Pusle Electrodeposition Of Nickel-chromium Alloy Coating And Anti-corrosion Performance

Electrodepostion nickel-chromium alloy have attractive properties such as resistance to corrosion, good wear resistance and high resistance, it is widely applied for surface finishing and microfabrication. Pulse plating can be used to improve the current distribution and to alter the prevailing mass transport conditions. It can also serve to control the microstructure and composition of electrodeposits.In this paper, we optimized the bath composition and achieved sodium citrate-acid system bath. The fluent of electrodeposits by changing pulse on-time, pulse off-time and peak current was studied. We used scanning electronic microscopy(SEM), atomic force microscopy(AFM) methods to investigate the structure of surface morphology and grain size, achieved the coating composition by energy spectrum, and evaluated corrosion resistance of the plating through the polarization curves and EIS test.By surface analysis, electrochemical test and hydrogen collection, we conclude that when pulse off-time and peak current are constant, the content of chromium in the electrodeposited alloy is greater with the longer of pulse on-time, the current efficiency of hydrogen evolution is bigger, and the grain size is smaller; when pulse on-time and peak current are constant, the content of chromium in the electrodeposited alloy is smaller with the longer of pulse off-time, the current efficiency of hydrogen evolution is smaller, and the grain size is bigger; when pulse on-time and pulse off-time are constant, the content of chromium in the electrodeposited alloy is greater with the greater of pulse peak current, the current efficiency of hydrogen evolution is smaller, and the grain size is bigger.