Method for preparing graphene reinforced metal-based composite material through discharge plasma (SPS) sintering

Abstract

The present invention relates to a method for preparing a graphene reinforced metal-based composite material through discharge plasma (SPS) sintering. The method is characterized in that the graphene reinforced metal-based block material is prepared through SPS sintering and has the following advantages that: the preparation method is simple, the material is compact and does not have pores, the graphene mass fraction can be arbitrarily regulated, the distribution is uniform, no aggregation is generated, the material mechanical property isotropy is provided, and the wettability of the metal and the graphene interface is good. The method comprises: (1) reducing graphene oxide through a chemical method or a hydrothermal method to obtain graphene sheets with a sheet layer thickness of not more than 4 nm and sheet layer diameter of not more than 50 [mu]m; and (2) preparing metal powder with a particle size of not more than 200 [mu]m through a rotating electrode atomization method, mechanical crushing or a high-speed ball milling method; (3) carrying out mechanical or ball milling mixing on the graphene powder and the metal powder according to the required mass ratio; and (4) carrying out SPS sintering forming on the mixed powder, wherein the obtained material has characteristics of improved mechanical property, decreased density, good heat conduction capability, and good electric conduction capability, and the performance customizing can be achieved by adjusting the preparation parameters.

Description

technical field [0001] The invention relates to a method for preparing a graphene-reinforced metal-matrix composite material by spark plasma (SPS) sintering, in particular to a method for preparing a dense metal-matrix composite material with high graphene content. Background technique [0002] Graphene is a two-dimensional planar carbonaceous material with a single layer of carbon atoms stacked into a honeycomb lattice structure. The thickness of the sheet is usually less than 10 carbon atoms. The volume is 1100GPa, and the electron mobility reaches 200000cm 2 / V·S, the thermal conductivity reaches 5000w / m·K, and it has the characteristics of low density. Adding graphene sheets to the metal matrix can reduce the density of the material, and it is expected to obtain high strength and maintain good electrical and thermal conductivity. For some specific alloys or pure metals, the addition of graphene will even make the material have certain properties. It becomes a functiona...

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Problems solved by technology

[0003] Relevant research and patents have reported the preparation of graphene-reinforced metal matrix composites. The main methods currently used are casting and hot isostatic pressing (hot pressing) sintering, but these two methods have obvious defects: due to the relationship between graphene and The density of liquid metal is quite different, the distribution of graphene in the casting material is uneven, and it is easy to agglomerate, so it is difficult to obtain a material with uniform properties; and the pretreatment of hot pressing and sintering preparation is very complicated, and the surface of the metal powder needs to be modified. The shape is also required, generally only suitable for flake metal powder, and the sintering temperature is high, the pressure applied is high, and the sintering time is also very long, usually several to dozens of hours, so the energy consumption is huge, and the obtained composite material Porosity is also high

Since graphene is neither hydrophilic nor lipophilic, its reactivity is not high, its surface wettability is very poor, and there is a huge difference in properties between it and metals, it is difficult to achieve interfacial bonding with the metal matrix, so the amount of graphene added is also low. Limited, the improvement of the performance of metal materials is limited, and the traditional powder mixing method adopts the liquid phase mixing method, the process is complicated, and the content of graphene cannot be accurately controlled

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