Electro And Electroless Plating Of Composite Coating On Carbon Fibers And Preparation Of CF/Al Composite

It plays an important role in the research of Cf/Al composites. As carbon fiber wetsbad with aluminum and the combination on the interface is difficult. Electroplating andelectroless plating are usually used to metalize carbon fiber. In this paper, Cu and Ni-Pcoatings on Cf were prepared by the two methods above. Currently, the preparation of Cf/Al composites generally use the squeeze casting method, vacuum impregnation liquidmethod, powder metallurgy method. However, those methods cost too high and the processare complex. In this paper, Cf/Al composites are prepared by conventional gravity castingmethod. Penetration between molten aluminum and carbon fiber was promoted by heatpreservation after the molten aluminum was poured.In this paper, a set of small sized coating bath for electroplating and electrolessplating was designed. At the same time, a frame for twining Cf was also designed. The topof the frame is a surface plate. Two copper sheet was clipped on it to set up an electriccircuit. A device for making a Cf/Al casting sand mold was designed. That device wascomposed by two locating steel sheets, four steel cores and two crews. Every set wasaccurately corresponded. A fixing device to fasten Cf was designed. Four pinks weredrilled corresponding to the four cores. That fixing device was used to maintain the Cf inthe center of the casting.. Four mounds weight5kg for each one was designed for fasteningthe Cf while casting.The result indicates that metal can be deposited on carbon fiber by electroplating andelectroless plating. But the phenomenon of “black center” was obvious while electroplatingcopper. This phenomenon doesn’t exist in the method of electroless plating. Only3kcarbon fiber can be metalized by electroplating. As there is too many monofilaments, andthey twined together, current distribution was bad, the electroless plating doesn’t fit12kcarbon. The best process parameters for electroless plating Ni-P was: NiSO425g/L,NaH2PO230g/L, C4H6O58g/L, C4H6O412g/L, temperature87℃, PH4.6~4.8. Using this process,3.92μm thick coating could be obtained in only5minutes. The rate is three timesof the process using single complexing agents.While preparing Cf/Al compound, untreated Cf reacted seriously with Al, section ofCf turned to heart shape from initial round shape. After metallization, the copper andnickel coating prevent Cf from touching Al to react. The shape of matallized Cf didn’tchange. Using gravity casting method, molten aluminum couldn’t Infiltrate into Cf.However, after10minutes’ heat preservation, the infiltration has been obviously improved.