Effects of pulse parameters on properties of nickel coating electroplated on surface of carbon steel Q235

The effects of pulse duty cycle,average current density and pulse frequency on the weight gain rate,surface morphology and microhardness of nickel coating prepared on Q235 steel substrates were studied.The composition of plating bath and other process parameters are as follows:NiSO4.6H2O 281 g/L,sodium dodecyl benzene sulfonate 0.08 g/L,NiCl2.6H2O 40 g/L,saccharin 1 g/L,H3BO3 35 g/L,butynediol 0.01 g/L,temperature 50 °C,pH 3.0-4.0,stirring rate 120 r/min,and time 30 min.The optimal pulse parameters were determined as follows:average current density 0.4 A/cm2,frequency 1 000 Hz,and duty cycle 30%.The nickel coating prepared using the optimal pulse parameters has the highest weight gain rate and microhardness,as well as a smooth and compact surface.