Effect of Conditions of deposition on the structure of Electro-deposited manganese

The effect of cathodic current density and pH of catholyte on the structure of manganese deposit obtained has been studied. Increase in current density from 5 to 30 amps/sq dm prevents the formation of gamma manganese from pure solutions and an amorphous brittle manganese contain-ing about 550 cc of hydrogen per 100 gm is obtained. The hardness of this amorphous deposit is similar to that of alpha manganese. In presence of sulphur dioxide, deposits obtained at low pH values of catholyte show a crystalline pattern of alpha manganese instead of the amorphous depo-sits obtained in the early stages of deposition from the same solution at high pH values.