Submicron crystal ceramic coating for hard alloy and preparation method of submicron crystal ceramic coating

Abstract

The invention relates to the technical field of hard alloy, in particular to a submicron crystal ceramic coating for hard alloy and a preparation method, and the submicron crystal ceramic coating comprises the following components in parts by weight: 60-80 parts of high-melting-point oxide, 10-20 parts of high-melting-point carbide, 15-30 parts of boride and 20-45 parts of nitride. The high-melting-point oxide, the high-melting-point carbide, the boride and the nitride are adopted to jointly prepare the ceramic coating, and the surface of the hard alloy is coated with the ceramic coating in a spraying or dip-coating mode, so that the prepared hard alloy is more excellent in oxidation resistance and heat insulation performance on the basis of excellent wear resistance and corrosion resistance, and the service life of the hard alloy is prolonged. And the coating repair is simpler, the production cost is lower, and the technical problems that although the TiCN and (Ti, Al) N coating adopted by the existing hard alloy has the advantage of excellent wear resistance, the oxidation resistance is poor, the heat insulation performance is poor, the coating repair is difficult, the production cost is high and the like are solved.

Description

Technical Field

[0001] The invention relates to the technical field of cemented carbide, and in particular to a submicron crystalline ceramic coating for cemented carbide and a preparation method thereof. Background Art

[0002] During use, cemented carbide often suffers from high-temperature oxidation, wear, and corrosion, which seriously affects the performance and service life of metal parts. Therefore, it is necessary to apply a protective coating on the alloy surface to improve the alloy's anti-oxidation and corrosion resistance.

[0003] At present, TiCN and (Ti, Al) N coatings are commonly used in cemented carbide coatings. TiCN coatings have the good toughness and hardness of both TiC and TiN coatings. During the coating process, the properties of TiCN can be controlled by continuously changing the composition of C and N, and a gradient structure of different components can be formed to reduce the internal stress of the coating, improve toughness, increase coating thickness, prevent crack propagation, and reduce chipping. (Ti, Al) N coatings have very high high temperature hardness and oxidation resistance, which can greatly improve the wear resistance, oxidation resistance, and corrosion resistance of the alloy.

[0004] However, although the TiCN and (Ti, Al) N coatings used above have the advantage of excellent wear resistance, they still have problems such as poor oxidation resistance, poor thermal insulation performance, difficulty in coating repair, and high production cost. Summary of the invention

[0005] The purpose of the present invention is to provide a submicron crystalline ceramic coating for cemented carbide and a preparation method thereof, which solves the technical problems that the TiCN and (Ti, Al) N coatings used in existing cemented carbide have the advantages of excellent wear resistance but still have poor oxidation resistance, poor thermal insulation performance, difficulty in coating repair, high production cost and other technical problems.

[0006] To achieve the above object, the present invention provides a submicron crystalline ceramic coating for cemented carbide, comprising the following components by weight: 60-80 parts of high melting point oxide, 10-20 parts of high melting point carbide, 15-30 parts of boride and 20-45 parts of nitride.

[0007] Wherein, the high melting point oxide is one or more of Al2O3, ZrO2, TiO2 and SiO2.

[0008] Wherein, the high melting point carbide is one or more of TiC, SiC, Zr2C and WC.

[0009] Wherein, the boride is one or more of TiB2, ZrB2, and CrB2.

[0010] Wherein, the nitride is one or more of TiN, BN, and Si3N4.

[0011] Wherein, the ceramic coating is applied to the surface of the cemented carbide by spraying or dipping.

[0012] The present invention also provides a method for preparing a submicron-crystalline ceramic coating for cemented carbide, comprising the following steps:

[0013] Weighing high melting point oxides, high melting point carbides, borides and nitrides as raw materials for preparing ceramic coatings, and crushing and filtering the weighed raw materials respectively to obtain the required raw material powders;

[0014] Adding the raw material powder into a mixing tank according to the weight components, stirring and mixing to obtain a mixture, and heating and melting the mixture to obtain a mixed solution;

[0015] After melting, the mixed solution is evenly coated on the surface of the cemented carbide by spraying or dipping;

[0016] After drying, the cemented carbide is heated and sintered, and after heating, it is cooled in a furnace to obtain a submicron crystalline ceramic coating for the cemented carbide.

[0017] The present invention discloses a submicron crystalline ceramic coating for cemented carbide and a preparation method thereof. The ceramic coating is prepared by using high melting point oxides, high melting point carbides, borides and nitrides, wherein the high melting point oxides are one or more of Al2O3, ZrO2, TiO2 and SiO2, the high melting point carbides are one or more of TiC, SiC, Zr2C and WC, the borides are one or more of TiB2, ZrB2 and CrB2, and the nitrides are one or more of TiN, BN and Si3N4. The ceramic coating is applied to the surface of the cemented carbide by spraying or dipping, so that the prepared cemented carbide has excellent wear resistance and corrosion resistance, and also has better oxidation resistance and heat insulation performance, and the coating is easier to repair and has lower production cost. The technical problems that the TiCN and (Ti, Al) N coatings used in the existing cemented carbide have the advantages of excellent wear resistance but still have poor oxidation resistance, poor heat insulation performance, difficult coating repair and high production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below.

[0019] Figure 1It is a process step diagram of a method for preparing a submicron-crystalline ceramic coating for cemented carbide according to a second embodiment of the present invention. DETAILED DESCRIPTION

[0020] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0021] First embodiment:

[0022] The invention provides a submicron crystal ceramic coating for hard alloy, which comprises the following components by weight: 60-80 parts of high melting point oxide, 10-20 parts of high melting point carbide, 15-30 parts of boride and 20-45 parts of nitride.

[0023] In this embodiment, a ceramic coating is prepared by using high melting point oxides, high melting point carbides, borides and nitrides, and the ceramic coating is applied to the surface of the cemented carbide by spraying or dipping. The prepared cemented carbide has excellent wear resistance and corrosion resistance, as well as better oxidation resistance and thermal insulation performance. The coating repair is simpler and the production cost is lower. This solves the technical problems that the TiCN and (Ti, Al) N coatings used in existing cemented carbides have the advantages of excellent wear resistance but still have poor oxidation resistance, poor thermal insulation performance, difficulty in coating repair, and high production cost.

[0024] The purity of the high melting point oxide, the high melting point carbide, the boride and the nitride is 90-98%, and the particle size of the high melting point oxide powder, the high melting point carbide powder, the boride powder and the nitride powder is 0.5-1.5 μm.

[0025] Secondly, the high melting point oxide is one or more of Al2O3, ZrO2, TiO2 and SiO2.

[0026] Again, the high melting point carbide is one or more of TiC, SiC, Zr2C and WC.

[0027] At the same time, the boride is one or more of TiB2, ZrB2, and CrB2.

[0028] In addition, the nitride is one or more of TiN, BN, and Si3N4.

[0029] Finally, the ceramic coating is applied to the surface of the cemented carbide by spraying or dipping.

[0030] When using a submicron-crystalline ceramic coating for cemented carbide of this embodiment, the ceramic coating is prepared by using 70 parts of high-melting-point oxide, 10 parts of high-melting-point carbide, 25 parts of boride and 40 parts of nitride, wherein the high-melting-point oxide is one or more of Al2O3, ZrO2, TiO2 and SiO2, the high-melting-point carbide is one or more of TiC, SiC, Zr2C and WC, the boride is one or more of TiB2, ZrB2, CrB2, the nitride is TiN, BN, Si3N4, and the ceramic coating is applied to the surface of the cemented carbide by spraying or dipping, so that the prepared cemented carbide has excellent wear resistance and corrosion resistance, and the oxidation resistance and thermal insulation performance are also better, and the coating repair is simpler and the production cost is lower. It solves the technical problems that the TiCN and (Ti, Al) N coatings used in the existing cemented carbide have the advantages of excellent wear resistance, but still have poor oxidation resistance, poor thermal insulation performance, difficult coating repair, high production cost and other technical problems.

[0031] Second embodiment:

[0032] Based on the first embodiment, please refer to Figure 1 , Figure 1 1 is a flow chart of a method for preparing a submicron crystalline ceramic coating for cemented carbide according to a second embodiment of the present invention. The present invention also provides a method for preparing a submicron crystalline ceramic coating for cemented carbide, comprising the following steps:

[0033] S101. Weigh high melting point oxides, high melting point carbides, borides and nitrides as raw materials for preparing ceramic coatings, and crush and filter the weighed raw materials to obtain required raw material powders.

[0034] Specifically, high melting point oxides, high melting point carbides, borides and nitrides are weighed as raw materials for preparing ceramic coatings, and the weighed raw materials are crushed and filtered respectively to obtain the required raw material powders, wherein the high melting point oxides are one or more of Al2O3, ZrO2, TiO2 and SiO2, the high melting point carbides are one or more of TiC, SiC, Zr2C and WC, the borides are one or more of TiB2, ZrB2, CrB2, the nitrides are one or more of TiN, BN, Si3N4, the purity of the high melting point oxides, high melting point carbides, borides and nitrides are all 90-98%, and the particle sizes of the high melting point oxide powders, high melting point carbide powders, boride powders and nitride powders obtained after crushing and filtering are all 0.5-1.5μm.

[0035] S102, adding the raw material powder into a mixing tank according to the weight components, stirring and mixing to obtain a mixture, and heating and melting the mixture to obtain a mixed solution.

[0036] Specifically, according to the weight composition of 70 parts of high-melting-point oxide, 10 parts of high-melting-point carbide, 25 parts of boride and 40 parts of nitride, the high-melting-point oxide powder, high-melting-point carbide powder, boride powder and nitride powder obtained after crushing and filtering are added into a mixing tank for stirring and mixing to obtain a mixture, and the mixed mixture is heated and melted at a heating temperature of 1500-1700°C for 3-5h to obtain a mixed solution.

[0037] S103, after melting, uniformly coating the mixed solution on the surface of the cemented carbide by spraying or dipping.

[0038] Specifically, after melting, the obtained mixed solution is evenly coated on the surface of the cemented carbide by spraying or dipping to ensure that the ceramic coating is uniform and dense with moderate thickness. After coating, the cemented carbide is sent to a drying oven for drying for 5-8 hours.

[0039] S104, after drying, heating and sintering the cemented carbide, and after heating, cooling with the furnace to obtain a submicron crystalline ceramic coating for the cemented carbide.

[0040] Specifically, after drying, the cemented carbide is heated and sintered at a heating rate of 10-25°C / min using a three-step step method, and after heating, it is cooled with the furnace to obtain a submicron crystalline ceramic coating for the cemented carbide, wherein the three-step step method heating process parameters are: first, heating to a temperature environment of 400-600°C, keeping warm for 1-3 hours to remove the binder in the coating, then heating to an environment of 1000-1200°C, keeping warm for 0.5-2.0 hours, and finally, heating to 1200-1500°C, keeping warm for 1.5-4.0 hours. The sintering of the cemented carbide is carried out in a vacuum sintering furnace, and the vacuum degree in the vacuum sintering furnace is controlled within the range of 0.0001-10Pa.

[0041] When using the preparation method of a submicron-crystalline ceramic coating for cemented carbide of the present embodiment, high-melting-point oxides, high-melting-point carbides, borides and nitrides are weighed as raw materials for preparing the ceramic coating, and the weighed raw materials are crushed and filtered respectively to obtain the required raw material powders, wherein the high-melting-point oxides are one or more of Al2O3, ZrO2, TiO2 and SiO2, the high-melting-point carbides are one or more of TiC, SiC, Zr2C and WC, the borides are one or more of TiB2, ZrB2, CrB2, and the nitrides are one or more of TiN, BN, and Si3N4, the purity of the high-melting-point oxides, high-melting-point carbides, borides and nitrides are all 90-98%, and the particle sizes of the high-melting-point oxide powders, high-melting-point carbide powders, boride powders and nitride powders obtained after crushing and filtering are all 0.5-1.5 μm.

[0042] Afterwards, the high melting point oxide powder, high melting point carbide powder, boride powder and nitride powder obtained after crushing and filtration are added into a mixing tank according to the weight composition of 70 parts of high melting point oxide, 10 parts of high melting point carbide, 25 parts of boride and 40 parts of nitride, and stirred and mixed to obtain a mixture, and the mixed mixture is heated and melted at a heating temperature of 1500-1700°C and a heating time of 3-5h to obtain a mixed solution.

[0043] After melting, the obtained mixed solution is evenly coated on the surface of the cemented carbide by spraying or dipping to ensure that the ceramic coating is uniform, dense and of moderate thickness. After coating, the cemented carbide is sent to a drying oven for drying for 5-8 hours. After drying, the cemented carbide is heated and sintered by a three-step ladder method at a heating rate of 10-25°C / min, and after heating, it is cooled with the furnace to obtain a submicron crystalline ceramic coating for the cemented carbide, wherein the three-step ladder method heating process parameters are: first, heating to a temperature environment of 400-600°C, keeping warm for 1-3 hours, removing the binder in the coating, then heating to an environment of 1000-1200°C, keeping warm for 0.5-2.0 hours, and finally heating to 1200-1500°C, keeping warm for 1.5-4.0 hours. The sintering of the cemented carbide is carried out in a vacuum sintering furnace, and the vacuum degree in the vacuum sintering furnace is controlled within the range of 0.0001-10Pa.

[0044] In summary, a ceramic coating is prepared by using 70 parts of high melting point oxide, 10 parts of high melting point carbide, 25 parts of boride and 40 parts of nitride, wherein the high melting point oxide is one or more of Al2O3, ZrO2, TiO2 and SiO2, the high melting point carbide is one or more of TiC, SiC, Zr2C and WC, the boride is one or more of TiB2, ZrB2, CrB2, the nitride is one or more of TiN, BN, Si3N4, and the ceramic coating is applied to the surface of the cemented carbide by spraying or dipping, so that the prepared cemented carbide has excellent wear resistance and corrosion resistance, and has better oxidation resistance and thermal insulation performance, and the coating repair is simpler and the production cost is lower. The technical problems that the TiCN and (Ti, Al) N coatings used in the existing cemented carbide have the advantages of excellent wear resistance but still have poor oxidation resistance, poor thermal insulation performance, difficulty in coating repair, high production cost and the like.

[0045] What is disclosed above is only one or more preferred embodiments of the present application, and cannot be used to limit the scope of rights of the present application. Ordinary technicians in this field can understand that all or part of the processes of implementing the above embodiments and equivalent changes made according to the claims of the present application are still within the scope covered by the present application.

Claims

1. A submicron-crystalline ceramic coating for cemented carbide, characterized in that: The invention comprises the following components by weight: 60-80 parts of high melting point oxide, 10-20 parts of high melting point carbide, 15-30 parts of boride and 20-45 parts of nitride.

2. The submicron-crystalline ceramic coating for cemented carbide according to claim 1, characterized in that: The high melting point oxide is one or more of Al2O3, ZrO2, TiO2 and SiO2.

3. The submicron-crystalline ceramic coating for cemented carbide according to claim 1, characterized in that: The high melting point carbide is one or more of TiC, SiC, Zr2C and WC.

4. The submicron-crystalline ceramic coating for cemented carbide according to claim 1, characterized in that: The boride is one or more of TiB2, ZrB2, and CrB2.

5. The submicron-crystalline ceramic coating for cemented carbide according to claim 1, characterized in that: The nitride is one or more of TiN, BN, and Si3N4.

6. The submicron-crystalline ceramic coating for cemented carbide according to claim 1, characterized in that: The ceramic coating is applied to the surface of the cemented carbide by spraying or dipping.

7. A method for preparing a submicron crystalline ceramic coating for cemented carbide, applied to the submicron crystalline ceramic coating for cemented carbide according to any one of claims 1 to 6, characterized in that: The following steps are involved: Weighing high melting point oxides, high melting point carbides, borides and nitrides as raw materials for preparing ceramic coatings, and crushing and filtering the weighed raw materials respectively to obtain the required raw material powders; Adding the raw material powder into a mixing tank according to the weight components, stirring and mixing to obtain a mixture, and heating and melting the mixture to obtain a mixed solution; After melting, the mixed solution is evenly coated on the surface of the cemented carbide by spraying or dipping; After drying, the cemented carbide is heated and sintered, and after heating, it is cooled in a furnace to obtain a submicron crystalline ceramic coating for the cemented carbide.

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