Electrodeposition & characterization of Co-W alloys

Cobalt-tungsten alloys have been electroplated from alkaline bath solutions under different plating and bath conditions. Diammonium hydrogen citrate a nd dimethyl sulfoxide in the bath solution have produced good quality depos its. The hardness and magnetic properties of the alloys are found to depend on composition and heat treatment. Cyclic voltammetric and spectral studie s revealed the complexation of cobalt ions with diammnonium hydrogen citrat e in the plating bath solution. Dimethyl sulfoxide has activated the codepo sition of tungsten. The alloys are amorphous under plating conditions and b ecome partially crystalline upon heat treatment. AES analysis revealed the absence of oxygen, chlorine and carbon on the surface of the coated alloys. Working conditions were optimized to get good quality deposits with apprec iable coercivity and hardness values.