Abstract: An additive manufacturing technique may include depositing, via a filament delivery device, a filament onto a surface of a substrate. The filament includes a binder and a powder including at least one metal or alloy and at least one braze alloy. The technique also includes sacrificing the binder to form a preform. The technique also includes sintering the preform to form a component including the at least one metal or alloy and the at least one braze alloy.

Abstract: In some examples, a method of forming an article for a gas turbine engine, the method comprising depositing a powder to form a protective coating on a leading edge of an airfoil substrate. The deposited powder includes carbide particles in a metal matrix and the carbide particles in the powder have an average particle size of about 1 micron or less. The protective coating on the leading edge of the airfoil substrate includes the carbide particles in the metal matrix.

Abstract: A suspension plasma spray deposition system comprising a suspension plasma spray device configured to deposit coating material on a surface of a component. The surface of the component includes a plurality of apertures. The system further includes a fluid flow system configured to flow fluid through the plurality of apertures in the surface of the component to reduce deposition of coating material in plurality of apertures. The fluid flow through each respective aperture of the plurality of apertures in the surface of the component is between about 0.095 and about 0.200 cubic feet per minute (cfm).

Abstract: An article may include a substrate and a coating system on the substrate. The coating system may include a thermal barrier coating (TBC) layer and a CMAS resistant layer on the TBC layer. The CMAS layer includes a rare-earth (RE) monosilicate composition including a plurality of RE metal cations, wherein RE monosilicate composition is configured to react with CMAS to form a reaction product including a RE apatite phase with a RE2O3·SiO2 composition, wherein the RE of the RE2O3·SiO2 composition includes at least one of the plurality of RE metal cations of the RE monosilicate.

Abstract: An article may include a substrate defining at least one at least partially obstructed surface. The substrate includes at least one of a ceramic or a ceramic matrix composite. The article also may include a multilayer, multi-microstructure environmental barrier coating on the at least partially obstructed substrate. The multilayer, multi-microstructure environmental barrier coating includes a first layer comprising a rare earth disilicate and a substantially dense microstructure; and a second layer on the first layer. The second layer includes a columnar microstructure and at least one of a rare earth monosilicate or a thermal barrier coating composition comprising a base oxide comprising zirconia or hafnia; a primary dopant comprising ytterbia; a first co-dopant comprising samaria; and a second co-dopant comprising at least one of lutetia, scandia, ceria, gadolinia, neodymia, or europia.

Abstract: In general, techniques are described for fused filament fabrication of abradable coatings. An additive manufacturing system comprising a substrate defining a major surface, a filament delivery device, and a computing device may be configured to perform various aspects of the techniques. The computing device may be configured to control the filament delivery device to deposit a filament on the substrate, the filament including a powder and a binder, wherein the binder is configured to be substantially removed from the filament and the powder includes a metal or alloy configured to be sintered to form an abradable layer.

Abstract: An article may include a substrate including a ceramic matrix composite (CMC); a composite coating layer including a first coating material that includes a rare-earth disilicate and a second coating material that includes at least one of a rare-earth monosilicate, a CMAS-resistant material, or a high-temperature dislocating material, where the second coating material forms a substantially continuous phase in the composite coating layer.

Abstract: An article that includes a substrate; a first layer including yttria and zirconia or hafnia, where the first layer has a columnar microstructure and includes predominately the zirconia or hafnia; a second layer on the first layer, the second layer including zirconia or hafnia, ytterbia, samaria, and at least one of lutetia, scandia, ceria, neodymia, europia, and gadolinia, where the second layer includes predominately zirconia or hafnia, and where the second layer has a columnar microstructure; and a third layer on the second layer, the third layer including zirconia or hafnia, ytterbia, samaria, and a rare earth oxide including at least one of lutetia, scandia, ceria, neodymia, europia, and gadolinia, where the third layer has a dense microstructure and has a lower porosity than the second layer.

Abstract: In some examples, an article may include a substrate and a coating system on the substrate. The coating system may include a layer comprising a plurality of voids, wherein respective voids of the plurality of voids define respective void volumes; and a nucleating agent within at least some of the respective void volumes of the layer, wherein the nucleating agent is configured to induce crystallization of the molten CMAS. The coating system may include an environmental barrier coating, thermal barrier coating, and/or abradable coating.

Abstract: In some examples, a method comprising: controlling a first ratio of a first liquid to a second liquid to form a first suspension comprising a powder and a first carrier liquid composition comprising at least one of the first liquid or the second liquid; directing the first suspension comprising the first carrier liquid and the powder to a plume of a thermal spray device; forming a first portion of a coating comprising the powder on a substrate from the first suspension; controlling a second ratio of the first liquid to the second liquid to form a second suspension comprising a second carrier liquid composition and the powder; directing the second suspension comprising the second carrier liquid composition and the powder to the plume of the thermal spray device; and forming a second portion of the coating comprising the powder on the substrate from the second suspension.

Abstract: An additive manufacturing technique includes depositing, via a filament delivery device, a filament onto a surface of a substrate. The filament includes a binder and a high entropy alloy powder. The technique also includes sacrificing the binder to form a preform and sintering the preform to form a component.

Abstract: An additively manufactured component that includes a tool with a region having a plurality of overlying metal layers each derived from a metal powder filament. The region has a predetermined yield point selected based on an operation to be performed with the tool.

Abstract: In some examples, an additive manufacturing technique including forming an as-deposited coating on a substrate by depositing a filament via a filament delivery device, wherein the filament includes a sacrificial binder and a powder; removing substantially all the binder from the as-deposited coating; and sintering the as-deposited coating to form a thermal coating; wherein the thermal coating is configured to ablate in response to absorption of energy from an external environment, and wherein the ablation of the thermal coating reduces the energy transferred to the substrate.

Abstract: The disclosure describes articles and techniques that include an airfoil having a hybrid coating system to provide improved particle impact resistance and improve CMAS attack resistance on the pressure side of the airfoil and improved thermal load protection on the suction side of the airfoil. An example article for a gas turbine engine may include a substrate, and a hybrid environmental barrier coating (EBC) including a relatively dense EBC layer on a first portion of the substrate and a relatively porous EBC layer on a second portion of the substrate, where the first portion of the substrate is different from the second portion of the substrate, and wherein at least a portion of the relatively porous EBC layer overlaps at least a portion of the relatively dense EBC layer in an overlap region.

Abstract: Techniques for abrasively blasting (e.g., grit blasting) components, such as ceramic or CMC components. In some examples, based on a comparison of component geometry to a target geometry, a blasting path over the surface of the component may be generated for a selected traverse speed. A computing device may control a blasting device to blast the component according to the generated blasting path with the selected traverse speed. In some examples, based on a comparison of a component geometry to a target geometry, a respective traverse speed for a blasting device relative the component for each section of a plurality of sections over a surface of the component may be generated. A computing device controls the blasting device to blast the component according to the respective traverse speeds relative over a surface of the component to remove material from the surface of the component.

Abstract: In some examples, an additive manufacturing technique for forming a vacuum insulator. For example, a method including forming an article including a first layer, a second layer, and at least one support member extending between the first and second layer by depositing a filament via a filament delivery device, wherein the filament includes a sacrificial binder and a powder, and wherein the first layer, second layer, and at least one support member define an open cavity within the article; removing the binder; and sintering the article to form the vacuum insulator, wherein the vacuum insulator defines a vacuum environment in the cavity.

Abstract: In some examples, a method for additively manufacturing a heat pipe, the method including depositing, via a filament delivery device, a filament to form a heat pipe preform, wherein the filament includes a binder and a metal or alloy powder; and sintering the heat pipe preform to form the heat pipe, the heat pipe including an outer shell, a wicking region, and a vapor transport region defined by the metal or alloy.

Abstract: A method may include fused filament fabricating a fused filament fabricated component by delivering a softened filament to selected locations at or adjacent to a build surface. The softened filament may include a sacrificial binder and a powder including a shape memory alloy (SMA). The method also may include removing substantially all the sacrificial binder from the fused filament fabricated component to leave an unsintered component; and sintering the unsintered component to join particles of the SMA and form an SMA component.

Abstract: A composite component may include a substrate including a first material and defining a surface; and at least one feature attached to the surface of the substrate. The at least one feature may include a second, different material attached to the surface using cold spraying. Cold spraying may include accelerating particles of the second material toward the surface without melting the particles.

Abstract: The disclosure describes an example technique that includes cold spraying first particles and second particles of a metal alloy on at least a portion of a surface of a substrate to form a deposit on the surface of the substrate. The first and second particles have been subjected to different heat treatments prior to cold spraying. Cold spraying involves accelerating the first particles and the second particles toward the surface of the substrate without melting or creating other thermally induced changes to a microstructure of the first and second particles. As a result, the first particles form a first, heat-treated component and the second particles form a second non-heat-treated or differently-heat-treated component, and the particles and substrate are not subject to a heat treatment during the cold spray process that may further modify their thermomechanical properties.