Study On Synthesis Of Carbon Nano Morphologies By Fe/Y Catalyst On Copper

Because of its excellent electro and thermal conductivity, high strength and elevated temperature stability, as well as low thermal expansion, copper matrix composite have important applications in mechanical, electronic, and aerospace fields. Conducting study on the development of new reinforcement and preparation method of copper matrix composite can better the technical problems of poor interface and uneven mixing between reinforcement and copper substrate, which has important theoretical significance and practical value in improving physical and mechanical properties of composites.In this paper, the carbon nano structures on copper matrix were in-situ synthesized by chemical vapor deposition (CVD) method with Fe catalyst. First of all, the Fe catalyst was prepared by a deposition-precipitation route. By comparing the influence of the concentration of Fe³⁺, calcination duration, and Fe content on the size of catalyst precursor and morphology of CVD product, the feasibility of in situ synthesis of carbon nano materials by Fe catalyst on copper substrate was studied, and the interaction between Fe and Cu was discussed. Further more, the catalytic activity of Fe on copper matrix for nano carbon structure synthesis was investigated by adding the rare earth element Y. The synthesis conditions of carbon nano structures with Fe/Y as the catalyst was decided by optimizing parameters including weight ratio of Fe to Y, Fe/Y content, and CVD temperature. The stabilization mechanism of Y on catalyst and growth mechanism of carbon nano materials in Fe/Y/Cu system was discussed. Study results showed that: 1) Carbon nano morphologies could be produced on copper matrix with Fe as the catalyst in appropriate conditions by CVD method. The concentration of Fe³⁺ has obvious influence on the size and morphology of catalyst precursor, and carbon nano materials can be obtained when Fe content was 10wt.%. The morphologies of carbon nano product were related to calcination duration. At the temperature of chemical vapor synthesis, the interaction between Fe catalyst and Cu substrate would happen and influence the catalytic activity of Fe. The main interaction way was the diffusion of Fe into Cu, which rendered Fe catalyst inactive; 2) It was found that advisable addition of Y element facilitated the formation of carbon nano morphology on copper. Carbon nanotubes (CNTs) and carbon nanoonions (CNOs) with relatively high yield and good morphology can be acquired at 650℃when Fe: Y: Cu= 16: 4: 80 (wt.%) in the composite powder. The solid solution of Y in Fe lattice made Fe and Cu difficult to diffuse together, thus keep Fe catalyst active; 3) The growth model based on CNOs being the initial form was advanced, according to the size of catalyst and the power of interface between catalyst and substrate, reaction product presented themselves in forms of tubular CNTs, catalyst-containing bamboo-like CNTs, CNO chains, catalyst-containing CNOs and hollow graphitic nesting balls.