| 摘要 |
In some cases it is necessary to coat aluminium with nickel, the most difficult operating conditions probably being encountered in aluminium pistons in internal combustion engines. Adhesion problems are encountered, during further coating with other metals when known processes are employed. Satisfactory solutions are not obtained without intermediate activation. However, this solution is obtained by high proportions of nickel sulphate, small proportions of an acid which stabilises the pH, very small proportions of a fluoride which disintegrates the oxide layer produced in the lithium/cerium bath, a chloride which promotes the dissolution of the nickel anodes and a phosphite which improves the adhesion of the nickel layer. The solids in the bath are kept in suspension by vigorously circulating, for example, air. The particle size should preferably be 3 micrometers.
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