Studies of Localized Corrosion in Welded Aluminum Alloys by the Scanning Reference Electrode Technique

NASA/TP-3588, Danford, M.D. and Nunes, A.C., Studies of Localized Corrosion in Welded Aluminum Alloys by the Scanning Reference Electrode Technique, Materials and Processes Laboratory, Science and Engineering Directorate. NASA Marshall Space Flight Center, AL 35812, November 1995, pp. 14, Format(s): PDF 679k

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Localized corrosion in welded samples of 2219-T87 Al alloy (2319 filler), 2090 Al-Li alloy (4043 and 2319 fillers), and 2195 Al-Li alloy (4043 and 2319 fillers) has been investigated using the relatively new scanning reference electrode technique. The weld beads are cathodic in all cases, leading to reduced anode/cathode ratios. A reduction in anode/cathode ratio leads to an increase in the corrosion rates of the welded metals, in agreement with results obtained in previous electrochemical and stress corrosion studies involving the overall corrosion rates of welded samples. The cathodic weld beads are bordered on both sides by strong anodic regions, with high propensity for corrosion.

Keywords:	aluminum-lithium alloys, localized corrosion, heterogeneous welds, 2219-t87 aluminum alloy
CASI Document ID Number:	96N22263
Subjects:	Chemistry and Materials: Metals and Metallic Materials: Aluminum
ID Code:	300
Deposited On:	27 June 2002