Synthesis And Characterization Of Ni-W-Cr₂O₃ Nanocomposite Coatings Using Electrochemical Deposition Technique

Steel 45 is one of the most commonly used metals in industry owing to its cost and relatively good mechanical properties.Its use is however subject to corrosion and wear phenomena which decrease its efficiency and cause failure.Surface modification techniques can be used to improve the surface performances of the industrial equipment and ensure reliability of industrial production.The surface properties and deposition parameters of Ni-W-Cr2O3 nanocomposite coatings were obtained by depositing the coatings using conventional electrodeposition technique.The influence of the deposition parameters on the properties of the deposited coatings was analysed and discussed.The optimum deposition characteristics for NiW/Cr2O3 nanocomposite coatings using conventional electrodeposition technique were obtained.The research and results of the research are as follows:(1)Determination of W concentration and Cr2O3 nanoparticle concentration.The Na2WO4.2H2O concentration was taken to be 10 g·L-1,20 g·L-1,30 g·L-1,and 40 g·L-1,respectively.The Ni-W binary alloy coating was prepared under the same process conditions,and the surface morphology of the coating at different W concentration was compared.The chemical composition,phase structure,microhardness,wear scar depth,surface roughness,and corrosion resistance were determined through comprehensive analysis to determine the optimal W concentration which was found to be 40 g·L-1.Based on the Ni-W binary alloy coating prepared after optimization of W concentration,20 nm Cr2O3 nanoparticles were selected,with varying concentrations of 0 g·L-1,2 g·L-1,6 g·L-1,10 g·L-1,and 20 g·L-1,respectively.The coatings were deposited with varying deposition parameters,and testing was done on the microhardness,wear scar depth,surface roughness,and corrosion resistance at different nanoparticle concentrations.Through comprehensive analysis,the optimal particle concentration was determined to be 10 g·L-1.(2)For the basic test research,research was done on electrodeposited Ni-W-Cr2O3 nanocomposite coatings.The value range of each process parameter:current density,electrolyte temperature,and stirring rate,was determined through preliminary exploration experiments,and the effects on the microhardness,wear track depth,surface roughness,and corrosion resistance was studied.From the test results,at a current density of 1 A·dm-2,electrolyte temperature of 55?,and stirring rate of 350 rpm,the comprehensive performance of the Ni-W-Cr2O3 nanocomposite coatings exhibited the best properties.(3)Design expert software was used to determine the process test research of the electrodeposited Ni-W-Cr2O3 nanocomposite coatings.The interaction relationship between the nanoparticle concentration,current density,electrolyte temperature,and electrolyte rotation rate were analysed,and influence of the interaction on the microhardness,wear track depth,and surface roughness was studied further.Firstly,the model was designed using Design Expert custom design.The corresponding regression equations were obtained through the test results and multiple-response optimization was carried out.The effect of the interaction between different factors on the coating performance was analyzed through threedimensional surface charts and contour maps.Multi-response optimization was carried out using three regression equations,and the predicted optimal process parameter combination was:Cr2O3 nanoparticle concentration 10.19 g·L-1,current density 1.06 A.dm-2,electrolyte temperature 56.16?,and stirring rate 343.67 rpm.Under these process conditions,the predicted value of the responses was:microhardness 610.49 HV0.2,wear track depth 11.4?m,and surface roughness 0.28 ?m.The error margin between the test results and the predicted results was small,and this indicates that the model has high reliability.