阅读说明：本技术 一种耐温1650℃纤维增强陶瓷基复合材料表面抗氧化/红外隐身涂层及其制备方法 (Anti-oxidation/infrared stealth coating on surface of fiber-reinforced ceramic matrix composite material with temperature resistance of 1650 ℃ and preparation method thereof ) 是由 刘海韬 黄文质 孙逊 于 2020-06-30 设计创作，主要内容包括：本发明涉及高温红外隐身材料技术领域,具体公开一种耐温1650℃纤维增强陶瓷基复合材料表面抗氧化/红外隐身涂层,所述红外隐身涂层为层状结构,从下到上依次包括陶瓷内层、陶瓷中间层、陶瓷外层和低红外发射率功能层,所述陶瓷内层为莫来石层,所述陶瓷中间层为稀土硅酸盐层,所述陶瓷外层为8YSZ层,所述低红外发射率功能层是以Pt为导电相、Bi<Sub>2</Sub>O<Sub>3</Sub>为粘结相的涂层。本发明还提供了耐温1650℃纤维增强陶瓷基复合材料表面抗氧化/红外隐身涂层的制备方法。本发明的红外隐身涂层提高了复合材料的抗氧化性能和高温稳定性,可以显著降低基材的红外辐射强度,具备优异抗氧化性能和红外隐身功能。(The invention relates to the technical field of high-temperature infrared stealth materials, and particularly discloses an anti-oxidation/infrared stealth coating on the surface of a fiber-reinforced ceramic matrix composite material with temperature resistance of 1650 ℃, wherein the infrared stealth coating is of a layered structure and sequentially comprises a ceramic inner layer, a ceramic intermediate layer, a ceramic outer layer and a low infrared emissivity from bottom to topThe ceramic inner layer is a mullite layer, the ceramic middle layer is a rare earth silicate layer, the ceramic outer layer is an 8YSZ layer, and the functional layer with low infrared emissivity is formed by taking Pt as a conductive phase and Bi 2 O 3 Is a coating of a binder phase. The invention also provides a preparation method of the anti-oxidation/infrared stealth coating on the surface of the fiber reinforced ceramic matrix composite material with the temperature resistance of 1650 ℃. The infrared stealth coating improves the oxidation resistance and the high-temperature stability of the composite material, can obviously reduce the infrared radiation intensity of the base material, and has excellent oxidation resistance and an infrared stealth function.)

1. The utility model provides a temperature resistant 1650 ℃ fiber reinforcement ceramic matrix composite surface oxidation resistance/infrared stealth coating, infrared stealth coating is laminated structure, its characterized in that, from the bottom up includes ceramic inlayer, ceramic intermediate layer, ceramic skin and low infrared emissivity functional layer in proper order, the ceramic inlayer is the mullite layer, the ceramic intermediate layer is the tombarthite silicate layer, the ceramic skin is 8YSZ layer, the low infrared emissivity functional layer is with Pt as conducting phase, Bi to low infrared emissivity functional layer₂O₃Is a coating of a binder phase.

2. The oxidation-resistant/infrared stealth coating of claim 1, wherein the conductive phase comprises 95-98% of the total mass of the conductive phase and the binder phase in the low infrared emissivity functional layer.

3. The oxidation/infrared stealth coating of claim 1, wherein said rare earth silicate layer is an erbium silicate, lutetium silicate, yttrium silicate, or ytterbium silicate layer.

4. The oxidation-resistant/infrared stealth coating of claim 1, wherein the thickness of the inner ceramic layer is 50 to 100 μm, the thickness of the middle ceramic layer is 50 to 100 μm, the thickness of the outer ceramic layer is 50 to 100 μm, and the thickness of the low-infrared-emissivity functional layer is 3 to 10 μm.

5. The oxidation resistant/infrared stealth coating of claim 1, wherein said fiber reinforced ceramic matrix composite is a non-oxide fiber reinforced non-oxide matrix composite.

6. The oxidation/infrared stealth coating of claim 5, wherein said non-oxide fiber reinforced non-oxide based composite material is a C/C composite material, a C/SiC composite material, or a C/Si composite material₃N₄A composite material.

7. A method for preparing the oxidation/infrared stealth coating as described in any one of claims 1 to 6, comprising the steps of:

(1) roughening the surface of the fiber reinforced ceramic matrix composite;

(2) spraying the ceramic inner layer material on the surface of the base material treated in the step (1) by an atmospheric plasma spraying process to obtain a ceramic inner layer;

(3) spraying a ceramic intermediate layer material on the surface of the ceramic inner layer obtained in the step (2) through an atmospheric plasma spraying process to obtain a ceramic intermediate layer;

(4) spraying a ceramic outer layer material on the surface of the ceramic intermediate layer obtained in the step (3) through an atmospheric plasma spraying process to obtain a ceramic outer layer;

(5) and (4) coating the low-infrared-emissivity coating on the surface of the outer layer of the ceramic obtained in the step (4) by adopting a screen printing process or a coating normal-pressure spraying process, and drying and sintering to finish the preparation of the antioxidant/infrared stealth coating.

8. The production method according to claim 7, wherein in the step (1), the roughening treatment is: placing the fiber reinforced ceramic matrix composite substrate in a sand blasting machine for sand blasting and coarsening treatment, wherein the sand blasting and coarsening treatment process parameters are as follows: the pressure is 0.1-0.3 MPa, the sand blasting distance is 80-150 mm, the sand grain diameter is 150-300 meshes, and the sand blasting time is 1-3 min;

in the step (2), the ceramic inner layer material is mullite spraying powder, the powder particles are spherical or quasi-spherical, the particle size of the powder is 48-105 μm, and the atmospheric plasma spraying process parameters are as follows: argon flow is 30-45L/min, hydrogen flow is 5-12L/min, current is controlled to be 500-580A, power is 30-38 kW, powder conveying argon flow is 2.5-4.0L/min, powder conveying amount is 15-35 g/min, and spraying distance is 100-140 mm;

in the step (3), the ceramic intermediate layer is made of rare earth silicate spraying powder, the powder particles are spherical or quasi-spherical, and the particle size of the powder is 48-105 mu m; the parameters of the atmospheric plasma spraying process are as follows: argon flow is 20-40L/min, hydrogen flow is 6-10L/min, current is controlled to be 450-550A, power is 30-35 kW, powder conveying argon flow is 2.0-3.5L/min, powder conveying amount is 10-30 g/min, and spraying distance is 100-140 mm;

in the step (4), the ceramic outer layer material is 8YSZ spraying powder, the powder particles are spherical or quasi-spherical, and the particle size of the powder is 38-150 mu m; the parameters of the atmospheric plasma spraying process are as follows: argon flow is 25-45L/min, hydrogen flow is 8-12L/min, current is controlled to be 500-600A, power is 35-42 kW, powder conveying argon flow is 2.0-4.0L/min, powder conveying amount is 20-40 g/min, and spraying distance is 110-150 mm;

in the step (5), the drying and sintering process parameters are as follows: the drying temperature is 120-200 ℃, and the drying time is 30-60 min; sintering is carried out in an air atmosphere, the sintering temperature is 900-1000 ℃, the heating rate is 15-20 ℃/min, and the sintering time is 10-60 min.

9. The method of manufacturing according to claim 8, wherein the method of manufacturing the rare earth silicate spray powder comprises the steps of:

carrying out centrifugal spray drying on the slurry to obtain rare earth silicate spraying powder;

said step (c) isThe high-temperature heat treatment temperature is 1000-1200 ℃, and the time is 2-5 h; the high-temperature solid-phase synthesis temperature is 1400-1500 ℃, and the synthesis time is 24-48 h;

said step (c) isIn the method, the mass fraction of deionized water is 50-55%, the mass fraction of Arabic gum powder is 1-2%, the mass fraction of triammonium citrate is 0.8-1.5%, and the balance is rare earth silicate powder; the ball milling mixing technological parameters are as follows: the ball milling speed is 380-450 r/min, and the time is 36-48 h;

said step (c) isIn the method, the technological parameters of centrifugal spray drying are as follows: the outlet temperature is 120-140 ℃, the inlet temperature is 220-240 ℃, the slurry feeding speed is 1.0-3.2L/min, and the rotation speed of the atomizing disc is 15000-20000 r/min.

10. The method of claim 8, wherein the low ir emissivity coating is prepared by: uniformly mixing bismuth oxide powder and platinum powder in a planetary gravity mixer to obtain mixed powder, mixing the mixed powder with an organic carrier, and grinding by a three-roll grinder to obtain the low-infrared-emissivity coating; the powder particle size of the platinum powder is 0.1-0.5 mu m, the mass fraction of the mixed powder in the low infrared emissivity coating is 75-85%, and the organic carrier accounts for 15-25%;

the mixing technological parameters of the planetary gravity mixer are as follows; the revolution speed is 1200-1500 rpm, the rotation speed is 40-60% of the revolution speed, and the stirring time is 60-90 min; the grinding parameters of the three-roller grinding machine are as follows: the rotation speed is 300-400 r/min, and the grinding and mixing time is 10-30 min.

Technical Field

The invention belongs to the technical field of high-temperature infrared stealth materials, and particularly relates to a 1650-DEG C-resistant fiber-reinforced ceramic matrix composite surface oxidation-resistant/infrared stealth coating and a preparation method thereof.

Background

In recent years, infrared detection and tracking technology is developed rapidly, an infrared guided weapon becomes a main threat in air combat, and in order to improve the survival and defense capability of a new generation of aircraft, an advanced and effective infrared stealth technology is urgently developed, wherein the infrared stealth technology is a technology for reducing the infrared radiation difference between a target and a background by controlling or reducing the infrared radiation characteristic of the target so as to reduce the discovered, tracked, identified and attacking distance and probability of the target, and a formula is calculated according to the infrared radiation energy difference, wherein △ W is sigma_{Eyes of a user}T_{Eyes of a user} ⁴-σ_{Back of body}T_{Back of body} ⁴In the formula (I), wherein,_{eyes of a user}Is the infrared emissivity of the target and is,_{back of body}Background infrared emissivity, T_{Eyes of a user}Is a target surface temperature, T_{Back of body}Is the background temperature. According to the formula, the total infrared radiation energy of the target mainly depends on the surface emissivity and the surface absolute temperature of the target, so that the reduction of the surface temperature of the target or the reduction of the infrared emissivity to change the infrared radiation characteristic of the target is two important technical ways for realizing infrared stealth.

Generally, the infrared radiation source of the aircraft mainly comes from high-temperature components, including thermal radiation of an engine, tail flame, thermal infrared radiation of a skin caused by pneumatic heating and the like, and infrared stealth of the high-temperature components of the aircraft is very important. The low infrared emissivity coating technology is a simple, convenient and effective technical approach for improving the infrared stealth performance of the aircraft by coating a low infrared emissivity coating on a high-temperature part of the aircraft so as to reduce the surface emissivity of the aircraft. Low ir emissivity coatings are generally composed of a binder and a low emissivity filler, and are classified into organic and inorganic systems. The low infrared emissivity coating of the organic system has low use temperature, generally not more than 400 ℃, so the organic system is not suitable for being used in a high-temperature environment. The low infrared emissivity coating of the inorganic system has a high use temperature region, and the temperature resistance of the prior disclosed technology can reach about 1000 ℃. Along with the increase of the thrust-weight ratio of an engine and the flying speed of the aircraft, the surface temperature of the aircraft and the temperature in the engine exceed 1000 ℃ or even higher temperature, the current low-infrared emissivity coating cannot meet the use requirement under the higher temperature environment, and mainly shows that most low-emissivity fillers have low melting point, are easy to oxidize at high temperature, are easy to migrate and diffuse at high temperature and have unstable high-temperature performance, so that the coating cannot be used under the high temperature environment; the compatibility of the coating and the base material is poor, and the coating and the base material are mismatched thermally, so that the coating is cracked or falls off; instability of the coating at high temperatures, phase transformation, cracking of the coating due to the volume change accompanying the transformation, and the like. In addition, the existing traditional physical platinum coating can resist high temperature, but the platinum coating is mainly physically combined with the base material, so that the bonding strength is low, the thermal mismatch with the base material is serious, the repeated thermal shock is easy to fall off, the performance is unstable in a high-temperature environment, and meanwhile, the problem of high preparation cost also exists.

As the high-temperature component structural material of the aircraft is promoted to be high-temperature and light, the traditional alloy material cannot meet the requirements, the ceramic matrix composite material taking carbon fibers as a reinforcing phase becomes a development key point, the composite material has the advantages of high temperature resistance, low density, high strength and the like, and can meet the requirements of high temperature and light weight, but the composite material is easy to oxidize under the conditions of high temperature, oxygen enrichment and water vapor, so that the performance of the material is seriously reduced, and in order to ensure that the composite material has stable performance under a high-temperature environment, the composite material needs to be subjected to anti-oxidation treatment. Therefore, the development of an oxidation/infrared integrated functional coating is very necessary.

With the rapid development of aerospace technology, the demand for high-temperature-resistant infrared stealth materials is increasingly urgent, and the development of an antioxidant/infrared stealth coating material with high-temperature resistance and stable high-temperature performance is of great significance.

Disclosure of Invention

The invention aims to provide an antioxidation/infrared stealth coating on the surface of a fiber reinforced ceramic matrix composite material capable of resisting 1650 ℃, which can be used in a high-temperature environment of 1650 ℃ and has antioxidation, low infrared emissivity and high-temperature stability, and a preparation method of the coating correspondingly.

In order to achieve the purpose, the technical scheme of the invention is that the surface oxidation-resistant/infrared stealth coating of the fiber-reinforced ceramic matrix composite material with the temperature resistance of 1650 ℃, the infrared stealth coating is of a layered structure and sequentially comprises a ceramic inner layer, a ceramic intermediate layer, a ceramic outer layer and a low infrared emissivity functional layer from bottom to top, the ceramic inner layer is a mullite layer, the ceramic intermediate layer is a rare earth silicate layer, the ceramic outer layer is an 8YSZ layer, and the low infrared emissivity functional layer takes Pt as a conductive phase and Bi as the conductive phase₂O₃Is a coating of a binder phase.

Preferably, in the antioxidant/infrared stealth coating, the conductive phase accounts for 95-98% of the total mass of the conductive phase and the bonding phase in the low-infrared-emissivity functional layer.

Preferably, in the antioxidant/infrared stealth coating, the rare earth silicate layer is an erbium silicate layer, a lutetium silicate layer, an yttrium silicate layer or an ytterbium silicate layer.

Preferably, in the antioxidant/infrared stealth coating, the thickness of the inner ceramic layer is 50-100 μm, the thickness of the middle ceramic layer is 50-100 μm, the thickness of the outer ceramic layer is 50-100 μm, and the thickness of the functional layer with low infrared emissivity is 3-10 μm.

Preferably, in the antioxidant/infrared stealth coating, the fiber reinforced ceramic matrix composite is a non-oxide fiber reinforced non-oxide matrix composite.

Preferably, in the antioxidant/infrared stealth coating, the non-oxidized fiber reinforced non-oxide based composite material is a C/C composite material, a C/SiC composite material or a C/Si composite material₃N₄A composite material.

A preparation method of the antioxidant/infrared stealth coating comprises the following steps:

(1) roughening the surface of the fiber reinforced ceramic matrix composite;

(2) spraying the ceramic inner layer material on the surface of the base material treated in the step (1) by an atmospheric plasma spraying process to obtain a ceramic inner layer;

(3) spraying a ceramic intermediate layer material on the surface of the ceramic inner layer obtained in the step (2) through an atmospheric plasma spraying process to obtain a ceramic intermediate layer;

(4) spraying a ceramic outer layer material on the surface of the ceramic intermediate layer obtained in the step (3) through an atmospheric plasma spraying process to obtain a ceramic outer layer;

(5) and (4) coating the low-infrared-emissivity coating on the surface of the outer layer of the ceramic obtained in the step (4) by adopting a screen printing process or a coating normal-pressure spraying process, and drying and sintering to finish the preparation of the antioxidant/infrared stealth coating.

Preferably, in the above preparation method, in the step (1), the roughening treatment is: placing the fiber reinforced ceramic matrix composite substrate in a sand blasting machine for sand blasting and coarsening treatment, wherein the sand blasting and coarsening treatment process parameters are as follows: the pressure is 0.1-0.3 MPa, the sand blasting distance is 80-150 mm, the sand grain diameter is 150-300 meshes, and the sand blasting time is 1-3 min;

in the step (2), the ceramic inner layer material is mullite spraying powder, the powder particles are spherical or quasi-spherical, the particle size of the powder is 48-105 μm, and the atmospheric plasma spraying process parameters are as follows: argon flow is 30-45L/min, hydrogen flow is 5-12L/min, current is controlled to be 500-580A, power is 30-38 kW, powder conveying argon flow is 2.5-4.0L/min, powder conveying amount is 15-35 g/min, and spraying distance is 100-140 mm;

in the step (3), the ceramic intermediate layer is made of rare earth silicate spraying powder, the powder particles are spherical or quasi-spherical, and the particle size of the powder is 48-105 mu m; the parameters of the atmospheric plasma spraying process are as follows: argon flow is 20-40L/min, hydrogen flow is 6-10L/min, current is controlled to be 450-550A, power is 30-35 kW, powder conveying argon flow is 2.0-3.5L/min, powder conveying amount is 10-30 g/min, and spraying distance is 100-140 mm;

in the step (4), the ceramic outer layer material is 8YSZ spraying powder, the powder particles are spherical or quasi-spherical, and the particle size of the powder is 38-150 mu m; the parameters of the atmospheric plasma spraying process are as follows: argon flow is 25-45L/min, hydrogen flow is 8-12L/min, current is controlled to be 500-600A, power is 35-42 kW, powder conveying argon flow is 2.0-4.0L/min, powder conveying amount is 20-40 g/min, and spraying distance is 110-150 mm;

in the step (5), the drying and sintering process parameters are as follows: the drying temperature is 120-200 ℃, and the drying time is 30-60 min; sintering is carried out in an air atmosphere, the sintering temperature is 900-1000 ℃, the heating rate is 15-20 ℃/min, and the sintering time is 10-60 min.

Preferably, in the above preparation method, the preparation method of the rare earth silicate spray powder includes the following steps:

respectively carrying out high-temperature heat treatment on rare earth oxide and silicon dioxide, mixing the rare earth oxide and the silicon dioxide according to a stoichiometric ratio, and then carrying out high-temperature solid-phase synthesis to obtain rare earth silicate powder;

secondly, ball-milling and mixing the rare earth silicate powder, deionized water, Arabic gum powder and triammonium citrate to obtain slurry;

thirdly, centrifugal spray drying is carried out on the slurry to obtain rare earth silicate spraying powder;

in the first step, the high-temperature heat treatment temperature is 1000-1200 ℃, and the time is 2-5 h; the high-temperature solid-phase synthesis temperature is 1400-1500 ℃, and the synthesis time is 24-48 h;

in the second step, the mass fraction of the deionized water is 50-55%, the mass fraction of the Arabic gum powder is 1-2%, the mass fraction of the triammonium citrate is 0.8-1.5%, and the balance is rare earth silicate powder; the ball milling mixing technological parameters are as follows: the ball milling speed is 380-450 r/min, and the time is 36-48 h;

in the third step, the centrifugal spray drying process parameters are as follows: the outlet temperature is 120-140 ℃, the inlet temperature is 220-240 ℃, the slurry feeding speed is 1.0-3.2L/min, and the rotation speed of the atomizing disc is 15000-20000 r/min.

Preferably, in the preparation method, the low infrared emissivity coating is prepared by the following steps: uniformly mixing bismuth oxide powder and platinum powder in a planetary gravity mixer to obtain mixed powder, mixing the mixed powder with an organic carrier, and grinding by a three-roll grinder to obtain the low-infrared-emissivity coating; the powder particle size of the platinum powder is 0.1-0.5 mu m, the mass fraction of the mixed powder in the low infrared emissivity coating is 75-85%, and the organic carrier accounts for 15-25%;

the mixing technological parameters of the planetary gravity mixer are as follows; the revolution speed is 1200-1500 rpm, the rotation speed is 40% -60% of the revolution speed, and the stirring time is 60-90 min; the grinding parameters of the three-roller grinding machine are as follows: the rotation speed is 300-400 r/min, and the grinding and mixing time is 10-30 min.

The oxidation-resistant/infrared stealth coating is a multilayer composite coating, wherein the compatibility of the ceramic inner layer and the composite material substrate is good, interface gaps, cracks and holes in the substrate are filled and sealed, the thermal expansion coefficient is matched with that of the substrate, the difference of the thermal expansion coefficient between the ceramic outer layer and the substrate is reduced, the oxygen diffusion coefficient is low, and the oxidation resistance effect is achieved; the ceramic intermediate layer resists oxidation and water vapor corrosion, prevents oxygen and water vapor from permeating into the base material, and improves the high-temperature oxidation resistance and high-temperature stability of the base material; the ceramic outer layer has high temperature resistance, can further enhance the water vapor corrosion resistance, and is used as a sintering substrate of the low infrared emissivity functional layer, so that the bonding strength of the ceramic outer layer and the low infrared emissivity functional layer is high; the ceramic inner layer, the ceramic intermediate layer and the ceramic outer layer meet the gradient thermal matching requirement; the low infrared emissivity functional layer is sintered on the ceramic outer layer to form chemical bonding with the ceramic outer layer, so that the bonding force between the coating layers is improved, and the low infrared emissivity functional layer takes Pt as a conductive phase and Bi₂O₃The Pt is a coating of a binding phase, the Pt has the characteristics of low emissivity, high temperature resistance, difficult migration at high temperature and the like, and the binding phase is Bi₂O₃The self-healing coating has the characteristics of low-temperature sintering, and has fluidity under the high-temperature condition, so that pores and cracks in the coating can be closed, the self-healing performance is good, the high-temperature performance of the coating is improved, and the service life of the coating is prolonged. Compared with the traditional physical platinum coating layer, the low-infrared-emissivity functional layer is chemically combined with the ceramic outer layer, has high bonding strength, and has ceramic between the functional layer and the base materialAnd the layer transition reduces the thermal mismatch with the base material and improves the thermal shock resistance.

Compared with the prior art, the invention has the following beneficial effects:

1. the fiber reinforced ceramic matrix composite material surface oxidation-resistant/infrared stealth coating capable of resisting temperature of 1650 ℃ has high temperature resistance, oxidation resistance and high temperature stability, and can be used in a high temperature environment above 1650 ℃. The coating has the characteristics of low infrared emissivity, low oxygen permeability coefficient and the like, has good compatibility with the fiber-reinforced ceramic matrix composite material and high thermal matching property, can fill and seal interface gaps, cracks and holes in the base material when being coated on the base material of the fiber-reinforced ceramic matrix composite material, isolates the base material from being contacted with oxygen and water vapor, ensures that the composite material is not corroded by oxidation and high-temperature water vapor, improves the oxidation resistance and high-temperature stability of the composite material, can obviously reduce the infrared radiation intensity of the base material, and has an excellent infrared stealth function.

2. The infrared stealth coating adopts a multilayer composite structure, is beneficial to reducing stress caused by mismatching of thermal expansion, and has excellent bonding strength and thermal shock resistance.

3. The preparation method of the infrared stealth coating is simple and relatively mature, and the ceramic inner layer, the ceramic intermediate layer and the ceramic outer layer are prepared by adopting an atmospheric plasma spraying process, so that the infrared stealth coating has the advantages of high deposition efficiency, good process stability and the like; by optimizing the shape and the size of the spraying powder particles, the flowability and the size uniformity of the spraying powder are improved, so that the densification degree of the plasma spraying coating is effectively improved, diffusion channels of oxygen and water vapor are reduced, and the oxidation resistance and the high-temperature stability of the composite material substrate are improved. The low infrared emissivity coating is coated on the surface of the ceramic outer layer by adopting a screen printing process or a coating normal-pressure spraying process, and the low infrared emissivity coating is sintered on the ceramic layer by a drying and sintering process to form chemical bonding with the ceramic outer layer, so that the bonding strength between the coatings is high.

4. Compared with the traditional physical platinized coating, the low-infrared-emissivity functional layer disclosed by the invention is chemically combined with the ceramic outer layer, the bonding strength is high, the ceramic layer transition exists between the functional layer and the base material, the thermal mismatch between the functional layer and the base material is reduced, and the thermal shock resistance is improved.

Drawings

FIG. 1 is a photograph of a sample of the surface oxidation resistant/IR stealth coating of the C/SiC composite material of example 1 of the present invention.

FIG. 2 is a photograph of a sample of the C/SiC composite surface oxidation resistant/infrared stealth coating of the present invention after temperature resistance examination.

Detailed Description

The following detailed description of specific embodiments of the invention is provided, but it should be understood that the scope of the invention is not limited to the specific embodiments.