Improvement in tensile ductility of electrodeposited bulk nanocrystalline Ni–W by sulfamate bath using propionic acid

In this study, the electrodeposition process for bulk nanocrystalline (nc) Ni–W was improved in order to enhance the tensile ductility of bulk nc Ni–W with improvements in residual stress and current efficiency, which are one of the major challenges faced in traditional electrodeposition processes for Ni–W, were realized. Nickel sulfamate electrolyte was chosen as the main bath composition to reduce residual stress in the electrodeposits. To increase current efficiency, Ni concentration in the bath was increased and propionic acid was used as a complexing agent. A sulfamate bath using propionic acid was used to produce bulk nc Ni–W with W concentrations of 1.4 wt.%. To fabricate bulk specimens, the pH and temperature of the bath were strictly maintained at 4.0 and 323 K, respectively. The bulk nc Ni–W exhibited tensile strength of about 1.3 GPa and tensile ductility of 2.7%.

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