MINOR ELEMENT ADDITIONS TO SINGLE CRYSTALS FOR IMPROVED OXIDATION RESISTANCE

摘要

Minor Element Additions to Single Crystals For Improved Oxidation Resistance The additions of minor additions of hafnium and silicon and mixtures thereof to nickel base superalloy single crystal articles provide significantly improved oxidation resistance. The oxidation resistance is improved both for the case of uncoated articles and in the case where a protective coating such as for example, a MCrAlY coating is present. For example the addition of .1% hafnium is observed to improve the oxidation resistance by a factor of 4 at 2100.degree.F and a similar addition improved the coated oxidation resistance by a factor of about 2.5 at 2150.degree.F.