Preparation method for in-situ synthesis of three-dimensional graphene-reinforced copper-based composite material

Abstract

The invention relates to a preparation method for in-situ synthesis of a three-dimensional graphene-reinforced copper-based composite material. The preparation method comprises the following steps: taking copper nitrate trihydrate as a copper source, mixing the copper source with a solid carbon source (glucose or citric acid) and a water-soluble salt template (sodium chloride), then adding the mixture into water to dissolve the mixture, performing stirring uniformly to obtain a precursor solution; performing freeze-drying dehydration to obtain a mixed powder precursor; performing heating to 600-800 DEG C, performing heat preservation for 1-3 h, and then perform cooling quickly to obtain self-assembly powder; washing off sodium chloride by suction filtration, and performing vacuum drying; pouring the product into an ethanol solution of copper nitrate; performing water-bath evaporation drying and vacuum drying; under atmosphere protection, performing heating to 600-800 DEG C, performing heat preservation for 1-3 h, and obtaining three-dimensional graphene-copper particle composite powder by furnace cooling; and molding according to a vacuum hot-pressing sintering technology. The blocky material prepared according to the method has the characteristic that the graphene has good dispersity and is closely combined with a copper base; and meanwhile, the blocky material has excellent toughness and mechanical properties.

Description

technical field [0001] The invention relates to a preparation method for in-situ synthesis of three-dimensional graphene-reinforced copper-based composite materials, which belongs to the preparation technology of nanometer materials. Background technique [0002] Graphene has excellent tensile strength and elastic modulus due to its special monoatomic layer structure. Bonding force and contact area; its unique two-dimensional structure can effectively hinder the migration of dislocations and significantly reduce the expansion of fine cracks in composite materials, so it has important application value in composite materials. Copper-based composites have been widely used in the fields of electronic materials and structural materials due to their excellent mechanical properties, high electrical conductivity, thermal conductivity and other functional properties. Existing research reports have confirmed that adding graphene to the copper matrix can effectively strengthen and to...

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Problems solved by technology

However, the maximum reinforcement ratio achieved by the existing reported methods is only 120%. It can be seen that in the existing powder composite technology, the potential of graphene reinforcement has not been fully realized, and the mechanical properties of graphene reinforced copper matrix composites are far lower. Based on theoretical expectations, the main reasons are: (1) The graphene used in the preparation of composite materials is generally prepared by the graphite oxide reduction method. This type of redox graphene has many structural defects, poor mechanical properties, and poor electrical and thermal conductivity. Interfacial reactions are prone to occur when the matrix is ​​composited, which greatly affects the mechanical and physical properties of the composite material; (2) there is a strong van der Waals force between graphene (including redox graphene), which is very easy to agglomerate to form graphite sheets, so it is very easy to It is difficult to achieve uniform dispersion in the copper matrix, and the severely agglomerated graphene will lose its special mechanical properties, electrical conductivity, structural stability and other excellent properties just like ordinary graphite flakes

The traditional high-energy mechanical ball milling method can promote the dispersion of graphene to a certain extent, but the severe mechanical force during the ball milling process seriously destroys the structure and properties of graphene, resulting in a significant decline in the strengthening effect.

In summary, the existing powder composite technology cannot meet the three basic conditions for graphene to fully exert its strengthening effect at the same time, that is, the structure is intact, the dispersion is uniform, and the interface with the matrix is ​​well bonded, which restricts the development of graphene-reinforced copper-based structural composites. the bottleneck

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