HEALING PERFORMANCE OF OXIDE SCALES ON MICROCRYSTALLINE SUPERALLOY COATING
高温合金微晶涂层上氧化膜的修复性

The healing performances of the protective oxide scales on mierocrystalline coatings of Ni-base superalloy K38G has been studied. The results indicated that the oxide scales on the mierocrystalline coatings may be healed when the original scales are destroyed, and the coatings still have excellent resistances against high temperature oxidation. When the original Al_2O_3 oxide scales are spalled on a small zone, external scales of Al_2O_3 can be formed on the surface. However, when the oxide scales are destroyed on a great zone, mixed oxide scales of (Al,Cr)_2O_3 and TiO_2 can be formed on the surface. The mixed scales are very protective and adherent.