Microstructure and Electrochemical Properties of Foamed Ni-Mo Alloy by Pulse-Electrodeposition

Abstract

A variety of foamed Ni-Mo alloys coatings have been obtained using pulsed electrodeposition technique. The deposit is mainly composed of amorphous structural through the X-ray diffractions (XRD), the morphology clearly contains large amounts of multi-bubble pore structure with pentagonal or hexagonal skeleton structure and obviously stratifys through scanning electron microscopy (SEM) experimentals. This pentagonal or hexagonal skeleton structure and obvious stratification has a larger surface area. The electrolysis experiments show that such foamed alloys have a low hydrogen evolution overpotential and a better corrosion resistance in 25°C, 7mol·L-1 KOH alkaline solution.

Effect of ultrasonication on Ni–Mo coatings produced by DC electroformation

“…36 As such, when the grain size increases, the hardness also increases. In agreement with the above results, previous studies reported 17,18,20 that hardness is strongly inuenced by the molybdenum content. The enhancement in the hardness of Ni-Mo coatings with ultrasonic assistance is ascribed to the Mo content along with the much higher content the Mo in the coating and ner grain size.…”

“…Some studies have reported that an increase in the Mo content of the coatings would cause the coating's structure to gradually transform from a crystalline phase to a nanocrystalline/ amorphous mixture. [19][20][21][22][23] When the Mo content increases up to 26 wt%, a two-phase structure with a mixture of nanocrystalline and amorphous phases arises, and the Ni-Mo alloys become quite amorphous/nanocrystalline when the content of Mo exceeds over 31 wt% to 35 wt%. 24 Thus, both Ni-Mo coatings with and without ultrasonication can be regarded as nanocrystalline phases.…”