Electroless Copper Plating On Ceramic Particles And Microstructure And Property Of Ceramic Particles /C-Cu Composites

In this paper, the fundamental principles and basic techniques about copper coating on the surface of TiB₂ and Ti₃SiC₂ ceramic particles by electroless plating were discussed. By optimizing the pretreatment process before electroless plating in order to add activated sites, and the adjustment of the traditional composition of copper electroless plating bath can decelerate electroless plating. The effect of temperature, PH value, initial concentration of CH₂O and loading capacity on the time of copper plating and copper coating quality were studied. It was found that under the temperature of reaction, the time of copper plating dropped off with the increase of temperature and when PH value rose, the time of reaction also reduced. The observation of Optical Microscope and SEM images indicated that when temperature was 60-65℃, PH value was about 12.5, initial concentration of CH₂O was 13 ml/1 and loading capacity was 3 g /L. The surface of TiB₂ and Ti₃SiC₂ were successfully coated with continuous copper layer, so that the interfacial strength between TiB₂ and Ti₃SiC₂ and copper matrix could be increased.By powder metallurgy technology, graphite-Cu matrix composite, TiB₂ and Ti₃SiC₂ ceramic particles and TiB₂ and Ti₃SiC₂ ceramic particles with copper coating reinforcing graphite-Cu matrix composite were fabricated. On the condition that the density of these five kinds of composites were almost the same, their electrical conductivity, vickers hardness and bending strength were tested. It was found that with the content increasing of ceramic particles, their HV hardness and bending strength were enhanced gradually, but the electrical conductivity was reduced. With the same content, compare vickers hardness, bending strength and electrical conductivity of ceramic particles-Cu-graphite composites with the copper coating ceramic particles-Cu-graphite composites, the physical property of the former in these three aspect was not so good as that of the latter. Finally, the mechanical and electrical wear was studied.The result shows that the weight loss of electrical wear is much more than that of the mechanical wear. In Cu-graphite composites, ceramic particle-Cu-graphite composites and copper coating ceramic particle-Cu-graphite composites, wear weight and contact voltage drop of the Cu-graphite composites is very serious, and the ceramic particle-Cu-graphite composite is in the middle, while the copper coating ceramic particle-Cu-graphite composite is the lowest.