Methods for making environmental barrier coatings using sintering aids

摘要

A method for making an environmental barrier coating (12) using a sintering aid comprising: combining at least water, and a primary transition material comprising mullite, BSAS, or a mullite/BSAS mixture to produce a transition layer slurry; applying the transition layer slurry to a ceramic component (10); combining at least water, and a primary outer material comprising BSAS to produce an outer layer slurry; applying the outer layer slurry to the component having the applied transition layer slurry; and sintering the component to produce the environmental barrier coating having at least a transition layer (16) and an outer layer (18) wherein at least one of the transition layer slurry or the outer layer slurry comprises a slurry sintering aid and wherein the transition layer comprises a porosity of from 0% to about 30% by volume of the transition layer, and the outer layer comprises a porosity of from 0% to about 15% by volume of the outer layer.