Preparation Of Carbon Aluminum Matrix Composites

With wide application potential in various industrial fields, aluminium matrix compoisite is always the focus of metal matrix composite development and research work, due to its distinct advantages including low density, size stability, high specific strength, corrosion resistance, excellent high temperature performance, and so on. With the development of the aviation、spaceflight、auto industry, the tradition carbon fibers and SiC/aliuminum-based composite materials can not meet the increasing requirements. Carbon nanotubes(CNTs) and graphene have been introduced as an ideal reinforcement phase of composites by their virtues of outstanding physical and chemical properties. Specially, they are used to be new reinforcement into aluminum-based composite matrials has good foreground.In this paper, CNTs are coated with metal and surface of grapheme are cladded with copper to improve the dispersion by three methods. It is used to produce metal matrix composites by powder metallurgy, of which the optimal process parameters is determined, such as ball milling time and speed, sintering time and temperature. Optical microscopy(OM), scanning electron microscope(SEM), energy-dispersive X-ray spectroscopy(EDS), conductivity instrument, hardness tester and other analytical tools were used to reseach the synthesis of composite materials. The experiment results show that:1. The method of electroless plating, aqueous reduction, and molecular water mixing was used to prepare a layer of nickel(Ni-CNTs), sliver(Ag-CNTs) and copper(Cu-CNTs) on the surface of CNTs. The results showed that a complete cladding layer formed on the surface of CNTs.2. By mechanical ball milling, the composite powder was preparated. Optimal parameters are as follows:the milling time is 300 r/min, the milling time was 1 h. The composite material was preparated by powder metallurgy method. Optimal parameters are as follows:the sintering temperature was 470℃, sintering time was 2 h.3. The structure, mechanical and conductivity properties with different amount (0, 0.5 wt%,1 wt%,2 wt%) of CNTs (CNTs, Ni-CNTs, Ag-CNTs, Cu-CNTs) were researched. The results showed that the best performance of composite was obtained when CNTs content was 0.5 wt%.The hardness of composite materials was increased 9.7%,8.9%,21.4%, while the conductivity was decreased 4.5%,3.4% and 11.3%.4. The structure, mechanical and conductivity properties with different amount of graphene (0,0.5 wt%,1 wt%,2 wt%,4 wt%) were researched. The results showed that the hardness of composite reach maximum value 40.2 HBW, when CNTs content was 2 wt%. They were increased 14.9%, while the conductivity was decreased, about 17.3%.