Composite material and method for producing composite material

Abstract

This method for producing a composite material includes: a first coating step for forming a coating layer on a base material that contains iron so as to have a VCx layer and a V2C layer in this order from the side closer to the base material; and a second coating step for forming a V2AlC layer on the V2C layer. In the second coating step, the V2C layer is subjected to cementation by an aluminum element.

Description

Composite material and method for manufacturing the composite material

[0001] The present disclosure relates to composite materials and methods for making composite materials.

[0002] Patent Document 1 describes a long-fiber-reinforced silicon carbide member. Patent Document 1 describes that the long-fiber-reinforced silicon carbide member has a composite material layer in which silicon carbide long fibers are combined with a silicon carbide matrix, an intermediate layer provided on the surface of the composite material layer, and a metal vapor-deposited layer provided on the surface of the intermediate layer. Examples of intermediate layers include vanadium aluminum carbide. Examples of metal vapor-deposited layers include simple metal materials such as vanadium. Patent Document 1 also describes that the intermediate layer is formed by a vapor deposition method. Patent Document 1 further describes that the inclusion of the intermediate layer and the metal vapor-deposited layer improves airtightness and environmental resistance.

[0003] Patent Document 2 discloses a method for manufacturing a silicon carbide alloy having a chemical composition M ｎ＋１ AX ｎ and a MAX phase compound having the formula: ２ Patent Document 2 describes the preparation of a ceramic matrix composite material by impregnating a porous fiber preform with a slurry containing solid particulate matter containing silicon carbide particles and a MAX phase precursor. Patent Document 2 also describes the use of the prepared ceramic matrix composite material as a turbine engine component.

[0004] Patent No. 6797605 Patent No. 6929622

[0005] Incidentally, the V film can be formed by vapor deposition as described in Patent Documents 1 and 2, or by impregnation with a slurry. ２ In the method of forming an AlC layer, if the substrate has irregularities or is a cylindrical body, V may be formed on the surface of the irregularities or on the inner peripheral surface of the cylindrical body. ２ It may be difficult to form an AlC layer on the surface of the substrate. ２ To facilitate the formation of an AlC layer, in other words, V ２ There is a need to improve the productivity of AlC layers.

[0006] A method for producing a composite material according to one embodiment of the present disclosure includes the steps of: forming a VCx layer and a V layer on a substrate containing iron, from the side closer to the substrate; ２ a first coating step of forming a coating layer in the order of a layer C; ２ V on C layer ２ and a second coating step of forming an AlC layer, wherein the second coating step is ２ This is a step of performing a diffusion and penetration treatment of aluminum element on the C layer.

[0007] A composite material according to one aspect of the present disclosure is a composite material having a substrate containing iron and a coating layer that coats the substrate, wherein the coating layer is made of VC in the order of proximity to the substrate. Ｘ layer, V ２ C layer and V ２ It has an AlC layer.

[0008] Fig. 1 is a cross-sectional SEM photograph of the composite material of Example 1 after the first coating step. Fig. 2 is a cross-sectional SEM photograph of the composite material of Example 1 after the second coating step. Fig. 3 is the result of elemental analysis in the depth direction of the composite material of Example 1. Fig. 4 is the result of crystal structure analysis of the surface of the composite material of Example 1. Fig. 5 is a cross-sectional SEM photograph of the composite materials of Example 2 and Comparative Examples 1 to 3. Fig. 6 is a cross-sectional SEM photograph of multiple locations of the composite material of Example 1 after the second coating step.

[0009] An embodiment of the composite material of the present disclosure will be described. The composite material of this embodiment has a substrate containing iron and a coating layer that coats the substrate. The coating layer is made of VC in the order from closest to the substrate. Ｘ layer, V ２ C layer and V ２ It has an AlC layer.

[0010] The composite material will be described in detail below. <Substrate> The substrate contains iron. The substrate preferably contains 50 mass % or more of iron as a main component. The substrate preferably also contains carbon element in addition to iron. By containing carbon element, V can be formed by utilizing the carbon element in the substrate. ２An AlC layer can be formed. Specific examples of the substrate containing carbon elements include steel materials such as steel, cast iron, and stainless steel.

[0011] The content of carbon element in the substrate is not particularly limited, but is preferably 0.02 mass% or more, and more preferably 0.3 mass% or more. When the content of carbon element is 0.02 mass% or more, V can be obtained by using the carbon element in the substrate. ２ The carbon content is preferably 2.14% by mass or less, and more preferably 1.2% by mass or less. When the carbon content is 2.14% by mass or less, the toughness of the substrate is likely to be improved, making it possible to use the composite material in applications requiring higher toughness. Generally, the carbon content of steel is about 0.02% by mass or more and 2.14% by mass or less, so the substrate is preferably steel.

[0012] The method for measuring the carbon element content in the substrate is not particularly limited, and any known measurement method can be used. The carbon element content in the substrate can be measured, for example, by the combustion-carbon dioxide gravimetric method, combustion-gas volumetric method, combustion-infrared absorption method, or the like, as specified in JIS G 1211.

[0013] The shape of the substrate is not particularly limited, and any shape suitable for the intended use of the composite material can be adopted. For example, as described below, when the composite material is used as a component of a chain, the shape of each component can be adopted as the shape of the substrate.

[0014] <Coating layer> The coating layer is made of VC, Ｘ layer, V ２ C layer and V ２ It has an AlC layer. Ｘ layer means a layer of vanadium carbide having a composition where X is greater than 0.66 and less than 0.88. Ｘ Specific examples of V ８ C ７ , V ６ C ５ , V ４ C ３ , V ３ C ２etc. Ｘ is one type of VC Ｘ or may be composed of multiple types of VCs Ｘ It may be composed of:

[0015] V ２ The C layer refers to a layer of vanadium carbide having a composition of two vanadium atoms per one carbon atom. ２ The AlC layer means a layer of vanadium aluminum carbide, also known as vanadium aluminum carbide. ２ AlC is a compound containing Al in a transition metal carbide, and is generally called a MAX compound. MAX compounds are known to have excellent wear resistance and corrosion resistance.

[0016] VC Ｘ layer, V ２ C layer and V ２ The AlC layers are formed continuously without any intervening layers. There are no particular limitations on the thickness of each layer constituting the coating layer. Ｘ The thickness of the layer is preferably 1 μm or more, and more preferably 3 μm or more. Ｘ The thickness of the layer is preferably 50 μm or less, and more preferably 30 μm or less.

[0017] V ２ The thickness of the C layer is preferably 1 μm or more, and more preferably 3 μm or more. ２ The thickness of the C layer is preferably 50 μm or less, and more preferably 30 μm or less.

[0018] V ２ The thickness of the AlC layer is preferably 1 μm or more, and more preferably 3 μm or more. ２ The thickness of the AlC layer is preferably 50 μm or less, and more preferably 30 μm or less.

[0019] V ２ When the thickness of the AlC layer is 1 μm or more, V ２ The AlC layer can provide excellent wear resistance and corrosion resistance. ２When the thickness of the AlC layer is 30 μm or less, V ２ The AlC layer is less likely to crack. ２ Since the time required to form the AlC layer can be shortened, the manufacturing cost can be reduced.

[0020] The method for measuring the thickness of the coating layer is not particularly limited, and for example, it can be measured by observing the cut surface or fracture surface of the composite material with a microscope. <Method for manufacturing composite material> The composite material can be manufactured by the following manufacturing method. The manufacturing method of the composite material is as follows: For a substrate containing iron, a VCx layer and a V layer are formed from the side closest to the substrate. ２ a first coating step of forming a coating layer in the order of a layer C; ２ V on C layer ２ and a second coating step of forming an AlC layer.

[0021] (First coating step) The first coating step is a step of performing a vanadium diffusion treatment on an iron-containing substrate. The vanadium diffusion treatment can be performed by filling a container with vanadium powder and the substrate, and then heating the container in an inert atmosphere. Specifically, the vanadium powder and the substrate are filled into a crucible serving as a container, and then a lid is attached to the crucible to seal the interior. This crucible is heated in a heat treatment furnace in an inert atmosphere.

[0022] The vanadium powder may be a powder of metallic vanadium or a powder of a vanadium alloy. An example of the vanadium alloy powder is iron-vanadium alloy powder. The iron-vanadium alloy powder may have a vanadium content of 50 mass% or more.

[0023] The vanadium powder may be mixed with other powders. That is, the vanadium powder may be a mixed powder with other powders. Examples of the other powders include powders of a sintering inhibitor and a reaction accelerator. Examples of the sintering inhibitor include aluminum oxide. Examples of the reaction accelerator include ammonium chloride (NH ４ Cl). Furthermore, iron powder may be mixed as another powder.

[0024] The content ratio of each powder in the mixed powder is not particularly limited. The content ratio of vanadium powder in the mixed powder is preferably 10% by mass or more, more preferably 50% by mass or more. Furthermore, the content ratio of vanadium powder in the mixed powder is preferably 95% by mass or less, more preferably 90% by mass or less. By having the content ratio of vanadium powder in the mixed powder be 95% by mass or less, sintering of the vanadium powder to the inner wall of the heat treatment furnace can be suitably suppressed. Furthermore, by having the content ratio of vanadium powder in the mixed powder be 90% by mass or less, sintering of the vanadium powder particles together can be suitably suppressed.

[0025] The content of the sintering inhibitor in the mixed powder is preferably 30% by mass or more, more preferably 40% by mass or more, and is preferably 70% by mass or less, more preferably 60% by mass or less.

[0026] The content of the reaction accelerator in the mixed powder is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less.

[0027] The content of the iron powder in the mixed powder is preferably approximately the same as the content of the vanadium powder. "Almost the same content" means that the difference between the content ratios of the two is 10% by mass or less. The difference between the content ratios of the two is preferably 5% by mass or less.

[0028] The inert atmosphere used in the diffusion and penetration treatment is not particularly limited, and may be, for example, an argon atmosphere or a nitrogen atmosphere. The heating temperature used in the diffusion and penetration treatment is not particularly limited, and any temperature that can diffuse the vanadium element into the base material may be appropriately used. The heating temperature is preferably, for example, 900°C or higher and 1600°C or lower.

[0029] The heating time in the diffusion penetration treatment is not particularly limited, but can be, for example, maintained at the above heating temperature for 5 to 25 hours. By adopting the above heating temperature and heating time in the diffusion penetration treatment, vanadium and ammonium chloride can be reacted to produce vanadium chloride gas. This chloride gas diffuses and reacts with iron on the substrate surface to release vanadium, which then penetrates into the substrate, reacting with carbon contained in the substrate and vanadium, forming VC on the substrate surface. Ｘ Furthermore, a VC layer can be formed. Ｘ V on the layer ２ A C layer can be formed.

[0030] In addition, since the mixed powder contains iron elements derived from the iron-vanadium alloy powder or iron powder, the penetration of chloride gas into the base material can be slowed down, and therefore, VC Ｘ V on the layer ２ This makes it easier to form layer C.

[0031] As described above, in the first coating step, by performing the diffusion and penetration treatment of vanadium element, it is possible to form VC on the surface of the substrate even if the substrate has a complex shape. Ｘ Layers and V ２ For example, even if the substrate has irregularities or is a cylindrical body, the chloride gas can reach the surface of the substrate sufficiently to form a VC layer on the irregular surface or the inner surface of the cylindrical body. Ｘ Layers and V ２ It is easy to form a C layer. Ｘ Layers and V ２ This makes it easier to make the thickness of each of the C layers more uniform. The diffusion and penetration treatment in the first coating step is also called a powder pack method.

[0032] (Second coating step) The second coating step is a step of coating the V formed in the first coating step. ２This is a step of performing a diffusion and penetration treatment of aluminum element into the C layer. The diffusion and penetration treatment of aluminum element can be performed by filling a container with aluminum powder and the substrate that has been subjected to the first coating step, and then heating in an inert atmosphere. Specifically, after the aluminum powder and the substrate are filled into a crucible serving as a container, a lid is attached to the crucible to seal the inside. The diffusion and penetration treatment of aluminum element can be performed by heating this crucible in an inert atmosphere in a heat treatment furnace.

[0033] The aluminum powder may be an aluminum alloy powder. For example, an iron-aluminum alloy powder may be used. For example, the iron-aluminum alloy powder may have an aluminum element content of 50 mass % or more.

[0034] As in the first coating step, the aluminum powder may be mixed with other powders, i.e., powders of a sintering inhibitor such as aluminum oxide and a reaction accelerator such as ammonium chloride may be mixed.

[0035] The content ratio of each powder in the mixed powder is not particularly limited. The content ratio of aluminum powder in the mixed powder is preferably about the same as the content ratio of vanadium powder in the mixed powder in the first coating step. In addition, the content ratios of the sintering inhibitor and reaction accelerator in the mixed powder are also preferably about the same as those in the mixed powder in the first coating step.

[0036] The inert atmosphere in the diffusion and penetration treatment is not particularly limited, and for example, an argon atmosphere or a nitrogen atmosphere can be used. The heating temperature in the diffusion and penetration treatment is not particularly limited, and a temperature that can diffuse the aluminum element into the base material can be appropriately used. The heating temperature is, for example, preferably 860°C or higher, more preferably 880°C or higher, and even more preferably 900°C or higher. The heating temperature is also preferably 960°C or lower, more preferably 940°C or lower, and even more preferably 920°C or lower.

[0037] The heating time in the diffusion and penetration treatment is not particularly limited, but can be, for example, maintained at the above heating temperature for 1 hour to 5 hours. By adopting the above heating temperature and heating time in the diffusion and penetration treatment, aluminum and ammonium chloride can be reacted to produce aluminum chloride gas. This chloride gas diffuses and forms V on the surface of the substrate. ２ It reacts with C to release aluminum, which then becomes V. ２ By penetrating into the C layer, V ２ C reacts with aluminum to form V ２ V on C layer ２ An AlC layer can be formed.

[0038] In addition, since the mixed powder contains iron elements derived from the iron-aluminum alloy powder, V ２ This allows the chloride gas to penetrate the C layer more slowly. ２ While maintaining the state in which the C layer is formed, ２ V on C layer ２ This makes it easier to form an AlC layer.

[0039] In addition, V ２ When forming the AlC layer, V ２ If the entire C layer reacts with aluminum, the diffusion of aluminum will be VC. Ｘ In order to reach the V layer ２ As the C layer disappears, V ２ The AlC layer also disappears. ２ V on C layer ２ The second coating step of forming the AlC layer is ２ Part of the C layer reacts with aluminum to form V ２ The AlC layer is formed, and even after the second coating process, the V ２ Layer C is present.

[0040] As described above, in the second coating step, by performing the diffusion and penetration treatment of aluminum elements, even if the substrate has a complex shape, it is possible to form a V layer on the surface of the substrate. ２For example, even if the substrate has irregularities or is a cylindrical body, the chloride gas can reach the surface of the substrate sufficiently, and the V layer can be formed on the irregular surface or the inner surface of the cylindrical body. ２ It is easy to form an AlC layer. ２ This makes it easier to make the thickness of the AlC layer more uniform. The diffusion treatment in the second coating step is also called a powder pack method.

[0041] Furthermore, the manufacturing method of the composite material has two coating steps, the first coating step and the second coating step, so that the V ２ An AlC layer can be formed. <Uses of the Composite Material> There are no particular limitations on the uses of the composite material. ２ Because AlC is a material with excellent wear resistance and corrosion resistance, it can be used in applications requiring wear resistance and corrosion resistance. Examples of applications requiring wear resistance and corrosion resistance include chains, pistons, and cylinders used in internal combustion engines and electric motors. Examples of applications requiring wear resistance and corrosion resistance include screws used in injection molding machines, extrusion molding machines, kneading machines, and the like. Specific examples of chains include transmission chains used in engines, conveyor chains used in logistics, and cable guide chains that protect and guide cables. Furthermore, composite materials can also be used in sprockets, which are components of chains.

[0042] <Actions and Effects> The actions and effects of this embodiment will be described. (1) The method for producing a composite material of this embodiment is to form a VCx layer and a V layer in the order from the side closest to the base material containing iron. ２ a first coating step of forming a coating layer in the order of a layer C; ２ V on C layer ２ The first coating step is a step of performing a diffusion and penetration treatment of vanadium element on the base material containing iron. ２ This is a step of performing a diffusion and penetration treatment of aluminum element on the C layer.

[0043] In the manufacturing method of this embodiment, the vanadium element is diffused and penetrated, so that the VC can be formed regardless of the shape of the substrate. Ｘ Layers and V ２ It is easy to form a C layer. ２ By performing a diffusion and penetration treatment of aluminum elements on the C layer, V can be obtained regardless of the shape of the substrate. ２ V on C layer ２ Therefore, it is easy to form an AlC layer. ２ The productivity of the AlC layer can be improved. ２ The thickness of the AlC layer is made more uniform, resulting in a continuous V ２ An AlC layer can be formed.

[0044] (2) The substrate contains 0.3 mass % or more of carbon element. VC is applied to the substrate surface by utilizing the carbon element contained in the substrate. Ｘ Layers and V ２ It is easy to form a C layer. ２ This makes it easier to form an AlC layer.

[0045] (3) The composite material of this embodiment has a substrate containing iron and a coating layer that coats the substrate. The coating layer is made up of a VCx layer, a V ２ C layer and V ２ It has an AlC layer. ２ The presence of the AlC layer makes it suitable for use in applications requiring wear resistance and corrosion resistance.

[0046] <Modifications> This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0047] In the present embodiment, the mixed powder used in the vanadium diffusion treatment contains a sintering inhibitor, a reaction accelerator, and iron powder as other powders, but this is not limiting. At least one of these powders may be omitted.

[0048] In the present embodiment, the first and second coating steps are performed by the powder pack method, but this is not limiting. At least one of the first and second coating steps may be performed by a method other than the powder pack method. Examples of methods other than the powder pack method include a paste method, a plating heating method, a fluidized bed furnace method, and a molten salt method.

[0049] The mixed powder used in the vanadium element diffusion and penetration treatment may contain powder other than that of this embodiment. Examples of powder other than that of this embodiment include carbon powder. The carbon powder reacts with the vanadium powder to form VC on the surface of the substrate. Ｘ Layers and V ２ For example, when an iron-containing substrate does not contain carbon or the carbon content is as low as less than 0.02 mass%, a vanadium powder can be reacted with a carbon powder to form a VC layer on the substrate surface. Ｘ Layers and V ２ That is, the first coating step of this embodiment is not limited to a method of performing a vanadium diffusion treatment on an iron-containing substrate. Instead of a method of performing a vanadium diffusion treatment on an iron-containing substrate, a VC layer can be formed on the substrate by reacting vanadium powder with carbon powder. Ｘ Layers and V ２ A method of forming a C layer may also be employed.

[0050] Examples will be given below to more specifically illustrate the configuration and effects of the present disclosure, but the present disclosure is not limited to these examples. (Example 1) An iron-containing substrate was prepared as an iron disc having an iron content of approximately 98.8% by mass, a carbon content of approximately 1.2% by mass, a diameter of approximately 15 mm, and a thickness of approximately 2 mm. This disc was placed in a cylindrical porous crucible with a bottom, and a mixed powder containing vanadium powder was filled around the disc. The mixed powder was a mixture of 18.5 g of commercially available iron-vanadium alloy powder having a vanadium content of 50% by mass or more, 27.8 g of commercially available aluminum oxide powder, and 1.7 g of commercially available ammonium chloride powder.

[0051] The mixed powder contained approximately 38% by mass of iron-vanadium alloy powder, approximately 58% by mass of aluminum oxide powder, and approximately 4% by mass of ammonium chloride powder.

[0052] A lid was attached to the open end of the porous crucible using alumina cement to seal the porous crucible. After the alumina cement hardened, the porous crucible was placed in a known heat treatment furnace and held at 980°C for 25 hours in an argon atmosphere to carry out a first covering step.

[0053] After cooling, the substrate was removed from the porous crucible. This substrate was placed in a cylindrical porous crucible with a bottom, and a mixed powder containing aluminum powder was filled around the disk. The mixed powder was a mixture of 18.5 g of commercially available iron-aluminum alloy powder having an aluminum content of 50 mass% or more, 27.8 g of commercially available aluminum oxide powder, and 1.7 g of commercially available ammonium chloride powder.

[0054] The content of iron-aluminum alloy powder in the mixed powder was approximately 38 mass %, the content of aluminum oxide powder was approximately 58 mass %, and the content of ammonium chloride powder was approximately 4 mass %.

[0055] A lid was attached to the open end of the porous crucible using alumina cement to seal the porous crucible. After the alumina cement hardened, the porous crucible was placed in a known heat treatment furnace and held at 900°C for 1 hour in an argon atmosphere to perform a second coating step. After cooling, the substrate was removed from the porous crucible to obtain a composite material.

[0056] Example 2 A composite material was produced in the same manner as in Example 1, except that the holding time in the first coating step was changed to 5 hours.

[0057] Comparative Example 1 A composite material was produced in the same manner as in Example 2, except that the temperature in the first covering step was changed to 900°C and the temperature in the second covering step was changed to 980°C.

[0058] Comparative Example 2 A composite material was produced in the same manner as in Example 2, except that the temperature in the second covering step was changed to 980°C.

[0059] Comparative Example 3 A composite material was produced in the same manner as in Example 2, except that the temperature in the second covering step was changed to 800°C.

[0060] (Evaluation Test) For the composite materials of Examples 1 and 2 and Comparative Examples 1 to 3, cross sections were observed after the first coating step and after the second coating step using a known scanning electron microscope (also referred to as SEM). Furthermore, for the composite material of Example 1, elemental analysis in the depth direction was performed using a known electron probe microanalyzer (also referred to as EPMA). Furthermore, for the composite material of Example 1, crystal structure analysis of the surface of the composite material was performed using a known X-ray diffraction device (also referred to as XRD device). Furthermore, for the composite material of Example 1, multiple locations on the cross section after the second coating step were observed using SEM, and V ２ The thickness of the AlC layer was evaluated.

[0061] Fig. 1 shows a cross-sectional photograph of the composite material of Example 1 after the first coating step. A first layer with a thickness of about 30 µm was observed on the substrate. In addition, a second layer with a thickness of about 5 µm was observed on the first layer.

[0062] Figure 2 shows a cross-sectional photograph of the composite material of Example 1 after the second coating step. A third layer with a thickness of about 3 μm was observed on the second layer. As shown in Figure 3, a V layer with a thickness of about 3 μm was observed on the left side of Figure 3, which is the outermost surface of the composite material. ２ AlC layer, V with a thickness of about 5 μm ２ C layer, V with a thickness of about 20 μm ８ C ７ , and V ６ C ５ A layer containing iron and a layer containing iron were identified.

[0063] As shown in FIG. 4, V is formed on the outermost surface of the composite material. ２ From the measurement results in Figures 3 and 4, it was confirmed that V as a first layer was formed on the substrate by performing the first coating step. ８ C ７ , and V ６ C ５ A layer is formed, and a second layer, V, is formed on top of it. ２ It was confirmed that a C layer was formed. In addition, by performing the second coating process,２ V on C layer ２ It was confirmed that an AlC layer was formed.

[0064] As shown in FIG. 5, in Example 2 in which the holding time of the first coating step was 5 hours, V after the first coating step ２ In Example 1, in which the holding time of the first coating step was 25 hours, the thickness of the C layer was about 2 μm. ２ Since the thickness of the C layer was about 5 μm, by adjusting the holding time of the first coating step, ２ It was confirmed that the thickness of the C layer could be adjusted. ２ The thickness of the AlC layer was about 2 μm. ２ By adjusting the thickness of the C layer, ２ It was suggested that the thickness of the AlC layer could be adjusted. ２ Since the presence of an AlC layer was confirmed, the result was judged as "good."

[0065] In Comparative Example 1, in which the heating temperature in the first coating step was as low as 900°C and the heating temperature in the second coating step was as high as 980°C, V ２ The C layer is not formed, and after the second coating process, V ２ An AlC layer was not formed, and therefore the result was judged as "X."

[0066] In addition, in Comparative Example 2, in which the heating temperature in the second coating step was as high as 980°C, V ２ The diffusion of aluminum elements into the C layer progressed too much, ２ C layer and V layer ２ The AlC layer disappeared. In addition, in Comparative Example 3, in which the heating temperature in the second coating step was as low as 800°C, ２ Since the diffusion of aluminum elements into the C layer has not progressed, ２ No AlC layer was formed, and therefore, both Comparative Examples 2 and 3 were judged as "X."

[0067] Figure 6 shows cross-sectional photographs of the composite material of Example 2 after the second coating step. Photos 1 to 6 represent observation points on the cross section of the disc-shaped composite material. Facing the cross section, Photo 1 represents the upper left, Photo 2 the upper center, Photo 3 the upper right, Photo 4 the lower left, Photo 5 the lower center, and Photo 6 the lower right.

[0068] As shown in Figure 6, in all of Photos 1 to 6, V ２ The AlC layer had a uniform thickness of about 2 μm. ２ It was confirmed that an AlC layer was formed.

Claims

1. For a substrate containing iron, the VCx layer and V are applied from the side closest to the substrate. ２ a first coating step of forming a coating layer in the order of a layer C; ２ V on C layer ２ and a second coating step of forming an AlC layer, ２ A method for manufacturing a composite material, which comprises a step of performing a diffusion and penetration treatment of aluminum element on the C layer.

2. The method for producing a composite material according to claim 1, wherein the first coating step is a step of performing a diffusion treatment of vanadium element on a substrate containing iron.

3. A method for producing a composite material according to claim 1 or claim 2, wherein the substrate contains 0.3 mass % or more of carbon element.

4. A composite material having an iron-containing substrate and a coating layer that coats the substrate, wherein the coating layer is made up of, in order from closest to the substrate, a VCx layer, a V ２ C layer and V ２ A composite material having an AlC layer.

5. The composite material according to claim 4, wherein the substrate contains 0.3 mass % or more of carbon element.

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