High temp. oxidn. resistant coated metal article

摘要

A coated article, for use at above 1000 deg.C in an oxygen-contg. environment, consists of a Ni, Co, Cr or Fe based alloy substrate and an oxygen barrier coating. The coating consists of either (a) a glass-ceramic comprising (by wt.) barium silicate (20-65% BaO and 25-65% SiO2) max. 50% additive and max. 5% B2O3 + R2O (R = Na, K, Li) or strontium silicate (20-60% SrO and 30-70% SiO2), max. 40% additive and max. 5% B2O3 + R2O, the additive comprising one or more of up to 15% Al2O3, up to 15% ZrO2, up to 15% Y2O3, up to 25% MnO, up to 25% NiO, up to 30% MgO, up to 30% CoO and up to 40% iron oxide; or (b) a glass-ceramic having a main crystalline phase selected from barium silicate-type, strontium silicate-type and cristobalite phase and contg. cristobalite crystals conc. near the interface between the glass-ceramic and the metal substrate.