JP2020143352A - Joined body and method for manufacturing joined body - Google Patents

Abstract

To provide a joined body the weight of which can be reduced while high strength and rigidity are maintained, and to provide a method for manufacturing the joined body.SOLUTION: The joined body comprises: a substrate having aluminum or aluminum alloy as a main component; and a metal film containing steel as a main component and carbon as a necessary additional material, laminated on the substrate and joined with the substrate. The metal film includes: a first hard layer forming the surface opposite to the substrate side, and composed of cementite and martensite; a heat-affected part having hardness lower than the hardness of the first hard layer, and composed of ferrite, martensite, and retained austenite; and a second hard layer provided between the first hard layer and the heat-affected part, and composed of martensite and retained austenite.SELECTED DRAWING: Figure 1

Description

The present invention relates to a bonded body formed by forming a metal film on a substrate and a method for producing the bonded body.

In recent years, it has been studied to increase the strength and hardness of parts such as automobile panels, tubular members, and rod-shaped members to improve wear resistance. For example, as a material used for this part, an iron-based material is used as a base material, and a metal material composed of at least one of nickel, cobalt, chromium, and molybdenum is sprayed on the base material to form a thermal spray coating, and laser light is applied. There is known a material in which an alloy layer is formed by melting a base material and a thermal spray coating by irradiating with (see, for example, Patent Document 1).

Japanese Patent No. 3015816

By the way, in recent years, replacement of iron-based materials with aluminum-based materials has been studied for the purpose of reducing the weight of various parts in automobile applications. While aluminum-based materials are suitable for weight reduction, it is difficult to obtain sufficient product strength if all aluminum-based materials are used. Therefore, it is being considered to replace a part of the iron-based material with an aluminum-based material. In particular, for parts that cause friction with other parts, it is required to increase the strength and hardness to impart abrasion resistance.

The present invention has been made in view of the above, and an object of the present invention is to provide a bonded body and a method for producing the bonded body, which have high strength and hardness and can be reduced in weight.

In order to solve the above-mentioned problems and achieve the object, the bonded body according to the present invention has a base material containing aluminum or an aluminum alloy as a main component and a metal film containing iron as a main component and carbon as an essential additive. The metal film is laminated on the base material and bonded to the base material, and the metal film forms a surface opposite to the base material side and is formed from cementite and martensite. Between the first hard layer and the heat-affected portion, which has a hardness lower than that of the first hard layer and is composed of ferrite, martensite, and retained austenite, and between the first hard layer and the heat-affected portion. It is provided and is characterized by having a second hard layer composed of martensite and retained austenite.

Further, the bonded body according to the present invention is characterized in that, in the above invention, the first hard layer has a Vickers hardness of Hv600 or more, and the heat-affected zone has a Vickers hardness of Hv200 or more and Hv400 or less. And.

Further, the bonded body according to the present invention is characterized in that, in the above invention, the metal film further contains a selective additive having at least one of copper, molybdenum, chromium, nickel and manganese.

Further, the method for producing a bonded body according to the present invention is a method for producing a bonded body in which a film formed by using a material powder is laminated on the surface of a base material containing aluminum or an aluminum alloy as a main component, and mainly using iron. A pretreatment film forming step of accelerating the material powder as a component together with gas and spraying it on the surface of the base material in a solid state to form a pretreatment film on the surface of the base material, and on the surface of the pretreatment film. It is characterized by including a coating step of applying carbon and a film forming step of forming a metal film by quenching the surface of the pretreatment film coated with carbon.

Further, in the method for producing a bonded body according to the present invention, in the above invention, in the pretreatment film forming step, the material powder containing the iron as a main component and carbon as an essential additive is sprayed onto the surface of the base material. It is characterized by that.

According to the present invention, it is possible to reduce the weight while having high strength and hardness.

FIG. 1 is a cross-sectional view showing the structure of a bonded body according to an embodiment of the present invention. FIG. 2 is an enlarged partial cross-sectional view of a part of the joint shown in FIG. FIG. 3 is a flowchart illustrating a method for manufacturing a bonded body according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a method for manufacturing a bonded body according to an embodiment of the present invention. FIG. 5 is a diagram illustrating a method for manufacturing a bonded body according to an embodiment of the present invention. FIG. 6 is a schematic view showing an outline of a cold spray device used for forming a metal film of a bonded body according to an embodiment of the present invention. FIG. 7 is a diagram showing an example of a material powder used for producing a bonded body according to an embodiment of the present invention. FIG. 8 is a diagram showing an example of a material powder used for producing a bonded body according to an embodiment of the present invention. FIG. 9 is a diagram showing an example of a material powder used for producing a bonded body according to an embodiment of the present invention. FIG. 10 is a diagram illustrating a method for manufacturing a bonded body according to an embodiment of the present invention. FIG. 11 is a diagram showing a cross-sectional image of the first embodiment. FIG. 12 is a diagram showing a cross-sectional image of the second embodiment. FIG. 13 is a diagram showing a cross-sectional image of Example 3. FIG. 14 is a diagram showing a cross-sectional image of Example 4. FIG. 15 is a diagram showing a cross-sectional image of Comparative Example 1. FIG. 16 is a diagram showing a cross-sectional image of Comparative Example 2. FIG. 17 is a diagram showing a cross-sectional image of Comparative Example 3. FIG. 18 is a diagram showing a cross-sectional image of Comparative Example 4. FIG. 19 is a diagram showing a cross-sectional image of Comparative Example 5. FIG. 20 is a diagram showing a cross-sectional image of Comparative Example 6. FIG. 21 is a diagram showing the results of EBSD analysis of the conjugate according to Example 1. FIG. 22 is a diagram showing the results of EBSD analysis of the conjugate according to Example 3. FIG. 23 is a diagram showing the results of EBSD analysis of the conjugate according to Comparative Example 2. FIG. 24 is a diagram showing the hardness measurement result of Example 1. FIG. 25 is a diagram showing the hardness measurement result of Example 2. FIG. 26 is a diagram showing the hardness measurement result of Example 3. FIG. 27 is a diagram showing the hardness measurement result of Example 4. FIG. 28 is a diagram showing the hardness measurement result of Comparative Example 1. FIG. 29 is a diagram showing the hardness measurement result of Comparative Example 2. FIG. 30 is a diagram showing the hardness measurement result of Comparative Example 3. FIG. 31 is a diagram showing the hardness measurement results of Comparative Example 4.

Hereinafter, embodiments for carrying out the present invention will be described in detail together with drawings. The present invention is not limited to the following embodiments. In addition, each of the figures referred to in the following description merely schematically shows the shape, size, and positional relationship to the extent that the content of the present invention can be understood. That is, the present invention is not limited to the shape, size, and positional relationship exemplified in each figure.

FIG. 1 is a cross-sectional view showing the structure of a bonded body according to an embodiment of the present invention. FIG. 2 is an enlarged partial cross-sectional view of a part of the joint shown in FIG. The bonded body 1 shown in FIG. 1 includes a base material 10 and a metal film 20 formed on one surface of the base material 10.

The base material 10 is a substantially plate-shaped member made of aluminum or an aluminum alloy containing aluminum as a main component.

The metal film 20 is composed of a powder of a material containing soft pure iron (Fe) as a main component and an essential additive. The essential additive is carbon (C).
Further, the metal film 20 may further contain a selective additive. The selective additive is at least one of copper (Cu), molybdenum (Mo), chromium (Cr), nickel (Ni) and manganese (Mn).
The metal film 20 is formed by spraying powder of a material containing at least the above-mentioned main component by a cold spray method described later.

The surface of the metal film 20 opposite to the base material 10 side is mainly composed of high-density martensite, and the base material 10 side is mainly composed of low-density ferrite. The metal film 20 has multiple layers. Specifically, the metal film 20 is composed of a first hard layer 21, a second hard layer 22, a heat-affected zone 23, and a non-heat-affected zone 24 from the side opposite to the base material 10.

Further, the structure of the metal film 20 is densified by quenching the surface of the film formed by the cold spray method. For the quenching process, for example, a laser is used. The layer densified by the quenching treatment corresponds to the first hard layer 21, the second hard layer 22, and the heat-affected zone 23, and is a hard layer formed by cementite, martensite, and retained austenite. On the other hand, the layer not subjected to the quenching treatment corresponds to the non-heat-affected zone 24 and has a sparse structure composed of a ferrite layer.

The first hard layer 21 is composed of cementite, which is a structure of iron carbide (Fe3C: iron carbide), and martensite, which is a structure of α'iron. The hardness of the first hard layer 21 is Vickers hardness of Hv600 or more.

The second hard layer 22 is composed of martensite, which is a structure of α'iron, and retained austenite, which is a structure in which other elements such as carbon and alloying elements are dissolved in γ-iron. The second hard layer 22 has a Vickers hardness of Hv300 or higher.

The heat-affected zone 23 consists of ferrite, which is a structure of α-iron, martensite, which is a structure of α'iron, and retained austenite, which is a structure in which other elements such as carbon and alloying elements are dissolved in γ-iron. Become. The heat-affected zone 23 has a Vickers hardness of Hv200 or higher.

The non-heat-affected zone 24 is made of ferrite, which is a structure of α-iron. The non-heat-affected zone 24 has a Vickers hardness of Hv80 or higher.

Next, a method for producing the bonded body 1 will be described with reference to FIGS. 3 to 10. FIG. 3 is a flowchart illustrating a method for manufacturing a bonded body according to an embodiment of the present invention. 4 and 5 are views for explaining a method for manufacturing a bonded body according to an embodiment of the present invention. FIG. 6 is a schematic view showing an outline of a cold spray device used for forming a metal film of a bonded body according to an embodiment of the present invention.

First, the above-mentioned base material 10 is prepared (see FIG. 4).
The cold spray device 30 shown in FIG. 6 accelerates the powder of the material for forming the metal film 20 together with the gas on the base material 10, and sprays and deposits the powder on the surface of the base material 10 in a solid state. A pre-heat treatment film 200 is formed (step S101: see FIG. 5).

The cold spray device 30 includes a gas heater 31 for heating the compressed gas, a powder supply device 32 for accommodating the powder of the material for forming the metal film 20, and supplying the powder to the spray gun 33, the heated compressed gas, and the compressed gas. A gas nozzle 34 for injecting the material powder supplied therefor onto the base material, and valves 35 and 36 for adjusting the supply amounts of compressed gas to the gas heater 31 and the powder supply device 32, respectively, are provided.

The material for forming the metal film 20 is a powder containing soft pure iron (Fe), which is the main component of the metal film 20, and the above-mentioned essential additives and selective additives. When the essential additive is applied after film formation, the powder may not contain the essential additive. On the other hand, when the essential additive is not applied after the film formation, the powder contains the essential additive.

7 to 9 are views showing an example of a material powder used for producing a bonded body according to an embodiment of the present invention. Material powders include, for example, base powders, essential additives, and selective additives. The base powder 100 is a powder made of pure iron (see FIG. 7). The essential additive is a powder made of carbon. The selective additive is at least one of copper (Cu), molybdenum (Mo), chromium (Cr), nickel (Ni) and manganese (Mn). Cast iron or high-grade steel may be used as the carbon-containing iron material.

Specifically, the powder material includes a temporary sintered powder or mixed powder containing a base powder and an essential additive, a temporary sintered powder or a mixed powder containing a base powder and a selective additive, a base powder, an essential additive, and the like. Temporarily sintered powder or mixed powder containing selective additives. For example, in the temporarily sintered powder 110 shown in FIG. 8, the essential additive 111 and the selective additives 112 and 113 are fixed to the base powder 100. On the other hand, unlike the mixed powder 120 shown in FIG. 9, the mixed powder does not have the base powder 100, the essential additive 111, and the selective additives 112 and 113 fixed to each other, and can move freely.

As the compressed gas, helium, nitrogen, air and the like are used. The compressed gas supplied to the gas heater 31 is heated to, for example, 50 ° C. or higher and lower than the melting point of the powder of the material for forming the metal film 20, and then supplied to the spray gun 33. Will be done. The heating temperature of the compressed gas is preferably 300 ° C. or higher and 900 ° C. or lower. On the other hand, the compressed gas supplied to the powder supply device 32 supplies the powder in the powder supply device 32 to the spray gun 33 so as to have a predetermined discharge amount.

The heated compressed gas is made into a supersonic flow (about 340 m / s or more) by the gas nozzle 34 having a divergent shape. At this time, the gas pressure of the compressed gas is preferably about 1 to 5 MPa. This is because the adhesion strength of the metal film 20 to the base material 10 can be improved by adjusting the pressure of the compressed gas to this extent. More preferably, the treatment is performed at a pressure of about 5 MPa. The powder of the material supplied to the spray gun 33 is accelerated by the injection of the compressed gas into the supersonic flow, collides with the base material 10 at high speed in the solid state, and is deposited, and the pretreatment film 200 (See FIG. 5). The device is not limited to the cold spray device 30 shown in FIG. 6 as long as it can form a film by colliding the material powder with the base material 10 in a solid state.

The pretreatment film 200 formed by the cold spray apparatus 30 described above contains a main component (iron), an essential additive, and a selective additive. In this pretreatment film 200, the selective additive acts as a sintering aid that assists in hardenability. Therefore, the pretreatment film 200 has a high density and is softer than the metal film 20. The pretreatment film 200 preferably has a Vickers hardness of Hv500 or less, for example.

After forming the pretreatment film 200, the surface is cut to form a desired shape (step S102: pretreatment film surface processing step). At this time, since the pretreatment film is a soft film that is only work-hardened by improving the dislocation density, it can be easily cut. Then, in order to improve the quenching characteristics, carbon is applied to the pretreatment film 200 (step S103: carbon coating step).

Then, the surface of the pretreatment film 200 is quenched by a high frequency or a laser (step S104: quenching treatment step). FIG. 10 is a diagram illustrating a method for manufacturing a bonded body according to an embodiment of the present invention. For example, as shown in FIG. 10, by irradiating the surface of the pretreatment film 200 with laser L and performing quenching treatment, the above-mentioned first hard layer 21, second hard layer 22, heat-affected zone 23, and non-treatment are performed. A metal film 20 composed of a heat-affected zone 24 is formed.
A high frequency may be used instead of the laser.

In the above-described embodiment, the powder of the material for forming the metal film 20 and containing the main component composed of iron, the essential additive composed of carbon, and the selective additive is mixed with the gas. After accelerating, the surface of the base material 10 was sprayed and deposited in a solid state to form a pretreatment film 200, and after surface cutting, the surface of the pretreatment film 200 was heat-treated. According to the above-described embodiment, since the metal film 20 having a hard layer on the surface side is formed on the base material 10 made of aluminum or an aluminum alloy, the bonding has high hardness and is lightweight. Body 1 can be obtained.

Further, according to the above-described embodiment, since the metal film 20 having a hard layer on the surface side and a soft layer on the base material 10 side is formed, the metal film 20 having high toughness can be obtained. Therefore, a metal film 20 having high strength against an external load can be obtained.

Further, according to the above-described embodiment, since the surface processing is performed in the state of the comparative example soft film before the quenching treatment, the shape of the metal film 20 can be easily processed.

In the above-described embodiment, an example of performing the quenching treatment after applying carbon to the pretreatment film has been described, but if the quenching treatment can be performed with the carbon contained in the material powder, the carbon coating step is omitted. You may.

As described above, the present invention may include various embodiments not described here, and make various design changes and the like within a range that does not deviate from the technical idea specified by the claims. It is possible.

Hereinafter, examples of the bonded body according to the present invention will be described. The present invention is not limited to these examples.

(Example 1)
As the base material 10, an aluminum alloy (A6063-T6) having a thickness of 50 mm and a plate thickness of 10 mm was used.
As the powder material for forming the metal film, α-iron (αFe: ABC manufactured by Höganäs) having a particle size of 150 μm, which is a base powder, was used.
This powder material was sprayed onto the base material 10 using the above-mentioned cold spray device to form a pretreatment film, carbon was applied to the pretreatment film after cutting, and quenching treatment was performed by a laser.
In the film forming treatment by the cold spray device, nitrogen was used as the working gas, the gas pressure was 5 MPa, and the gas temperature was 800 ° C.
Then, carbon (essential additive) was applied to the surface of the film formed, and quenching treatment was performed.
For the quenching treatment, a semiconductor laser having an irradiation range of 6 mm (rectangular shape) and an irradiation path of 1 was used as the laser oscillator. The output of the laser was 1250 W, the quenching treatment temperature was 1600 ° C., and the construction speed, which is the moving speed of the laser, was 200 mm / min. Here, the quenching temperature is a target temperature (target temperature) of the temperature of the pretreatment film heated by laser irradiation.
Regarding the metal film after the quenching treatment, each internal layer was confirmed by a cross-sectional image.
The composition of the metal film of Example 1 and the formed layer are shown in Table 1.

(Example 2)
As the powder material for forming the metal film, a metal film was formed in the same manner as in Example 1 except that the above-mentioned base powder plus an essential additive (carbon) and a selective additive was used. As the essential additive, carbon having a particle size of 25 μm (C: UF4 manufactured by Höganäs) was used. As the selective additive, copper having a particle size of 25 μm (Cu: Distaloy ACu manufactured by Höganäs) was used. In the material powder, carbon is adjusted so that the volume content of the final material powder is 2%. Further, copper is adjusted so that the volume content of the final material powder is 2%.
The composition of the metal film of Example 2 and the formed layer are shown in Table 1.

(Example 3)
As the powder material for forming the metal film, a metal film was formed in the same manner as in Example 1 except that the above-mentioned base powder plus an essential additive (carbon) and a selective additive was used. As the essential additive, carbon having a particle size of 25 μm (C: UF4 manufactured by Höganäs) was used. As the selective additive, copper having a particle size of 25 μm (Cu: Distaloy ACu manufactured by Höganäs) was used. In the material powder, carbon is adjusted so that the volume content of the final material powder is 7%. Further, copper is adjusted so that the volume content of the final material powder is 2%.
The composition of the metal film of Example 3 and the formed layer are shown in Table 1.

(Example 4)
As the powder material for forming the metal film, a metal film was formed in the same manner as in Example 1 except that the above-mentioned base powder plus an essential additive and a selective additive was used. As the essential additive, carbon having a particle size of 25 μm (C: UF4 manufactured by Höganäs) was used. As the selective additive, copper having a particle size of 25 μm (Cu: Distaloy ACu manufactured by Höganäs) was used. In the material powder, carbon is adjusted so that the volume content of the final material powder is 12%. Further, copper is adjusted so that the volume content of the final material powder is 2%.
The composition of the metal film of Example 4 and the formed layer are shown in Table 1.

(Comparative Example 1)
A metal film was formed in the same manner as in Example 1 except that the pretreated film after the cutting process was quenched by a laser without applying carbon.
Table 1 shows the composition of the metal film of Comparative Example 1 and the formed layer.

(Comparative Example 2)
As the powder material for forming the metal film, the above-mentioned base powder with essential additives and selective additives added was used, and the pretreated film after cutting was hardened by a laser without applying carbon. A metal film was formed in the same manner as in Example 1 except that the treatment was performed. As the essential additive, carbon having a particle size of 25 μm (C: UF4 manufactured by Höganäs) was used. As the selective additive, copper having a particle size of 25 μm (Cu: Distaloy ACu manufactured by Höganäs) was used. In the material powder, carbon is adjusted so that the volume content of the final material powder is 2%. Further, copper is adjusted so that the volume content of the final material powder is 2%.
Table 1 shows the composition of the metal film of Comparative Example 2 and the formed layer.

(Comparative Example 3)
As the powder material for forming the metal film, the above-mentioned base powder with essential additives and selective additives added was used, and the pretreated film after cutting was hardened by a laser without applying carbon. A metal film was formed in the same manner as in Example 1 except that the treatment was performed. As the essential additive, carbon having a particle size of 25 μm (C: UF4 manufactured by Höganäs) was used. As the selective additive, copper having a particle size of 25 μm (Cu: Distaloy ACu manufactured by Höganäs) was used. In the material powder, carbon is adjusted so that the volume content of the final material powder is 7%. Further, copper is adjusted so that the volume content of the final material powder is 2%.
Table 1 shows the composition of the metal film of Comparative Example 3 and the formed layer.

(Comparative Example 4)
As the powder material for forming the metal film, the above-mentioned base powder with essential additives and selective additives added was used, and the pretreated film after cutting was hardened by a laser without applying carbon. A metal film was formed in the same manner as in Example 1 except that the treatment was performed. As the essential additive, carbon having a particle size of 25 μm (C: UF4 manufactured by Höganäs) was used. As the selective additive, copper having a particle size of 25 μm (Cu: Distaloy ACu manufactured by Höganäs) was used. In the material powder, carbon is adjusted so that the volume content of the final material powder is 12%. Further, copper is adjusted so that the volume content of the final material powder is 2%.
Table 1 shows the composition of the metal film of Comparative Example 4 and the formed layer.

(Comparative Example 5)
A metal film was formed in the same manner as in Example 1 except that the laser output during the quenching treatment was 950 W and the temperature was 1200 ° C.
Table 1 shows the composition of the metal film of Comparative Example 5 and the formed layer.

(Comparative Example 6)
A metal film was formed in the same manner as in Example 1 except that the construction speed during the quenching treatment was set to 40 mm / min.
Table 1 shows the composition of the metal film of Comparative Example 6 and the formed layer.

Subsequently, a cross-sectional image of the joined body produced in each example will be described with reference to FIGS. 11 to 20. FIG. 11 is a diagram showing a cross-sectional image of the first embodiment. FIG. 12 is a diagram showing a cross-sectional image of the second embodiment. FIG. 13 is a diagram showing a cross-sectional image of Example 3. FIG. 14 is a diagram showing a cross-sectional image of Example 4.
Further, FIG. 15 is a diagram showing a cross-sectional image of Comparative Example 1. FIG. 16 is a diagram showing a cross-sectional image of Comparative Example 2. FIG. 17 is a diagram showing a cross-sectional image of Comparative Example 3. FIG. 18 is a diagram showing a cross-sectional image of Comparative Example 4. FIG. 19 is a diagram showing a cross-sectional image of Comparative Example 5. FIG. 20 is a diagram showing a cross-sectional image of Comparative Example 6.

Further, EBSD (Electron Back Scatter Diffraction) analysis of the surface layer of the metal film was performed on Example 1, Example 3 and Comparative Example 2. The EBSD analysis results are shown in FIGS. 21 to 23. FIG. 21 is a diagram showing the results of EBSD analysis of the conjugate according to Example 1. FIG. 22 is a diagram showing the results of EBSD analysis of the conjugate according to Example 3. FIG. 23 is a diagram showing the results of EBSD analysis of the conjugate according to Comparative Example 2. In FIGS. 21 to 23, α iron (Iron-Alpha), γ iron (Iron-Gamma), iron carbide (Iron-Carbide), and graphite (Graphite) are displayed as components with different hatching densities.

From FIGS. 11 to 14, 21 and 22, it can be seen that the first hard layer 211, the second hard layer 212, and the heat-affected zone 213 are formed in the joints according to Examples 1 to 4. In addition, in FIGS. 11 and 12, it can be confirmed that the non-heat-affected zone 214 is formed.

On the other hand, from FIGS. 15 to 20 and 23, the modified examples 1 to 6 show a joint in which the first hard layer 211, the second hard layer 212, and the heat-affected zone 213 are not formed, and the heat-affected zone 213. It can be seen that the bonded body is formed only.

Next, the hardness of Examples 1 to 4 and Comparative Examples 1 to 4 was measured (Micro Vickers hardness test: Hv0.025). The results of the hardness measurement are shown in FIGS. 24 to 31 and Table 2. FIG. 24 is a diagram showing the hardness measurement result of Example 1. FIG. 25 is a diagram showing the hardness measurement result of Example 2. FIG. 26 is a diagram showing the hardness measurement result of Example 3. FIG. 27 is a diagram showing the hardness measurement result of Example 4. Further, FIG. 28 is a diagram showing the hardness measurement result of Comparative Example 1. FIG. 29 is a diagram showing the hardness measurement result of Comparative Example 2. FIG. 30 is a diagram showing the hardness measurement result of Comparative Example 3. FIG. 31 is a diagram showing the hardness measurement results of Comparative Example 4. In FIGS. 24 to 31, cross-sectional images of each embodiment are displayed in association with the depth from the surface of the metal film.

From Table 2 and FIGS. 24 to 31, the first hard layer forming the surface of Examples 1 to 4 has a hardness of Hv600 or more, whereas in Comparative Examples 1 to 4, the heat-affected zone and the non-heat-affected zone are It can be seen that the surface is formed and the hardness is less than Hv600. From this result, it can be seen that Examples 1 to 4 have higher hardness than Comparative Examples 1 to 4.

As described above, the bonded body and the method for producing the bonded body according to the present invention are suitable for obtaining a bonded body having high strength and hardness and being lightweight.

1 Bonded body 10 Base material 20 Metal film 21 1st hard layer 22 2nd hard layer 23 Heat-affected zone 24 Non-heat-affected zone 30 Cold spray device 31 Gas heater 32 Powder supply device 33 Spray gun 34 Gas nozzle 35, 36 Valve 200 Pretreatment film

Claims (5)

A base material mainly composed of aluminum or an aluminum alloy,
A metal film containing iron as a main component and carbon as an essential additive, which is laminated on the base material and bonded to the base material.
With
The metal film is
A first hard layer composed of cementite and martensite, which forms a surface opposite to the base material side,
A heat-affected zone having a hardness lower than that of the first hard layer and composed of ferrite, martensite and retained austenite.
A second hard layer provided between the first hard layer and the heat-affected zone and composed of martensite and retained austenite,
A conjugate characterized by having. The first hard layer has a Vickers hardness of Hv600 or more.
The bonded body according to claim 1, wherein the heat-affected zone has a Vickers hardness of Hv200 or more and Hv400 or less. The bonded body according to claim 1, wherein the metal film further contains a selective additive having at least one of copper, molybdenum, chromium, nickel and manganese. A method for manufacturing a bonded body in which a film formed by using a material powder is laminated on the surface of a base material containing aluminum or an aluminum alloy as a main component.
A pretreatment film forming step of accelerating the material powder containing iron as a main component together with gas and spraying it on the surface of the base material in a solid state to form a pretreatment film on the surface of the base material.
The coating process of applying carbon to the surface of the pretreatment film and
A film forming step of forming a metal film by quenching the surface of the pretreated film coated with carbon.
A method for producing a bonded body, which comprises. The method for producing a bonded body according to claim 4, wherein the pretreatment film forming step is spraying the material powder containing the iron as a main component and carbon as an essential additive onto the surface of the base material.