Thermal Stability and Aging Characteristics of Chromate Conversion Coatings on Aluminum Alloy 2024-T3.

Laget, V. ; Jeffcoate, C. ; Isaacs, H. S. ; Buchheit, R. G.

Technical Information Center Oak Ridge Tennessee

关键词: Aluminium alloys;    Thermal stability;    Aging;    Protective coatings;    Chromates;   

RP-ID  :  DE2004770783

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

XANES and electrochemical impedance spectroscopes were used in parallel to correlate the amount of Cr(VI) in chromate conversion coatings (CCC) on Al 2024 and their corrosion resistance in order to understand the degradation mechanisms upon aging or heating. Cr(VI) species appear to be immobilized for temperatures higher than 80 C due to dehydration. CCC are shown to be dynamic in the first month of aging with no significant dehydration. Another degradation mechanism involving chemical changes is to be considered.