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Nanometer WC particles , the composite plating method add pure nickel plating bath prepared out the Ni-nWC nanocomposite coating system to the the composite plating Ni-nWC process cathode current density , pH value , the plating temperature , nano WC particles content , agitation rate , the impact of process conditions on the coating quality and performance . Using scanning electron microscopy ( SEM ) , metallographic microscope to study the composition , structure and surface morphology of the coating . Optimized bath composition derived through comparative study of NiSO4 6H2O : 280 to 350g / L NiCl2 · 6H2O : 35 to 45g / L , H3BO3 : 30 ~~ 40g / L brightener :0.1- 0 .2 g / L , the the the Nanometer WC particles added amount :5 - 15g / L , the surfactant and dispersing agent amount. The optimum conditions are as follows: The cathode current density of 2-4A/dm2 pH value of from 4.0 to 4.8 , the plating temperature is 45 to 55 ° C , the stirring rate of 120 to 150 revolutions / min , the plating time is 8 hours , nano composite plating solution is configured ultrasonic dispersion . The organization of the composite coatings obtained under the formulation and process conditions are uniform, dense , high hardness, and the substrate with a good , but in the electroplating process , a long time , the WC particles will occur agglomeration . Stainless steel, nickel-plated layer , the nano - composite coating microhardness , abrasion performance , corrosion performance comparison study found : Ni - nWC nano- composite coatings average microhardness (HV1006 ) is much higher than stainless steel (HV227) and the average hardness of nickel plating layer (HV623) , the addition of nano WC particles significantly increase the hardness of the coating , the coating does exist the nano WC strengthen role ; under the same testing conditions , Ni-nWC nanocomposite the coating abrasion performance of stainless steel 1.4 times , but only ordinary nickel plating layer 1.01 times . Nanocomposite Coatings abrasion performance relative stainless greater degree of improvement , but relatively ordinary nickel plating layer has increased much , the reunion of of nanometer WC particles in the electroplating process directly affects the composite coatings increased abrasion performance , significantly improve the abrasion performance of the composite coating must overcome the agglomeration of the nanoparticles in the electroplating process and ; Ni - nwc nano composite coatings and the general corrosion resistance of the nickel-plated layer are much better than stainless steel, but the corrosion resistance of the composite coating is but slightly Less than ordinary nickel plating layer , nanometer WC particles added can not significantly improve corrosion resistance of the coating .
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