Patent ID: 8501840

Claim:
A water based slurry composition adapted to be sintered to form an environmental barrier coating, the slurry composition comprising: from about 1 wt % to about 99.9 wt % water; from about 0.1 wt % to about 72 wt % of a primary material chosen from the group consisting of rare earth disilicates, doped rare earth disilicates, rare earth monosilicates, doped rare earth monosilicates, barium-strontium-aluminosilicates or rare earth doped barium-strontium-aluminosilicates; and from about 0.1 wt % to about 25 wt % of at least one slurry sintering aid that is reactive with the primary material to form a secondary material; wherein if the primary material is rare earth disilicate, doped rare earth disilicate, rare earth monosilicate, or doped rare earth monosilicate, then the at least one sintering aid contains at least one doping composition capable of doping the primary material during sintering of the slurry composition, the doping composition being chosen from the group consisting of iron, aluminum, titanium, gallium, nickel, boron, alkali metals, alkaline-earth metals, and Lnb rare earth metals; and wherein if the primary material is barium-strontium-aluminosilicate or rare earth doped barium-strontium-aluminosilicate, then the at least one sintering aid is a rare earth nitrate, rare earth acetate, rare earth chloride, rare earth oxide, ammonium phosphate, phosphoric acid, polyvinyl phosphoric acid, or a combination thereof.