Patent ID: 9005717
Filing Date: 2015-04-14
Classification: C04B

Abstract:
1. A method for making an environmental barrier coating using a sintering aid, the method comprising: applying a bond coat layer to a ceramic component; combining at least an organic solvent, at least one slurry sintering aid, and a primary transition material comprising a rare earth disilicate to produce a transition layer slurry, the at least one slurry sintering aid containing at least one doping composition chosen from the group consisting of iron, aluminum, titanium, gallium, nickel, boron, alkali metals, alkaline-earth metals, and Lnb rare earth metals; optionally combining at least an organic solvent and a primary outer material comprising a rare earth monosilicate or a doped rare earth monosilicate to produce an outer layer slurry; optionally combining at least an organic solvent and a primary compliant material comprising BSAS or a rare earth doped BSAS to produce a compliant layer slurry; applying at least the transition layer slurry and optionally applying the outer layer slurry and/or the compliant layer slurry to the bond coat layer on the ceramic component; and sintering the ceramic component to produce the environmental barrier coating having at least the bond coat layer, a transition layer formed by the transition layer slurry, optionally an outer layer formed by the outer layer slurry, and optionally a compliant layer formed by the compliant layer slurry, the sintering step causing the at least one slurry sintering aid to dissolve into at least the primary transition material to form therein a doped rare earth disilicate containing the at least one doping composition, optionally any of the at least one slurry sintering aid that does not dissolve into the primary transition material forming a secondary material, the transition layer containing 0% to about 15% by volume of porosity.