Alloying Effect of Copper Concentration on the Localized Corrosion of Aluminum Alloy for Heat Exchanger Tube

作者：Hong Min Sung; Park In Jun; Kim Jung Gu

来源：Metals and Materials International, 2017, 23(4): 708-714.

DOI：10.1007/s12540-017-6589-9

• alloys
• intermetallics
• corrosion
• electrochemistry
• secondary ion mass spectroscopy (SIMS)

This study examined the alloying effect of Cu content on the localized corrosion properties of Al alloy in synthetic acid rain containing 200 ppm of Cl-ion. In aluminum alloy tubes, a small amount of Cu is contained as the additive to improve the mechanical strength or as the impurity. The Cu-containing intermetallic compound, Al2Cu can cause galvanic corrosion because it has more noble potential than Al matrix. Therefore aluminum tube could be penetrated by localized corrosion attack. The results were obtained from electrochemical test, scanning electron microscopy, and time of flight secondary ion mass spectrometry (ToF-SIMS) mapping. Severe localized corrosion was occurred on the Al-0.03 wt% Cu alloy. The negative effect of Cu on the pitting corrosion was attributed to the presence of the Al2Cu precipitates.

• 出版日期2017-7