 566; I: 0.43.

Example 16: The procedure was carried out as in Example 1. ZrOp powder stabilized with pO- the fraction 25 to 50 μm was used as the coating material with additional joint introduction of AlpO _^ particles with a specific surface area of 28 to 39 m / g and polyvinyl alcohol into the coating formation zone. A coating with the following characteristics was obtained:

OP: 0.1 to 0.15; T: 646; Sh: 491; I: 0.61.

Example 17:

The procedure was carried out as in Example 1. As a coating material, 25 to 50 μm of the fraction was stabilized with YpO «

ZrOp powder with additional joint introduction of AlpO ^ particles with a specific surface area of 28 to 30 m / g and sodium stearate in

Water is used in the coating formation zone. The coating received had the following characteristics:

OP: 0.1 to 0.12; T: 835, Sh: 709; I: 0.46.

Example 18: The procedure was carried out as in Example 1. ZrOp powder stabilized with YpO ,, the fraction 25 to 50 μm was used as the coating material with the additional joint introduction of a CrO solution in the concentration of 1000 g / l and of polyvinyl alcohol into the coating formation zone. A coating with the following characteristics was obtained:

0P: 0.08 to 0.12; T: 684; Sh: 562; I: 0.5.

Example 19:

The procedure was carried out as in Example 1. ZrOp powder stabilized with Yp0 _{3 from} the fraction 25 to 50 μm was used as the coating material with the additional joint introduction of a CrO ^ solution in the concentration of 1200 g / 1 and of sodium stearate into the coating formation zone. The coating obtained had the following characteristics: 0P: 0.08 to 0.1; T: 913; Sh: 800; I: 0.40.

Example 20:

The procedure was carried out as in Example 1. ZrOp powder stabilized with MgO of the fraction 25 to 45 μm was used as the coating material with the additional introduction of AlpO particles with a specific surface area of 28 to 30 m / g and a CrO solution in a concentration of 1000 g / 1 together with polyvinyl alcohol used in the coating formation zone. A coating was obtained with the following characteristics: 0P: 0.09 to 0.11; T: 759; Sh: 637; I: 0.41.

Example 21:

The procedure was carried out as in Example 1. As a coating material, Yp0 _{3 of} the fraction stabilized 25 to 50 μm ZrOp powder with the additional introduction of Alp0 "particles with a specific surface area of 28 to 30 / g and a Cr0 ₃ solution in a concentration of 1000 g / 1 together with Sodium stearate is used in the coating formation zone. The coating obtained had the following Characteristics on:

OP: 0.09 to 0.15; T: 946; Sh: 821; I: 0.39.

Claims

Patent claims:

1. Coating for metallic or non-metallic substrates that are accessible to thermal material application, at least parts of the

Surface of the substrate with a heat, thermal shock, wear, impact and / or corrosion resistant, multi-layer coating applied by means of a thermal process based on at least one coating component from at least one of the groups of the thermal layer-forming substances, " Cermets ", oxides, carbides, nitrides, borides, suicides, fluorides, phosphates, silicates, metals, intermetallic compounds and metal alloys are provided, fine particles of a solid phase being distributed in at least one layer, characterized in that the coating in essentially comprises at least two layers bonded to one another, wherein an essentially compact, at least single-layer base layer (“1st layer”) applied by means of a thermal coating process is bonded to the substrate itself, which in turn is coated with at least one further, even very fine or ultra-disperse particles of at least one or one of the above-mentioned layer images ner, compounds, metals and / or alloys with a specific

2 2

Surface area of at least 6 / g, in particular at least 8 m / g, (after

Blaine) distributed containing, applied by means of thermal spraying, at least single-layer second or top layer ("second layer") is connected, in which second layer said particles from one with them before spraying the second layer intermediate layer formed in the base layer and are distributed therein.

2. Coating according to claim 1, characterized in that the base layer and second layer (s) each have a total thickness of about 20 to 100 microns, preferably from about 30 to 50 microns, and the ultradisperse particles from an intermediate layer with a thickness from about 0.5 to 5 μm, preferably from about 0.5 to 1 μm, are entered in the second layer.

.

3. Coating according to claim 1 or 2, characterized in that the base and second layer, optionally also the particles of the second layer originating from the intermediate layer, of the coating are formed with substantially identical coating components with respect to the material composition.

4. Coating according to one of claims 1 to 3, characterized characterized in that the layers of the coating mutually different or the same material with at least one oxide of the transition metals of the 4th to 6th subgroup of the periodic table and the elements Be, Mg, B, Al, Si, Sn, Cu and Zn as the main component are formed, the base and / or second layer, if with. Transition metal oxides are formed, optionally stabilized with at least one oxide of Y and / or Mg with a particle size fraction of 25 to ^" 50 microns.

5. Coating according to one of claims 1 to 4, characterized in that the ultradisperse particles originating from the intermediate layer in the second layer have a particle size corresponding to a specific surface area of 10 to 45 m ^z / g, preferably 25 to 40 m ² / g (according to Blaine).

6. Coating according to one of claims 1 to 5, characterized in that the finely dispersed particles are formed with at least one material from the group of oxides of Al, Si, Ti, Zr and Cr.

7. Coating according to one of claims 1 to 6, characterized gekenn¬ characterized in that it to achieve the desired overall thickness of the coating with a plurality of applied to the base layer, each with its own intermediate layer, originating, containing ultradisperse particles distributed "second -Schichteπ "is formed.

8. Coating according to one of claims 1 to 7, characterized in that the second layer or a single second layer located within a coating comprising a plurality of second layers, in each case starting from the base layer or one directly below it arranged second layer has a negative gradient of the amount of ultradisperse particles per unit volume (decreasing "particle concentration").

9. A method for forming a coating of coatings according to one of claims 1 to 8, characterized in that at least

Parts of the surface of the substrate, a coating comprising at least three layers based on at least one coating component from at least one of the groups mentioned in claim 1 is applied, at least one of which is applied to the substrate by means of application, thermal deposition, thermal spraying, sputtering or melt dipping a single-layer base layer ("1st layer") is bound, onto which at least one of the coating components themselves or corresponding starting materials for in. by the supply of very finely or ultra-dispersely distributed particles In situ formation of ultradispersive particles of which an at least single-layer intermediate layer bonded to the above-mentioned base layer is applied, which particles of at least one of the above-mentioned coating components with a specific surface area of at least 6 m ² / g (according to Blaine) on which by means of thermal and / or electrical spraying a further, at least single-layer, second or top layer ^: ("2nd layer") is applied on the basis of at least one ^"of the coating components, during the spraying process and / or by there is an immediate entry of the ultradisperseπ particles of the intermediate layer into the forming second layer.

10. The method according to claim 9, characterized in that to form coatings of desired higher thickness after binding the base layer to the substrate in a plurality of operations each, preferably in succession, an intermediate coating with ultradisperse particles and, preferably directly thereafter , the application of a "second layer" - with simultaneous entry of the ultradisperse particles into it - is carried out.

11. The method according to claim 9 or 10, characterized in that the intermediate layer by applying, preferably spraying, a dispersion of finely or ultra-dispersively distributed, a specific surface area of at least 6 m ² / g, in particular at least 8 m ² / g (according to Blaine) having particles of the intermediate layer-forming component (s) itself in a carrier fluid, preferably polyvinyl alcohol, on which the base layer is not formed.

12. The method according to any one of claims 9 to 11, characterized in that to form the intermediate layer, preferably in a carrier fluid, very fine or ultra-disperse particles of by decomposition, conversion and / or chemical reaction to the intended composition of the intermediate layer forming component (s) leading starting componentπ, in particular salts or organometallic compounds, are applied to the base layer or to a previously applied second layer.

13. The method according to any one of claims 9 to 12, characterized in that in the formation of the intermediate layer the intended components or starting components or their particles surface-active salts or surfactants, preferably those based on aliphatic acids, especially alkali palmitates or - stearates.

14. The method according to any one of claims 9 to 13, characterized gekennzeich¬ net that the formation of the intermediate layer, the ratio of the mass of the very finely or ultra-dispersively distributed particles of the intermediate layer-forming components or starting components to the total Mass carrier fluid and particles to values from 0.5: 100 to 50: 100, preferably from 0.8: 100 to 14: 100.

15. The method according to any one of claims 9 to 14, characterized in that the ultradisperse particles or components or the starting components for the formation of the intermediate layer are kept uniformly distributed by vibration in the carrier fluid at least during the Au bring them.

16. The method according to any one of claims 9 to 15, characterized in that as the ultradisperse particles of the Ausgaπgs components for the formation of the intermediate layer used in the form of a solution or suspension of at least one salt of the elements mentioned in claim 4 and finely dispersed on the Base or a previously applied second layer can be applied.

17. The method according to any one of claims 1 to 16, characterized gekenn¬ characterized in that a mixture or a suspension of ultradisperse solid particles in the solution of at least one salt of the elements mentioned in claim 4 or a liquid compound thereof (starting components for ultra-disper particles) and is applied finely dispersed to the base layer or a previously applied second layer.

18. Device for carrying out the method according to one of claims 9 to 17 for the preparation of a particle dispersion provided for applying the ultradispersive particles of an intermediate layer in a coating according to one of claims 1 to 8, characterized by a with a pressure control device (6) pressure-sensitive dispersing vessel (4) with flow-controllable feed line (5) for the pressure-promoted introduction of a suspension of particles suspended in a carrier fluid of the components or starting components intended for the formation of the intermediate layer and with one from the inside of the vessel (4) outgoing, flow-controllable discharge line (12) for supplying a dispersion of particles dispersed in the carrier fluid in a very fine or ultra-dispersive manner into an atomization or spray application device (16), the dispersion vessel (4) having an amplitude and / or frequency controllable vibration device essentially directly connected or at least Partial areas of the dispersion vessel (4) are arranged within a vibration medium (2) which can be oscillated by means of a vibration device (1).

19. Use of at least one or one heat-decomposable, organometallic compound and / or salt of the elements mentioned in claim 4 alone, dissolved in a solvent or suspended in a carrier fluid, with the proviso that they are particles with a specific surface area of at least 6 m / g are present or are brought to this for the production of the intermediate layer of a heat, thermal shock, wear, impact and / or corrosion-resistant coating of metallic or non-metallic substrates according to one of claims 1 to 8, in particular in a method according to any one of claims 9 to 17.