Improved pitting corrosion behaviour of electrodeposited nanocrystalline Ni–Cu alloys in 3.0 wt. NaCl solution

摘要

Nanocrystalline (nc) Ni–Cu alloys have been electrodeposited by using pulse current (PC) as well as direct current (dc) electrolysis. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were employed to characterise the deposits. High-resolution electron microscopic (HREM) examination revealed that deposited nc alloys were dense in nature. Corrosion behaviour of both nc as well as Monel-400 were compared in 3.0 wt.% NaCl solution and was found that corrosion current density (icorr) of nc alloys were superior to Monel-400. Both optical as well as scanning electron microscopic (SEM) examination of the corroded surface revealed a well-defined pitting type of attack for Monel-400 unlike nc alloys; akin to homogeneous corrosion.