CN110331403B

CN110331403B - System and method for preparing ZrC and ZrN coating layers in fluidization mode

Info

Publication number: CN110331403B
Application number: CN201910619519.0A
Authority: CN
Inventors: 向茂乔; 朱庆山; 宋淼; 赵宏丹
Original assignee: Institute of Process Engineering of CAS
Current assignee: Institute of Process Engineering of CAS
Priority date: 2019-07-10
Filing date: 2019-07-10
Publication date: 2020-07-17
Anticipated expiration: 2039-07-10
Also published as: CN110331403A

Abstract

The invention discloses a system and a method for preparing ZrC and ZrN coating layers in a fluidized manner. After being pretreated in a fluidized bed, the zirconium source powder is transferred into a coating reactor and is coated in nitrogen source gas or carbon source gas at low temperature, so that compact ZrC and ZrN coating layers can be prepared on substrates or powder materials with various shapes. Compared with the traditional process, the method has the advantages of low deposition temperature, obvious extension of the types of coating materials, low production cost, environmental friendliness, particular suitability for large-scale batch production of ZrN or ZrC coating layers in industry and good economic and social benefits.

Description

System and method for preparing ZrC and ZrN coating layers in fluidization mode

Technical Field

The invention belongs to the field of chemical engineering and materials, and particularly relates to a system and a method for preparing ZrC and ZrN cladding coatings.

Background

Zirconium carbide and zirconium nitride simultaneously have metallic bond, ionic bond and covalent bond, show excellent thermochemical stability, good ablation resistance, thermal shock resistance and high-speed airflow (particle flow) scouring resistance, and play an irreplaceable role in key parts in the fields of aerospace and the like. However, the high melting point and hardness of the zirconium carbide and zirconium nitride materials make the processing and forming difficult, so that the critical parts are usually covered with a layer of zirconium carbide and zirconium nitride to play a role in protection. The coating method can reduce environmental pollution, save resources and create economic benefits. Currently, the methods for preparing zirconium carbide and zirconium nitride coatings are mainly classified into the following two categories:

(1) physical vapor phase coating methods include magnetron sputtering deposition, pulsed laser deposition, electron beam physical vapor deposition and the like. In the magnetron sputtering deposition, under the inert Ar atmosphere, Ar ions bombard the pure zirconium target material through magnetron sputtering (direct current reactive magnetron sputtering, pulse magnetron sputtering, radio frequency magnetron sputtering, microwave-plasma enhanced magnetron sputtering and alternating current reactive magnetron sputtering), a nitrogen source (ammonia gas and nitrogen gas) or a carbon source (methane) is introduced, and sputtered zirconium ions and ionized nitrogen ions or carbon ions are deposited on the substrate to obtain the ZrN or ZrC coating. Pulsed laser deposition, i.e. focusing high-energy laser on the Surface of a high-purity zirconium target to generate high temperature and molten pool on the Surface, and further generating high-temperature and high-pressure plasma, wherein the plasma is directionally and locally expanded and sprayed to form a ZrN or ZrC coating on the Surface of a substrate (Surface and Coatings Technology, 1999, 116: 1189, pulsed laser film preparation Technology, vacuum and low temperature, 2000, 6: 63). The electron beam physical vapor deposition is that ZrN or ZrC fine powder and coarse powder are mixed according to a certain proportion to prepare ZrN or ZrC ceramic rod as an evaporation source, and then the ceramic rod is bombarded by electron beams to evaporate and deposit on a substrate. Although these methods can produce ZrC or ZrN coatings, they all require high purity zirconium targets as raw materials and are very expensive. Meanwhile, the cost of the processing equipment is very high, and the ZrN or ZrC protective layer is difficult to coat on a large-size substrate with a complex shape. Therefore, the wide application of these expensive processes in industry is greatly limited.

(2) The chemical vapor deposition coating method is that zirconium source gas and nitrogen source or carbon source are adopted to carry out chemical reaction at high temperature, and a ZrN or ZrC coating is formed on the substrate material. The most common zirconium source at present is ZrCl₄，ZrBr₄(ii) a The nitrogen source is N₂，NH₃(ii) a The carbon source is CH₄，C₃H₆. For example, Hollabaugh et al (NuclearTechn,1977,35(2):527), at the university of California, los Alamous scientific laboratory, each employed ZrCl₄-CH₄，ZrCl₄-C₃H₆System, ThO at 1200 deg.C₂The surface of the spherical powder is coated with a ZrC protective layer. ZrCl was used by Kudapa et al (Surface and Coatings technol.,1999,120,259) in USA₄-N₂-H₂In the system, a ZrN coating layer was prepared at 1200 ℃. However, the deposition temperature is high, and the method is only suitable for a part of high-temperature resistant matrixes, and the application range of the method is severely limited. Based on this, some low temperature deposition processes have been developed, such as plasma assisted chemical vapor deposition, metallorganic low temperature depositionThermal cracking chemical vapor deposition. For example, Anderson et al (Journal of Crystal Growth, 2007, 304: 324), university of Florida, USA, employs a zirconium-based organic (ZrNp)₄or ZrBn₄) A ZrC cladding layer was prepared at about 600 ℃. Devi et al (crystal. growth des.2012,12,5079) at german boyhen luer university based on ammonia organics of zirconium ([ Zr (NMe)₂)₄]And [ Zr (NEt)₂)₄]) A ZrN cladding layer was prepared at 600 ℃. Although zirconium metallorganics can significantly lower the deposition temperature of ZrN or ZrC, these zirconium metallorganics are expensive, very dangerous, explosive, and toxic, and are unacceptable in the industry.

In summary, the ZrN or ZrC cladding coating prepared by the conventional process has high cost and high temperature, and lacks a system applicable to industry, which severely limits the industrial application of the ZrN or ZrC cladding coating. Therefore, there is a need in the art to develop a new process for mass production of ZrN or ZrC cladding layer at a lower temperature and with low cost and high efficiency.

Disclosure of Invention

Aiming at the problems, the invention provides a system and a method for preparing ZrC and ZrN coating layers in a fluidized manner, and ZrN or ZrC coating layers are produced in a large-scale batch mode at low temperature and with low cost and high efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme:

the system for preparing the ZrC and ZrN coating comprises the following components: the device comprises a first powder bin 1, a fluidized bed reactor 2, a gasification device 3, a first cyclone separation device 4, a transfer bin 5, a bin to be coated 6, a coating device 7, a second cyclone separation device 8, a tail gas treatment device 9, a second bin 10, a powder recovery bin 11 and a product bin 12;

the first powder bin 1 is connected with the fluidized bed reactor 2 through a pipeline and a material valve; the fluidized bed reactor 2 has a bottom air inlet, Ar gas and H gas₂Is connected with a gas valve through a pipeline; an air inlet at the bottom of the gasification device 3 is connected with Ar gas through a pipeline and an air valve; the gas outlet of the gasification device 3 is connected with the gas inlet of the fluidized bed reactor 2 through a pipelineConnecting; the gas outlet of the fluidized bed reactor 2 is connected with the gas inlet of the first cyclone separation device 4 through a pipeline; the discharge hole of the first cyclone separation device 4 is connected with the feed inlet of the fluidized bed reactor 2 through a pipeline and a material valve; the gas outlet of the first cyclone separation device 4 is connected with the gas inlet of the tail gas treatment device 9 through a pipeline; the discharge hole of the fluidized bed reactor 2 is connected with the feed inlet of the transfer bin 5 through a pipeline and a material valve; an air inlet of the transfer bin 5 is connected with Ar gas through a pipeline and an air valve; the discharge hole of the transfer bin 5 is connected with the feed inlet of the coating device 7 through a pipeline; the discharge hole of the bin 6 to be coated is connected with the feed inlet of the coating device 7 through a pipeline and a material valve; the air inlet at the bottom of the coating device 7 is respectively communicated with Ar gas and H gas₂、N₂Or NH₃、CH₄Or C₃H₆Is connected with a gas valve through a pipeline; the air outlet of the coating device 7 is connected with the air inlet of the second cyclone separation device 8 through a pipeline; the discharge hole of the second cyclone separation device 8 is connected with the feed inlet of the coating device 7 through a pipeline and a material valve; the air outlet of the second cyclone separation device 8 is connected with the air inlet of the tail gas treatment device 9 through a pipeline; the discharge hole of the coating device 7 is connected with the feed inlet of the second storage bin 10 through a pipeline and a material valve; the discharge hole of the second storage bin 10 is connected with the feed inlet of the powder recovery storage bin 11 through a pipeline and a material valve; the discharge hole of the second storage bin 10 is connected with the feed hole of the product storage bin 12 through a pipeline and a material valve.

The method for preparing the ZrC and ZrN coating layer based on the system comprises the following steps:

the material in the first powder bin 1 enters the fluidized bed reactor 2 through a material valve and a pipeline, and meanwhile, the material in the gasification device 3 is gasified at a certain temperature and is carried by Ar gas to enter the fluidized bed reactor 2; the material in the fluidized bed reactor 2 is in a fluidized state under the fluidization effect of Ar and reacts for a period of time at a certain temperature, wherein fine powder and gas enter the first cyclone separation device 4 along with a pipeline, the separated fine powder is recycled and enters the fluidized bed reactor 2 through a pipeline and a material valve, and tail gas enters the tail gas treatment device 9 along with a pipeline to realize treatment and recycling of the tail gas; the reacted materials in the fluidized bed reactor 2 enter the transfer bin 5 through a material valve, are purified and gasified and enter the coating device 7, meanwhile, the materials in the bin 6 to be coated enter the coating device 7 and react for a period of time under the atmosphere of a corresponding nitrogen source or carbon source, and the tail gas is separated by the second cyclone separation device 8 and then enters the tail gas treatment device 9 to realize the treatment and recycling of the tail gas; fine powder in the tail gas in the coating device 7 is separated by the second cyclone separation device 8 and then recycled into the coating device 7; and the reacted material powder and the coating material in the coating device 7 enter the second storage bin 10 to be separated, wherein the material powder enters the powder recovery storage bin 11 to recycle the zirconium source, and the product enters the product storage bin 12 to obtain the coating product.

Preferably, the powder in the first powder bin 1 is any one of sponge zirconium or zirconium hydride or mixed in any proportion.

Preferably, the reaction temperature in the fluidized bed reactor 2 is 300 ℃ to 1000 ℃, and the average powder residence time is more than 5 min.

Preferably, the material in the gasification device 3 is any one of zirconium tetrachloride or zirconium tetraiodide or a mixture of zirconium tetrachloride and zirconium tetraiodide in any proportion, and the temperature range is 80 ℃ to 450 ℃.

Preferably, the reaction temperature in the coating device 7 is more than or equal to 450 ℃, and the deposition coating time is more than 5 min.

In the invention, zirconium source powder is transferred into a coating reactor after being pretreated in a fluidized bed, and is coated in nitrogen source gas or carbon source gas at low temperature, so that compact ZrC and ZrN coating layers can be prepared on substrates or powder materials with various shapes.

Compared with the prior art, the process for preparing the ZrC and ZrN coating layer has the following outstanding advantages: the deposition temperature is low, the minimum deposition temperature is reduced by about 500 ℃ compared with the deposition temperature of the prior art, the types of coating materials are remarkably expanded, the method is particularly suitable for coating materials with complex shapes, the production cost is reduced by 30% compared with the traditional process, the method is environment-friendly, the cyclic utilization of a zirconium source can be realized, and the method is suitable for large-scale batch production of ZrN or ZrC coating layers in industry.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

FIG. 1 is a schematic diagram of a system for preparing ZrC and ZrN cladding layers according to the invention;

FIG. 2 is an SEM image of ZrN-clad M2 high speed steel;

fig. 3 is an SEM image of ZrC coated 316L stainless steel.

Reference numerals: first powder feed bin 1, fluidized bed reactor 2, gasification equipment 3, first cyclone 4, transfer feed bin 5, treat cladding feed bin 6, cladding device 7, second cyclone 8, tail gas processing apparatus 9, second feed bin 10, powder recovery feed bin 11, product feed bin 12.

Detailed Description

Any feature disclosed in this specification may be replaced by alternative features serving equivalent or similar purposes, unless expressly stated otherwise. Unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features. The description is only for the purpose of facilitating understanding of the present invention and should not be construed as specifically limiting the present invention.

The invention is described in further detail below with reference to the figures and the detailed description.

Example 1

Referring to fig. 1, the system for preparing ZrC and ZrN coating in a fluidized manner in this embodiment includes a first powder bin 1, a fluidized bed reactor 2, a gasification device 3, a first cyclone separation device 4, a transfer bin 5, a bin to be coated 6, a coating device 7, a second cyclone separation device 8, a tail gas treatment device 9, a second bin 10, a powder recovery bin 11, and a product bin 12;

the first powder bin 1 and the stationThe fluidized bed reactor 2 is connected with a material valve through a pipeline; the bottom air inlet of the fluidized bed reactor 2, Ar and H₂Is connected with a gas valve through a pipeline; an air inlet at the bottom of the gasification device 3 is connected with Ar gas through a pipeline and an air valve; the gas outlet of the gasification device 3 is connected with the gas inlet of the fluidized bed reactor 2 through a pipeline; the gas outlet of the fluidized bed reactor 2 is connected with the gas inlet of the first cyclone separation device 4 through a pipeline; the discharge hole of the first cyclone separation device 4 is connected with the feed inlet of the fluidized bed reactor 2 through a pipeline and a material valve; the gas outlet of the first cyclone separation device 4 is connected with the gas inlet of the tail gas treatment device 9 through a pipeline; the discharge hole of the fluidized bed reactor 2 is connected with the feed inlet of the transfer bin 5 through a pipeline and a material valve; an air inlet of the transfer bin 5 is connected with Ar gas through a pipeline and an air valve; the discharge hole of the transfer bin 5 is connected with the feed inlet of the coating device 7 through a pipeline; the discharge hole of the bin 6 to be coated is connected with the feed inlet of the coating device 7 through a pipeline and a material valve; the air inlet at the bottom of the coating device 7 is respectively communicated with Ar gas and H gas₂、N₂Or NH₃、CH₄Or C₃H₆Is connected with a gas valve through a pipeline; the air outlet of the coating device 7 is connected with the air inlet of the second cyclone separation device 8 through a pipeline; the discharge hole of the second cyclone separation device 8 is connected with the feed inlet of the coating device 7 through a pipeline and a material valve; the air outlet of the second cyclone separation device 8 is connected with the air inlet of the tail gas treatment device 9 through a pipeline; the discharge hole of the coating device 7 is connected with the feed inlet of the second storage bin 10 through a pipeline and a material valve; the discharge hole of the second storage bin 10 is connected with the feed inlet of the powder recovery storage bin 11 through a pipeline and a material valve; the discharge hole of the second storage bin 10 is connected with the feed hole of the product storage bin 12 through a pipeline and a material valve.

Example 2

The embodiment of the method for preparing the ZrC and ZrN cladding layer by using the system in the above embodiment 1 specifically comprises the following steps: the material in the first powder bin 1 enters the fluidized bed reactor 2 through a material valve and a pipeline, and meanwhile, the material in the gasification device 3 is gasified at a certain temperature and is carried by Ar to enter the fluidized bed reactor 2; the material in the fluidized bed reactor 2 is in a fluidized state under the fluidization effect of Ar and reacts for a period of time at a certain temperature, wherein fine powder and gas enter the first cyclone separation device 4 along with a pipeline, the separated fine powder is recycled and enters the fluidized bed reactor 2 through a pipeline and a material valve, and tail gas enters the tail gas treatment device 9 along with a pipeline to realize treatment and recycling of the tail gas; the reacted materials in the fluidized bed reactor 2 enter the transfer bin 5 through a material valve, are purified and gasified and enter the coating device 7, meanwhile, the materials in the bin 6 to be coated enter the coating device 7 and react for a period of time under the atmosphere of a corresponding nitrogen source or carbon source, and the tail gas is separated by the second cyclone separation device 8 and then enters the tail gas treatment device 9 to realize the treatment and recycling of the tail gas; fine powder in the tail gas in the coating device 7 is separated by the second cyclone separation device 8 and then recycled into the coating device 7; and the reacted material powder and the coating material in the coating device 7 enter the second storage bin 10 to be separated, wherein the material powder enters the powder recovery storage bin 11 to recycle the zirconium source, and the product enters the product storage bin 12 to obtain the coating product.

Example 3

In this embodiment, on the basis of the above embodiment 2, the powder in the first powder bin 1 is sponge zirconium, the reaction temperature in the fluidized bed reactor 2 is 300 ℃, and the reaction time is 120 min; the fluidizing gas in the fluidized bed reactor 2 is Ar; the material in the gasification device 3 is zirconium tetrachloride, and the temperature is 450 ℃; the material in the bunker 6 to be coated is high-speed steel M2; the temperature in the coating device 7 is 450 ℃, and the nitrogen source gas entering the coating device 7 is NH₃The reaction time is 120 min; and obtaining ZrN coated M2 high-speed steel in the product bin 12. Fig. 2 is an SEM image of ZrN coated M2 high speed steel prepared. The graph shows that the surface of the film is coated with the nanocrystalline ZrN coating, and the deposition temperature is lower than that of the prior artAbout 500 deg.c lower.

Example 4

In this embodiment, on the basis of the above embodiment 2, the powder in the first powder bin 1 is zirconium hydride; the material in the gasification device 3 is zirconium tetraiodide, the temperature is 80 ℃, and the carrier gas is Ar gas; the reaction temperature in the fluidized bed reactor 2 is 1000 ℃, and the fluidizing gas is Ar and H₂Ar and H₂The flow ratio of the raw materials is 1:5, the reaction time is 5min, the material in the bunker 6 to be coated is 316L stainless steel, the temperature in the coating device 7 is 800 ℃, and the carbon source gas entering the coating device 7 is CH₄And reacting for 5min, obtaining ZrC-coated 316L stainless steel in the product bin 12, and obtaining an SEM image of the ZrC-coated 316L stainless steel prepared in FIG. 3. As seen from the SEM image, the ZrC-coated stainless steel is coated on the surface of the ZrC-coated 316L stainless steel, the grain size is about 3 microns, and the deposition efficiency is improved by 20 percent compared with the prior art.

The method can be realized by upper and lower limit values and interval values of intervals of process parameters (such as temperature, time and the like), and embodiments are not listed.

Conventional technical knowledge in the art can be used for the details which are not described in the present invention.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and are not limited. Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A system for preparing ZrC and ZrN coating in a fluidized mode is characterized by comprising: the device comprises a first powder bin (1), a fluidized bed reactor (2), a gasification device (3), a first cyclone separation device (4), a transfer bin (5), a bin to be coated (6), a coating device (7), a second cyclone separation device (8), a tail gas treatment device (9), a second bin (10), a powder recovery bin (11) and a product bin (12);

the first powder bin (1) andthe fluidized bed reactor (2) is connected with a material valve through a pipeline; the bottom air inlet of the fluidized bed reactor (2), Ar gas and H₂Is connected with a gas valve through a pipeline; an air inlet at the bottom of the gasification device (3) is connected with Ar gas through a pipeline and a gas valve; the gas outlet of the gasification device (3) is connected with the gas inlet of the fluidized bed reactor (2) through a pipeline; the gas outlet of the fluidized bed reactor (2) is connected with the gas inlet of the first cyclone separation device (4) through a pipeline; the discharge hole of the first cyclone separation device (4) is connected with the feed inlet of the fluidized bed reactor (2) through a pipeline and a material valve; the air outlet of the first cyclone separation device (4) is connected with the air inlet of the tail gas treatment device (9) through a pipeline; the discharge hole of the fluidized bed reactor (2) is connected with the feed inlet of the transfer bin (5) through a pipeline and a material valve; an air inlet of the transfer bin (5) is connected with Ar gas through a pipeline and an air valve; the discharge hole of the transfer bin (5) is connected with the feed inlet of the coating device (7) through a pipeline; the discharge hole of the bin (6) to be coated is connected with the feed inlet of the coating device (7) through a pipeline and a material valve; the air inlet at the bottom of the coating device (7) is respectively communicated with Ar gas and H gas₂、N₂Or NH₃、CH₄Or C₃H₆Is connected with a gas valve through a pipeline; the air outlet of the coating device (7) is connected with the air inlet of the second cyclone separation device (8) through a pipeline; the discharge hole of the second cyclone separation device (8) is connected with the feed inlet of the coating device (7) through a pipeline and a material valve; the air outlet of the second cyclone separation device (8) is connected with the air inlet of the tail gas treatment device (9) through a pipeline; the discharge hole of the coating device (7) is connected with the feed inlet of the second storage bin (10) through a pipeline and a material valve; the discharge hole of the second storage bin (10) is connected with the feed inlet of the powder recovery storage bin (11) through a pipeline and a material valve; the discharge hole of the second storage bin (10) is connected with the feed inlet of the product storage bin (12) through a pipeline and a material valve.

2. A method for preparing a ZrC, ZrN cladding layer based on the system of claim 1, the method comprising the steps of:

the material in the first powder bin (1) enters the fluidized bed reactor (2) through a material valve and a pipeline, and meanwhile, the material in the gasification device (3) is gasified and carried by Ar gas to enter the fluidized bed reactor (2); materials in the fluidized bed reactor (2) are in a fluidized state under the fluidization effect of Ar gas and react, fine powder and gas after reaction enter the first cyclone separation device (4) along a pipeline, the fine powder after separation enters the fluidized bed reactor (2) through a pipeline and a material valve in a recovery mode, and tail gas enters the tail gas treatment device (9) along a pipeline to realize treatment and recovery and reutilization of the tail gas; the material reacted in the fluidized bed reactor (2) enters the transfer bin (5) through a material valve, is purified and gasified and enters the coating device (7), meanwhile, the material to be coated in the bin (6) enters the coating device (7) and reacts in the atmosphere of a corresponding nitrogen source or carbon source, and reaction tail gas enters the tail gas treatment device (9) after being separated by the second cyclone separation device (8) to realize treatment and recycling of the tail gas; fine powder in tail gas in the coating device (7) is separated by the second cyclone separation device (8) and then recycled into the coating device (7); and the material powder and the coating material after reaction in the coating device (7) enter the second storage bin (10) for separation, wherein the material powder enters the powder recovery storage bin (11) to realize the recovery and reutilization of the zirconium source, and the product enters the product storage bin (12) to obtain the coating product.

3. The method for preparing a ZrC and ZrN coating layer as defined in claim 2, wherein the powder in the first powder bin (1) is any one of sponge zirconium and zirconium hydride or mixed in any proportion.

4. A method of producing a ZrC, ZrN cladding layer according to claim 2, characterized in that the reaction temperature in the fluidized bed reactor (2) is 300 ℃ to 1000 ℃ and the average powder residence time is more than 5 min.

5. A method of producing a ZrC, ZrN cladding layer according to claim 2, characterized in that the material in the gasifying device (3) is any one of zirconium tetrachloride or zirconium tetraiodide or mixed in any proportion, and the temperature range is 80 ℃ to 450 ℃.

6. A method for preparing a ZrC, ZrN cladding layer according to claim 2, characterized in that the reaction temperature in the cladding device (7) is not less than 450 ℃ and the deposition cladding time is more than 5 min.