Lignin reinforced copper matrix composite, preparation method and application

Abstract

This invention belongs to the field of copper-based composite material technology, and discloses a lignin-reinforced copper-based composite material, its preparation method, and its application. The method includes the following steps: mixing lignin powder and copper powder uniformly; the amount of lignin powder added is 0.5 wt.%, and the amount of copper powder added is 99.5 wt.% by mass percentage; the uniformly mixed powder is placed in a vacuum drying oven for drying and sieving to obtain composite powder; the composite powder is sintered in a vacuum hot-pressing sintering furnace to obtain a blocky copper-based composite material. This invention, by adding lignin as a precursor to the copper matrix, can fill the voids between the copper matrix particles. Furthermore, during the hot-pressing sintering process, lignin can be transformed into amorphous carbon or graphitized carbon phase, which has a better interfacial bond with the copper matrix, thus serving as a reinforcing phase to improve the overall performance of the composite material.

Description

Technical Field

[0001] This invention belongs to the field of copper-based composite material technology, specifically relating to a lignin-reinforced copper-based composite material, its preparation method, and its application. Background Technology

[0002] Traditional copper-based composite materials, limited by their crystal structure and strengthening mechanisms, are prone to cracking, deformation, and accelerated wear when subjected to external impacts, cyclic loading, or alternating thermal conditions, thus affecting equipment reliability. For example, in industrial equipment that needs to withstand frequent mechanical vibrations, high-speed friction, or rapid temperature changes, copper-based composite components are prone to premature failure due to their high brittleness and insufficient strength, leading to equipment downtime and potentially safety hazards. In aerospace, high-end electronics, and other fields with extremely high material performance requirements, devices need to operate for extended periods under extreme mechanical and thermodynamic environments. The performance limitations of traditional copper-based composite materials prevent them from meeting the requirements for long-term stable and highly reliable operation, thus restricting their application in relevant critical components.

[0003] Chinese patent publication number CN117403087A, entitled "A TC4-reinforced copper-based composite material and its preparation method," describes a method comprising: placing TC4 spherical particles and dendritic copper powder into a ball mill jar, then adding a small amount of mixing agent, introducing argon protective gas, and performing low-speed ball milling to obtain TC4. Cu composite powder; after ball milling, the composite powder was placed in a vacuum drying oven for drying, and then subjected to rapid hot pressing sintering technology for TC4. TC4-reinforced copper-based composite material can be obtained by sintering Cu composite powder. The method in this patent application can improve the strength and plasticity of copper-based composite materials, but it is costly and the material is difficult to process and obtain. Summary of the Invention

[0004] In order to overcome the problems existing in the prior art, the present invention aims to provide a lignin-reinforced copper matrix composite material, preparation method and application. By adding lignin as a precursor to the copper matrix, the voids between the copper matrices can be filled. In addition, lignin can be transformed into amorphous carbon or graphitized carbon phase during hot pressing and sintering, which has a better interfacial bond with the copper matrix and serves as a reinforcing phase to improve the overall performance of the composite material.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a lignin-reinforced copper-based composite material comprising, by weight percentage, 0.5 wt.% lignin and 99.5 wt.% copper.

[0006] Optionally, the lignin has a particle size of 50~150 nm.

[0007] Secondly, the present invention provides a method for preparing the lignin-reinforced copper-based composite material, comprising the following steps: The lignin powder and copper powder were mixed evenly; by mass percentage, the amount of lignin powder added was 0.5 wt.%, and the amount of copper powder added was 99.5 wt.%. The uniformly mixed powder is placed in a vacuum drying oven for drying and then sieved to obtain composite powder. The composite powder is sintered in a vacuum hot-pressing sintering furnace to obtain a block copper-based composite material.

[0008] Optionally, the method for preparing lignin powder includes the following steps: Mix pine wood powder with DES solution and react. The solution after the mixed reaction is separated and extracted to obtain lignin; The DES solution is a mixture of choline chloride and lactic acid.

[0009] Optionally, the drying temperature of the vacuum drying oven is 60°C and the drying time is 12 hours.

[0010] Optionally, the lignin powder and copper powder are mixed evenly in a ball mill jar with a ball-to-powder ratio of 10:1, and ball milling is carried out under argon protection.

[0011] Optionally, the heating rate of the vacuum hot pressing sintering furnace is 10°C / min.

[0012] Optionally, the maximum sintering temperature of the vacuum hot-press sintering furnace is 850℃, the pressure is 30MPa, the holding time is 3h, and then the furnace is naturally cooled to 200℃.

[0013] Optionally, before mixing the copper powder with the lignin powder, take an appropriate amount of anhydrous ethanol and pour it together with the weighed copper powder into a beaker, use an ultrasonic cleaner to ultrasonically vibrate for 10 minutes, and then discard the upper suspension.

[0014] Thirdly, the present invention provides the application of the lignin-reinforced copper-based composite material in the field of engineering.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a lignin-reinforced copper-based composite material comprising, by weight percentage, 0.5 wt.% lignin and 99.5 wt.% copper.

[0016] This invention adds lignin as a precursor to a copper matrix. Lignin has a long molecular chain structure. For lignin-reinforced copper matrix composites, the extremely low content and small size (nanoscale) of lignin can fill the gaps between the copper matrix. Furthermore, lignin can be transformed into amorphous carbon or graphitized carbon phase during hot pressing and sintering, which has a better interfacial bond with the copper matrix. As a reinforcing phase, it can improve the overall performance of the composite material.

[0017] Furthermore, lignin is widely available, inexpensive, and environmentally friendly. Using it as a precursor as a reinforcing phase in copper-based materials not only reduces the preparation cost of copper-based composites but also achieves efficient resource utilization, aligning with the industrial trends of green manufacturing and sustainable development. Compared to traditional reinforcing phases, lignin-reinforcing phases not only improve the overall performance of composite materials but also optimize the economics and environmental friendliness of the preparation process. This provides a new technological path for the high-end and large-scale application of copper-based composites and offers a practical solution to current technical challenges in the field, providing important development ideas.

[0018] This invention also provides a method for preparing lignin-reinforced copper-based composite materials, which involves mixing lignin powder with copper powder and then preparing the material through hot pressing and sintering. This method is characterized by its simplicity and short preparation cycle. Under vacuum high-temperature sintering, lignin undergoes pyrolysis, transforming into amorphous carbon or graphitized carbon phases. These substances can fill the voids between the copper matrix components, forming a unique microstructure. This unique structure can improve the density of the composite material and enhance its overall performance. Attached Figure Description

[0019] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely schematic to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. In the drawings: Figure 1 Here is a SEM image of the composite powder prepared in Example 1 of this invention; Figure 2 This is a schematic diagram of the preparation method according to an embodiment of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0021] Therefore, the following detailed description of embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention.

[0022] The theories or mechanisms described and disclosed in this invention, whether right or wrong, should not limit the scope of the invention in any way; that is, the contents of this invention can be implemented without being limited by any particular theory or mechanism.

[0023] In this invention, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are for the sake of brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be regarded as covering and specifically disclosing all possible secondary ranges and individual numerical values ​​(including integers and fractions) within those ranges.

[0024] In this invention, unless otherwise specified, the terms “comprising,” “including,” “containing,” “having,” or similar terms cover the meanings of “composed of” and “mainly composed of”. For example, “A contains a” covers the meanings of “A contains a and others” and “A contains only a”.

[0025] In this invention, for the sake of brevity, not all possible combinations of the technical features in each embodiment or example are described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered within the scope of this specification.

[0026] It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In the description of this invention, it should be understood that the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or collections thereof.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the specification and appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0028] The present invention will now be described in detail with reference to the accompanying drawings.

[0029] Metal matrix composites, with their unique comprehensive performance advantages, have been increasingly widely used in various fields of production and daily life, especially in industrial manufacturing and high-end equipment, where they occupy an indispensable core position and have become key basic materials supporting the upgrading of related industries. Among the many metal matrix composites, copper matrix composites, with copper as the matrix and processed by adding specific reinforcing phases and special preparation processes, are among the most widely used composite materials in the industrial field. These materials inherit the excellent electrical and thermal conductivity of the copper matrix, effectively reducing energy consumption and improving equipment operating efficiency; at the same time, they also possess good mechanical properties, maintaining their stability under various operating conditions, and are widely used in key technology fields such as electronics, rail transportation, aerospace, and precision machinery equipment.

[0030] Despite the many excellent properties of copper-based composite materials, they still have inherent technical defects in actual preparation and application. The most prominent defects are high brittleness, insufficient strength, and difficulty in achieving synergistic improvement in electrical and thermal conductivity and toughness.

[0031] The present invention provides a lignin-reinforced copper-based composite material comprising, by weight percentage, 0.5 wt.% lignin and 99.5 wt.% copper.

[0032] like Figure 2 As shown, the preparation method of the lignin-reinforced copper-based composite material includes the following steps: The lignin powder and copper powder were mixed evenly; by mass percentage, the amount of lignin powder added was 0.5 wt.%, and the amount of copper powder added was 99.5 wt.%. The uniformly mixed powder is placed in a vacuum drying oven for drying and then sieved to obtain composite powder. The composite powder is sintered in a vacuum hot-pressing sintering furnace to obtain a block copper-based composite material.

[0033] This invention adds lignin as a precursor to a copper matrix. Lignin has a long molecular chain structure. For lignin-reinforced copper matrix composites, the extremely low content and small size (nanoscale) of lignin can fill the gaps between the copper matrix. Furthermore, lignin can be transformed into amorphous carbon or graphitized carbon phase during hot pressing and sintering, which has a better interfacial bond with the copper matrix. As a reinforcing phase, it can improve the overall performance of the composite material.

[0034] The graphite reinforcing phase exhibits better interfacial bonding with the copper matrix and is uniformly dispersed within the matrix, thereby increasing dislocation density, transferring loads, and refining grain size. Grain refinement significantly improves the material's strength and toughness while avoiding the increased brittleness caused by coarse grains, fundamentally addressing the core defects of traditional copper-based composites, such as high brittleness and susceptibility to cracking. In terms of load transfer, the tightly bonded graphite reinforcing phase acts as a stress transfer carrier, uniformly distributing externally applied loads to the entire copper matrix, reducing localized stress concentration, and lowering the probability of deformation and failure during stress, thus improving the density and mechanical properties of the composite material.

[0035] Example 1 This embodiment provides a lignin-reinforced copper-based composite material, comprising 0.5 wt.% lignin powder and 99.5 wt.% copper powder by weight. The lignin has a particle size of 50-150 nm.

[0036] Example 2 This embodiment provides a method for preparing a lignin-reinforced copper-based composite material according to Example 1, specifically including the following steps: Step 1: Mix pine wood powder with DES solution and react to separate and extract lignin, wherein the DES solution is a mixture of choline chloride and lactic acid.

[0037] Step 2: Using a high-precision electronic balance (accuracy of 0.01mg), weigh 0.5 wt.% of lignin powder and 99.5 wt.% of copper powder according to their mass percentages, where the copper powder is 92g and the lignin powder is 0.46g. The measurements are calculated based on the dimensions of the hot-pressing sintering mold, which has a diameter of 44mm and a height of 6mm.

[0038] Step 3: Take an appropriate amount of anhydrous ethanol and pour it into a beaker together with the copper powder weighed in Step 2. Use an ultrasonic cleaner to ultrasonically vibrate for 10 minutes and then discard the upper suspension.

[0039] Step 4: Pour the lignin powder weighed in Step 2 and the ultrasonically treated copper powder from Step 3 into a ball mill jar for wet milling: mill for 10 minutes, stop for 5 minutes, repeat 36 cycles, and mill for 6 hours. The rotation speed is 200 r / min, using zirconia grinding balls with a ball-to-material ratio of 10:1, and the milling is carried out under argon protection.

[0040] Step 5: After ball milling, the mixed powder is dried in a vacuum drying oven at 60°C for 12 hours. The fully dried composite powder is then sieved to obtain a composite powder with smaller and more uniform particle size.

[0041] Step 6: Sinter the composite powder obtained in Step 5 using a vacuum hot-pressing sintering furnace. The composite powder is loaded into a graphite mold within the sintering furnace. Before sintering begins, the vacuum level of the hot-pressing sintering furnace is reduced to 2 × 10⁻⁶. -2 Below Pa. Hot pressing sintering begins with a heating rate of 10°C / min, a maximum sintering temperature of 850°C, and a holding time of 3 hours. Then, it is allowed to cool naturally in the furnace. During hot pressing sintering, a pressure of 30 MPa is continuously applied until the temperature drops to 200°C. After hot pressing sintering, the resulting material has dimensions of... A 44mm × 6mm block copper-based composite material.

[0042] The fracture toughness of the lignin-reinforced copper-based composite material prepared as described above is significantly improved, making it applicable to engineering fields.

[0043] Example 3 This embodiment provides the application of the lignin-reinforced copper-based composite material described in Embodiment 1, which is applied in the engineering field.

[0044] Comparative Example 1 A method for preparing a pure copper-based material, comprising the following steps: Step 1: Using a high-precision electronic balance (accuracy of 0.01 mg), weigh out 100 wt.% of copper powder, which weighs 92 g.

[0045] Step 2: Take an appropriate amount of anhydrous ethanol and pour it into a beaker together with the copper powder weighed in Step 1. Use an ultrasonic cleaner to ultrasonically vibrate for 10 minutes and then discard the upper suspension.

[0046] Step 3: The copper powder obtained in Step 2 is further wet-milled using anhydrous ethanol as the grinding medium in a ball mill. The milling process involves 10 minutes of milling followed by a 5-minute pause, for a total of 36 cycles, and a total milling time of 6 hours. The milling speed is 200 rpm, using zirconia grinding beads with a ball-to-material ratio of 10:1, and the milling is carried out under argon protection.

[0047] Step 4: Dry the copper powder using a vacuum drying oven at 60°C for 12 hours to obtain fully dried copper powder.

[0048] Step 5: The fully dried copper powder is sieved to obtain a composite powder with smaller and more uniform particle size.

[0049] Step 6: Sinter the copper powder obtained in Step 5 using a vacuum hot-pressing sintering furnace. The composite powder is loaded into a graphite mold in the sintering furnace. Before sintering begins, the vacuum level of the hot-pressing sintering furnace is reduced to below 2 × 10⁻² Pa. Hot-pressing sintering begins with a heating rate of 10°C / min, a maximum sintering temperature of 850°C, and a holding time of 3 hours. The powder is then allowed to cool naturally in the furnace. During hot-pressing sintering, a pressure of 30 MPa is continuously applied until the temperature drops to 200°C. After hot-pressing sintering, the resulting material has dimensions of… A block of pure copper material measuring 44mm x 6mm.

[0050] The lignin-reinforced copper-based composite material prepared in the examples and the pure copper material prepared in the comparative examples were subjected to physical and mechanical tests. The results are shown in Table 1, which compares the mechanical properties of the 0.5 wt.% lignin-reinforced copper-based composite material and the pure copper material.

[0051] Table 1

[0052] Table 1 shows that when 0.5% lignin is added, the hardness, yield strength, and tensile strength of the lignin-reinforced copper matrix composite are significantly improved, increasing by 26.37%, 19.37%, and 22.28%, respectively. Furthermore, the lignin-reinforced copper matrix composite also exhibits excellent elongation at break. Compared with the composite without lignin, its overall performance is improved. In addition, characterization methods such as XRD, Raman surface scanning, FT-IR, and ultra-depth-of-field microscopy demonstrate that lignin in the lignin-reinforced copper matrix composite is successfully transformed into amorphous carbon or graphitized carbon phase during hot-pressing sintering.

[0053] Unless otherwise specified, the equipment components involved in the above embodiments are all conventional equipment components, and the structural settings, working methods or control methods involved are all conventional settings, working methods or control methods in the art unless otherwise specified.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Any other modifications or equivalent substitutions made by those skilled in the art to the technical solutions of the present invention, as long as they do not depart from the spirit and scope of the technical solutions of the present invention, should be covered within the scope of the claims of the present invention.

Claims

1. A lignin-reinforced copper-based composite material, characterized in that, It contains 0.5 wt.% lignin and 99.5 wt.% copper by weight.

2. The lignin-reinforced copper-based composite material according to claim 1, characterized in that, The particle size of lignin is 50~150nm.

3. The method for preparing the lignin-reinforced copper-based composite material according to any one of claims 1 to 2, characterized in that, Includes the following steps: The lignin powder and copper powder were mixed evenly; by mass percentage, the amount of lignin powder added was 0.5 wt.%, and the amount of copper powder added was 99.5 wt.%. The uniformly mixed powder is placed in a vacuum drying oven for drying and then sieved to obtain composite powder. The composite powder is sintered in a vacuum hot-pressing sintering furnace to obtain a block copper-based composite material.

4. The method for preparing the lignin-reinforced copper-based composite material according to claim 3, characterized in that, The preparation method of lignin powder includes the following steps: Mix pine wood powder with DES solution and react. The solution after the mixed reaction is separated and extracted to obtain lignin; The DES solution is a mixture of choline chloride and lactic acid.

5. The method for preparing lignin-reinforced copper-based composite material according to claim 3, characterized in that, The drying temperature of the vacuum drying oven is 60℃, and the drying time is 12 hours.

6. The method for preparing lignin-reinforced copper-based composite material according to claim 3, characterized in that, The lignin powder and copper powder were mixed evenly in a ball mill jar with a ball-to-powder ratio of 10:1 and ball milled under argon protection.

7. The method for preparing lignin-reinforced copper-based composite material according to claim 3, characterized in that, The heating rate of the vacuum hot pressing sintering furnace is 10°C / min.

8. The method for preparing lignin-reinforced copper-based composite material according to claim 3, characterized in that, The maximum sintering temperature of the vacuum hot-press sintering furnace is 850℃, the pressure is 30MPa, the holding time is 3h, and then it is naturally cooled to 200℃ with the furnace.

9. The lignin-reinforced copper-based composite material according to claim 3, characterized in that, Before mixing copper powder with lignin powder, take an appropriate amount of anhydrous ethanol and pour it into a beaker together with the weighed copper powder. Use an ultrasonic cleaner to ultrasonically vibrate for 10 minutes and then discard the upper suspension.

10. The application of the lignin-reinforced copper-based composite material according to any one of claims 1 to 2, characterized in that, It is applied in the field of engineering.

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