Accession Number:

ADA280093

Title:

Electrochemical Impedance Spectroscopy of Trivalent Chromium Pre-Treated Aluminum Alloys

Descriptive Note:

Progress rept.,

Corporate Author:

NAVAL AIR WARFARE CENTER AIRCRAFT DIV WARMINSTER PA AIR VEHICLE AND CREW SYSTEMS TECHNOLOGY DEPT

Personal Author(s):

• Agarwala, Vinod S.
• Beckert, Dieter W.

Report Date:

1993-12-14

Pagination or Media Count:

22.0

Abstract:

A chemical conversion coating on aluminum alloys was developed using a trivalent chromium bath. Electrochemical impedance spectroscopy EIS was made to characterize the corrosion resistant properties of the surface films formed. The results showed a 10 to 100 fold increase in the polarization resistance of the surface films compared to the untreated aluminum alloy. These electrochemical results compared well with the corrosion behavior in salt spray tests. The trivalent chromium-treated surfaces showed no corrosion for up to 200 hours in 5 salt spray. A post-treatment with an oxidizer even further raised the coatings resistance due to an improved corrosion protection. Corrosion protection, Conversion coatings, Ac-impedance, Chromate, Aluminum alloys.

Descriptors:

• *ALUMINUM ALLOYS
• *SPECTROSCOPY
• *COATINGS
• *CHROMIUM
• *ELECTROCHEMISTRY
• *IMPEDANCE
• TEST AND EVALUATION
• CONVERSION
• CHEMICALS
• FILMS
• CORROSION RESISTANCE
• SALT SPRAY TESTS
• BATHS
• OXIDIZERS
• PROTECTION
• SURFACES
• ALTERNATING CURRENT
• CHROMATES
• RESISTANCE
• POLARIZATION
• AIRCRAFT
• CORROSION

Subject Categories:

• Inorganic Chemistry
• Physical Chemistry
• Properties of Metals and Alloys
• Atomic and Molecular Physics and Spectroscopy

Distribution Statement:

APPROVED FOR PUBLIC RELEASE