Research On Nano SiC Composite Coating For The Surface Of45Steel

Electro-brush plating is one kind of specific electroplating technique, which is a newdevelopment direction. It has the advantages such as the equipment needing simplyoperating, the electric current density being very high, the deposition rate on the coatingmaterial being pretty fast and well-adapted. As a result the electro-brush plating has beenwidely applied in the field of Surface Engineering. The composite coating is a new fieldfor composite material study, which has become a hot area for the techniques of SurfaceEngineering. So combining the both new fields to clad on the surface of NO.45steel has abroad application prospects. And this is the basis of the paper’s research.At the stage of experimenting, we first need to design, procure and install theexperimental facilities. We choose the WYJ–150to supply power for the coating, thesingle-phase geared and non-polar adjusting motor connected with speed controller as therotary table, the graphite anode as the brush plating pen. Then is the turn to prepare thebrush plating solution, compounded with Ni and the SiC particles. At the meantime, weneed use1#electro-cleaning solution and2#activating liquid to deal with the base ofNo.45. After the preparation we should begin the experiment with designed and differenttechnological parameters. The whole coating process may be composed as: sandpaper theworkpieces, electro-clean with the solution, wash by distilled water, activate with theliquid, wash by distilled water again, plate the base coat with fast Ni plating solution,make the composite coating, inspect and analyze.Through all the experiments and relative analysis we get some conclusionssummarized as follows:(1) When the process parameters of the fast Ni plating solution set at8v,10m/min,40℃, the micro-hardness of the coating reach maximum value,505HV。 (2) When the concentration of SiC nano-particles in the plating solution is10g/l, thedensity, the quality and the performance of the coating surface is the best. As theconcentration of SiC nano-particles in the plating solution becomes more and more, theSiC proportion in the coating continue to increase. But, as soon as it get to10g/l, theincrease turns very slowly. So the value of10g/l is the best.(3) In the process of the wear testing, the fast Ni coating and the composite coatingboth has some loss and grinding crack relative to the basal body. It means the coating hasdeveloped the resistance to wear, and adding the SiC nano-particles may make this moreobviously.(4) At the end, through analyzing the forming reason, we discover how the compositecoating gets strengthened. It’s mainly because of the mechanism of dislocationstrengthening. When the SiC nano-particles mixed in the solution, Ni icons can be made toarrive the anode surface and get negative ions to become Ni particles depositing on theworkpieces. At the same time, the SiC nano-particles follows to inlay in the coating.