CN108285291A - A kind of thermal barrier coating nano ceramic powder and the preparation method and application thereof, thermal barrier coating - Google Patents

Abstract

The present invention relates to a kind of thermal barrier coating nano ceramic powder and the preparation method and application thereof, thermal barrier coatings, belong to Material Field.Preparation method includes：Nanoscale 8YSZ and additive are configured to 8YSZ slurries, then mist projection granulating.Additive includes dispersant and bonding agent.Above-mentioned preparation method is simple and efficient, pollution-free, can improve the yield rate that powder stablizes compound probability and powder.The thermal barrier coating being prepared nano ceramic powder is reunited, and preferable, mobility is higher, while powder particle is smaller, size distribution is more uniform, sphericity is high, and performance is stablized.The thermal barrier coating for using it for production engine components enables to engine components to adapt to more severe high temperature, high pressure and deep-etching working environment.Thermal barrier coating containing above-mentioned thermal barrier coating nano ceramic powder has higher heat-proof quality and high-temperature oxidation resistance.

Description

A kind of nano-ceramic powder for thermal barrier coating and its preparation method and application, thermal barrier coating

technical field

The invention relates to the field of materials, and in particular to a nano-ceramic powder for a thermal barrier coating, a preparation method and application thereof, and a thermal barrier coating.

Background technique

With the development of aviation gas turbine engines in the direction of high flow ratio, high thrust-to-weight ratio, and high inlet temperature, the gas temperature and pressure in the combustion chamber continue to increase, but the existing high-temperature alloys and cooling technologies are difficult to meet the needs. Therefore, the development Thermal barrier coating technology is an inevitable development trend. Thermal barrier coatings (TBCs), also known as thermal barrier coatings, are ceramic protective layers that deposit ceramic materials on the surface of superalloy hot-end components by coating processes (such as atmospheric plasma spraying) to isolate components from high-temperature gas , by using the low thermal conductivity of ceramics, a large temperature drop occurs between the high-temperature gas and metal parts, so as to achieve the purpose of protecting the hot end parts, improving the thermal efficiency of the gas and prolonging the life of the heat engine.

After decades of research, the service temperature of superalloys has been able to reach 1050°C. Combining directional solidification, single crystal technology and advanced film cooling technology can make superalloys withstand high temperatures of 1400°C, but it inevitably reduces the engine temperature. thermal efficiency. Through the analysis of the current research results, it is very difficult to adapt the blades to a large temperature increase through continuous breakthroughs in cooling technology, further research on base materials and improvements in engine structure. However, the continuous increase of the service temperature and pressure in the engine combustion chamber is an inevitable trend of future development. Since the 1940s, the operating temperature has almost maintained an increase rate of 15°C/year, and the gas pressure has increased by nearly 3 times. , the current working temperature of the hot-end components is 1400-1500°C, and the gas temperature has reached 1600°C, and may soon reach 1930°C. Therefore, the study of the thermal barrier Xu layer is of great significance for increasing the working temperature of the hot-end components and ensuring thermal efficiency.

The properties of the powder used to prepare the thermal barrier coating determine the performance of the coating. Over the past 30 years, yttria-stabilized zirconia (YSZ) has been widely used as the surface ceramic material for thermal barrier coatings. It has high melting point (2680°C), large thermal expansion coefficient (11×10 ^-6 K ^-1 at 1200°C), low thermal conductivity (2.2W·m ^-1 ·K ^-1 ), low elastic modulus (40GPa), The technology is mature and the price is cheap. Traditional thermal barrier coatings are generally prepared from micron-sized YSZ powders by thermal spraying technology. However, due to the large particle size of the micron-sized YSZ powder, incomplete melting, low deposition efficiency, and uneven mechanical properties of the coating will occur during the thermal spraying process. Nanoscale YSZ fine powder can improve the overall performance of thermal barrier coatings, but it cannot be directly used for thermal spraying to prepare coatings due to the disadvantages of poor fluidity and easy adsorption.

Therefore, based on the above analysis, it is necessary to use nanoscale YSZ powder as raw material and find a suitable granulation method to prepare a thermal spray powder for thermal barrier coating with better agglomeration, higher fluidity, smaller powder particles and more uniform particle size distribution. To further improve the quality of thermal barrier coatings.

Contents of the invention

One of the objectives of the present invention is to provide a preparation method of nano-ceramic powder for thermal barrier coating, which is simple, efficient, pollution-free, and can increase the probability of stable compounding of powder and the yield of powder.

The second object of the present invention is to provide a nano-ceramic powder for thermal barrier coating prepared by the above preparation method, the nano-ceramic powder for thermal barrier coating has better agglomeration, higher fluidity, and smaller powder particles , The particle size distribution is relatively uniform, the sphericity is high, and the performance is stable.

The third object of the present invention is to provide an application of the above-mentioned nano-ceramic powder for thermal barrier coating, for example, it can be used to produce thermal barrier coatings of engine parts, which can make engine parts adapt to more severe high temperature, high pressure and strong Corrosive working environment.

The fourth object of the present invention is to provide a thermal barrier coating containing the above-mentioned nano-ceramic powder for thermal barrier coating, which has high thermal insulation performance and high temperature oxidation resistance.

The present invention solves its technical problem and adopts the following technical solutions to realize:

The invention proposes a preparation method of nano-ceramic powder for thermal barrier coating, comprising the following steps: preparing nano-scale 8YSZ and additives into 8YSZ slurry, and then spraying and granulating.

Additives include dispersants and binders.

Preferably, the dispersant includes polyacrylic acid, and the binder includes polyvinylpyrrolidone.

Preferably, 8YSZ is 8YSZ powder with a particle size of 20-40 nm.

Preferably, the mass ratio of dispersant, adhesive and 8YSZ is 1-10:4-14:100.

The present invention also proposes a nano-ceramic powder for thermal barrier coating, which is prepared by the above preparation method.

The present invention also proposes an application of the above-mentioned nano-ceramic powder for thermal barrier coating, for example, it can be used for producing thermal barrier coating of engine parts.

The present invention also proposes a thermal barrier coating, which contains the above-mentioned nano-ceramic powder for thermal barrier coating.

The nano-ceramic powder for thermal barrier coating provided by the preferred embodiment of the present invention, its preparation method and application, and the beneficial effects of thermal barrier coating include:

In the embodiment of the present invention, the nano-scale 8YSZ powder is used as the raw material, and the nano-ceramic powder for the thermal barrier coating is prepared by a spray granulation process. The use of dispersant and binder can make the powder agglomeration and dispersion effect better, and the viscosity of the slurry is moderate. Since the nano-powder cannot be directly used for spraying, the poor fluidity will block the spray gun, and it is easy to oxidize and burn during the spraying process, which cannot meet the application requirements. Without changing the nanostructure of the powder, the nanopowder is agglomerated into a micron powder suitable for thermal spraying, which solves the difficulties of poor fluidity and difficulty in spraying of ceramic powder. In addition, compared with the conventional micron powder of the same composition, the mechanical properties and wear resistance and corrosion resistance of the nano 8YSZ powder have been greatly improved, and it has good comprehensive performance and use value, which is the preparation of high-performance nano-coating And applications provide new ways and scientific basis.

The preparation method of the nano-ceramic powder for thermal barrier coating provided by the preferred embodiment of the present invention is simple, efficient, and pollution-free, and can increase the probability of stable compounding of the powder and the yield of the powder. The prepared nano-ceramic powder for thermal barrier coatings has good agglomeration and high fluidity, and at the same time, the powder particles are small, the particle size distribution is relatively uniform, the sphericity is high, and the performance is stable. It is used to produce thermal barrier coatings for engine components, which can make engine components adapt to harsher high temperature, high pressure and strong corrosion working environments. The thermal barrier coating containing the above-mentioned nano-ceramic powder for thermal barrier coating has high heat insulation performance and high temperature oxidation resistance performance.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art.

Fig. 1 is the TEM figure of original 8YSZ nanometer powder in the embodiment 1 in the test example;

Fig. 2 is the SEM picture of original 8YSZ nanometer powder in embodiment 1 in the test example;

Fig. 3 is the XRD pattern of the original 8YSZ nanometer powder prepared in Example 1 and the nanometer agglomerated powder after spray granulation;

Fig. 4 is the particle size analysis diagram of the nano ceramic agglomerated powder prepared by embodiment 1 in the test example;

Fig. 5 is the SEM topography figure of the nano-ceramic agglomerated powder prepared by embodiment 1 in the test example;

Fig. 6 is the SEM topography figure of the nano ceramic agglomerated powder prepared by embodiment 2 in the test example;

Fig. 7 is a SEM image of the nano-ceramic agglomerated powder prepared in Example 3 of the test example.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Those who do not indicate the specific conditions in the examples are carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used were not indicated by the manufacturer, and they were all conventional products that could be purchased from the market.

The nano-ceramic powder for thermal barrier coating, its preparation method and application, and thermal barrier coating according to the embodiments of the present invention are described in detail below.

The preparation method of the nano-ceramic powder for thermal barrier coating provided by the embodiment of the present invention includes the following steps: preparing 8YSZ and additives into 8YSZ slurry, and then spraying and granulating.

Preferably, the 8YSZ in the embodiment of the present invention adopts nanoscale YSZ powder. Nano-scale YSZ powder can effectively improve the preparation efficiency and coating uniformity of thermal barrier coatings compared with micron-scale YSZ powder. In addition, compared with conventional coatings, the coatings prepared by nano-powders have higher hardness, fracture toughness, wear resistance and corrosion resistance due to their particularity, thereby improving coating quality and service life .

Optionally, the YSZ powder in the embodiment of the present invention is preferably 8YSZ powder with a particle size of 20-40 nm. This particle size range is more conducive to the preparation of thermal barrier coatings. If the particle size is too coarse, it will affect the quality of the final thermal barrier coating. Moreover, when the particle size of the powder is greater than 40nm, the particle size of the powder prepared after spray drying will also be too large, which does not meet the requirements. Requirements.

Additives may include dispersants and binders. Alternatively, the dispersant preferably includes polyacrylic acid, and the binder preferably includes polyvinylpyrrolidone. The reason why the dispersant is preferably polyacrylic acid is that polyacrylic acid is relatively cheap and has the best dispersion effect. The reason why the binder is preferably polyvinylpyrrolidone is that the agglomeration effect of the powder prepared by some other binders is not as good as that of polyvinylpyrrolidone, and some other binders are more expensive than polyvinylpyrrolidone.

Preferably, the mass ratio of the dispersant, binder and 8YSZ may be 1-10:4-14:100. If the mass ratio range of the dispersant is lower than this range, the dispersion effect will be poor; if it is higher than this range, the viscosity of the slurry is too high, which is not conducive to subsequent preparation. If the mass ratio range of the binder is lower than this range, the agglomeration effect will be unsatisfactory, and if the viscosity is too high above this range, the slurry cannot be spray-dried.

Preferably, before mixing with additives, 8YSZ is mixed with a solvent to obtain the first slurry. Wherein, the solvent includes water or absolute alcohol, preferably deionized water. Optionally, the mass ratio of solvent to 8YSZ is preferably (7:3)-(5.5:4.5). Within this range, powders of the required quality can be produced. The particle size of the powder prepared by spray drying is too large if it is lower than this ratio, and the agglomeration effect of the formed powder is poor if it is higher than this ratio.

Further, the preparation of the 8YSZ slurry in the embodiment of the present invention includes the following steps: mixing the first slurry with a dispersant and a ball milling medium, and ball milling for 2-4 hours to obtain a second slurry; mixing the second slurry with an adhesive Mix and continue ball milling for 2-4h to obtain 8YSZ slurry.

The reason why the dispersant and binder are mixed with 8YSZ at different time periods is that the dispersant and binder will produce competitive adsorption on the surface of powder particles, and the viscosity of the slurry will increase significantly in a short period of time. Therefore, in order to avoid this situation, add the dispersant first, and then add the binder to the slurry after the distribution is even. In this way, the use efficiency of additives can be improved, and the viscosity of the slurry can be better controlled. In other words, the main purpose of the first ball mill is to achieve uniform and stable dispersion of the 8YSZ powder, and the main purpose of the second ball mill is to achieve a uniform dispersion of the binder in the slurry of the 8YSZ powder and a certain agglomeration of the powder .

As an option, the ball milling medium in the embodiment of the present invention is preferably zirconia balls, because the powder is 8YSZ powder, and its main component is zirconia, so choosing zirconia balls can prevent pollution.

Preferably, the ball milling media also includes zirconia balls of different particle sizes. The preparation of nano-powder into slurry and compound ball milling with ball milling balls of different sizes can not only improve the uniformity of nano-powder distribution, but also effectively avoid the competitive adsorption of dispersants and binders on the surface of nanoparticles.

As an option, the above-mentioned ball milling media may also include zirconia balls with particle sizes of 4-8mm, 8-12mm and 18-22mm. The quantity of the zirconia balls with three particle sizes can be 8:4:1 in turn, and can also be adjusted according to actual usage conditions.

Preferably, the mass ratio of ball milling medium to 8YSZ is (1:1)-(3:1), for example, it may be 2:1. If the ball-to-material ratio is too high, the ball milling efficiency will be low, and if the ball-to-material ratio is too low, the ball-to-material ratio will be uneven and insufficient.

In the ball milling process of preparing the second slurry and preparing the 8YSZ slurry, the rotational speed of the ball mill can be 200-400 rpm. When it is higher than 400rpm, the heat will be serious, which will affect the performance of the slurry; if it is lower than 200rpm, the dispersion effect will not be good.

The advantage of spray granulation of 8YSZ slurry is that heat and mass can be transferred quickly in a very short time, and the preparation efficiency is high; at the same time, the preparation equipment is simple, the preparation temperature is low, it is convenient for mass production, and the powder can be precisely controlled material components. The principle is as follows: use an atomizer to disperse the feed liquid into fine mist droplets, and quickly evaporate the solvent in the hot drying medium to form a dry powder product. Generally, it includes four stages: 1 feed liquid atomization; 2 mist group and heat drying medium Contact mixing; 3 evaporative drying of droplets; 4 separation of dry product from drying medium. The fine suspension is atomized into the drying chamber, where it is heated by the hot air stream or the inner walls. Rapid heat and mass transfer and evaporation of liquid occur during drying so that dry particles are finally obtained. The dried particles can be roughly divided into the following types: uniform spheres, slender spheres, pancakes, rings, needles or hollow particles, and the shape of the powder after granulation can be effectively controlled by adjusting the parameters of the spray drying process. Appearance and granularity.

For reference, the process conditions of spray granulation in the embodiment of the present invention may include, for example: feeding speed of 40-100ml/min, inlet temperature of 260-290°C, outlet temperature of 90-120°C, and chamber pressure of 1- 2bar, the atomizer is adjusted to 3-6m ³ /h.

Among them, the feeding speed is mainly to control the particle size of the powder after spray drying, too large or too low will lead to uneven particle size distribution or large difference in particle size. The inlet and outlet temperatures mainly affect the dryness of the powder. If the temperature is lower than this range, the drying will not be sufficient. If it is higher than this range, the sphericity will be poor and there will be more potholes. Pressure and atomizer adjustment are similar to temperature adjustment. Within this range, the powder prepared by spray drying has better sphericity and uniform particle size distribution; beyond this range, fully dried and well-formed agglomerated powder cannot be obtained.

Based on the above, the present invention uses nano-scale 8YSZ powder as raw material, adopts a combination of ball milling and spray granulation, and through ball milling, the nano-powder is evenly distributed in the slurry and forms a stable nano-dispersed powder. Nano-powders cannot be directly used for spraying, and the poor fluidity will block the spray gun, and it is easy to oxidize and burn easily during the spraying process, which cannot meet the application requirements. Without changing the nanostructure of the powder, the nanopowder is agglomerated into a micron powder suitable for thermal spraying, which solves the difficulties of poor fluidity and difficulty in spraying of ceramic powder. In addition, compared with the conventional micron powder of the same composition, the mechanical properties and wear resistance and corrosion resistance of the nano 8YSZ powder have been greatly improved, and it has good comprehensive performance and use value, which is the preparation of high-performance nano-coating And applications provide new ways and scientific basis.

The nano-ceramic powder for thermal barrier coating prepared by the above preparation method has better agglomeration, higher fluidity, smaller powder particles, more uniform particle size distribution, high sphericity, and stable performance.

The embodiment of the present invention also provides an application of the above-mentioned nano-ceramic powder for thermal barrier coating, for example, it can be used to produce thermal barrier coatings for engine parts, especially commercial and military turbine engine parts, such as combustion chambers, high-pressure Thermal barrier coatings for turbine blades, nozzles, combustion chambers, heat shields, and flame tubes can make turbine combustion chambers adapt to harsher high-temperature, high-pressure, and highly corrosive working environments.

In addition, the embodiment of the present invention also provides a thermal barrier coating, which contains the above-mentioned nano-ceramic powder for thermal barrier coating, and has higher heat insulation performance and high temperature oxidation resistance performance.

The characteristics and performance of the present invention will be described in further detail below in conjunction with the examples.

Example 1

Mix 8YSZ powders of different particle sizes with a particle size of 20-40nm and deionized water at a mass ratio of 6.5:3.5, and then add them to a QM-3SP4 planetary ball mill to obtain the first slurry.

The first slurry was mixed with polyacrylic acid and ball milling medium, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a speed of 400 rpm for 3 hours to obtain the second slurry. Wherein, the ball milling medium also includes zirconia balls with particle diameters of 6 mm, 10 mm and 20 mm in a quantity ratio of 8:4:1. The mass ratio of polyacrylic acid to 8YSZ powder is 6:100, and the mass ratio of ball milling media to 8YSZ powder is 2:1.

The second slurry was mixed with polyvinylpyrrolidone, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a rotation speed of 400 rpm for 3 hours to obtain a third slurry. The mass ratio of polyvinylpyrrolidone to 8YSZ powder is 10:100.

The third slurry was spray-dried and granulated in the MOBILE MINOR ^TM research and development spray dryer under the following process conditions. Process conditions: feeding speed is 60ml/min, inlet temperature is 280°C, outlet temperature is 120°C, chamber pressure is 1.4bar, atomizer is adjusted to 4m ³ /h.

The prepared nano-ceramic agglomerated powder is spherical and has excellent fluidity, and can be directly used for thermal spraying to prepare thermal barrier coatings.

Example 2

Mix 8YSZ powder with a particle size of 30nm and deionized water at a mass ratio of 6:4 and add it to a QM-3SP4 planetary ball mill to obtain the first slurry.

The first slurry was mixed with polyacrylic acid and ball milling medium, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a speed of 400 rpm for 3 hours to obtain the second slurry. Wherein, the ball milling medium also includes zirconia balls with particle diameters of 6 mm, 10 mm and 20 mm in a quantity ratio of 8:4:1. The mass ratio of polyacrylic acid to 8YSZ powder is 6:100, and the mass ratio of ball milling media to 8YSZ powder is 2:1.

The second slurry was mixed with polyvinylpyrrolidone, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a rotation speed of 400 rpm for 4 hours to obtain a third slurry. The mass ratio of polyvinylpyrrolidone to 8YSZ powder is 10:100.

The third slurry was spray-dried and granulated in the MOBILE MINOR ^TM research and development spray dryer under the following process conditions. Process conditions: feeding speed is 70ml/min, inlet temperature is 280°C, outlet temperature is 120°C, chamber pressure is 1.4bar, atomizer is adjusted to 4.8m ³ /h.

The prepared nano-ceramic agglomerated powder is spherical and has excellent fluidity, and can be directly used for thermal spraying to prepare thermal barrier coatings.

Example 3

Mix 8YSZ powder with a particle size of 30nm and deionized water at a mass ratio of 6.5:3.5, and then add it to a QM-3SP4 planetary ball mill to obtain the first slurry.

The first slurry was mixed with polyacrylic acid and ball milling medium, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a speed of 400 rpm for 3 hours to obtain the second slurry. Wherein, the ball milling medium also includes zirconia balls with particle diameters of 6 mm, 10 mm and 20 mm in a quantity ratio of 8:4:1. The mass ratio of polyacrylic acid to 8YSZ powder is 6:100, and the mass ratio of ball milling media to 8YSZ powder is 2:1.

The second slurry was mixed with polyvinylpyrrolidone, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a rotation speed of 400 rpm for 3 hours to obtain a third slurry. The mass ratio of polyvinylpyrrolidone to 8YSZ powder is 12:100.

The third slurry was spray-dried and granulated in the MOBILE MINOR ^TM research and development spray dryer under the following process conditions. Process conditions: feeding speed is 60ml/min, inlet temperature is 280°C, outlet temperature is 120°C, chamber pressure is 1.4bar, atomizer is adjusted to 4.4m ³ /h.

The prepared nano-ceramic agglomerated powder is spherical and has excellent fluidity, and can be directly used for thermal spraying to prepare thermal barrier coatings.

Example 4

Mix 8YSZ powder with a particle size of 30nm and deionized water at a mass ratio of 6.5:3.5, and then add it to a QM-3SP4 planetary ball mill to obtain the first slurry.

The first slurry was mixed with polyacrylic acid and ball milling medium, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a speed of 400 rpm for 3 hours to obtain the second slurry. Wherein, the ball milling medium also includes zirconia balls with particle diameters of 6 mm, 10 mm and 20 mm in a quantity ratio of 8:4:1. The mass ratio of polyacrylic acid to 8YSZ powder is 6:100, and the mass ratio of ball milling media to 8YSZ powder is 2:1.

The second slurry was mixed with polyvinylpyrrolidone, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a rotation speed of 400 rpm for 3 hours to obtain a third slurry. The mass ratio of polyvinylpyrrolidone to 8YSZ powder is 9:100.

The third slurry was spray-dried and granulated in the MOBILE MINOR ^TM research and development spray dryer under the following process conditions. Process conditions: feeding speed is 60ml/min, inlet temperature is 280°C, outlet temperature is 120°C, chamber pressure is 1.4bar, atomizer is adjusted to 3.6m ³ /h.

The prepared nano-ceramic agglomerated powder is spherical and has excellent fluidity, and can be directly used for thermal spraying to prepare thermal barrier coatings.

Example 5

Mix 8YSZ powder with a particle size of 30nm and deionized water at a mass ratio of 7.5:2.5 and then add it to a QM-3SP4 planetary ball mill to obtain the first slurry.

The first slurry was mixed with polyacrylic acid and ball milling medium, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a speed of 400 rpm for 2 hours to obtain the second slurry. Wherein, the ball milling medium also includes zirconia balls with particle diameters of 6 mm, 10 mm and 20 mm in a quantity ratio of 8:4:1. The mass ratio of polyacrylic acid to 8YSZ powder is 6:100, and the mass ratio of ball milling media to 8YSZ powder is 2:1.

The second slurry was mixed with polyvinylpyrrolidone, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a rotation speed of 400 rpm for 4 hours to obtain a third slurry. The mass ratio of polyvinylpyrrolidone to 8YSZ powder is 7:100.

The third slurry was spray-dried and granulated in the MOBILE MINOR ^TM research and development spray dryer under the following process conditions. Process conditions: feeding speed is 60ml/min, inlet temperature is 280°C, outlet temperature is 120°C, chamber pressure is 1.4bar, atomizer is adjusted to 3.6m ³ /h.

The prepared nano-ceramic agglomerated powder is spherical and has excellent fluidity, and can be directly used for thermal spraying to prepare thermal barrier coatings.

Example 6

Mix 8YSZ powder with a particle size of 20nm and alcohol at a mass ratio of 3:7 to obtain the first slurry.

The first slurry was mixed with polyacrylic acid and ball milling medium, and ball milled for 4 hours with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a speed of 200 rpm to obtain the second slurry. Wherein, the ball milling medium also includes zirconia balls with particle diameters of 4 mm, 8 mm and 18 mm in a quantity ratio of 8:4:1. The mass ratio of polyacrylic acid to 8YSZ powder is 1:100, and the mass ratio of ball milling media to 8YSZ powder is 1:1.

The second slurry was mixed with polyvinylpyrrolidone, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a rotation speed of 200 rpm for 4 hours to obtain a third slurry. The mass ratio of polyvinylpyrrolidone to 8YSZ powder is 4:100.

The third slurry was spray-dried and granulated under the following process conditions. Process conditions: feeding speed is 40ml/min, inlet temperature is 260°C, outlet temperature is 90°C, chamber pressure is 1bar, atomizer is adjusted to 3m ³ /h.

The prepared nano-ceramic agglomerated powder is spherical and has excellent fluidity, and can be directly used for thermal spraying to prepare thermal barrier coatings.

Example 7

Mix 8YSZ powder with a particle size of 40 nm and deionized water at a mass ratio of 4.5:5.5 to obtain the first slurry.

The first slurry was mixed with polyacrylic acid and ball milling medium, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a speed of 400 rpm for 2 hours to obtain the second slurry. Wherein, the ball milling medium also includes zirconia balls with particle diameters of 8mm, 12mm and 22mm at the quantity ratio of 8:4:1. The mass ratio of polyacrylic acid to 8YSZ powder is 10:100, and the mass ratio of ball milling media to 8YSZ powder is 3:1.

The second slurry was mixed with polyvinylpyrrolidone, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a rotation speed of 400 rpm for 2 hours to obtain a third slurry. The mass ratio of polyvinylpyrrolidone to 8YSZ powder is 14:100.

The third slurry was spray-dried and granulated under the following process conditions. Process conditions: feeding speed is 100ml/min, inlet temperature is 290°C, outlet temperature is 120°C, chamber pressure is 2bar, atomizer is adjusted to 6m ³ /h.

The prepared nano-ceramic agglomerated powder is spherical and has excellent fluidity, and can be directly used for thermal spraying to prepare thermal barrier coatings.

Example 8

Mix 8YSZ powder with a particle size of 35m and deionized water at a mass ratio of 4:6 to obtain the first slurry.

The first slurry was mixed with polyacrylic acid and ball milling medium, and ball milled for 3 hours with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a speed of 300 rpm to obtain the second slurry. Wherein, the ball milling medium also includes zirconia balls with particle diameters of 6 mm, 10 mm and 20 mm in a quantity ratio of 8:4:1. The mass ratio of polyacrylic acid to 8YSZ powder is 5:100, and the mass ratio of ball milling media to 8YSZ powder is 2:1.

The second slurry was mixed with polyvinylpyrrolidone, and ball milled with a QM-3SP4 planetary ball mill of Nanjing Nanda Instrument Co., Ltd. at a rotation speed of 300 rpm for 3 hours to obtain a third slurry. The mass ratio of polyvinylpyrrolidone to 8YSZ powder is 9:100.

The third slurry was spray-dried and granulated under the following process conditions. Process conditions: feeding speed is 70ml/min, inlet temperature is 275°C, outlet temperature is 105°C, chamber pressure is 1.5bar, atomizer is adjusted to 4.5m ³ /h.

The prepared nano-ceramic agglomerated powder is spherical and has excellent fluidity, and can be directly used for thermal spraying to prepare thermal barrier coatings.

Example 9

This embodiment provides an application of a nano-ceramic powder for a thermal barrier coating, that is, it is used to produce a thermal barrier coating for a nozzle in a turbine engine. The nano-ceramic powder can be prepared by any one of the above-mentioned embodiments 1-8. The obtained nano-ceramic powder is used for the thermal barrier coating.

Example 10

This embodiment provides an application of nano-ceramic powder for thermal barrier coatings, that is, it is used to produce thermal barrier coatings for pressure cooker turbine blades in turbine engines, and nano-ceramic powders can be implemented by any of the above-mentioned embodiments 1-8. Example Preparation of nano-ceramic powder for thermal barrier coating.

Example 11

This embodiment provides an application of nano-ceramic powder for thermal barrier coatings, that is, it is used to produce thermal barrier coatings for flame cylinders in turbine engines, and nano-ceramic powders can be used in any of the above-mentioned embodiments 1-8. The obtained nano-ceramic powder for thermal barrier coating is prepared.

Example 12

This embodiment provides a thermal barrier coating, the thermal barrier coating contains nano-ceramic powder, and the nano-ceramic powder can be the nano-ceramic powder for thermal barrier coating prepared by any one of the above-mentioned embodiments 1-8.

Test case

The above-mentioned embodiments 1-8 are repeated to obtain enough nano-ceramic powders for thermal barrier coatings.

Taking Example 1 as an example, when preparing 8YSZ nano-agglomerated ceramic powder, the original 8YSZ powder was sampled to observe the microscopic morphology and original particle size of the powder particles with a transmission electron microscope and a scanning electron microscope, and the results are shown in Figure 1 and Figure 2 respectively Shown; Adopt X-ray diffractometer (XRD) to analyze phase composition and its structure respectively to original 8YSZ powder, nano agglomerated powder after spray-drying, the result is as shown in Figure 3, A among the figure is original powder, and B is powder after spray-drying The particle size distribution of nano-ceramic agglomerated powder is analyzed by laser particle size analyzer, and the obtained results are shown in Figure 4; the spray-dried nano-ceramic agglomerated powder is sampled and the morphology of nano-ceramic agglomerated powder is analyzed by scanning electron microscope, and the obtained results are shown in Fig. 5.

Scanning electron microscopy was used to analyze the morphology of the nano-ceramic agglomerated powders prepared in Example 2 and Example 3, and the results are shown in Figure 6 and Figure 7 respectively.

It can be concluded from FIG. 1 that the particle size of the original 8YSZ nanopowder in Example 1 is less than 50nm, and roughly in the range of 20-40nm.

From Figure 2, we can see the microscopic morphology of the original 8YSZ nano-powder. Compared with Figures 5-7, the prepared finished product has improved the uniformity of nano-powder distribution compared with the original 8YSZ nano-powder.

It can be seen from Figure 3 that there is no obvious change in the phase of the powder before and after spray drying, which proves that the physical properties of the original powder have not changed before and after spray drying.

From Figure 4, it can be concluded that 80% of the powder particle size distribution after spray drying is between 6.25-20.51 μm.

In summary, the preparation method of the nano-ceramic powder for thermal barrier coating provided by the embodiment of the present invention is simple, efficient, and pollution-free, and can improve the probability of stable compounding of the powder and the yield of the powder. The prepared nano-ceramic powder for thermal barrier coatings has good agglomeration and high fluidity, and at the same time, the powder particles are small, the particle size distribution is relatively uniform, the sphericity is high, and the performance is stable. It is used to produce thermal barrier coatings for engine components, which can make engine components adapt to harsher high temperature, high pressure and strong corrosion working environments. The thermal barrier coating containing the above-mentioned nano-ceramic powder for thermal barrier coating has high heat insulation performance and high temperature oxidation resistance performance.

The embodiments described above are some, not all, embodiments of the present invention. The detailed description of the embodiments of the invention is not intended to limit the scope of the claimed invention but to represent only selected embodiments of the invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Claims (10)

1. a kind of preparation method of thermal barrier coating nano ceramic powder, which is characterized in that include the following steps：By nanoscale 8YSZ is configured to 8YSZ slurries with additive, then mist projection granulating；

The additive includes dispersant and bonding agent；

Preferably, the dispersant includes polyacrylic acid, and the bonding agent includes polyvinylpyrrolidone；

Preferably, the 8YSZ is the 8YSZ powder that granularity is 20-40nm；

Preferably, the mass ratio of the dispersant, the bonding agent and the 8YSZ are 1-10:4-14:100.

2. preparation method according to claim 1, which is characterized in that before being mixed with the additive, the 8YSZ first with Solvent mixes, and obtains the first slurry；

The solvent includes water or absolute alcohol；

Preferably, the mass ratio of the solvent and the 8YSZ are (7：3)-(5.5:4.5).

3. preparation method according to claim 2, which is characterized in that the preparation of the 8YSZ slurries includes the following steps： First slurry is mixed with the dispersant and ball-milling medium, ball milling 2-4h obtains the second slurry；By second slurry It is mixed with the bonding agent, continues ball milling 2-4h, obtain the 8YSZ slurries.

4. preparation method according to claim 3, which is characterized in that the ball-milling medium is zirconia ball；

Preferably, the ball-milling medium includes the zirconia ball of different-grain diameter simultaneously；

Preferably, the mass ratio of the ball-milling medium and the 8YSZ are (1:1)-(3:1).

5. preparation method according to claim 4, which is characterized in that the ball-milling medium is respectively simultaneously 4- including grain size The zirconia ball of 8mm, 8-12mm and 18-22mm.

6. preparation method according to claim 3, which is characterized in that prepare second slurry and prepare the 8YSZ Rotational speed of ball-mill is 200-400rpm in the mechanical milling process of slurry.

7. preparation method according to claim 1, which is characterized in that the process conditions of mist projection granulating include：Feeding speed For 40-100ml/min, inlet temperature is 260-290 DEG C, outlet temperature is 90-120 DEG C, cavity pressure 1-2bar, atomizer It is adjusted to 3-6m³/h。

8. a kind of thermal barrier coating nano ceramic powder, which is characterized in that the thermal barrier coating is with nano ceramic powder by such as weighing Profit requires any preparation methods of 1-7 to be prepared.

9. the application of thermal barrier coating nano ceramic powder as claimed in claim 8, which is characterized in that the thermal barrier coating is used Nano ceramic powder is used to produce the thermal barrier coating of engine components.

10. a kind of thermal barrier coating, which is characterized in that the thermal barrier coating contains thermal barrier coating as claimed in claim 8 with receiving Rice ceramic powders.