ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Intergranular corrosion (IGC) of model alloys in the 6000-series, with and without 0.2 wt% Cu,was studied using an accelerated corrosion test (BS ISO 11846 B), FE-SEM and FE-TEM. Low Cualloys (0.02wt%) did not exhibit IGC even though they contained excess Si. The high-Cu, naturallyaged material (T4) was susceptible to severe superficial etching. In the underaged state (belowpeak strength), the Cu-containing material was highly susceptible to IGC. Materials aged to peakstrength (T6) or overaged were only slightly susceptible to IGC, with localized, shallow attacks.FE-TEM investigation of the underaged material revealed scattered, small AlMgSiCu-typeprecipitates, as well as a Cu-enriched film along the grain boundaries. The overaged materialshowed more extensive, coarse grain boundary precipitation. However, the Cu-enriched film wasstill present at localized sites. The reduced susceptibility to IGC upon artificial ageing wasattributed to breaking of the continuity of the grain boundary film. The possible role of matrixprecipitation is also discussed
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/13/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.519-521.667.pdf
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