Control method for C-Al interface reaction of SLM graphene reinforced aluminum matrix composite

Abstract

The invention provides a control method for a C-Al interface reaction of an SLM graphene reinforced aluminum-based composite material. The composite material comprises graphene and an Al-Cu alloy. The total volume of the composite material is taken as a reference, the content of the graphene reinforcement is 0.01 vol.% to 10.00 vol.%, the total content of the Al-Cu alloy matrix is 90.00 vol.% to 99.99 vol.%, the content of Al is 79.00 vol.% to 99.79 vol.%, and the content of Cu is 0.20 vol.% to 11.00 vol.%. According to the preparation method of the graphene reinforced aluminum-based composite material, the graphene is dispersed in cold welding Cu particles through wet stirring in combination with mechanical ball milling, direct contact between the graphene and Al is effectively avoided, generation of an Al4C3 hard and brittle phase through a C-Al interface reaction in the SLM process is avoided, and a Al2Cu intermetallic compound is generated through a reaction between Cu and Al, so that the graphene reinforced aluminum-based composite material is prepared. Therefore, the problem of poor wettability of a C-Al interface is improved.

Description

Technical Field

[0001] This invention relates to the field of manufacturing graphene-reinforced aluminum matrix composites, and more specifically to a method for controlling the C-Al interface reaction of SLM graphene-reinforced aluminum matrix composites. Background Technology

[0002] Graphene, as a novel reinforcement for aluminum-based composites, boasts ultra-high mechanical properties (elastic modulus up to 1100 GPa and tensile strength up to 130 GPa). Theoretically, it can achieve a super-reinforcing effect of "small addition, significant modification," potentially surpassing the reinforcement effects of traditional fiber and particulate reinforcements. However, the poor wettability of graphene at the Al interface often results in weak graphene-Al bonding interfaces, and may even trigger interfacial reactions to form the hard and brittle A4C3 phase. This severely hinders its widespread application in aerospace and other fields, becoming a primary bottleneck problem that urgently needs to be solved.

[0003] To address the poor wettability between graphene nanosheets and aluminum, the patent "A Method for Improving the Interfacial Wettability between Graphene and Pure Aluminum (Application No.: 2017106304663, Application Date: July 28, 2017; Publication No.: CN107538016A, Publication Date: January 5, 2018)" utilizes a salt template method and tube furnace annealing to prepare a graphene hybrid composite material. Copper nanoparticles loaded on graphene react with the aluminum matrix to generate the intermetallic compound Al₂Cu, thereby improving the non-wetting condition between aluminum and carbon during composite material preparation, enhancing interfacial bonding, and controlling the formation of the hard and brittle Al₄C₃ phase at the C-Al interface. However, this method has drawbacks: complex process, high cost, poor mass production feasibility, and the risk of graphene damage during grinding. Uneven distribution of copper particles can lead to localized Al₂Cu phase segregation, making it difficult to completely suppress Al₄C₃ formation.

[0004] The patent "A method for preparing graphene-reinforced aluminum matrix composite material with strong interfacial bonding strength (Application No.: 2020101302199, Application Date: February 28, 2020; Publication No.: CN111321314A, Publication Date: June 23, 2020)" utilizes a coherent interface with covalent bonds between graphene and an aluminum matrix to improve the reinforcing efficiency of graphene. Under high current density, graphene ionizes, and partially ionized graphene bonds with aluminum, forming a structure with periodically and regularly arranged Al and C atoms in a specific orientation, while avoiding the formation of Al4C3, thus improving the interfacial bonding force. The disadvantages of this method are that the preparation process of graphene ionization and the coherent interface under high current density is complex, costly, and has poor mass production feasibility. Furthermore, it has poor compatibility with subsequent thermal processing, and quality control and testing costs are high. Summary of the Invention

[0005] To address the problems in the prior art, the purpose of this invention is to provide a method for controlling the C-Al interface reaction in SLM graphene-reinforced aluminum matrix composites. By introducing copper foil, the contact between the Al and graphene interfaces during the composite material preparation process is avoided, thereby controlling the C-Al interface reaction, reducing the formation of the Al4C3 hard and brittle phase, and simultaneously generating the Al2Cu phase to improve the wettability of the C-Al interface, thus optimizing the microstructure of the composite material and improving its mechanical properties.

[0006] Unlike existing technologies such as chemical vapor deposition and vacuum arc melting, this application addresses the issue of easy reaction at the C-Al interface in SLM graphene-reinforced aluminum matrix composites. It employs a wet stirring combined with mechanical ball milling to disperse graphene within Cu particles, avoiding direct contact between graphene and Al and improving the poor wettability between them. Simultaneously, it prevents the formation of the hard and brittle Al4C3 phase through an interfacial reaction between graphene and Al at high temperatures. This invention develops a simple and effective method for uniformly dispersing GNPs and avoiding the formation of the hard and brittle Al4C3 phase through C-Al interfacial reaction, providing significant guidance for the preparation of graphene-reinforced aluminum matrix composites.

[0007] To achieve this objective, the present invention adopts the following technical solution: A method for controlling the C-Al interface reaction of SLM graphene-reinforced aluminum matrix composites is proposed. The method involves wrapping graphene powder with Cu foil to avoid direct contact between graphene and Al during the SLM process, thereby controlling the C-Al interface reaction to generate the Al4C3 hard and brittle phase. The specific steps of the method of encapsulating graphene powder with Cu foil are as follows: (1) Wet stirring of graphene-Cu foil: Cu foil and graphene are mechanically stirred in an alcohol solvent while being heated in a water bath until graphene is distributed on the surface of Cu foil. After drying, Cu foil with graphene attached is prepared. (2) Mechanical ball milling of graphene-Cu foil: The graphene-attached Cu foil is ball milled until the graphene is wrapped inside the cold-welded copper foil particles to prepare graphene-copper powder. (3) Mechanical ball milling of graphene-AlCu composite powder: The graphene-Cu powder and Al powder obtained in step (2) are ball milled into small spherical shapes to prepare uniformly dispersed graphene-AlCu composite powder. (4) SLM preparation of graphene-reinforced aluminum matrix composites: graphene-AlCu composite powder was subjected to SLM forming process to finally obtain graphene-reinforced aluminum matrix composite bulk material; Based on the total volume of the graphene-reinforced aluminum matrix composite material, the graphene reinforcement content is 0.01 vol.% to 10.00 vol.%, the total content of the Al-Cu alloy matrix is ​​90 vol.% to 99.99 vol.%, of which the Al content is 79.00 vol.% to 99.79 vol.% and the Cu content is 0.20 vol.% to 11.00 vol.%.

[0008] Furthermore, in the above-mentioned method for controlling the C-Al interface reaction of SLM graphene-reinforced aluminum matrix composite material, the graphene reinforcement content is 0.2 vol.%, the total content of Al-Cu alloy matrix is ​​99.8 vol.%, the Al content is 94.80 vol.%, and the Cu content is 5.00 vol.%.

[0009] Furthermore, in the above-mentioned method for controlling the C-Al interface reaction of SLM graphene-reinforced aluminum matrix composite material, the mechanical stirring process parameters in step (1) are: stirring speed 200 rpm / min~2000 rpm / min, heating temperature 50℃~100℃, stirring time 1h~10h; drying temperature 100℃~200℃, drying time 1h~20h; preferably, stirring speed 1000 rpm / min, heating temperature 80℃, stirring time 10h; drying temperature 200℃, drying time 5h.

[0010] Furthermore, in the above-mentioned method for controlling the C-Al interface reaction of SLM graphene-reinforced aluminum matrix composite material, the process parameters of high-energy ball milling in step (2) are: ball-to-material ratio of 10:1 to 20:1, ball milling speed of 200 rpm / min to 500 rpm / min, and ball milling on a planetary ball mill for 1 to 10 hours, so that the graphene is finally encapsulated inside the cold-welded copper particles; preferably, the ball-to-material ratio is 15:1, the ball milling speed is 300 rpm / min, and ball milling on a planetary ball mill for 8 hours.

[0011] Furthermore, in the above-mentioned method for controlling the C-Al interface reaction of SLM graphene-reinforced aluminum matrix composite material, the process parameters of the high-energy ball milling in step (3) are a ball-to-material ratio of 10:1 to 20:1, a ball milling speed of 200 rpm / min to 500 rpm / min, and ball milling on a planetary ball mill for 1 h to 10 h. The high-energy ball milling causes the alloy powder to undergo mechanical alloying, thereby preparing a uniformly distributed graphene-AlCu composite powder; preferably, the ball-to-material ratio is 15:1, the ball milling speed is 400 rpm / min, and ball milling on a planetary ball mill for 10 h.

[0012] Furthermore, in the above-mentioned method for controlling the C-Al interface reaction of SLM graphene-reinforced aluminum matrix composite material, the process parameters of SLM in step (4) are: laser power P = 50W~500W, scanning speed V = 100mm / s~2000mm / s, powder layer thickness hs = 10μm~500μm, and scanning spacing l = 50μm~500μm, so as to finally obtain a graphene / aluminum matrix composite material bulk. Preferably, the laser power P = 300W, scanning speed V = 150mm / s, powder layer thickness hs = 100μm, and scanning spacing l = 80μm, so as to finally obtain a graphene / aluminum matrix composite material bulk.

[0013] The advantages and beneficial effects of this invention are: (1) Wet stirring is used to disperse graphene on the surface of Cu foil, which can both disperse graphene and avoid serious damage to the graphene structure. (2) High-energy ball milling is used to disperse graphene inside cold-welded Cu particles, which avoids direct contact between graphene and Al and prevents the C-Al interface from reacting during SLM preparation. At the same time, it reduces the density difference between graphene and Al powder, which is beneficial to uniformly disperse graphene. (3) The wettability between graphene and Al is poor. The problem of poor wettability between graphene and Al can be improved by using Cu coated with graphene to react with Al to generate intermetallic compounds. Attached Figure Description

[0014] Figure 1 The surface morphology of the graphene@copper foil prepared by mixing graphene and Cu foil using a wet stirring method is shown in the image. Figure 2 To disperse graphene inside cold-welded copper particles using high-energy ball milling, the morphology of the cold-welded Cu particles is shown. Figure 3 To prepare graphene-AlCu composite powder morphology by uniformly mixing graphene-Cu powder and Al powder using high-energy ball milling; Figure 4 This is a surface scanning analysis image of graphene-AlCu composite powder. Figure 5 To obtain a block diagram of graphene-reinforced aluminum matrix composite material by performing SLM treatment on graphene-AlCu composite powder; Figure 6 Microstructure of graphene-reinforced aluminum matrix composite material; Figure 7 This is the XRD pattern of graphene-reinforced aluminum composite material. Detailed Implementation

[0015] The following embodiments are a further detailed description of the present invention. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0016] Example 1 This embodiment describes a method for controlling the C-Al interface reaction in SLM graphene-reinforced aluminum matrix composites, specifically including the following steps: (1) Wet stirring of graphene-Cu foil: 5.00 vol.% Cu foil and 0.01 vol.% graphene were mechanically stirred in an alcohol solvent at a stirring speed of 200 rpm / min, a heating temperature of 50℃ and a stirring time of 1 h, until the graphene was distributed on the surface of the Cu foil; the drying temperature was 100℃ and the drying time was 1 h to prepare a Cu foil with graphene attached. (2) Mechanical ball milling of graphene-Cu foil: The Cu foil with graphene attached is ball milled at a ball-to-material ratio of 10:1 and a ball milling speed of 200 rpm / min on a planetary ball mill for 1 hour, so that the graphene is finally wrapped inside the cold-welded copper particles.

[0017] (3) Mechanical ball milling of graphene-AlCu composite powder: Graphene-Cu powder and 94.99 vol.% Al powder were ball milled at a ball-to-powder ratio of 10:1 and a ball milling speed of 200 rpm / min on a planetary ball mill for 1 h. The ball milling process caused mechanical alloying of the alloy powder, thereby preparing a uniformly distributed graphene-AlCu composite powder.

[0018] (4) SLM preparation of graphene-reinforced aluminum-based composite material: graphene-AlCu composite powder was subjected to SLM forming treatment with laser power P=50W, scanning speed V=100mm / s, powder layer thickness hs=10μm, and scanning spacing l=50μm to finally obtain graphene / aluminum-based composite material bulk.

[0019] The graphene in the prepared composite material is uniformly dispersed, and no hard and brittle Al4C3 phase is formed.

[0020] Example 2 This embodiment describes a method for controlling the C-Al interface reaction in SLM graphene-reinforced aluminum matrix composites, specifically including the following steps: (1) Wet stirring of graphene-Cu foil: 5.0 vol.% Cu foil and 0.2 vol.% graphene were mechanically stirred in an alcohol solvent at a stirring speed of 1000 rpm / min, a heating temperature of 80℃, and a stirring time of 10 h, until graphene was distributed on the surface of the Cu foil; the drying temperature was 200℃ and the drying time was 5 h, to prepare a graphene-attached Cu foil. Figure 1 As can be seen, graphene is uniformly distributed on the Cu surface, with no obvious agglomeration.

[0021] (2) Mechanical ball milling of graphene-Cu foil: The Cu foil with graphene attached is ball milled in a high-energy ball mill with a ball-to-material ratio of 15:1 and a ball milling speed of 300 rpm / min for 8 hours on a planetary ball mill, so that the graphene is finally wrapped inside the cold-welded copper particles. Figure 2 The cold-welded Cu particle sheets encapsulate graphene, effectively preventing direct contact between graphene and Al.

[0022] (3) Mechanical ball milling of graphene-AlCu composite powder: Graphene-Cu powder and 94.8 vol.% Al powder were ball-milled at a ball-to-powder ratio of 15:1 and a milling speed of 400 rpm / min on a planetary ball mill for 10 h. Ball milling caused mechanical alloying of the alloy powder, thereby preparing uniformly distributed graphene-AlCu composite powder. Figure 3 The results show that the ball-milled graphene-AlCu particles are uniform in size and spherical in shape, which is beneficial for subsequent SLM forming. Furthermore, surface scanning analysis of the composite powder reveals... Figure 4 As shown, the Cu particles encapsulating the graphene are uniformly distributed on the surface of the Al particles, wherein... Figure 4 Image a shows the morphology of the graphene-AlCu composite powder; the particles are spherical. Surface scan analysis reveals the elemental distributions of Al and Cu as shown below. Figure 4 As shown in b and 4c, Cu is uniformly adhered to the surface of the Al particles. Its compositional analysis is shown in the energy dispersive spectroscopy (EDS) results. Figure 4 As shown in d, no other impurity elements are present except for Al and Cu.

[0023] (4) SLM preparation of graphene-reinforced aluminum-based composite material: Graphene-AlCu composite powder was subjected to SLM forming treatment. The laser power P=300W, the scanning speed V=150mm / s, the powder layer thickness hs=100μm, and the scanning spacing l=80μm to finally obtain a graphene / aluminum-based composite material bulk. Figure 5 As shown in the figure, the macroscopic morphology of the sample indicates that the sample prepared by SLM is of good quality and has no obvious defects.

[0024] Finally, the distribution of graphene in the composite material was characterized and analyzed. Figure 6 As can be seen, graphene is uniformly distributed in the Cu matrix without obvious agglomeration. Furthermore, XRD phase analysis was performed on the composite material. Figure 7 The presence of obvious Al, C, and Al2Cu peaks, with no Al4C3 peak detected, indicates that the present invention effectively controls the C-Al interface reaction to generate the Al4C3 hard and brittle phase.

[0025] The graphene in the prepared composite material is uniformly dispersed, and no hard and brittle Al4C3 phase is formed.

[0026] Example 3 This embodiment describes a method for controlling the C-Al interface reaction in SLM graphene-reinforced aluminum matrix composites, specifically including the following steps: (1) Wet stirring of graphene-Cu foil: 0.2 vol.% Cu foil and 0.01 vol.% graphene were mechanically stirred in an alcohol solvent at a stirring speed of 2000 rpm / min, a heating temperature of 100℃ and a stirring time of 10 h, until the graphene was distributed on the surface of the Cu foil; the drying temperature was 200℃ and the drying time was 20 h to prepare a Cu foil with graphene attached. (2) Mechanical ball milling of graphene-Cu foil: The Cu foil with graphene attached is ball milled at a ball-to-material ratio of 20:1 and a ball milling speed of 500 rpm / min on a planetary ball mill for 10 hours, so that the graphene is finally wrapped inside the cold-welded copper particles.

[0027] (3) Mechanical ball milling of graphene-AlCu composite powder: Graphene-Cu powder and 99.79 vol.% Al powder were ball milled at a ball-to-powder ratio of 20:1 and a ball milling speed of 500 rpm / min on a planetary ball mill for 10 h. The high-energy ball milling caused mechanical alloying of the alloy powder, thereby preparing a uniformly distributed graphene-AlCu composite powder.

[0028] (4) SLM preparation of graphene-reinforced aluminum-based composite material: graphene-AlCu composite powder was subjected to SLM forming treatment with laser power P=500W, scanning speed V=2000mm / s, powder layer thickness hs=500μm, and scanning spacing l=500μm to finally obtain graphene / aluminum-based composite material bulk.

[0029] The graphene in the prepared composite material is uniformly dispersed, and no hard and brittle Al4C3 phase is formed.

[0030] Example 4 This embodiment describes a method for controlling the C-Al interface reaction in SLM graphene-reinforced aluminum matrix composites, specifically including the following steps: (1) Wet stirring of graphene-Cu foil: 11.0 vol.% Cu foil and 10.0 vol.% graphene were mechanically stirred in an alcohol solvent at a stirring speed of 1000 rpm / min, a heating temperature of 80℃ and a stirring time of 10 h, until the graphene was distributed on the surface of the Cu foil; the drying temperature was 200℃ and the drying time was 5 h to prepare a Cu foil with graphene attached. (2) Mechanical ball milling of graphene-Cu foil: The Cu foil with graphene attached is ball milled at a ball-to-material ratio of 15:1 and a ball milling speed of 300 rpm / min on a planetary ball mill for 8 hours, so that the graphene is finally wrapped inside the cold-welded copper particles.

[0031] (3) Mechanical ball milling of graphene-AlCu composite powder: Graphene-Cu powder and 79.0 vol.% Al powder were ball milled at a ball-to-powder ratio of 15:1 and a ball milling speed of 400 rpm / min on a planetary ball mill for 10 h. The ball milling process caused mechanical alloying of the alloy powder, thereby preparing a uniformly distributed graphene-AlCu composite powder.

[0032] (4) SLM preparation of graphene-reinforced aluminum-based composite material: graphene-AlCu composite powder was subjected to SLM forming treatment with laser power P=300W, scanning speed V=150mm / s, powder layer thickness hs=100μm, and scanning spacing l=80μm to finally obtain graphene / aluminum-based composite material bulk.

[0033] The graphene in the prepared composite material is uniformly dispersed, and no hard and brittle Al4C3 phase is formed.

[0034] Example 5 This embodiment describes a method for controlling the C-Al interface reaction in SLM graphene-reinforced aluminum matrix composites, specifically including the following steps: (1) Wet stirring of graphene-Cu foil: 11.0 vol.% Cu foil and 0.01 vol.% graphene were mechanically stirred in an alcohol solvent at a stirring speed of 1000 rpm / min, a heating temperature of 80℃ and a stirring time of 10 h, until the graphene was distributed on the surface of the Cu foil; the drying temperature was 200℃ and the drying time was 5 h to prepare a Cu foil with graphene attached. (2) Mechanical ball milling of graphene-Cu foil: The Cu foil with graphene attached is ball milled at a ball-to-material ratio of 15:1 and a ball milling speed of 300 rpm / min on a planetary ball mill for 8 hours, so that the graphene is finally wrapped inside the cold-welded copper particles.

[0035] (3) Mechanical ball milling of graphene-AlCu composite powder: Graphene-Cu powder and 88.99 vol.% Al powder were ball milled at a ball-to-powder ratio of 15:1 and a ball milling speed of 400 rpm / min on a planetary ball mill for 10 h. The ball milling process caused mechanical alloying of the alloy powder, thereby preparing a uniformly distributed graphene-AlCu composite powder.

[0036] (4) SLM preparation of graphene-reinforced aluminum-based composite material: graphene-AlCu composite powder was subjected to SLM forming treatment with laser power P=300W, scanning speed V=150mm / s, powder layer thickness hs=100μm, and scanning spacing l=80μm to finally obtain graphene / aluminum-based composite material bulk.

[0037] The graphene in the prepared composite material is uniformly dispersed, and no hard and brittle Al4C3 phase is formed.

Claims

1. A method for controlling the C-Al interfacial reaction in SLM graphene-reinforced aluminum matrix composites, characterized in that: Graphene powder is wrapped with Cu foil to avoid direct contact between graphene and Al during the SLM process, thereby controlling the C-Al interface reaction to generate the Al4C3 hard and brittle phase. The specific steps of the method of encapsulating graphene powder with Cu foil are as follows: (1) Wet stirring of graphene-Cu foil: Cu foil and graphene are mechanically stirred in an alcohol solvent while being heated in a water bath until graphene is distributed on the surface of Cu foil. After drying, Cu foil with graphene attached is prepared. (2) Mechanical ball milling of graphene-Cu foil: The graphene-attached Cu foil is ball milled until the graphene is wrapped inside the cold-welded copper foil particles to prepare graphene-copper powder. (3) Mechanical ball milling of graphene-AlCu composite powder: The graphene-Cu powder and Al powder obtained in step (2) are ball milled into small spherical shapes to prepare uniformly dispersed graphene-AlCu composite powder. (4) SLM preparation of graphene-reinforced aluminum matrix composites: graphene-AlCu composite powder is subjected to SLM forming treatment to finally obtain graphene-reinforced aluminum matrix composite bulk.

2. The method for controlling the C-Al interfacial reaction of the SLM graphene-reinforced aluminum matrix composite material according to claim 1, characterized in that, Based on the total volume of the graphene-reinforced aluminum matrix composite material, the graphene reinforcement content is 0.01 vol.% to 10.00 vol.%, the total content of the Al-Cu alloy matrix is ​​90 vol.% to 99.99 vol.%, of which the Al content is 79.00 vol.% to 99.79 vol.% and the Cu content is 0.20 vol.% to 11.00 vol.%.

3. The method for controlling the C-Al interfacial reaction of the SLM graphene-reinforced aluminum matrix composite material according to claim 1, characterized in that: Based on the total volume of the graphene-reinforced aluminum matrix composite, the graphene reinforcement content is 0.2 vol.%, the total content of the Al-Cu alloy matrix is ​​99.8 vol.%, of which the Al content is 94.80 vol.% and the Cu content is 5.00 vol.%.

4. The method for controlling the C-Al interfacial reaction of the SLM graphene-reinforced aluminum matrix composite material according to claim 1, characterized in that: The process parameters for mechanical stirring in step (1) are: stirring speed 200 rpm / min~2000 rpm / min, heating temperature 50℃~100℃, stirring time 1h~10h; drying temperature 100℃~200℃, drying time 1h~20h.

5. The method for controlling the C-Al interfacial reaction of the SLM graphene-reinforced aluminum matrix composite material according to claim 1, characterized in that: Step (2) The ball milling process parameters are a ball-to-material ratio of 10:1 to 20:1, a ball milling speed of 200 rpm / min to 500 rpm / min, and ball milling on a planetary ball mill for 1 to 10 hours, ultimately encapsulating graphene inside the cold-welded copper particles.

6. The method for controlling the C-Al interfacial reaction of the SLM graphene-reinforced aluminum matrix composite material according to claim 1, characterized in that: The process parameters for ball milling in step (3) are a ball-to-material ratio of 10:1 to 20:1, a ball milling speed of 200 rpm / min to 500 rpm / min, and ball milling on a planetary ball mill for 1 to 10 hours. Through ball milling, the alloy powder undergoes mechanical alloying, thereby preparing a uniformly distributed graphene-AlCu composite powder.

7. The method for controlling the C-Al interfacial reaction of the SLM graphene-reinforced aluminum matrix composite material according to claim 1, characterized in that: The process parameters of SLM in step (4) are: laser power P=50W~500W, scanning speed V=100mm / s~2000mm / s, powder layer thickness hs=10μm~500μm, scanning spacing l=50μm~500μm, and finally obtain graphene / aluminum-based composite material bulk.

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