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: A method for connecting or joining a first substrate and a second substrate across an interface between the first substrate and the second substrate. The method includes disposing a fastener precursor in the bore and sintering the fastener precursor in the bore. The fastener precursor densifies and shrinks in at least one dimension to mechanically interlock with a contour in the bore and form a mechanical fastener in the bore, and the mechanical fastener forms an interlock between the first substrate and the second substrate.

Abstract: A dual walled component includes a spar comprising a plurality of pedestals; a coversheet attached to a first set of pedestals from the plurality of pedestals; and a repaired coversheet portion attached to a second set of pedestals from the plurality of pedestals and to the coversheet, where the repaired coversheet portion includes a braze material.

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: A method may include removing a portion of a base component adjacent to a damaged portion of the base component to define a repair portion of the base component. The base component may include a cobalt- or nickel-based superalloy, and the repair portion of the base component may include a through-hole extending from a first surface of the base component to a second surface of the base component. The method also may include forming a braze sintered preform to substantially reproduce a shape of the through-hole. The braze sintered preform may include a Ni- or Co-based alloy. The method additionally may include placing the braze sintered preform in the through-hole and heating at least the braze sintered preform to cause the braze sintered preform to join to the repair portion of the base component and change a microstructure of the braze sintered preform to a brazed and diffused microstructure.

Abstract: A dual walled component includes a spar comprising a plurality of pedestals; a coversheet attached to a first set of pedestals from the plurality of pedestals; and a repaired coversheet portion attached to a second set of pedestals from the plurality of pedestals and to the coversheet, where the repaired coversheet portion includes a braze material.

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: 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 binder and a primary material. The binder is configured to release a secondary material upon heating at or above a conversion temperature. The method also may include heating the fused filament fabricated component to a temperature at or above the conversion temperature to sinter the primary material to form a sintered part and cause the binder to release the secondary material within the sintered part.

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 method may include removing a portion of a base component adjacent to a damaged portion of the base component to define a repair portion of the base component. The base component may include a cobalt- or nickel-based superalloy, and the repair portion of the base component may include a through-hole extending from a first surface of the base component to a second surface of the base component. The method also may include forming a braze sintered preform to substantially reproduce a shape of the through-hole. The braze sintered preform may include a Ni- or Co-based alloy. The method additionally may include placing the braze sintered preform in the through-hole and heating at least the braze sintered preform to cause the braze sintered preform to join to the repair portion of the base component and change a microstructure of the braze sintered preform to a brazed and diffused microstructure.

Abstract: In some examples, a technique including positioning supports such that the supports are between a first metallic substrate and a second metallic substrate, wherein an undulating member is located between the first metallic substrate and the second metallic substrate, the undulating member defining a plurality of first peaks adjacent to a first surface of the first metallic substrate and a plurality of second peaks adjacent to a second surface of the second metallic substrate, wherein a first support of the supports is positioned such that the first support extends between a first peak of the plurality of first peaks and the second surface of the second metallic substrate; welding the first peak to the first surface of the first metallic substrate in an area of the first support; and removing the first support by at least one of a thermal removal process or a chemical removal process.

Abstract: A method may include removing a portion of a base component adjacent to a damaged portion of the base component to define a repair portion of the base component. The base component may include a cobalt- or nickel-based superalloy, and the repair portion of the base component may include a through-hole extending from a first surface of the base component to a second surface of the base component. The method also may include forming a braze sintered preform to substantially reproduce a shape of the through-hole. The braze sintered preform may include a Ni- or Co-based alloy. The method additionally may include placing the braze sintered preform in the through-hole and heating at least the braze sintered preform to cause the braze sintered preform to join to the repair portion of the base component and change a microstructure of the braze sintered preform to a brazed and diffused microstructure.

Abstract: A method for connecting or joining a first substrate and a second substrate across an interface between the first substrate and the second substrate. The method includes disposing a fastener precursor in the bore and sintering the fastener precursor in the bore. The fastener precursor densifies and shrinks in at least one dimension to mechanically interlock with a contour in the bore and form a mechanical fastener in the bore, and the mechanical fastener forms an interlock between the first substrate and the second substrate.

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: In some examples, a braze material includes a first set of particles, a second set of particles, and a polymeric binder. The first set of particles includes a braze powder, where the braze powder comprises an Si-containing alloy. The first set of particles defines an average or median particle diameter between about 1 ?m and about 40 ?m. The second set of particles includes at least one of SiC or a transition metal carbide, where the second set of particles has a multimodal particle size distribution.

Abstract: In some examples, a method for forming a ballistic armor article, the method including forming a preform article by depositing a filament via a filament delivery device, wherein the filament includes a sacrificial binder and a powder; removing the binder from the preform article; and sintering the preform article to form the ballistic armor article, wherein the ballistic armor article is configured to absorb energy from an external projectile that impacts the ballistic armor article, and wherein the ballistic armor article is configured to prevent the projectile from penetrating through the ballistic armor article.

Abstract: An example article may include a component, a substrate including a first ceramic, a joining layer between the component and the substrate, and a joint surface coating between the substrate and the joining layer. The joint surface coating may include a diffusion barrier layer including a second ceramic material, and a compliance layer including at least one of a metal or a metalloid. An example technique may include holding a first joining surface of a coated component adjacent a second joining surface of a second component. The example technique may further include heating at least one of the coated component, the second component, and a braze material, and brazing the coated component by allowing the braze material to flow in a region between the first joining surface and the second joining surface.