A metal surface ceramic layer and a preparation method and application thereof

Abstract

The application provides a metal surface ceramic layer and a preparation method and application thereof, and the preparation method comprises the following steps: S1, pretreating a metal material, controlling the surface roughness of the metal material to be 0.02-0.3 microns, ultrasonic cleaning, drying and reserving; S2, placing the metal material obtained in S1 in an inert gas, heating to a first temperature, introducing a reaction gas and heating to a second temperature, after heat preservation for 1-6 hours, stopping the introduction of the reaction gas; introducing an inert gas, heating to a third temperature, then cooling to 450-500 DEG C, and naturally cooling to room temperature; the first temperature is 400-500 DEG C, the second temperature is 450-900 DEG C ， the third temperature is 500-1000 DEG C, and the first temperature

Description

Technical Field

[0001] This invention relates to the field of metal surface treatment technology, and more specifically, to a ceramicized layer on a metal surface, its preparation method, and its application. Background Technology

[0002] Metallic materials, due to their excellent mechanical properties and corrosion resistance, are widely used in aerospace, rail transportation, biomedicine, new energy, and other fields. However, in daily production and life, metals and their alloys are inevitably affected by the external environment during use, such as corrosion from gases, water, and certain chemical media; wear caused by relative movement between them; oxidation due to excessively high temperatures; and erosion due to contact with high-temperature molten metals or other molten materials. Under these circumstances, the surface of metal workpieces may be damaged or fail. Statistics show that approximately 70% of premature failures of various metal products are caused by corrosion and wear on the surface of metal materials, resulting in huge losses to the national economy. Therefore, researching and developing surface protection and surface strengthening technologies for metal products is of great significance for improving the service life and reliability of metal products, improving the performance and quality of mechanical equipment, enhancing product competitiveness, and promoting the development of high technology and new technologies.

[0003] Currently, the commonly used surface treatment processes for metal materials are carburizing and nitriding. These processes strengthen the metal surface by increasing the carbon / nitrogen content of the workpiece surface to form carbides / nitrides. However, carburizing inevitably leads to internal oxidation and surface decarburization, while nitriding results in thin layers, high costs, and poor mechanical properties. In recent years, the development of metal surface nano-sizing has introduced numerous advanced surface strengthening technologies. These technologies involve subjecting the metal surface to intense plastic deformation, refining the surface grain size to the nanometer scale, and achieving a gradient distribution of grain size from the surface to the matrix. However, this technology suffers from poor controllability of the gradient structure, limited surface strengthening layer depth, and problems such as severe temperature rise during processing and surface contamination by the cooling medium, significantly impacting the surface treatment effect.

[0004] Chinese patent CN109706421A, "Method and Application for Preparing Oxidized Ceramic Layer on Zirconium and Zirconium Alloy Surfaces", discloses a method for preparing an oxide ceramic layer on the surface of zirconium and zirconium alloys. However, this method has high requirements for initial surface roughness and smoothness, is costly, and its mechanical properties still need further improvement.

[0005] Therefore, it is of great significance to develop a low-cost, high-efficiency, well-controllable, and mechanically superior ceramic coating for metal surfaces and its preparation method. Summary of the Invention

[0006] Given that existing surface strengthening technologies for metal materials are costly and their mechanical properties still need further improvement, this invention provides a ceramicized layer on a metal surface and its preparation method. The preparation method of this invention can obtain a low-cost, high-efficiency, well-controllable, and mechanically superior ceramicized layer on a metal surface, which is conducive to large-scale industrial production and has significant economic value and promotional significance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0009] S1. Perform pretreatment on the metallic material, control its surface roughness to 0.02-0.3μm, ultrasonically clean, dry, and set aside;

[0010] S2. Place the metal material obtained in S1 in an inert gas, heat it to the first temperature, introduce the reaction gas and heat it to the second temperature, keep it at the temperature for 1-6 hours, then stop introducing the reaction gas; introduce the inert gas, heat it to the third temperature, then cool it down to 450-500℃, and let it cool naturally to room temperature.

[0011] The first temperature is 400-500℃, and the second temperature is 450-900℃. ， The third temperature is 500-1000℃, and the first temperature < the second temperature < the third temperature;

[0012] S3. Polish, clean, and dry the metal material obtained in S2 to obtain the ceramicized layer on the metal surface.

[0013] The first temperature, 400-500℃, is the ceramization initiation temperature, which only heats the metal material to ensure it is fully heated and prevents premature oxidation, which would generate impurities and affect the overall strength. The second temperature, 450-900℃, reaches the high-speed oxidation stage, ensuring the formation of a ceramized layer on the surface of the metal material. The third temperature, 500-1000℃, is the high-temperature diffusion stage, which allows oxygen to fully diffuse into the ceramized layer on the metal surface, eliminating thermal stress and improving mechanical strength.

[0014] Furthermore, the heating rate of the third heating in S2 is 0.5-5℃ / min.

[0015] Slow heating at a rate of 0.5-5℃ / min facilitates the full diffusion of oxygen during the high-temperature diffusion stage, which can further improve mechanical properties.

[0016] Furthermore, after the third heating in S2, the process also includes holding the temperature in an inert gas for 0-30 minutes.

[0017] Maintaining the temperature for a period of time during the high-temperature diffusion stage helps eliminate thermal stress and further improves mechanical properties.

[0018] Furthermore, in step S2, the cooling rate to 450-500℃ is 5-10℃ / min.

[0019] Furthermore, in step S2, the heating rate to the first temperature is 10-20℃ / min.

[0020] Furthermore, in step S2, the heating rate to the second temperature is 5-10℃ / min.

[0021] The metallic material mentioned in S1 is one or more of zirconium and zirconium alloys, aluminum and aluminum alloys, and titanium and titanium alloys.

[0022] Furthermore, the pretreatment described in S1 is one or more of grinding, rough polishing with sandpaper, fine polishing with polishing paste, fine polishing with polishing liquid, finishing, and vibratory polishing; and / or, the pretreatment described in step S1 is one or more of grinding, rough polishing with sandpaper, fine polishing with polishing paste, fine polishing with polishing liquid, finishing, and vibratory polishing.

[0023] Furthermore, the inert gas in S2 is independently selected from argon and / or helium;

[0024] And / or, the reactant gas in S2 is oxygen and / or nitrogen.

[0025] Another object of the present invention is to provide a ceramicized layer on a metal surface.

[0026] A ceramicized layer on a metal surface, prepared by any of the preceding methods.

[0027] Another object of the present invention is to provide an application of a ceramicized layer on a metal surface.

[0028] The application of the above-mentioned metal surface ceramic coating on the surface of metal products.

[0029] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0030] The method for preparing a ceramicized layer on a metal surface according to the present invention controls the surface roughness of the metal material within the range of 0.02-0.3 μm, thereby controlling the uniformity of the thickness of the ceramicized layer formed by oxidation and improving the average mechanical properties of the ceramicized layer. The method involves first heating the metal material to a certain temperature in an inert gas to ensure sufficient heating and prevent premature oxidation that could generate impurities affecting the overall strength. Then, a reaction gas is introduced to oxidize and form the ceramicized layer. After reaching the high-speed oxidation stage, the sample is kept at a certain temperature to ensure sufficient thickness of the ceramicized layer, effectively improving surface strength. After the holding period, oxygen introduction is stopped, and the temperature is further increased in an inert gas environment. High-temperature diffusion treatment ensures sufficient oxygen diffusion in the ceramicized layer, eliminating thermal stress and significantly improving the overall uniformity and mechanical properties of the ceramicized layer. The preparation method of the present invention can obtain a low-cost, high-efficiency, highly controllable, and mechanically superior ceramicized layer on a metal surface, which is beneficial for large-scale industrial production and has significant economic value and promotional significance. Attached Figure Description

[0031] The invention will be further illustrated with reference to the accompanying drawings, but the embodiments in the drawings do not constitute any limitation on the invention. For those skilled in the art, other drawings can be obtained based on the following drawings without any creative effort.

[0032] Figure 1 This is a microscopic morphology diagram of the ceramicized layer on the metal surface in Embodiment 1 of the present invention.

[0033] Figure 2 These are the XRD patterns of embodiments 1-4 of the present invention.

[0034] Figure 3 These are the XRD patterns of comparative examples 1-3 of the present invention.

[0035] Figure 4 This is a microscopic morphology diagram of the ceramicized layer on the metal surface of Comparative Example 6 of the present invention. Detailed Implementation

[0036] To better illustrate the objectives, technical solutions, and advantages of this invention, the following embodiments are provided. Obviously, the following embodiments are only a part of the embodiments of this invention, and not all of them; it should be understood that the embodiments of this invention are only used to illustrate the technical effects of this invention, and not to limit the scope of protection of this invention.

[0037] All raw materials used in the examples are commercially available; unless otherwise specified, the reagents, methods and equipment used in this invention are conventional reagents, methods and equipment in this technical field.

[0038] Example 1

[0039] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0040] S1. The surface of the zirconium metal material is coarsely polished with sandpaper, then finely polished with polishing paste and polishing liquid to control its surface roughness to 0.02-0.1μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0041] S2. Place the zirconium metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to expel the air from the furnace, heat to the initial temperature of 450°C at 10°C / min, introduce oxygen, further heat to 500°C at 5°C / min, hold for 1 hour, and stop introducing oxygen; introduce argon gas, heat to 550°C at a heating rate of 0.5°C / min, then cool to 450°C at 5°C / min, and allow to cool naturally to room temperature;

[0042] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in ethanol, and dry it to obtain the ceramicized layer on the metal surface.

[0043] Example 2

[0044] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0045] S1. The surface of the zirconium alloy metal material is coarsely polished with sandpaper, finely polished with polishing paste and polishing liquid, and its surface roughness is controlled to be 0.02-0.2μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning liquid and acetone in sequence, and then air-dried for later use.

[0046] S2. Place the zirconium alloy metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to expel the air from the furnace, heat it to the initial temperature of 450°C at a rate of 10°C / min, introduce oxygen gas, further heat it to 550°C at a rate of 6°C / min, hold it at this temperature for 2 hours, and then stop introducing oxygen gas; introduce argon gas, heat it to 600°C at a rate of 1°C / min, then cool it down to 450°C at a rate of 6°C / min, and allow it to cool naturally to room temperature.

[0047] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in acetone, and dry it to obtain the ceramicized layer on the metal surface.

[0048] Example 3

[0049] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0050] S1. The surface of the zirconium alloy metal material is coarsely polished with sandpaper, finely polished with polishing paste and polishing liquid, and its surface roughness is controlled to be 0.02-0.2μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0051] S2. Place the zirconium alloy metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to expel the air from the furnace, heat it to the initial temperature of 450°C at a rate of 10°C / min, introduce oxygen gas, further heat it to 600°C at a rate of 7°C / min, hold it at this temperature for 2 hours, and then stop introducing oxygen gas; introduce argon gas, heat it to 650°C at a rate of 1°C / min, then cool it down to 450°C at a rate of 7°C / min, and allow it to cool naturally to room temperature.

[0052] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in acetone, and dry it to obtain the ceramicized layer on the metal surface.

[0053] Example 4

[0054] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0055] S1. The surface of the zirconium alloy metal material is coarsely polished with sandpaper, finely polished with polishing paste and polishing liquid, and its surface roughness is controlled to be 0.02-0.2μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning liquid and acetone in sequence, and then air-dried for later use.

[0056] S2. Place the zirconium alloy metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to expel the air from the furnace, heat it to the initial temperature of 450°C at a rate of 10°C / min, introduce oxygen gas, further heat it to 650°C at a rate of 8°C / min, hold it at this temperature for 2 hours, and then stop introducing oxygen gas; introduce argon gas, heat it to 750°C at a rate of 2°C / min, then cool it down to 450°C at a rate of 8°C / min, and allow it to cool naturally to room temperature.

[0057] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in acetone, and dry it to obtain the ceramicized layer on the metal surface.

[0058] Example 5

[0059] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0060] S1. The surface of the aluminum alloy metal material is coarsely polished with sandpaper, then finely polished with polishing paste and polishing liquid to control its surface roughness to 0.02-0.3μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and acetone in sequence, and then air-dried for later use.

[0061] S2. Place the aluminum alloy metal material obtained in S1 in an atmosphere muffle furnace, introduce helium to expel the air from the furnace, heat to the initial temperature of 500℃ at 10℃ / min, introduce nitrogen, further heat to 600℃ at 5℃ / min, hold for 2 hours, stop introducing nitrogen; introduce helium, heat to 700℃ at a heating rate of 2℃ / min, then cool to 500℃ at 10℃ / min, and allow to cool naturally to room temperature;

[0062] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in acetone, and dry it to obtain the ceramicized layer on the metal surface.

[0063] Example 6

[0064] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0065] S1. The surface of the aluminum alloy metal material is coarsely polished with sandpaper, finely polished with polishing paste and polishing liquid, and its surface roughness is controlled to be 0.02-0.2μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0066] S2. Place the aluminum alloy metal material obtained in S1 in an atmosphere muffle furnace, introduce helium to expel the air from the furnace, heat to the initial temperature of 500℃ at 10℃ / min, introduce oxygen, further heat to 650℃ at 5℃ / min, hold for 3 hours, stop introducing oxygen; introduce helium, heat to 750℃ at a heating rate of 2℃ / min, then cool to 500℃ at 10℃ / min, and allow to cool naturally to room temperature;

[0067] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in ethanol, and dry it to obtain the ceramicized layer on the metal surface.

[0068] Comparative Example 1

[0069] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0070] S1. The surface of the zirconium metal material is coarsely polished with sandpaper, then finely polished with polishing paste and polishing liquid to control its surface roughness to 0.02-0.1μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0071] S2. Place the zirconium metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to drive the air out of the furnace, heat it to the initial temperature of 450°C at 10°C / min, introduce oxygen, further heat it to 500°C at 5°C / min, hold it at 1 hour, cool it down to 450°C at 5°C / min, and let it cool naturally to room temperature.

[0072] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in ethanol, and dry it to obtain the ceramicized layer on the metal surface.

[0073] Compared with Example 1, step S2 in this comparative example does not include high-temperature diffusion treatment.

[0074] Comparative Example 2

[0075] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0076] S1. The surface of the zirconium alloy metal material is coarsely polished with sandpaper, finely polished with polishing paste and polishing liquid, and its surface roughness is controlled to be 0.02-0.2μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning liquid and acetone in sequence, and then air-dried for later use.

[0077] S2. Place the zirconium alloy metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to drive the air out of the furnace, heat it to the initial temperature of 450°C at 10°C / min, introduce oxygen, further heat it to 550°C at 6°C / min, hold it at the temperature for 2 hours, cool it down to 450°C at 6°C / min, and let it cool naturally to room temperature.

[0078] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in acetone, and dry it to obtain the ceramicized layer on the metal surface.

[0079] Compared with Example 2, step S2 in this comparative example does not include high-temperature diffusion treatment.

[0080] Comparative Example 3

[0081] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0082] S1. The surface of the zirconium alloy metal material is coarsely polished with sandpaper, finely polished with polishing paste and polishing liquid, and its surface roughness is controlled to be 0.02-0.2μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0083] S2. Place the zirconium alloy metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to drive the air out of the furnace, heat it to the initial temperature of 450°C at 10°C / min, introduce oxygen, further heat it to 600°C at 7°C / min, hold it at 2h, cool it down to 450°C at 7°C / min, and let it cool naturally to room temperature.

[0084] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in acetone, and dry it to obtain the ceramicized layer on the metal surface.

[0085] Compared with Example 3, step S2 in this comparative example does not include high-temperature diffusion treatment.

[0086] Comparative Example 4

[0087] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0088] S1. The surface of the zirconium alloy metal material is coarsely polished with sandpaper, finely polished with polishing paste and polishing liquid, and its surface roughness is controlled to be 0.02-0.2μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning liquid and acetone in sequence, and then air-dried for later use.

[0089] S2. Place the zirconium alloy metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to drive the air out of the furnace, heat it to the initial temperature of 450°C at 10°C / min, introduce oxygen, further heat it to 650°C at 8°C / min, hold it at the temperature for 2 hours, cool it down to 450°C at 8°C / min, and let it cool naturally to room temperature.

[0090] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in acetone, and dry it to obtain the ceramicized layer on the metal surface.

[0091] Compared with Example 4, step S2 in this comparative example does not include high-temperature diffusion treatment.

[0092] Comparative Example 5

[0093] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0094] S1. The surface of the zirconium metal material is coarsely polished with sandpaper, then finely polished with polishing paste and polishing liquid to control its surface roughness to 0.02-0.1μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0095] S2. Place the zirconium metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to drive the air out of the furnace, heat it to the initial temperature of 550°C at 10°C / min, introduce oxygen, hold for 1 hour, stop introducing oxygen; introduce argon gas, hold for 1 hour, cool down to 450°C at 5°C / min, and let it cool naturally to room temperature.

[0096] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in ethanol, and dry it to obtain the ceramicized layer on the metal surface.

[0097] Compared with Example 1, step S2 of this comparative example does not involve segmented heating.

[0098] Comparative Example 6

[0099] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0100] S1. The surface of the zirconium metal material is coarsely polished with sandpaper, then finely polished with polishing paste and polishing liquid to control its surface roughness to 0.3-0.5μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0101] S2. Place the zirconium metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to expel the air from the furnace, heat to the initial temperature of 450°C at 10°C / min, introduce oxygen, further heat to 500°C at 5°C / min, hold for 1 hour, and stop introducing oxygen; introduce argon gas, heat to 550°C at a heating rate of 0.5°C / min, then cool to 450°C at 5°C / min, and allow to cool naturally to room temperature;

[0102] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in ethanol, and dry it to obtain the ceramicized layer on the metal surface.

[0103] Compared with Example 1, the roughness of step S1 in this comparative example is too large.

[0104] Comparative Example 7

[0105] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0106] S1. The surface of the zirconium metal material is coarsely polished with sandpaper, then finely polished with polishing paste and polishing liquid to control its surface roughness to 0.02-0.05μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0107] S2. Place the zirconium metal material obtained in S1 in an atmosphere muffle furnace, introduce argon gas to expel the air from the furnace, heat to the initial temperature of 450°C at 10°C / min, introduce oxygen, further heat to 500°C at 5°C / min, hold for 1 hour, and stop introducing oxygen; introduce argon gas, heat to 550°C at a heating rate of 0.5°C / min, then cool to 450°C at 5°C / min, and allow to cool naturally to room temperature;

[0108] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in ethanol, and dry it to obtain the ceramicized layer on the metal surface.

[0109] Compared with Example 1, the roughness of step S1 in this comparative example is less.

[0110] Comparative Example 8

[0111] A method for preparing a ceramicized layer on a metal surface includes the following steps:

[0112] S1. The surface of the zirconium metal material is coarsely polished with sandpaper, then finely polished with polishing paste and polishing liquid to control its surface roughness to 0.02-0.1μm. Then, the metal material is ultrasonically cleaned in deionized water, cleaning solution and ethanol in sequence, and then air-dried for later use.

[0113] S2. Place the zirconium metal material obtained in S1 in an atmosphere muffle furnace, introduce an inert gas-oxygen mixture (volume ratio of 1:1) to expel the air from the furnace, heat to the initial temperature of 450℃ at 10℃ / min, further heat to 500℃ at 5℃ / min, hold for 1 hour, introduce argon gas, heat to 550℃ at a heating rate of 0.5℃ / min, then cool to 450℃ at 5℃ / min, and allow to cool naturally to room temperature;

[0114] S3. Polish the metal material obtained in S2 with polishing liquid, clean it in ethanol, and dry it to obtain the ceramicized layer on the metal surface.

[0115] Compared to Example 1, this comparative example introduces a mixed gas in step S2.

[0116] Mechanical properties and surface morphology were tested for Examples 1-6 and Comparative Examples 1-8, as detailed below:

[0117] The surface hardness of Examples 1-4 and Comparative Examples 1-5 was tested using a Vickers hardness tester, and the thickness of their oxide layers was measured.

[0118] The test results are shown in the table below.

[0119] Table 1. Test results of Examples 1-4 and Comparative Examples 1-5

[0120]

[0121]

[0122] Microscopic morphology analysis was performed on Example 1, and the results are as follows: Figure 1 As shown, its surface oxide layer has a uniform thickness and a clear interface with the substrate.

[0123] XRD tests were performed on Examples 1-4 and Comparative Examples 1-3, and the results are as follows: Figure 2 and Figure 3 As shown in the comparison, the characteristic peaks of the embodiment are obvious and the crystal structure is clear, while the characteristic peaks of the comparative example are lower.

[0124] Microscopic morphology analysis was performed on Comparative Example 6, and the results are as follows: Figure 4 As shown, the thickness of its surface oxide layer is uneven, with significant undulations.

[0125] The test results for the other embodiments were basically consistent.

[0126] The comprehensive test results show that all embodiments of the present invention have high Vickers hardness and uniform oxide layer thickness, exhibiting excellent mechanical properties and controllability; while comparative examples 1-3, which have not undergone high-temperature diffusion treatment, have much lower hardness than examples 1-3 under the same conditions; comparative example 4 has a high surface Vickers hardness due to its high thickness, but because it has not undergone high-temperature diffusion treatment, the oxide layer contains cracks and cannot be used in practice.

[0127] Comparative Example 5, without segmented heating, has an oxide layer thickness of 3 μm, a hardness below 250 MPa, and poor mechanical properties.

[0128] The excessive roughness of Comparative Example 6 affects the uniformity of the ceramicized layer, resulting in uneven oxide layer thickness and poor mechanical properties.

[0129] Comparative Example 7 shows that the roughness is too small, which affects the uniformity of the ceramicized layer, and thus affects the surface stress of the material, resulting in poor mechanical properties and high cost, making it unsuitable for practical use.

[0130] Comparative Example 8 introduced a mixed gas, which accelerated the heating and oxidation process. As a result, the oxide layer contained nitrides, leading to poor mechanical properties.

[0131] In summary, this invention, through controlling the surface roughness of the metal, fully heating and then reacting with oxidation, and employing a high-temperature diffusion treatment method, reduces the stress during the formation of the ceramicized layer during oxidation, allowing for sufficient oxygen diffusion in the oxide layer and eliminating thermal stress. This significantly improves the overall uniformity and mechanical properties of the ceramicized layer on the metal surface. The preparation method of this invention can obtain low-cost, high-efficiency, highly controllable, and mechanically superior ceramicized layers for metal surfaces, which is beneficial for large-scale industrial production and has significant economic value and promotional significance.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for producing a ceramic layer on a metal surface, characterized in that The method comprises the following steps: S1. Pre-treating the metal material to control the surface roughness at 0.02-0.3 μm, ultrasonic cleaning, drying, and standby; S2. Placing the metal material obtained in S1 in an inert gas, heating to a first temperature, introducing a reaction gas and heating to a second temperature, maintaining for 1-6 h, then stopping the introduction of the reaction gas; introducing an inert gas, heating to a third temperature, then cooling to 450-500 ℃, and naturally cooling to room temperature; The first temperature is 400-500 ℃, the second temperature is 450-650 ℃, and the third temperature is 500-750 ℃, and the first temperature < the second temperature < the third temperature; S3. Polishing, cleaning, and drying the metal material obtained in S2 to obtain the metal surface ceramic layer.

2. The method for producing a ceramic layer on a metal surface according to claim 1, characterized by, The heating rate for heating to the third temperature in S2 is 0.5-5 ℃ / min.

3. The method for producing a metal surface ceramic layer according to claim 1 or 2, characterized in that, The temperature is maintained for 0-30 min after heating to the third temperature in S2.

4. The method for producing a ceramic layer on a metal surface according to claim 1, characterized by The cooling rate for cooling to 450-500 ℃ in step S2 is 5-10 ℃ / min.

5. The method of claim 1, wherein the metal surface is a metal surface of a metal substrate. The heating rate for heating to the first temperature in step S2 is 10-20 ℃ / min.

6. The method of claim 1, wherein The heating rate for heating to the second temperature in step S2 is 5-10 ℃ / min.

7. The method of claim 1, wherein the metal surface is a metal surface of a metal substrate. The metal material in step S1 is one or more of zirconium and zirconium alloy, aluminum and aluminum alloy, titanium and titanium alloy; And / or, the pre-treatment in step S1 is one or more of grinding, sandpaper rough polishing, polishing paste fine polishing, polishing liquid fine polishing, finishing, and vibration polishing.

8. The method of claim 1, wherein the metal surface is a metal surface of a metal substrate. The inert gas in step S2 is independently selected from argon and / or helium; And / or, the reaction gas in step S2 is oxygen and / or nitrogen.

9. A metal surface ceramicized layer, characterized in that, Prepared by the method of any one of claims 1-8.

10. Use of the metal surface ceramic layer according to claim 9 on the surface of a metal product.

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