中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 19 No. 4 August 2009 |
（1. Industrial Technology Research Institute of Okayama Prefecture,
5301 Haga, Okayama-shi, Okayama 701-1296, Japan;
2. Okayama University of Science, 1-1, Ridai-cho, Okayama-shi, Okayama 700-0005, Japan）
Abstract:The effects of alloying elements on zincate treatment and adhesion of electroless Ni-P coating onto various aluminum alloy substrates were examined. Surface morphology of zinc deposits in the 1st zincate treatment and its adhesion were changed depending on the alloying element. The zinc deposits in the 2nd zincate treatment became thinly uniform, and the adhesion between aluminum alloy substrate and Ni-P coating was improved irrespective of the alloying element. XPS analysis revealed the existence of zinc on the surface of each aluminum alloy substrate after the pickling in 5% nitric acid. This zinc on the surface should be an important factor influencing the morphology of zinc deposit at the 2nd zincate treatment and its adhesion.
Key words: electroless Ni-P coating; aluminum alloy; zincate treatment; adhesion
