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SAŽETAK
Korozijska svojstva lijevanih Al-Si slitina eutektičkog sastava ispitivana
su u neutralnom kloridnom mediju obzirom na utjecaj Si i mikrostrukturne
modifikacije uvjetovane metalurškom obradbom taljevine. Pokazalo se da
Si djeluje kao katodni konstituent u Al-matriksu i pozitivira korozijski
potencijal u odnosu na čisti Al. Korozijske struje slitina manje su nego
kod Al, no sklonost pitingu je veća. Suprotno tome, eutektički Si poboljšava
repasivacijsku sposobnost slitina.
KLJUČNE RIJEČI
lijevane Al-Si slitine eutektičkog sastava, metalurška obradba taljevine,
mikrostruktura, ciklička polarizacija, korozijska svojstva
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SUMMARY
Corrosion properties of as-cast Al-Si eutectic alloys in a neutral chloride
solution were examined considering silicium and microstructural modifications
by melt treatment. It was shown that Si acts as a cathodic constituent
in Al-matrix and moves the corrosion potential to a more noble direction
compared to pure Al. Corrosion currents of alloys were lower than those
for pure Al, while the susceptibility to pitting was greater. On the contrary,
eutectic Si has a benefitial influence on the repassivation ability of
alloys tested.
KEY WORDS
as-cast Al-Si eutectic alloys, metallurgical treatment, microstructure,
cyclic polarization, corrosion properties
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