CN113174621A - Cr (chromium)xCyMethod for preparing ceramic coating - Google Patents

Cr (chromium)xCyMethod for preparing ceramic coating Download PDF

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CN113174621A
CN113174621A CN202110476308.3A CN202110476308A CN113174621A CN 113174621 A CN113174621 A CN 113174621A CN 202110476308 A CN202110476308 A CN 202110476308A CN 113174621 A CN113174621 A CN 113174621A
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coating
ceramic coating
substrate
carbon coating
base material
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CN113174621B (en
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王艳丽
吴家杰
王畅轩
张盛华
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Guangxi University
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Guangxi University
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D9/00—Electrolytic coating other than with metals
    • C25D9/04—Electrolytic coating other than with metals with inorganic materials
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/40—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using liquids, e.g. salt baths, liquid suspensions
    • C23C8/42—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using liquids, e.g. salt baths, liquid suspensions only one element being applied
    • C23C8/44—Carburising
    • C23C8/46—Carburising of ferrous surfaces
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

Abstract

The invention discloses CrxCyThe preparation method of the ceramic coating comprises the following operation steps: 1) pretreatment of a base material: selecting stainless steel as a base material, and carrying out oxidation treatment at high temperature after punching, polishing, chamfering and cleaning; 2) preparing a carbon coating: performing partial electro-deoxidation on the surface of the pretreated substrate, and then performing electro-deposition on a carbon coating on the surface of the substrate; 3) conversion of carbon coating to CrxCyLayer (b): and (3) soaking the substrate prepared with the carbon coating in a molten chloride system containing Cr, and performing chromium carbide conversion by utilizing Cr disproportionation reaction. The method has simple and convenient operation, the thickness of the chromium carbide coating can be controlled by controlling the deposition time of the carbon coating, and the carbon coating is taken as a template to carry out the conversion of the chromium carbide so as to lead the prepared Cr to be obtainedxCyThe ceramic coating has good compactness and is well combined with the base material.

Description

Cr (chromium)xCyMethod for preparing ceramic coating
Technical Field
The invention belongs to the technical field of metal material surface treatment, and particularly relates to CrxCyA method for preparing a ceramic coating.
Background
The chromium carbide is a wear-resistant, acid corrosion resistant and high-temperature oxidation resistant high-melting-point material, has a similar thermal expansion coefficient with stainless steel, is used as a protective coating on the surface of a structural material, and can be used for the material in an acid high-temperature environmentThe corrosion resistance is improved, and the potential is great. Chromium carbide exists in four forms: CrC, Cr3C2、Cr7C3、Cr23C6Wherein Cr is3C2The corrosion resistance and the high temperature resistance are optimal. At present, the method for preparing the chromium carbide coating on the surface of the material mainly comprises a spraying method, a laser cladding method and a magnetron sputtering method. The spraying method is to add chromium carbide powder into the coating, and then fix the chromium carbide powder on the surface of the material by adopting a spraying method so as to improve the corrosion resistance and the wear resistance, but the chromium carbide powder in the coating is not absolutely uniform, the coating is loose and porous, the compactness and the combination with a matrix are poor, and the hidden danger of the material in long-term service is large; the coating prepared by the magnetron sputtering method is easy to generate cracks, and the coating is difficult to prepare on the surface of a material with a complex structure; the coating prepared by the laser cladding method has the problem of uneven component distribution.
Disclosure of Invention
The invention aims to provide CrxCyMethod for preparing ceramic coating, and prepared CrxCyThe ceramic coating is good in continuous compactness, good in combination with a substrate and stable in preparation process, and can effectively solve the corrosion problem of structural materials such as metal and the like in an acidic high-temperature environment.
The invention solves the technical problems by the following technical scheme:
the invention relates to CrxCyThe preparation method of the ceramic coating comprises the following operation steps:
1) pretreatment of a base material: pre-oxidizing a stainless steel substrate at high temperature to form compact Cr on the surface of the substrate2O3An oxide layer;
2) preparing a carbon coating: connecting the matrix obtained in the step (1) with a steel wire to serve as a working electrode, soaking the matrix in a graphite crucible filled with molten chloride, wherein the molten chloride is formed by mixing LiCl and KCl, the mass ratio of LiCl to KCl is 9:7, water and oxygen are fully removed, the graphite crucible serves as a counter electrode and a reference electrode, a voltage of-2.5V relative to the reference electrode is applied to the working electrode for 10min to perform partial electro-deoxidation, and then K is added into the molten chloride2CO3，K2CO3The dosage of the carbon coating is 1 percent of the total molar weight of LiCl and KCl, after standing for 30min, carbon deposition is carried out by a constant current method by taking a working electrode as a cathode and a graphite crucible as an anode to obtain a carbon coating;
3) conversion of carbon coating to CrxCyCeramic coating: soaking the substrate treated in the step (2) in a molten chloride system containing Cr at 850-900 ℃, converting carbon into chromium carbide by utilizing Cr disproportionation reaction, and obtaining CrxCyAnd (3) coating the ceramic.
In the step 1), 316L stainless steel is selected as the stainless steel, the stainless steel is cut into slices with the size of 23 multiplied by 6 multiplied by 2mm, punching, polishing, chamfering and cleaning are carried out before oxidation treatment, the punching is convenient for connecting with a steel wire, the polishing and chamfering are carried out by sand paper treatment to obtain a continuous and flat substrate surface, then the substrate is sequentially subjected to oil removal and cleaning by ethanol and deionized water, and then pre-oxidation treatment is carried out.
In the step 1), during the pre-oxidation operation, the stainless steel substrate is pre-oxidized for 120min at 800 ℃.
In step 2), the molten chloride salt was heated to 450 ℃.
In the step 2), when constant current deposition is carried out, the adopted constant current density is 0.01-0.02A cm-2The deposition time was 1.5 h.
In the step 3), the Cr-containing molten chloride system consists of basic molten salt and active substances, wherein the basic molten salt is NaCl and KCl, and the active substances are Cr powder and CrF3Powder, in terms of mole ratio, NaCl: KCl ═ 1:1, Cr: CrF3The mass ratio of the basic molten salt to the active substance is 10:1, and the conversion time of the chromium carbide is 60 min.
The method has simple and convenient operation, the thickness of the chromium carbide coating can be controlled by controlling the deposition time of the carbon coating, and the carbon coating is taken as a template to carry out the conversion of the chromium carbide so as to lead the prepared Cr to be obtainedxCyThe ceramic coating is good in continuous compactness, good in combination with a substrate and stable in preparation process, and can effectively solve the corrosion problem of structural materials such as metal and the like in an acidic high-temperature environment.
Drawings
FIG. 1 is a surface topography of a carbon coating of example 1 of the present invention.
FIG. 2 shows Cr in example 1 of the present inventionxCyXRD pattern of ceramic coating (i.e. chromium carbide coating).
FIG. 3 shows Cr in example 1 of the present inventionxCyCross-sectional scanning electron micrographs of ceramic coatings (i.e., chromium carbide coatings).
FIG. 4 shows Cr in example 2 of the present inventionxCyXRD pattern of ceramic coating (i.e. chromium carbide coating).
FIG. 5 shows Cr in example 2 of the present inventionxCyCross-sectional scanning electron micrographs of ceramic coatings (i.e., chromium carbide coatings).
Detailed Description
The technical scheme of the invention is further explained in detail by combining the attached drawings and examples.
Example 1
Taking 316L stainless steel (the components are shown in table one) containing 16 wt.% of Cr as a base material, cutting the stainless steel base material into 23 x 6 x 2mm slices, then punching the base material for subsequent connection of steel wires, then sequentially using 400-mesh, 600-mesh and 1000-mesh SiC sand papers to polish and chamfer the base material so as to obtain a continuous and flat base material surface, ultrasonically degreasing the continuous and flat base material surface by using absolute ethyl alcohol, then washing the continuous and flat base material surface by using deionized water, drying the cleaned continuous and flat base material surface, and oxidizing the cleaned continuous and flat base material surface for 120min at 800 ℃. Then the steel wire is connected with the steel wire, and the perforated part is sealed in the corundum tube by high-temperature cement. Then the carbon film is used as a working electrode and put into molten chloride (each 100g of the molten chloride contains 56.25g of LiCl and 43.75g of KCl) at 450 ℃ which is fully dehydrated and deoxidized, the molten chloride is placed in a graphite crucible, the graphite crucible is used as a counter electrode and a reference electrode, the working electrode is applied with-2.5V relative to the reference electrode for 600s to perform partial electro-deoxidation, so that an oxygen vacancy is created in an oxide layer on the surface of a substrate, a Cr-O-C transition layer can be formed during subsequent carbon deposition, and the binding force between a carbon coating and the substrate is enhanced. Then adding K to the molten chloride salt2CO3The dosage is 1 percent of the total molar weight of LiCl and KCl, standing for 30min, and then adopting a working electrode as a cathode and a graphite crucible as an anode to adopt constant currentCarbon deposition by flow method with constant deposition current density of 0.02A cm-2And the deposition time is 1.5h, so that the carbon coating can be prepared on the surface of the base material, and the carbon coating is formed by growing, winding and accumulating carbon nano tubes, and the appearance of the carbon coating is shown in figure 1. After the carbon coating is prepared, the base material is slowly taken out and then slowly put into a corundum crucible containing molten chloride containing Cr at 850 ℃, wherein the molten chloride containing Cr consists of basic molten salt and active substances, the basic molten salt is NaCl and KCl, and the active substances are Cr powder and CrF3Powder, in terms of mole ratio, NaCl: KCl ═ 1:1, Cr: CrF3The mass ratio of basic molten salt to active substance is 10:1, the base material is soaked in a Cr-containing molten chloride salt system for 60min to convert the carbon coating into a chromium carbide coating, the base material is taken out, cooled to room temperature, ultrasonically cleaned in deionized water for 3 times and dried to obtain CrxCyCeramic coating (i.e. chromium carbide coating), CrxCyXRD results of the ceramic coating are shown in FIG. 2, and the coating contains a plurality of chromium carbides, in the form of Cr7C3Is the main component. Cr (chromium) componentxCyThe cross-sectional morphology of the coating is shown in FIG. 3, the coating is uniform in thickness, continuous and compact, and is well combined with the substrate.
Watch 1
Figure BDA0003047505690000051
Example 2
Taking 316L stainless steel (the components are shown in table one) containing 16 wt.% of Cr as a base material, cutting the stainless steel base material into 23 x 6 x 2mm slices, then punching the base material for subsequent connection of steel wires, then sequentially using 400-mesh, 600-mesh and 1000-mesh SiC sand papers to polish and chamfer the base material so as to obtain a continuous and flat base material surface, ultrasonically degreasing the continuous and flat base material surface by using absolute ethyl alcohol, then washing the continuous and flat base material surface by using deionized water, drying the cleaned continuous and flat base material surface, and oxidizing the cleaned continuous and flat base material surface for 120min at 800 ℃. Then the steel wire is connected with the steel wire, and the perforated part is sealed in the corundum tube by high-temperature cement. Then, the electrode was used as a working electrode which was charged with a 450 ℃ molten chloride salt (56.2 per 100g of molten chloride salt) which had been sufficiently removed in water and oxygen5g LiCl and 43.75g KCl, molten chloride is placed in a graphite crucible which is used as a counter electrode and a reference electrode), partial electro-deoxidation is carried out on the working electrode at the voltage of-2.5V relative to the reference electrode for 600s, so that an oxide layer on the surface of the base material creates oxygen vacancies, a Cr-O-C transition layer can be formed during subsequent carbon deposition, and the binding force of a carbon coating is enhanced. Then adding K to the molten chloride salt2CO3The amount of the carbon is 1 percent of the total molar weight of LiCl and KCl, standing for 30min, performing carbon deposition by a constant current method with a working electrode as a cathode and a graphite crucible as an anode, and keeping the constant deposition current density at 0.01A cm-2The deposition time is 1.5h, namely a carbon coating can be prepared on the surface of the base material, after the carbon coating is prepared, the base material is slowly taken out and then slowly put into a corundum crucible containing molten chloride containing Cr at 900 ℃, wherein the molten chloride containing Cr consists of basic molten salt and active substances, the basic molten salt is NaCl and KCl, and the active substances are Cr powder and CrF3Powder, in terms of mole ratio, NaCl: KCl ═ 1:1, Cr: CrF3The mass ratio of basic molten salt to active substance is 10:1, the base material is soaked in a Cr-containing molten chloride salt system for 60min to convert the carbon coating into a chromium carbide coating, the base material is taken out, cooled to room temperature, ultrasonically cleaned in deionized water for 3 times and dried to obtain CrxCyCeramic coating (i.e. chromium carbide coating), CrxCyXRD results of the ceramic coating are shown in FIG. 4, and the coating contains a plurality of chromium carbides, in terms of Cr7C3Is the main component. The section morphology of the chromium carbide coating is shown in figure 5, the coating is uniform in thickness, continuous and compact, and the chromium carbide coating is well combined with a matrix.

Claims (6)

1. Cr (chromium)xCyThe preparation method of the ceramic coating is characterized by comprising the following operation steps:
1) pretreatment of a base material: pre-oxidizing a stainless steel substrate at high temperature to form compact Cr on the surface of the substrate2O3An oxide layer;
2) preparing a carbon coating: connecting the matrix obtained in the step (1) with a steel wire to be used as a working electrode, and putting the working electrode into a stone filled with molten chlorideSoaking in an ink crucible, wherein the molten chloride salt is formed by mixing LiCl and KCl, the mass ratio of LiCl to KCl is 9:7, water and oxygen are sufficiently removed, the graphite crucible is used as a counter electrode and a reference electrode, a voltage of-2.5V relative to the reference electrode is applied to a working electrode for 10min to perform partial electro-deoxidation, and then K is added to the molten chloride salt2CO3，K2CO3The dosage of the carbon coating is 1 percent of the total molar weight of LiCl and KCl, after standing for 30min, carbon deposition is carried out by a constant current method by taking a working electrode as a cathode and a graphite crucible as an anode to obtain a carbon coating;
3) conversion of carbon coating to CrxCyCeramic coating: soaking the substrate treated in the step (2) in a molten chloride system containing Cr at 850-900 ℃, and carrying out chromium carbide conversion by utilizing Cr disproportionation reaction to obtain CrxCyAnd (3) coating the ceramic.
2. The Cr of claim 1xCyThe preparation method of the ceramic coating is characterized in that in the step 1), 316L stainless steel is selected as the stainless steel, the stainless steel is cut into slices with the size of 23 multiplied by 6 multiplied by 2mm, punching, grinding, chamfering and cleaning are carried out before oxidation treatment, the punching is convenient for being connected with a steel wire, grinding and chamfering are carried out by sand paper treatment to obtain a continuous and flat substrate surface, then the substrate is sequentially subjected to oil removal and cleaning by ethanol and deionized water, and then pre-oxidation treatment is carried out.
3. The Cr of claim 1xCyThe preparation method of the ceramic coating is characterized in that in the step 1), the stainless steel substrate is pre-oxidized for 120min at 800 ℃ during pre-oxidation operation.
4. The Cr of claim 1xCyThe method for preparing the ceramic coating is characterized in that in the step 2), the molten chloride salt is heated to 450 ℃.
5. The Cr of claim 1xCyThe preparation method of the ceramic coating is characterized in thatAnd in the step 2), when constant current deposition is carried out, the adopted constant current density is 0.01-0.02A-cm-2The deposition time was 1.5 h.
6. The Cr of claim 1xCyThe preparation method of the ceramic coating is characterized in that in the step 3), the Cr-containing molten chloride system consists of basic molten salt and active substances, wherein the basic molten salt is NaCl and KCl, and the active substances are Cr powder and CrF3Powder, in terms of mole ratio, NaCl: KCl ═ 1:1, Cr: CrF3The mass ratio of the basic molten salt to the active substance is 10:1, and the conversion time of the chromium carbide is 60 min.
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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4430170A (en) * 1983-01-17 1984-02-07 The United States Of America As Represented By The Secretary Of The Navy Electrodeposition of refractory metal carbides
US5364659A (en) * 1992-02-21 1994-11-15 Ohio State University Research Foundation Codeposition of chromium and silicon diffusion coatings in FE-base alloys using pack cementation
CN109943872A (en) * 2019-04-11 2019-06-28 广西大学 It is a kind of for melting the preparation method for the composite coating that stainless steel containing Cr in fluoride salt protects
CN110911690A (en) * 2019-12-06 2020-03-24 武汉大学 Liquid metal battery positive current collector with concave-convex surface microstructure carbide coating
CN111039290A (en) * 2018-10-12 2020-04-21 中国科学院金属研究所 Method for preparing transition metal carbide powder in situ by molten salt disproportionation reaction

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4430170A (en) * 1983-01-17 1984-02-07 The United States Of America As Represented By The Secretary Of The Navy Electrodeposition of refractory metal carbides
US5364659A (en) * 1992-02-21 1994-11-15 Ohio State University Research Foundation Codeposition of chromium and silicon diffusion coatings in FE-base alloys using pack cementation
CN111039290A (en) * 2018-10-12 2020-04-21 中国科学院金属研究所 Method for preparing transition metal carbide powder in situ by molten salt disproportionation reaction
CN109943872A (en) * 2019-04-11 2019-06-28 广西大学 It is a kind of for melting the preparation method for the composite coating that stainless steel containing Cr in fluoride salt protects
CN110911690A (en) * 2019-12-06 2020-03-24 武汉大学 Liquid metal battery positive current collector with concave-convex surface microstructure carbide coating

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