A Study of the Environment–Friendly Chrome-Free Chemical Conversion Coating on 2024 Aluminium Alloy
In order to develop an environment-friendly method of forming a chemical conversion coating on 2024 aluminium alloy surface without the toxic hexavalent chromium compounds, in this paper a process with sodium molybdate and potassium permanganate as the main compositions of the treating bath has been investigated. Solution composition and process parameters have been optimized. The chemical conversion coating has good corrosion resistance, evaluated with dropping test. Micro-structure and components of the conversion coating have been studied by various micro-analysis methods, and the growth mechanism of the chemical conversion coating has also been investigated.
Jitai NIU, Zuyan LIU, Cheng JIN and Guangtao Zhou
D. C. Chen et al., "A Study of the Environment–Friendly Chrome-Free Chemical Conversion Coating on 2024 Aluminium Alloy", Materials Science Forum, Vols. 575-578, pp. 864-868, 2008