Ceramic / metal three-dimensional interpenetrating structure composite coating on carbon steel surface and preparation method thereof

Abstract

The application discloses a preparation method of a carbon steel surface ceramic / metal three-dimensional interpenetrating structure composite coating material, and comprises the following steps: performing first carburizing treatment on the surface of the carbon steel after polishing to obtain a substrate with a carburized layer; alternately depositing a first metal layer and an iron layer on the surface of the substrate with the carburized layer by using a first film layer preparation process to form a first part of a metal multilayer film; continuing to alternately deposit the first metal layer and a second metal layer by using a second film layer preparation process to form a second part of the metal multilayer film; preparing a patterned iron layer by using a selected area patterning process to obtain a preform; placing the preform into a carburizing furnace to perform second carburizing treatment; after the second carburizing treatment, removing the patterned iron layer on the surface by using dilute hydrochloric acid to obtain the carbon steel surface ceramic / metal three-dimensional interpenetrating structure composite coating, the interface between the layers has a micro-irregular shape, has metallurgical bonding, and the material strength, toughness, shear resistance and erosion resistance are significantly improved.

Description

Technical Field

[0001] This invention belongs to the technical field of surface modification methods for metallic materials, and relates to a ceramic / metal three-dimensional interpenetrating structure composite coating on the surface of carbon steel, as well as a method for preparing the ceramic / metal three-dimensional interpenetrating structure composite coating on the surface of carbon steel. Background Technology

[0002] Steel parts operating in dusty environments are prone to failure due to erosion by solid particles, limiting their performance and lifespan. Under small-angle erosion conditions, solid particles wear and cut the surface; under large-angle erosion conditions, solid particles continuously impact the surface. Therefore, preparing a metal / ceramic composite coating on the steel surface with high hardness, high toughness, and high adhesion is an effective way to improve erosion resistance.

[0003] Currently, typical composite coating structures include ceramic particle-reinforced structures and ceramic / metal layered structures. A common characteristic of both structures is that the ceramic phase is separated from the metal phase. Under erosion conditions, the metal phase is prone to fatigue failure, leading to the detachment of ceramic particles or localized peeling of the ceramic layer.

[0004] The preparation technologies for ceramic / metal composite coatings mainly include laser cladding, thermal spraying, and vapor deposition. Among them, ceramic-metal composite coatings prepared by laser cladding and thermal spraying are mainly composed of ceramic particle-reinforced structures. When the volume fraction of ceramic particles is high, cracks and pores are prone to occur. Ceramic-metal composite coatings prepared by vapor deposition are mainly composed of stacked structures, with each layer stacked along a direction perpendicular to the surface. However, due to phase abrupt changes and lattice mismatches at the film-substrate interface, the bonding force is usually weak.

[0005] In summary, in terms of structure, current ceramic-metal composite coatings lack ceramic-metal configuration designs for erosion environments, such as the lack of layered arrangement of ceramics and metals parallel to the surface; in terms of preparation methods, it is difficult to achieve a controllable geometric distribution of ceramics and metals in the direction parallel to the surface, and it is also difficult to achieve both high density and strong metallurgical bonding interface.

[0006] To address the aforementioned issues, this invention designs a three-dimensional interpenetrating ceramic / metal composite coating on carbon steel surfaces and proposes a method for preparing such a coating, ultimately obtaining an erosion-resistant coating that combines high hardness, high toughness, and high adhesion. Summary of the Invention

[0007] The purpose of this invention is to provide a three-dimensional interpenetrating ceramic / metal composite coating on carbon steel surfaces to solve the problem that existing ceramic / metal composite coatings lack ceramic-metal configuration design for erosion environments, and to improve the phenomenon of easy local peeling caused by metal isolating ceramic.

[0008] Another objective of this invention is to provide a method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface, in order to solve the problem that existing methods are difficult to achieve a controllable geometric distribution of ceramics and metals in the direction parallel to the surface, and to obtain a high-performance erosion-resistant coating with both high density and strong metallurgical bonding interface.

[0009] This invention discloses a three-dimensional interpenetrating ceramic / metal composite coating on a carbon steel surface, comprising a substrate and a carburized layer. An interpenetrating columnar array is disposed on the upper surface of the carburized layer, above which is a coplanar interlocking stacked layer, and above that is a composite ceramic stacked layer. The coplanar interlocking stacked layer is formed by ceramic and metal portions interlocking in a complementary geometric pattern parallel to the substrate surface; the ceramic and metal portions are coplanar. The interpenetrating columnar array includes alternately stacked ceramic carbide layers and metal connecting layers, both arranged parallel to the substrate surface and alternately stacked in a direction perpendicular to the substrate surface. Adjacent ceramic carbide layers are connected at multiple points via several ceramic connecting pillars, and adjacent metal connecting layers are connected at multiple points via several metal connecting pillars. The ceramic and metal connecting pillars are spatially interwoven. The ceramic portion is composed of the material of the ceramic carbide layer. The composite ceramic stack includes the ceramic carbide layer, and the metal portion is composed of the material of the metal connecting layer.

[0010] The preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface of the present invention is carried out according to the following steps: Step 1: After grinding the carbon steel surface, perform the first carburizing treatment to obtain a substrate with a carburized layer; Step 2: Using the first film preparation process, the first metal layer and iron layer are alternately deposited on the surface of the substrate with the carburized layer to form the first part of the metal multilayer film on the substrate; Step 3: On the first part of the metal multilayer film, the first metal layer and the second metal layer are deposited alternately using the second film preparation process to form the second part of the metal multilayer film; Step 4: A patterned iron layer is prepared on the second part of the metal multilayer film using a selective area patterning process to obtain the preform; Step 5: The preform is placed in a carburizing furnace for a second carburizing treatment. After the second carburizing treatment, a thicker ceramic layer is formed in the area covered by the patterned iron layer, and a thinner ceramic layer is formed in the area not covered by the patterned iron layer. The remaining incompletely ceramicized first and second metal layers constitute the metal bonding layer. The patterned iron layer on the surface is removed using dilute hydrochloric acid to obtain a three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface. The three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface includes columnar interpenetrating stacks, coplanar interlocking stacks, and composite ceramic stacks.

[0011] The invention is further characterized in that: in step 1, the first carburizing treatment adopts one of solid carburizing, gas carburizing, vacuum carburizing or plasma carburizing, and the temperature range of the first carburizing treatment is 800℃-1000℃.

[0012] In step 1, the thickness L of the carburized layer of the carbon steel is in the range of 10-200 μm, and the carbon content is 0.5-2.0 wt%.

[0013] The first film preparation process in step 2 is either physical vapor deposition or chemical vapor deposition, and the thickness of the first part of the metal multilayer film is 3-25 μm.

[0014] The second film preparation process in step 3 is either physical vapor deposition or chemical vapor deposition, and the thickness of the second part of the metal multilayer film is 3-25 μm.

[0015] In step 2, the first metal layer and in step 3, the second metal layer are both metal layers capable of forming carbides. The metal layer capable of forming carbides is selected from one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. The first metal layer and the second metal layer are not the same metal.

[0016] Step 4 specifically involves setting a mask on the surface of the second part of the metal multilayer film, depositing a patterned iron layer in the area not covered by the mask using a selective patterning process, and then removing the mask to obtain the preform. The selective patterning process is selected from one of mask vapor deposition, selective electroplating, and selective etching of the iron layer.

[0017] The second carburizing treatment in step 5 uses one of the following: solid carburizing, gas carburizing, vacuum carburizing, or plasma carburizing. The temperature range for the second carburizing treatment is 800℃-1000℃.

[0018] The beneficial effects of this invention are: (1) The composite ceramic stack is a composite ceramic stack formed during carburizing after alternating deposition of the first and second metal layers. It has uniform thickness, is dense and non-porous. Among them, the ceramic phase in the composite ceramic stack below the patterned iron layer contains dissolved Fe, while the ceramic phase below the area not covered by the patterned iron layer does not contain dissolved iron. The composite ceramic layer completely covers the entire surface, which can play a good protective role in wear resistance, cutting resistance and ploughing resistance, and is beneficial to resisting small-angle impacts; (2) In the coplanar interlocking stacked layer, a ceramic region is formed below the area covered by the patterned iron layer on the surface, and a metal region is formed below the area not covered by the patterned iron layer. The ceramic and metal are arranged in a stacked pattern parallel to the surface direction, forming a large number of ceramic-metal heterojunction interfaces perpendicular to the surface. Among them, the ceramic phase in the ceramic region is dissolved with Fe element. The structural feature of the coplanar interlocking stacked layer is that the ceramic part and the metal part are arranged parallel to the surface, which is mainly different from the feature of the ceramic layer and the metal layer being arranged perpendicular to the surface in ordinary ceramic / metal multilayer films. This is conducive to inducing the deflection of cracks that extend parallel to the surface, and realizing toughening parallel to the surface dimension. In addition, the ceramic part is composed of a stacked structure of ceramic carbides formed by at least two metals with carbide forming ability, and the metal part is composed of a stacked structure of corresponding metals. The interlayer interfaces are all parallel to the surface, which can further exert the toughening mechanism of the stacked structure. Therefore, the coplanar interlocking stacked layer structure is responsible for toughening parallel to the surface and is used to resist large-angle impacts. (3) The first part of the bottom metal multilayer film reacts in situ during carburizing to form a columnar interpenetrating stacked structure. Among them, the ceramic phase of the ceramic carbide layer contains iron element dissolved in it. The main feature of this columnar interpenetrating structure is that the iron-containing metal layer parallel to the surface not only plays a buffering role against large-angle erosion, but also plays a role in inducing the deflection of cracks perpendicular to the surface, which helps to improve toughness. The ceramic carbide layers are connected by ceramic connecting pillars, and the metal layers are connected by metal connecting pillars, so that the ceramic phase and the metal phase are each in a three-dimensional interconnected structure, avoiding the problem of the ceramic layer being completely isolated by the metal layer, thereby improving the strength, rigidity, shear resistance and fracture toughness of the coating; (4) In the three-dimensional interpenetrating ceramic / metal composite coating on carbon steel, the surface composite ceramic stack, the ceramic part of the middle coplanar interlocking stack, the ceramic carbide layer of the bottom columnar interpenetrating stack, and its ceramic connecting pillars together constitute a three-dimensional interconnected ceramic skeleton; the metal part of the middle coplanar interlocking stack, the iron-containing metal layer of the bottom layer, and the metal connecting pillars together constitute a three-dimensional interconnected metal skeleton. The ceramic skeleton and the metal skeleton form a three-dimensional interpenetrating structure, which helps to exert the toughening effect of the three-dimensional interpenetrating structure, so that the entire coating has the characteristics of high hardness, high strength, high stiffness, and high toughness.

[0019] (5) In the three-dimensional interpenetrating ceramic / metal composite coating on carbon steel surface, the interfaces between different ceramic carbide layers in the composite ceramic stack, as well as the interfaces between the ceramic carbide layers and the iron-containing metal layers, have serrated metallurgical bonding characteristics, and the bonding force of such interfaces is extremely strong; in the coplanar interlocking stacked layer, the ceramic-metal heterogeneous interface between the ceramic part and the metal part has fractal and interlocking characteristics, which can enhance the mechanical properties of the interface from multiple scales; the interface between the ceramic carbide layer adjacent to the substrate and the substrate has serrated metallurgical bonding characteristics, providing excellent film-substrate bonding force.

[0020] (6) In the preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on carbon steel surface, the C atoms required for the transformation of the bottom first part of the metal multilayer film into the columnar interpenetrating stacked structure come from the steel substrate, rather than from the carburizing atmosphere. Since only short-distance diffusion is required, the high carbon content of the substrate is beneficial to refine the bottom ceramic grains and improve the ceramicization rate; (7) In the preparation method of ceramic / metal three-dimensional interpenetrating composite coating on carbon steel surface, during the process of carburizing the second part of the metal multilayer film to generate composite ceramic stack and coplanar interlocking stack, the C atoms come from the carburizing atmosphere. Based on the synergistic effect of epitaxial growth and interlocking layer growth, the grain size is controlled by the layer thickness of the coplanar interlocking stack, which can avoid the columnar crystal structure formed by physical vapor deposition, which is beneficial to improving strength and corrosion resistance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the cross-section of the carburized layer obtained in step 1 of the preparation method of the ceramic / metal three-dimensional interpenetrating structure composite coating on the carbon steel surface of the present invention. Figure 2 This is a schematic diagram of the first part of the cross-sectional structure of the metal multilayer film obtained in step 2 of the preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface of the present invention. Figure 3 This is a schematic diagram of the cross-sectional structure of the second part of the metal multilayer film obtained in step 3 of the preparation method of the ceramic / metal three-dimensional interpenetrating structure composite coating on the carbon steel surface in Embodiment 2 of the present invention. Figure 4 This is a schematic diagram of the cross-sectional structure of the preform obtained in step 4 of the preparation method of the three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface in Embodiment 2 of the present invention. Figure 5 This is a schematic diagram of the cross-sectional structure of the preform obtained after the second carburizing treatment of the preform in step 5 of the preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface in Embodiment 2 of the present invention. Figure 6 This is a schematic cross-sectional view of the three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface, which is the preparation method of the three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface in Embodiment 2 of the present invention. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0023] This invention relates to a ceramic / metal three-dimensional interpenetrating composite coating on carbon steel surfaces, such as... Figure 6As shown, it includes a composite ceramic stack, a coplanar interlocking stack, and a columnar interpenetrating stack. The composite ceramic stack is formed by alternating stacking of ceramic carbide layers formed by a first metal layer and ceramic carbide layers formed by a second metal layer in a direction perpendicular to the surface.

[0024] Coplanar interlocking stacked layer: This layer comprises a ceramic portion and a metal portion forming complementary geometries in a direction parallel to the surface. The ceramic portion is composed of ceramic carbide layers formed by the first metal layer and ceramic carbide layers formed by the second metal layer stacked in a direction perpendicular to the surface; the metal portion is composed of the first metal layer and the second metal layer stacked in a direction perpendicular to the surface. The first metal carbide layer in the ceramic portion and the first metal layer in the metal portion are located in the same plane; the second metal carbide layer in the ceramic portion and the second metal layer in the metal portion are located in the same plane.

[0025] Interpenetrating columnar stack: Serving as the bottom support structure of the coating, it is positioned between the coplanar interlocking stacked layers and the carburized layer. Both the ceramic carbide layer and the metal connecting layer are arranged parallel to the substrate surface and alternately stacked in a direction perpendicular to the substrate surface. Adjacent ceramic carbide layers are connected at multiple points via ceramic connecting columns, and adjacent metal connecting layers are connected at multiple points via metal connecting columns. The ceramic and metal connecting columns are spatially interpenetrating. This structure not only buffers large-angle impacts through the plastic deformation of the metal connecting layers but also effectively prevents the ceramic layers from being completely isolated by the metal layers through the three-dimensional interconnected columnar array structure, significantly improving the overall shear resistance and toughness of the coating.

[0026] In the three-dimensional interpenetrating ceramic / metal composite coating on carbon steel, the surface composite ceramic stack, the ceramic portion of the middle coplanar interlocking stack, and the ceramic connecting pillars of the bottom columnar interpenetrating stack together construct a three-dimensional interconnected ceramic skeleton. The metal portion of the middle coplanar interlocking stack, the metal connecting layer of the bottom columnar interpenetrating stack, and their supporting metal connecting pillars constitute a three-dimensional interconnected metal skeleton. This multi-scale ceramic and metal bicontinuous structure forms a typical three-dimensional interpenetrating configuration, not only achieving coating densification but also effectively leveraging the synergistic effect of the three-dimensional interpenetrating structure in strengthening and toughening, endowing the coating with excellent comprehensive mechanical properties of high hardness, high strength, high stiffness, and high toughness.

[0027] This invention relates to a method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface, such as... Figures 1-6 As shown, please follow these steps: Step 1: After grinding the carbon steel surface, perform the first carburizing treatment to obtain a substrate with a carburized layer. The thickness of the carburized layer is L, and the carbon content of the carburized layer ranges from 0.5wt% to 2.0wt%. The first carburizing treatment method is one of solid carburizing, gas carburizing, vacuum carburizing, or plasma carburizing, and the temperature range is 800℃-950℃. Step 2: Using a first film preparation process, alternately deposit a first metal layer and an iron layer on the surface of a substrate with a carburized layer to form a first part of a multilayer metal film on the substrate. The first film preparation process includes one of physical vapor deposition and chemical vapor deposition. The thickness of the first metal layer ranges from 1 μm to 3 μm, and the thickness of the Fe layer ranges from 0.5 μm to 1.0 μm. Preferably, magnetron sputtering is used in physical vapor deposition. In Step 2, the first metal layer is a metal with carbide-forming ability. The metal with carbide-forming ability is one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. Step 3: On the first part of the metal multilayer film, the first metal layer and the second metal layer are alternately deposited using a second film preparation process to form the second part of the metal multilayer film. The second film preparation process includes one of physical vapor deposition and chemical vapor deposition. The thickness range of tungsten is 0.05μm-2μm, and the thickness range of molybdenum is 0.05μm-2μm. Preferably, magnetron sputtering is used. The second metal layer in step 3 is a metal with carbide forming ability. The metal with carbide forming ability is one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. The first metal layer and the second metal layer are not the same metal. Step 4: A patterned iron layer is prepared on the second part of the metal multilayer film using a selective patterning process to obtain a preform. The selective patterning process is selected from one of mask vapor deposition, selective electroplating or selective etching of iron layer, and the thickness of the patterned iron layer ranges from 5μm to 30μm. Step 5: The preform is placed in a carburizing furnace for a second carburizing treatment. After the second carburizing treatment, a thicker ceramic part forms in the area covered by the patterned iron layer, and a thinner metal part forms in the area not covered by the patterned iron layer. The patterned iron layer on the surface is removed using dilute hydrochloric acid to obtain a three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface. The three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface includes columnar interpenetrating stacks, coplanar interlocking stacks, and composite ceramic stacks. The second carburizing treatment uses one of the following methods: solid carburizing, gas carburizing, vacuum carburizing, or plasma carburizing. The temperature range for the second carburizing is 800℃-1000℃, preferably vacuum carburizing.

[0028] In the preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface of the present invention: in step 1, the role of the first carburizing is to increase the carbon content of the carbon steel surface layer, so as to supply carbon to the bottom first part of the metal multilayer film as an internal carbon source during the second carburizing process in step 5.

[0029] Example 1 This embodiment presents a three-dimensional interpenetrating ceramic / metal composite coating on a carbon steel surface, comprising a substrate and a carburized layer. An interpenetrating columnar WC / Fe stack is disposed on the upper surface of the carburized layer. Above the interpenetrating columnar WC / Fe stack is a coplanar interlocking stack layer, and above the coplanar interlocking stack layer is a Mo2C / WC composite ceramic stack layer. The coplanar interlocking stack layer is formed by the ceramic portion and the metal portion interlocking in a complementary geometric pattern parallel to the substrate surface. The ceramic portion is a Mo2C / WC stack structure, and the metal portion is a Mo / W stack structure. The 2C layer and the Mo layer are coplanar, and the WC layer and the W layer are coplanar. The interpenetrating WC / Fe stack includes alternately stacked WC ceramic layers and Fe metal layers. Both WC ceramic layers and Fe metal layers are arranged parallel to the substrate surface and are alternately stacked in a direction perpendicular to the substrate surface. Adjacent WC ceramic layers are connected at multiple points through several WC ceramic pillar arrays, and adjacent Fe metal layers are connected at multiple points through several Fe metal pillar arrays. The WC ceramic pillar arrays and Fe metal pillar arrays are interpenetrating in space.

[0030] Example 2 The preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface in this embodiment is specifically implemented according to the following steps: Step 1: Grind the carbon steel surface and perform the first vacuum carburizing to obtain carbon steel with a carburized layer thickness L of 10μm and a carbon content of 0.8wt%. The temperature of the first vacuum carburizing is 800℃. Step 2: A multilayer film of W layer / Fe layer / W layer is deposited on the carbon steel surface with a carburized layer using a first chemical vapor deposition process. The thickness of the W layer is 2μm, the thickness of the Fe layer is 2μm, and the total thickness of the multilayer film of W layer / Fe layer / W layer is 6μm. Step 3: A W layer with a thickness of 2 μm and a Mo layer with a thickness of 2 μm are deposited on the surface of the film layer formed in Step 2 using a second chemical vapor deposition process. The total thickness of the W / Mo multilayer film is 8 μm. Step 4: On the surface of the W / Mo multilayer film formed in step 3, a patterned iron layer of 10 μm is deposited by selective electroplating using a special anti-electroplating coating. Then, the anti-electroplating coating is removed with an organic solvent to obtain the preform. Step 5: Place the preform obtained in Step 4 into a carburizing furnace for a second vacuum carburizing at a temperature of 900℃, resulting in a carbon steel surface with a three-dimensional interpenetrating ceramic / metal composite coating.

[0031] In this embodiment, the preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface is as follows: the metal multilayer film formed by alternating deposition of W / Fe layers in step 2, combined with the second carburizing of the sample in step 5, transforms the initial alternating W / Fe multilayer film in the stacked structure coating into an interpenetrating columnar WC / Fe ceramic-metal layer in situ, improving the strength, rigidity, toughness, and shear resistance of the film. The formation principle of the bottom WC / Fe is as follows: carbon atoms on the surface of the steel substrate diffuse into the W / Fe metal multilayer film, causing the W layer to transform into a WC layer, while the Fe layer is not ceramicized. In this process, iron and tungsten interdiffusion occur, forming a Fe-WC ternary compound region with C. As the carbon content increases, the ternary compound decomposes into a WC ceramic phase and a metallic Fe phase. This process forms WC ceramic pillars connected between ceramic layers, metallic Fe pillars connected between metal layers, and a metallurgically bonded WC / Fe interface.

[0032] In this embodiment, the method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface is as follows: The second carburizing process in step 5 on the preform aims to accelerate the growth of the ceramic layer beneath the iron layer, achieving complete ceramization. The growth rate is slow in the uncovered area, preventing complete ceramization of the Mo / W multilayer film; only a ceramic layer forms on the surface, while the coplanar interlocking stacked layer remains a Mo / W metal layer. Therefore, after carburizing, the surface layer is a fully covered Mo2C / WC composite ceramic layer, the thickness of which depends on the thickness of the ceramic layer beneath the uncovered area. The coplanar interlocking stacked layer is a ceramic-metal patterned configuration layer, with the geometric features of its ceramic region consistent with the surface iron layer pattern.

[0033] In this embodiment, the method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface involves the following steps: Step 5, the secondary carburizing process, allows C atoms to diffuse into the Fe / Mo / W multilayer film deposited in steps 2 and 3, and also ceramicizes the Mo and W atoms. Simultaneously, the high-temperature environment of carburizing promotes interdiffusion of elements at the interlayer interfaces, forming a high-strength metallurgical bond. Furthermore, the precipitation of carbides in the interdiffusion regions creates microscopically irregular interlayer interfaces, which, compared to flat interfaces, more effectively enhance the coating's toughness.

[0034] In step 3 of the method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface in this embodiment, the reason for depositing a Mo / W metal multilayer film is that a Mo2C / WC multilayer film is formed during the carburizing and ceramicizing process. The longitudinal dimension of the Mo2C grains is consistent with the thickness of the Mo layer, and the longitudinal grain size of the WC layer is consistent with the thickness of the W layer. Therefore, the grain size can be controlled by the layer thickness geometry. These two ceramics are formed in situ during the carburizing process, which changes the columnar crystal structure of the deposited metal multilayer film and is beneficial to improving corrosion resistance.

[0035] Example 3 The preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface in this embodiment is specifically implemented according to the following steps: Step 1: Grind the surface of the carbon steel and perform the first gas carburizing to obtain carbon steel with a carburized layer thickness L of 50μm and a carbon content of 2.0wt%. The temperature of the first gas carburizing is 900℃. Step 2: A multilayer film of Mo / Fe / Mo layers is deposited on the carbon steel surface with a carburized layer using a first physical vapor deposition process. The thickness of the Mo layer is 1 μm, the thickness of the Fe layer is 1 μm, and the total thickness of the multilayer film of Mo / Fe / Mo layers is 10 μm. Step 3: A second physical vapor deposition process is used to deposit a Ta layer with a thickness of 0.75 μm and a Mo layer with a thickness of 0.05 μm on the surface of the film layer formed in Step 2. The total thickness of the Ta / Mo multilayer film is 8 μm. Step 4: On the surface of the film layer formed in step 3, a patterned iron layer of 30μm is formed by selectively mapping the area with a special anti-electroplating coating and performing mask vapor deposition. Then, the anti-electroplating coating is removed with an organic solvent to obtain the preform. Step 5: Place the preform obtained in Step 4 into a carburizing furnace for plasma carburizing at a temperature of 1000℃ to obtain a carbon steel surface with a three-dimensional interpenetrating ceramic / metal composite coating.

[0036] Example 4 The preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface in this embodiment is specifically implemented according to the following steps: Step 1: Grind the carbon steel surface and perform solid carburizing to obtain carbon steel with a carburized layer thickness L of 200μm and a carbon content of 2.0wt%. The temperature of the first solid carburizing is 1000℃. Step 2: A multilayer film of W / Fe / W layers is deposited on the carbon steel surface with a carburized layer using a first chemical vapor deposition method. The thickness of the W layer is 3 μm, the thickness of the Fe layer is 0.5 μm, and the total thickness of the multilayer film of W / Fe / W layers is 7 μm. Step 3: A W layer with a thickness of 2 μm and a Ta layer with a thickness of 2 μm are deposited on the surface of the film layer formed in Step 2 by a second chemical vapor deposition. The total thickness of the W / Ta multilayer film is 16 μm. Step 4: On the surface of the film layer formed in step 3, a patterned iron layer of 15μm is patterned by selectively etching a special anti-electroplating coating. Then, the anti-electroplating coating is removed with an organic solvent to obtain the preform.

[0037] Step 5: Place the preform obtained in Step 4 into a carburizing furnace for vacuum carburizing at a temperature of 1200℃ to obtain a carbon steel surface with a three-dimensional interpenetrating ceramic / metal composite coating.

[0038] Example 5 The preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface in this embodiment is specifically implemented according to the following steps: Step 1: Grind the carbon steel surface and perform the first gas carburizing to obtain carbon steel with a carburized layer thickness L of 10μm and a carbon content of 2.0wt%. The temperature of the first gas carburizing is 800℃. Step 2: A multilayer film of Cr / Fe / Cr layers is deposited on the carbon steel surface with a carburized layer using physical vapor deposition. The thickness of the Cr layer is 3 μm, the thickness of the Fe layer is 0.8 μm, and the total thickness of the multilayer film of Cr / Fe / Cr layers is 7.6 μm. Step 3: Deposit a Ta layer with a thickness of 1 μm and a Cr layer with a thickness of 1 μm on the surface of the film layer formed in Step 2 using a magnetron sputtering process. The total thickness of the Ta / Cr multilayer film is 25 μm. Step 4: On the surface of the film layer formed in step 3, a patterned iron layer of 20 μm is formed by selective area mapping using a special anti-electroplating coating and selective area masking vapor deposition. Then, the anti-electroplating coating is removed with an organic solvent to obtain the preform. Step 5: Place the preform obtained in Step 4 into a carburizing furnace for plasma carburizing at a temperature of 1000℃ to obtain a carbon steel surface with a three-dimensional interpenetrating ceramic / metal composite coating.

[0039] Example 6 The preparation method of the ceramic / metal three-dimensional interpenetrating composite coating on the carbon steel surface in this embodiment is specifically implemented according to the following steps: Step 1: Grind the surface of the carbon steel and perform the first gas carburizing to obtain carbon steel with a carburized layer thickness L of 100μm and a carbon content of 0.8wt%. The temperature of the first gas carburizing is 1000℃. Step 2: A multilayer film of Nb / Fe / Nb layers is deposited on the carbon steel surface with a carburized layer using a first physical vapor deposition process. The thickness of the Nb layer is 3 μm, the thickness of the Fe layer is 0.5 μm, and the total thickness of the multilayer film of Nb / Fe / Nb layers is 7 μm. Step 3: A Zr layer with a thickness of 1 μm and an Nb layer with a thickness of 1 μm are deposited on the surface of the film layer formed in Step 2 using a second physical vapor deposition process. The total thickness of the Zr / Nb multilayer film is 20 μm. Step 4: On the surface of the film layer formed in step 3, a patterned iron layer of 30μm is deposited by selective electroplating using a special anti-electroplating coating. Then, the anti-electroplating coating is removed with an organic solvent to obtain the preform. Step 5: Place the preform obtained in Step 4 into a carburizing furnace for plasma carburizing at a temperature of 800℃ to obtain a carbon steel surface with a three-dimensional interpenetrating ceramic / metal composite coating.

[0040] Comparative Example 1 The preparation method of the carbon steel surface coating in this comparative example is carried out according to the following steps: Step 1: Grind the carbon steel surface and perform the first vacuum carburizing to obtain carbon steel with a carburized layer thickness L of 10μm and a carbon content of 0.8wt%. The temperature of the first vacuum carburizing is 800℃. Step 2: A multilayer film of W layer / Fe layer / W layer is deposited on the carbon steel surface with a carburized layer using a first chemical vapor deposition process. The thickness of the W layer and the Fe layer is 5 μm. Step 3: A second chemical vapor deposition process is used to deposit two W layers and two Mo layers with a thickness of 3 μm on the surface of the film layer formed in step 2, to obtain a W / Mo / Fe multilayer film coating.

[0041] Comparative Example 2 The preparation method of the carbon steel surface coating in this comparative example is carried out according to the following steps: Step 1: Grind the surface of the carbon steel; Step 2: A multilayer film of W layer / Fe layer / W layer is deposited on the carbon steel surface using a first chemical vapor deposition process. The thickness of the W layer and Fe layer is 5 μm. Step 3: A second chemical vapor deposition process is used to deposit two W layers and two Mo layers with a thickness of 3 μm on the surface of the film layer formed in step 2. Step 4: Apply a special anti-electroplating coating to the surface of the film layer formed in Step 3 to perform selective area mapping, deposit a 5μm patterned iron layer using a selective area electroplating process, and then remove the anti-electroplating coating with an organic solvent to obtain the preform; Step 5: Place the preform obtained in Step 4 into a carburizing furnace for vacuum carburizing at a temperature of 900℃ to obtain a W-Mo-C / Fe composite coating.

[0042] The mechanical properties of the ceramic / metal three-dimensional interpenetrating composite coatings on the carbon steel surface prepared in Examples 2-6 and the carbon steel surface coatings in Comparative Examples 1-2 were tested. The results of the mechanical property tests are shown in Table 1. Table 1 Mechanical performance test results

[0043] As shown in Table 1, the fracture toughness of the composite coatings prepared in Examples 2 to 6 of this invention all exceed 10 MPa·m. 1 / 2 The maximum pressure can reach 13.6 MPa·m 1 / 2 The surface hardness of all samples exceeded 2000 HV, reaching a maximum of 2600 HV, demonstrating excellent comprehensive mechanical properties. In contrast, Comparative Example 1, lacking secondary carburizing and patterned iron layer induction, failed to form a ceramic phase, ultimately yielding a multilayer metallic film with a fracture toughness of only 30 MPa·m. 1 / 2 The hardness of the first example was only 1000 HV; the comparative example 2, due to the lack of a bottom carbon source provided by the first carburizing, failed to form a WC layer at the bottom, instead forming an Fe3W3C layer with low hardness and poor toughness, and the overall film fracture toughness was only 6.5 MPa·m. 1 / 2 The hardness is only 1900 HV. This fully verifies the necessity of the process route of the present invention, which involves the first carburizing carbon supply, patterning induction, and the second carburizing reaction.

[0044] This invention's coating constructs a unique omnidirectional toughening structure, using a three-dimensionally interconnected ceramic phase as its framework to endow the coating with extremely high hardness, strength, and rigidity. Simultaneously, ceramic and metal connecting pillars interpenetrate spatially, working in conjunction with the horizontal metal portions of the middle coplanar interlocking stacked layers to form a multi-dimensional metal toughening network distributed vertically and horizontally. This typical three-dimensional interpenetrating configuration, with a ceramic framework providing load-bearing capacity and a metal network providing toughness, not only achieves synergistic enhancement of the ceramic and metal properties but also effectively improves the coating's omnidirectional toughness and shear resistance under complex stress conditions, solving the technical problem of traditional ceramic coatings being strong but not tough, or metal coatings being tough but not strong.

Claims

1. A ceramic / metal three-dimensional interpenetrating composite coating on carbon steel surface, comprising a substrate and a carburized layer, characterized in that, The carburized layer has an interpenetrating columnar array on its upper surface, a coplanar interlocking stacked layer above the interpenetrating columnar array, and a composite ceramic stack above the coplanar interlocking stacked layer. The coplanar interlocking stacked layer is formed by ceramic and metal parts interlocking in a complementary geometric pattern in a direction parallel to the substrate surface, and the ceramic and metal parts are coplanar. The interpenetrating columnar array includes alternately stacked ceramic carbide layers and metal connecting layers. Both the ceramic carbide layers and the metal connecting layers are arranged parallel to the substrate surface and alternately stacked in a direction perpendicular to the substrate surface. Adjacent ceramic carbide layers are connected at multiple points by several ceramic connecting pillars, and adjacent metal connecting layers are connected at multiple points by several metal connecting pillars. The ceramic connecting pillars and metal connecting pillars are spatially interspersed. The ceramic part is made of the same material as the ceramic carbide layer. The composite ceramic stack includes the ceramic carbide layer, and the metal part is made of the same material as the metal connecting layer.

2. A method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface, characterized in that, The specific steps are as follows: Step 1: After grinding the carbon steel surface, perform the first carburizing treatment to obtain a substrate with a carburized layer; Step 2: Using the first film preparation process, the first metal layer and iron layer are alternately deposited on the surface of the substrate with the carburized layer to form the first part of the metal multilayer film on the substrate; Step 3: On the first part of the metal multilayer film, the first metal layer and the second metal layer are deposited alternately using a second film preparation process to form the second part of the metal multilayer film; Step 4: A patterned iron layer is prepared on the second part of the metal multilayer film using a selective area patterning process to obtain the preform; Step 5: The preform is placed in a carburizing furnace for a second carburizing treatment. After the second carburizing treatment, a thicker ceramic layer is formed in the area covered by the patterned iron layer, and a thinner ceramic layer is formed in the area not covered by the patterned iron layer. The remaining incompletely ceramicized first and second metal layers constitute the metal bonding layer. The patterned iron layer on the surface is removed using dilute hydrochloric acid to obtain a three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface. The three-dimensional interpenetrating ceramic / metal composite coating on the carbon steel surface includes columnar interpenetrating stacks, coplanar interlocking stacks, and composite ceramic stacks.

3. The method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface according to claim 2, characterized in that, In step 1, the first carburizing treatment is performed using one of solid carburizing, gas carburizing, vacuum carburizing, or plasma carburizing, and the temperature range of the first carburizing treatment is 800℃-1000℃.

4. The method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface according to claim 2, characterized in that, The thickness L of the carburized layer of the carbon steel with the carburized layer mentioned in step 1 ranges from 10μm to 200μm, and the carbon content is from 0.5wt% to 2.0wt%.

5. The method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface according to claim 2, characterized in that, The first film preparation process in step 2 is either physical vapor deposition or chemical vapor deposition, with a deposition thickness of 3μm-25μm.

6. The method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface according to claim 2, characterized in that, The second film preparation process in step 3 is one of physical vapor deposition or chemical vapor deposition, with a deposition thickness of 3μm-25μm.

7. The method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface according to claim 2, characterized in that, In step 2, the first metal layer and in step 3, the second metal layer are both metal layers with carbide-forming ability. The metal layer with carbide-forming ability is selected from one of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W. The first metal layer and the second metal layer are not the same metal.

8. The method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface according to claim 2, characterized in that, Step 4 specifically involves setting a mask on the surface of the second part of the metal multilayer film, depositing a patterned iron layer in the area not covered by the mask using a selective patterning process, and then removing the mask to obtain a preform. The selective patterning process is selected from one of mask vapor deposition, selective electroplating, or selective etching of the iron layer, and the thickness of the patterned iron layer ranges from 5μm to 30μm.

9. The method for preparing a ceramic / metal three-dimensional interpenetrating composite coating on a carbon steel surface according to claim 2, characterized in that, The second carburizing treatment in step 5 adopts one of solid carburizing, gas carburizing, vacuum carburizing, and plasma carburizing, and the temperature range of the second carburizing treatment is 800℃-1000℃.

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