Abstract: An example system includes at least one acoustic sensor configured to generate at least one time-dependent acoustic data signal indicative of an acoustic signal generated by a thermal spray system performing a process possessing a plurality of process attributes, and a computing device including an acoustic data signal processing module configured to receive the at least one time-dependent acoustic data signal, and transform the at least one time-dependent acoustic data signal to a frequency-domain spectrum, wherein each process attribute of the plurality of process attributes is associated with at least one respective frequency band, and a correlation module configured to determine a process attribute of the plurality of process attributes by identifying at least one characteristic of the frequency-domain spectrum.

Abstract: An article may include a substrate including a metal or alloy; a bond coat directly on the substrate; an intermediate ceramic layer on the bond coat; and an abradable ceramic layer directly on the intermediate ceramic layer. The intermediate ceramic layer includes a stabilized tetragonal prime phase constitution and defines a first porosity. The abradable ceramic layer includes zirconia or hafnia stabilized in the tetragonal prime phase by a second mixture including between about 5 wt. % and about 10 wt. % ytterbia, between about 0.5 wt. % and about 2.5 wt. % samaria, and between about 1 wt. % and about 4 wt. % of at least one of lutetia, scandia, ceria, neodymia, europia, or gadolinia, and a balance zirconia or hafnia. The abradable ceramic layer defines a second porosity, and the second porosity is higher than the first porosity.

Abstract: An example system includes at least one acoustic sensor configured to generate at least one acoustic data signal indicative of an acoustic signal generated by a thermal spray system comprising a flowstream, a computing device, and an acoustic data signal processing module operable by the computing device to determine an ignition attribute of the thermal spray system by analyzing at least a pre-ignition window of the acoustic data signal received by the computing device.

Abstract: In some examples, the disclosure describes an article and a method of making the same that includes a substrate including a ceramic or a ceramic matrix composite including silicon carbide, where the substrate defines an outer substrate surface and a plurality of grooves formed in the outer substrate surface, where each respective groove of the plurality of grooves exhibits an anchor tooth that spans an edge of the respective groove, and where the plurality of grooves define an average groove width less than about 20 micrometers, and a coating formed on the outer surface of the substrate, where the coating at least partially fills the plurality of grooves of the substrate.

Abstract: The disclosure relates to a high temperature mechanical system, such as a gas turbine engine, including a first coating deposited on a first substrate and a second coating deposited on a second substrate. The first coating includes a first bond layer, a second bond layer, and a first ceramic outer layer, wherein the second bond layer is between the first bond layer and first ceramic outer layer. The second coating includes a third bond layer deposited on the substrate and a second ceramic outer layer deposited on the third bond layer. The second coating is configured to abrade the first coating, e.g., during operation of the high temperature mechanical system.

Abstract: An example system includes at least one acoustic sensor configured to generate at least one acoustic data signal indicative of an acoustic signal generated by a thermal spray system comprising a flowstream, a computing device, and an acoustic data signal processing module operable by the computing device to determine an ignition attribute of the thermal spray system by analyzing at least a pre-ignition window of the acoustic data signal received by the computing device.

Abstract: An example system includes at least one acoustic sensor configured to generate at least one time-dependent acoustic data signal indicative of an acoustic signal generated by a thermal spray system performing a process possessing a plurality of process attributes, and a computing device including an acoustic data signal processing module configured to receive the at least one time-dependent acoustic data signal, and transform the at least one time-dependent acoustic data signal to a frequency-domain spectrum, wherein each process attribute of the plurality of process attributes is associated with at least one respective frequency band, and a correlation module configured to determine a process attribute of the plurality of process attributes by identifying at least one characteristic of the frequency-domain spectrum.

Abstract: An article may include an array of features formed in a substrate and may be coated with a coating layer. The array of features may mitigate stress experienced by the coated article. In particular, the array of features may reduce or limit crack propagation at the interface between the substrate and the coating layer. In some examples, the article is an airfoil that includes a tip that defines an edge. An array of features is formed on the surface of the tip, where the array of features is proximate to the edge, and the array of features does not intersect the edge. The airfoil includes a coating layer formed on the surface of the tip and the array of features.

Abstract: An article may include an array of features formed in a substrate and may be coated by a thermal barrier coating (TBC). The array of features may mitigate thermal stress experienced by the coated article. In particular, the array of features may reduce or limit crack propagation at or above the interface of a thermally insulative layer and a bond coat in the TBC. In some embodiments, the array may be formed proximate to and substantially aligned with cooling holes formed in the substrate. In other embodiments, an article may include a first array of features formed in a first location of a substrate and a second array of features formed in a second location of a substrate. The first and second locations may be determined or selected based on a prediction of thermal stresses that the substrate will experience at the first and second locations during use.

Abstract: The disclosure relates to a high temperature mechanical system, such as a gas turbine engine, including a first coating deposited on a first substrate and a second coating deposited on a second substrate. The first coating includes a first bond layer, a second bond layer, and a first ceramic outer layer, wherein the second bond layer is between the first bond layer and first ceramic outer layer. The second coating includes a third bond layer deposited on the substrate and a second ceramic outer layer deposited on the third bond layer. The second coating is configured to abrade the first coating, e.g., during operation of the high temperature mechanical system.

Abstract: An abradable coating may include a rare earth silicate. The abradable coating may be deposited over a substrate, an environmental barrier coating, or a thermal barrier coating. The abradable coating may be deposited on a gas turbine blade track or a gas turbine blade shroud to form a seal between the gas turbine blade track or gas turbine blade shroud and a gas turbine blade. The abradable coating may also include a plurality of layers, such as alternating first and second layers including, respectively, a rare earth silicate and stabilized zirconia or stabilized hafnia.

Abstract: An abradable coating may include a rare earth silicate. The abradable coating may be deposited over a substrate, an environmental barrier coating, or a thermal barrier coating. The abradable coating may be deposited on a gas turbine blade track or a gas turbine blade shroud to form a seal between the gas turbine blade track or gas turbine blade shroud and a gas turbine blade. The abradable coating may also include a plurality of layers, such as alternating first and second layers including, respectively, a rare earth silicate and stabilized zirconia or stabilized hafnia.

Abstract: An article may include an array of features formed in a substrate and may be coated by a thermal barrier coating (TBC). The array of features may mitigate thermal stress experienced by the coated article. In particular, the array of features may reduce or limit crack propagation at or above the interface of a thermally insulative layer and a bond coat in the TBC. In some embodiments, the array may be formed proximate to and substantially aligned with cooling holes formed in the substrate. In other embodiments, an article may include a first array of features formed in a first location of a substrate and a second array of features formed in a second location of a substrate. The first and second locations may be determined or selected based on a prediction of thermal stresses that the substrate will experience at the first and second locations during use.

Abstract: A method of coating a substrate, the method including depositing mullite on the substrate during a first time period via thermal spraying to form a first layer, the mullite comprising mullite powder formed via at least one of a fused plus crush or sinter plus crush process; and depositing a second material on the first layer to form a second layer, wherein the substrate is at a temperature less than approximately 50 degrees Celsius at approximately a beginning of the first time period. In some embodiments, the method may further include depositing silicon to form a silicon bond layer between the substrate and mullite layer.

Abstract: An article may include an array of features formed in a substrate and may be coated with a coating layer. The array of features may mitigate stress experienced by the coated article. In particular, the array of features may reduce or limit crack propagation at the interface between the substrate and the coating layer. In some examples, the article is an airfoil that includes a tip that defines an edge. An array of features is formed on the surface of the tip, where the array of features is proximate to the edge, and the array of features does not intersect the edge. The airfoil includes a coating layer formed on the surface of the tip and the array of features.

Abstract: An abradable coating may include a rare earth silicate. The abradable coating may be deposited over a substrate, an environmental barrier coating, or a thermal barrier coating. The abradable coating may be deposited on a gas turbine blade track or a gas turbine blade shroud to form a seal between the gas turbine blade track or gas turbine blade shroud and a gas turbine blade. The abradable coating may also include a plurality of layers, such as alternating first and second layers including, respectively, a rare earth silicate and stabilized zirconia or stabilized hafnia.

Abstract: The present invention relates to a method for depositing braze alloy on a surface of a component that will be subsequently joined to a second component. In one form a braze alloy is sprayed by a thermal process. The braze alloy is sprayed in such a fashion that substantially all of the powder braze alloy is unmolten, but is heated to a state deformable enough to bond to the surface. One form of the spraying operation utilizes a High Velocity Oxygen Fuel spray gun.