The effect of multi-walled carbon nanotube pretreatments on the electrodeposition of Ni-MWCNTs coatings

► In the current research, MWCNTs are pretreated by two different chemical treatments and then electrodeposited with nickel from a modified Watt's plating bath. The main results are as bellows ► In similar plating condition, shortened nanotubes were more co-deposited than elongated ones. ► Shortened nanotubes are behaved as inert ceramic particles, and embedded into the nickel matrix, whilst the long functionalized nanotubes showed metallic behavior and incorporated into the nickel matrix. ► SMWCNTs enhance more effectively the hardness of matrix due to their smaller length and higher co-deposition in comparison with LMWCNTs. ► Inclusion of nanotubes into the nickel matrix modifies grain orientation from (1 0 0) soft mode toward (1 1 1) direction. ► As LMWCNTs are more tightly incorporated into the nickel matrix than SMWCNTs, the dissention of them from the matrix posterior is more occurred results in lower corrosion current density in comparison with Ni-SMWCNTs coating.