| 摘要 |
A method of producing smooth zinc coatings on aluminium substrates comprises forming a zinc or zinc alloy deposit on the substrate and then employing a nitric acid bath containing a source of Group VIII metal ions, eg ferric ions as a zinc remover. Optionally the step of forming the zinc or zinc alloy deposit on the substrate is repeated. The zinc deposit is preferably formed by electroless deposition. In an alternative embodiment a method of forming a metal coating, other than zinc, on an aluminium substrate having a zinc or zinc alloy coating comprises forming a metal coating by electroless plating using a metal plating composition comprising a source of metal ions, a source of cadmium ions and a reducing agent. The coated product may be used as a memory disc. |
