Looking for a surface treatment to deposit a reactive element with potential industrial use in high temperature oxidation field

摘要

In order to introduce a so-called reactive element simultaneously at all the surfaces of a NiCr (Ni-20wt.%Cr-1.5wt.%Si) metallic substrate alloy, an easy to apply surface treatment was used: an yttrium containing thin film (constituted of a hydrated yttrium hydroxide nitrate) was electrodeposited from a mixed water-ethanol solution. After a thermal conversion treatment at 600℃ under argon, leading to an Y{sub}2O{sub}3 coating, specimens were submitted to high-temperature oxidation testing, under artificial air at atmospheric pressure, in order to evaluate in these conditions the effect of the coatings on the behaviour of the studied alloy. Expected effects of the introduced reactive element (REE) were effectively shown: decrease of the coated sample weight gain, suppression of the formation of the base metal oxides and change of the oxide grains morphology.