The Study Of SiC Particle Surface Modification For Composite Materials

SiC/Al composites show superior properties such as low density, high inflexibility and high strength, etc. They can be widely used in many industrial fields, e.g. the aerospace vehicles, cars, sports and electron devices. The problems of the interfacial behavior between SiC and Al and interface products which affect the nature of SiCp/Al composite are not yet very clear until now.In this study, electrolyses plating copper and oxidation were used to modify SiCp surface. SEM technique was used to check the morphologies. Pretreatment, plating parameters and technology which affect the deposition rate and plating results on the 40μm and 5μm SiC were analyzed. High temperature oxidation kinetics of SiCp was also studied.It was found that the electrolyses plating method could achieve compact, homogeneous copper layer on SiC particles. In the electrolyses plating technology,"degreasing"and"coarsing"could increase deposition rate. Hydrofluoric acid to coarsing SiC could get better results. In order to get better plating results, EDTA should be completely dissolved and in the plating process constantly stirring is necessary. The best bath technological parameter on 40μm SiCp is 5～7g/L CuSO4·5H2O, 9mL/L formaldehyde, 40～50mg/L stabilizer, 10～15dm2/L load capacity, 40℃, 13.0 pH value. For 5μm SiCp, the best bath technological parameter is 11～13g/L CuSO4·5H2O, 10mL/L formaldehyde, 40～50mg/L stabilizer, 100dm2/L load capacity, 70℃,13.0 pH value. In the oxidation prophase of SiCp, the oxidation speed was controlled by interface reaction, kinetics model is kc=143.37exp(-70994/RT). In the anaphase, the oxidation speed was controlled by diffusion, kinetics model is kD=3.61×108exp(-192758/RT); The velocity constant of the two stages are both in agreement with the following relationships, k1400K>k1300K>k1200K. The apparent activation energy in the prophase of oxidation was lager than anaphase.