Graphene film conformal deposition method and device for metal 3D printing

Abstract

The application discloses a graphene film conformal deposition method for metal 3D printing, comprising the following steps: forming a solution droplet containing metal particles on a support table by spraying, evaporating the liquid phase by heating the support table, sintering the metal particles to form a metal layer; forming active carbon gas by catalytic cracking of carbon source-containing gas, spraying the active carbon gas on the surface of the metal layer; alternately and repeatedly spraying the droplet containing metal particles and the active carbon gas. The graphene film deposition method can form a graphene layer and a metal layer alternately, increase the strength and flexibility of the construction, and has better heat conductivity. The active carbon gas after catalytic cracking is high-temperature mixed gas, the high temperature carried by the active carbon gas can increase the evaporation of the metal solvent, improve the printing efficiency, the graphene film can prevent the oxidation of the metal, and the selectivity of the metal printing raw material is wider.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and more specifically to a method and apparatus for conformal deposition of graphene thin films in metal 3D printing. Background Technology

[0002] NPJ (Nano Particle Jetting) is a metal 3D printing process that includes multiple steps such as metal particle refinement, metal particle distribution in droplets, droplet jetting, liquid phase ejection, and sintering. Compared with ordinary laser 3D printing, it uses nano-liquid metal and deposits it in an inkjet manner. The printing speed is 5 times faster than ordinary laser printing, and it has excellent precision and surface roughness. Therefore, it has high application in aerospace, automotive, medical, dental and other fields.

[0003] However, this printing method utilizes the process of heating to evaporate the solvent and then removing the liquid phase, which limits the availability of raw materials that can be used for this printing method. Furthermore, since sintered metals are prone to oxidation, a common solution is to spray antioxidants onto their surface. However, antioxidants can cause incompatibility with the human body, reducing their application potential in fields such as medicine and dentistry. Therefore, the main raw materials currently available are only 316L stainless steel and two ceramic materials: zirconium oxide and alumina. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention proposes a method and apparatus for conformal deposition of graphene films in metal 3D printing, which can deposit graphene films on the metal surface while printing metal.

[0005] To achieve the above objectives, the present invention provides a method for conformal deposition of graphene films in metal 3D printing, comprising the following steps:

[0006] The solution containing dissolved metal particles is sprayed onto a stage to form droplets. The stage is heated to evaporate and discharge the liquid phase, and the metal particles are sintered to form a metal layer.

[0007] The carbon-containing gas is catalytically cracked to form activated carbon gas, which is then sprayed onto the surface of the metal layer.

[0008] Droplets containing metal particles and activated carbon gas are sprayed alternately and repeatedly.

[0009] Furthermore, the stage is heated to 300°C to evaporate the liquid, and the metal particles are sintered at low temperature.

[0010] Furthermore, the metal is copper, and the copper layer formed by a single sintering is less than 2 μm.

[0011] Furthermore, the carbon source gas is CH4, which is transported through a heated nickel tube, causing the internal CH4 to decompose into activated carbon gas.

[0012] The beneficial effects of the above-mentioned method for conformal deposition of graphene film in metal 3D printing are: (1) The graphene film is deposited at the moment the metal is discharged from the liquid phase, which can form a thin metal layer and a graphene layer, which not only increases the strength of the construction, but also increases the flexibility. In addition, graphene has thermal conductivity that is dozens of times that of metal, which is more conducive to the construction effect of 3D molding.

[0013] (2) The activated carbon gas after catalytic cracking is also a high-temperature mixed gas. The high temperature it carries can increase the evaporation of metal solvents and improve printing efficiency.

[0014] (3) The graphene film coating can prevent metal oxidation, making the selection of metal printing materials wider. Some easily oxidized metals, such as copper and iron, can also be used for 3D printing. In addition, graphene film has high inertness and can achieve better compatibility with the human body, making it suitable for medical and other fields.

[0015] (4) The thickness of the copper layer in 3D printing can be less than 2μm. Graphene can be directly formed on the copper layer. Compared with the existing technology of super copper which grows graphene film on the thinnest commercial 4.5μm copper foil and then laminates it, it has a lower thickness, thus obtaining a higher graphene content. Moreover, it can be formed in one piece without lamination.

[0016] A conformal deposition apparatus for graphene films in metal 3D printing includes a reaction vessel, a stage, a metal printing device, a gas injection pipe, and a catalyst tube;

[0017] The reaction vessel is a closed container with an air inlet and an air outlet. The stage, metal printing equipment and jet pipe are all installed inside the reaction vessel. The metal printing equipment and jet pipe are both oriented towards the stage. The jet pipe is connected to the catalytic tube through the air inlet. The catalytic tube is connected to the gas source and has a heating zone on its exterior.

[0018] Furthermore, the catalytic tube is spiral-shaped.

[0019] Furthermore, the catalytic tube is a nickel tube, and the heating temperature of the heating zone is 25-1050℃.

[0020] Furthermore, a water-cooling zone is provided outside the heating zone.

[0021] Furthermore, the reaction vessel is also provided with a second inlet for introducing a protective gas, wherein the protective gas is Ar.

[0022] In the metal printing equipment, inkjet nozzles spray droplets containing metal particles onto a stage. Upon contact with the heated stage, the liquid evaporates, leaving the remaining metal particles that adhere together. Carbon-source gas enters the reaction vessel through a catalytic tube, where it is catalytically decomposed. The resulting activated carbon gas is then sprayed onto the surface of the metal layer, depositing to form a graphene film. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of the present invention, the accompanying drawings used in the specific embodiments will be briefly described below. In all the drawings, the elements or parts are not necessarily drawn to scale.

[0024] Figure 1 This is a schematic flowchart of a method for conformal deposition of graphene thin films in metal 3D printing, provided by an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of a conformal deposition apparatus for graphene thin films in metal 3D printing, provided in an embodiment of the present invention.

[0026] Figure 3 This is a schematic diagram of the metal and graphene structures obtained by a conformal deposition apparatus and method for metal 3D printing according to an embodiment of the present invention.

[0027] Figure label:

[0028] 1-Reaction vessel, 11-Gas inlet, 12-Second gas inlet, 13-Gas outlet, 2-Stage, 3-Metal printing equipment, 4-Injection pipe, 5-Catalyst pipe, 51-Heating zone, 52-Water cooling zone, 6-Gas source, 7-Protective gas. Detailed Implementation

[0029] The embodiments of the technical solution of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the technical solution of the present invention and are therefore intended to limit the scope of protection of the present invention.

[0030] This invention provides a method and apparatus for conformal deposition of graphene films in metal 3D printing, which can deposit graphene films on the surface of metal layers while printing metal.

[0031] Specifically, such as Figure 1 As shown, the steps of the method are as follows:

[0032] The solution containing dissolved metal particles is sprayed onto a stage to form droplets. The stage is heated to evaporate and discharge the liquid phase, and the metal particles are sintered to form a metal layer.

[0033] The carbon-containing gas is catalytically cracked to form activated carbon gas, which is then sprayed onto the surface of the metal layer.

[0034] Droplets containing metal particles and activated carbon gas are sprayed alternately and repeatedly.

[0035] Specifically, the stage is heated to 300°C. When the solution containing metal particles comes into contact with the stage, the liquid phase is evaporated, and the remaining metal particles are sintered under the action of heat.

[0036] Specifically, copper is used as the metal, and the copper layer formed in a single sintering process is less than 2μm. The carbon source gas is CH4, which is transported through a heated nickel tube to decompose the internal CH4 into activated carbon gas, thereby directly forming a graphene film on the 3D printed copper layer.

[0037] Specifically, such as Figure 2 As shown, the device includes a reaction vessel, a stage, a metal printing device, a gas injection pipe, and a catalytic tube. The reaction vessel is a closed container with an inlet and a second inlet on one side for inputting activated carbon gas and protective gas, and an outlet on the opposite side for exhausting gas. The stage, the metal printing device, and the injection pipe are all located inside the reaction vessel. The inkjet nozzle and the injection pipe of the metal printing device are both oriented towards the stage. The injection pipe is connected to the catalytic tube through the inlet, and the catalytic tube is connected to a gas source and has an external heating zone.

[0038] Furthermore, the catalytic tube is spiral-shaped and made of nickel. The heating temperature of the heating zone is 25-1050℃, and an external water-cooling zone is provided. The spiral shape of the tube increases the travel within the heating zone, allowing the gas to undergo sufficient catalytic cracking. Since the heating temperature of the nickel tube can reach 1000℃, an external water-cooling zone is required for cooling.

[0039] The process of preparing graphene films using the above method and apparatus is as follows: The stage is heated to 300°C. Solvent droplets containing copper particles are sprayed from the inkjet nozzle of the metal printing equipment and deposited onto the stage. Upon contact with the stage, the liquid phase evaporates, and the remaining copper particles bond together to form a copper layer with a thickness of less than 2 μm. A protective gas, Ar, is injected into the reaction vessel. CH4, upon passing through a nickel tube heated to 1000°C, is decomposed into activated carbon: CH4 → C + 4H, and then sprayed through the nozzle onto the surface of the copper layer, directly forming a graphene film. The alternating spraying of metal solvent and gas allows for the formation of... Figure 3 The diagram shows a structure consisting of one metal layer and one graphene film layer.

[0040] Using the above-mentioned method and apparatus for conformal deposition of graphene film in metal 3D printing, the following effects can be achieved: (1) The metal deposits graphene film at the moment of liquid phase discharge and alternately sprays it to form a structure of one thin metal layer and one thin graphene layer, which not only increases the strength of the construction, but also increases the flexibility. In addition, graphene has thermal conductivity that is dozens of times that of metal, which is more conducive to the construction effect of 3D molding.

[0041] (2) The activated carbon gas after high-temperature catalytic cracking of nickel tube is also a high-temperature mixed gas. The high temperature it carries can increase the evaporation of metal solvent and improve printing efficiency by 50%.

[0042] (3) The graphene film coating can prevent metal oxidation, making the selection of metal printing materials wider. Some easily oxidized metals, such as copper and iron, can also be used for 3D printing. In addition, graphene film has high inertness and can be better adapted to the human body, making it suitable for medical and other fields.

[0043] (4) The preparation of super copper in the prior art involves growing a graphene film on a copper foil and then laminating it. The thinnest copper foil currently available is 4.5 μm. However, the copper layer thickness obtained by 3D printing using the NPJ process of this method can be less than 2 μm. Therefore, the graphene content of the obtained super copper is twice that of the prior art. Furthermore, graphene is directly integrally formed on the copper layer without the need for lamination, which opens up more application scenarios.

[0044] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A method for conformal deposition of graphene thin films in metal 3D printing, characterized in that: Includes the following steps: The solution containing dissolved metal particles is sprayed onto a stage to form droplets. The stage is heated to evaporate and discharge the liquid phase, and the metal particles are sintered to form a metal layer. The carbon-containing gas is catalytically cracked to form activated carbon gas, which is then sprayed onto the surface of the metal layer. Droplets containing metal particles and activated carbon gas are sprayed alternately and repeatedly; The stage is heated to 300°C to evaporate the liquid and sinter the metal particles at low temperature. The metal is copper, and the copper layer formed by a single sintering is less than 2 µm. The carbon source gas is CH4, which is transported through a heated nickel tube, causing the internal CH4 to decompose into activated carbon gas.

2. A conformal deposition apparatus for graphene thin films in metal 3D printing, used in the method of claim 1, characterized in that: This includes a reaction vessel, a stage, a metal printing device, a gas injection pipe, and a catalyst tube; The reaction vessel is a closed container with an air inlet and an air outlet. The stage, metal printing equipment and jet pipe are all installed inside the reaction vessel. The metal printing equipment and jet pipe are both oriented towards the stage. The jet pipe is connected to the catalytic tube through the air inlet. The catalytic tube is connected to the gas source and has a heating zone on its exterior.

3. The conformal deposition apparatus for graphene thin films in metal 3D printing according to claim 2, characterized in that: The catalytic tube is spiral-shaped.

4. The conformal deposition apparatus for graphene thin films in metal 3D printing according to claim 2, characterized in that: The catalyst tube is a nickel tube, and the heating temperature of the heating zone is 25-1050℃.

5. The conformal deposition apparatus for graphene thin films in metal 3D printing according to claim 4, characterized in that: A water-cooling zone is provided outside the heating zone.

6. The conformal deposition apparatus for graphene thin films in metal 3D printing according to claim 4, characterized in that: The reaction vessel is also provided with a second inlet for introducing a protective gas, which is Ar.

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