Electrodeposition of high Mo content amorphous/nanocrystalline Ni–Mo alloys using 1-methyl-imidazolium chloride ionic liquid as an additive

Amorphous/nanocrystalline Ni–Mo alloy containing more than 49wt.% Mo has been electrodeposited onto mild steel from aqueous ammonia citrate solution by pulse plating technique in the presence of ionic liquid additive 1-methyl-imidazolium chloride. The deposits were quite bright, compact, metallic and adherent. In the presence of ionic liquid and pH=8.5, deposits containing over 49wt.% Mo have been obtained while in the absence of ionic liquid no deposit was obtained at the same conditions. Microstructure, morphology and chemical composition of the Ni–Mo coatings were investigated using scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analysis respectively. The textural components of the coatings were also evaluated employing X-ray diffraction spectra. ►In additive-free bath at pH of 8.5 poor codeposition of Mo with Ni is obtained. ►In the presence of 100ppm IL at pH=8.5 high Mo content Ni–Mo films were obtained. ►High Mo film developed here at 200rpm whilst others obtained it under high convection. ►Substrate preparation affects on morphology of deposited Ni–Mo films.