Abstract: There is set forth herein a silicon-based patch formulation comprising about 25 to 66 percent by volume of a solvent; about 4 to 10 percent by volume of a silicon-comprising binding material; and about 30 to 65 percent by volume of a patching material, the patching material comprising particles having one or more non-actinide Group IIIA elements, wherein a molar ratio of the one or more non-actinide Group IIIA elements to silicon within the patch formulation is about 0.95 to 1.25.

Abstract: In one example of the present technology, a method for forming an article includes disposing an electrically conductive coating on a substrate. The method further includes disposing a layer stack on the electrically conductive coating by (i) disposing a first barrier coating by electrophoretic deposition; (ii) heat treating the first barrier coating; (iii) disposing an electrically conductive layer on the first barrier coating; and (iv) optionally repeating steps (i) to (iii). The method further includes disposing a second barrier coating on an outermost electrically conductive layer in the layer stack by electrophoretic deposition; and heat treating the second barrier coating.

Abstract: A rare earth silicate-based hermetic layer includes a thermal sprayed coating including a rare earth silicate having a hermetic microstructure. An environmental barrier coating includes a bond coat layer including silicon; and at least one rare earth silicate-based hermetic layer deposited on the bond coat layer by thermal spraying. The rare earth silicate-based hermetic layer includes a thermal sprayed coating including a rare earth silicate having a hermetic microstructure. An article for service in extreme environments may be provided with such an environmental barrier coating. A thermal spray feedstock for producing a rare earth silicate-based hermetic layer.

Abstract: Methods of manufacturing turbine shrouds with an abradable coating that balance the apparently contradictory requirements of high flowpath solidity, low blade tip wear, and good durability in service. The methods include obtaining a shroud substrate. The methods may include obtaining a coating system on the shroud substrate. The methods include forming an abradable coating on a surface of the coating system so as to form a substantially smooth flowpath surface. Forming the abradable coating includes forming a relatively dense scaffold and relatively porous filler regions in-between the relatively dense abradable scaffold. The methods may also include machining the abradable so as to achieve a substantially smooth flowpath surface comprising a relatively porous abradable phase surrounded by a relatively dense, high-durability corrale phase.

Abstract: An environmentally resistant patch includes one or more rare earth silicates, wherein an inorganic composition of the environmentally resistant patch includes, once cured, from about 80 mole percent to about 100 mole percent of a rare earth monosilicate and/or rare earth disilicate composition and from about 0 mole percent to about 20 mole percent of an inorganic additive, and, wherein the environmentally resistant patch has, once cured, an adhesive strength of at least about 3 MPa and a coefficient of thermal expansion of from about 3.5×10?6/° C. to about 7.5×10?6/° C.

Abstract: A bond layer may be applied to the substrate of an article and a first layer may be applied to the bond layer by thermal spray. A second layer may be applied above the first layer by slurry coating.

Abstract: Processes for fabricating ceramic membranes include providing a porous substrate having at least one inner channel extending therethrough and having surfaces defined by porous walls, depositing a coating slurry on surfaces of the inner channel(s), and sintering. Sintering temperatures for the processes range from about 400° C. to 800° C. Coating slurries for use in the processes include a boehmite sol and a colloidal suspension of porous alumina particles.