Study On The Process And Mechanism Of Preparing WC Reinforced Nickel Matrix Composite By Composite Electroplating

In terms of improving the wear and corrosion resistance of the material surface to achieve material protection,the composite electrodeposition method has attracted widespread attention due to its simple preparation process,low energy consumption,and excellent coating performance.This paper explores the process,mechanism and performance of Ni-nanoWC composite coatings prepared by pulse electrodeposition.The effects of process parameters such as wet milling pretreatment of WC particles before plating,the amount of WC particles added in the plating solution,current density,and surfactant concentration in the plating solution on the WC content in the Ni-nanoWC composite coating and the analysis of the formation mechanism of the coating were studied.At the same time,the microstructure,surface morphology,and distribution of WC in the Ni-nanoWC composite coating were studied using SEM,XRD,and EDS.The micro-hardness,abrasion resistance and corrosion resistance of Ni-nanoWC composite coatings were studied by using a micro-hardness tester,a friction and wear tester,an electrochemical workstation and a full-etching experiment.The specific research results are as follows:The effects of the process parameters such as wet-milling pretreatment of WC particles before plating,the amount of WC particles added in the plating solution,the current density,and the concentration of the surfactant in the plating solution,and the plating method on the Ni-nanoWC composite coatings are obtained through a comparative study.Under the pulse electrodeposition method,when wet milling pretreatment for 10 hours,the content of WC particles in the plating solution is 7g/1,the current density is 15 A/dm2,and the surfactant concentration in the plating solution is 0.15g/1,the content of WC in the Ni-nano WC composite coating is the highest,reaching about 4.17%,and the surface of the coating is relatively uniform,dense and flat.The microhardness of the pure nickel coating is about 216.8HV,and the microhardness of the Ni-nanoWC composite coating is about 313.4HV.In addition,the WC particles were subjected to wet grinding pre-treatment before plating and the addition of surfactants in the plating solution,which made the microhardness of the Ni-nanoWC composite coating increase significantly,and the friction coefficient was the smallest in the friction and wear test,and the wear resistance was the best.With the increase of WC content in the coating,the friction coefficient and wear of the coating both decrease first and then increase.The wear resistance is best when the WC content is 7g/1.The results of the Electric potential polarization curve test show that in a 0.5mol/1 H2SO4 solution,the corrosion potential of the pure nickel coating is positively shifted by 0.0574V compared to the Ni-nanoWC composite coating.At the same time,the corrosion resistance of Ni-nanoWC composite coatings with WC particles after wet grinding treatment and surfactant added in the plating solution is relatively better.Full-etching experiments show that Ni-nanoWC composite coatings have poor corrosion resistance in strong acidic environments,and have little difference in corrosion resistance with pure nickel coatings in weakly acidic and alkaline environments.Corrosion resistance is relatively better than pure nickel plating in neutral environment.