| 摘要 |
Nickel plating baths contain 500-700 g. nickel sulphamate per litre. Nickel chloride and boric acid may also be present, and pH is preferably 2-5.5. Temperatures up to 70 DEG C. at high current density may be used, to form thick coatings of the electroforming type, which may have a hard coating and a thicker less hard coating. Internal stress is stated to be low, and graphs are given of stress, current density, sulphamate concentration, and temperature. Brighteners are not essential but these may be added, e.g. saccharin, and acetylenic alcohols. The electrolyte may be purified and freed from Cu by low C.D. electrolysis. |
