Synthesis and characterization of nickel tungsten alloys by electrodeposition

The objective of the current work was to study in detail the effect of bath chemistry, additives and operating conditions on the chemical composition, microstructure and properties of Ni–W alloys deposited from citrate-containing baths, in the absence of ammonia or ammonium salts, on stationary working electrodes. The morphology of the deposits was studied by scanning electron microscopy (SEM) as well as atomic force microscopy (AFM), and the approximate composition by energy dispersive spectroscopy (EDS). Metallographic cross-sections were also analyzed, and micro-hardness tests conducted. The results are discussed in detail with emphasis on routes to increase the tungsten content and deposit thickness, while reducing the extent of cracking.