Properties of Fe–Ni–Cr alloy coatings by using direct and pulse current electrodeposition

Abstract

This paper describes the effects of using direct and pulse current on composition and corrosion resistance of Fe–Ni–Cr alloy coatings. In both direct and pulse current electrodeposition, increasing the current density has a decreasing effect on Fe and Ni and an increasing influence on Cr. In pulse current electrodeposition, duty cycle has a greater effect than frequency on composition of the alloy coating, particularly in the range of 10–50%. In this range, by increasing the duty cycle, Ni decreases, Fe sharply increase and Cr shows an increasing trend. Following a study of the microhardness of coatings, it is determined that the microhardness increases about 1.5 times by pulse current electrodeposition. The corrosion resistance of the alloy coatings (electrodeposited by direct and pulse current) has been investigated in NaCl solution. The micro-cracks of alloy coating can be decreased by using pulse current, which demonstrates a better corrosion resistance than direct current coating.