A technique is described for the application of three-dimensional (3D) relief to a substrate such as a ceramic tile using digital inkjet technology. A computer system receives information defining a relief pattern for forming the 3D relief using a digital inkjet printer. From the information, a feature vector is extracted comprising one or more features describing the 3D relief. A machine learning model is used to generate control commands based on the feature vector. The machine learning model is trained to generate the control commands to configure the digital inkjet printer to apply binder ink to a first region of a surface of the substrate. The applied binder ink is configured to form a protective layer over the first region of the surface of the substrate. The digital inkjet printer is configured to apply solvent ink to the surface of the substrate.

A honeycomb filter includes: a honeycomb substrate having porous partition walls disposed so as to surround cells extending from an inflow end face to an outflow end face, an outer peripheral coating layer disposed so as to surround an outer periphery of the honeycomb substrate, and plugging portions that are disposed at any one of ends on the inflow end face and ends on the outflow end face, of the cells, wherein, the outer peripheral coating layer has an inflection point at which thermal expansion in thermal expansion behavior of the outer peripheral coating layer turns to contraction and a temperature T1 of which is 1000 to 1500 C., and the outer peripheral coating layer has a porosity P1 of 36 to 48%, and a thermal expansion coefficient C1 between 40 to 800 C. of 2.5 to 3.510.sup.6/ C.

A blade outer air seal includes a center web having a radially inner face and a radially outer face, at least one mounting arm extending from the radially outer face, and a coating disposed on the radially inner face. The coating includes an environmental barrier coating layer and an abradable layer disposed on the environmental barrier layer. The abradable layer has a Mohs hardness of 3.5 to 7.5 and the porosity of the abradable layer is chosen in view of the Mohs hardness, which significantly improves the durability of the abradable layer. A gas turbine engine and a method of protecting a blade outer air seal are also disclosed.

The ceramic structure includes a first layer containing a first crystal particle and a second layer positioned on the first layer and containing a second crystal particle. The first crystal particle and the second crystal particle contain at least one metal element selected from the group consisting of Al, Si, Ti, Cr, Zr, and Y, and at least one non-metallic element selected from the group consisting of N, C, and B. The first crystal particle and the second crystal particle are identical compounds. When a half-width of a peak of a Miller index of a maximum intensity of the first crystal particle in an X-ray diffraction of the first layer is W1 and a half-width of a peak same as that of the Miller index of the second crystal particle in an X-ray diffraction of the second layer is W2, 9W1>W2>W1 is satisfied.

A gas-phase deposition process for coating a carbonaceous substrate with a tantalum carbide coating, the process includes a coating step. The coating step includes placing a carbonaceous substrate into a reaction chamber, heating the reaction chamber to a temperature between about 1100 C. to about 1500 C. for a duration of between about 1 h to about 24 h. The coating step further includes supplying a process gas to the reaction chamber, the process gas includes a halide containing species and for at least 15 minutes after the start of the process, the process gas includes less than 4 at.-% of carbon and less than 10 vol.-% of H.sub.2. Further, the coating step includes supplying a tantalum containing species to the reaction chamber, or placing a solid comprising tantalum into the reaction chamber. Alternatively, the process includes placing a solid with a tantalum halide into the reaction chamber.

A method includes forming a crystallized metal carbide undercoat on a surface of a carbon-carbon composite substrate. The method further includes forming an overcoat on a surface of the undercoat. The overcoat includes a plurality of crystallized ultra-high melting point overcoat layers. Each overcoat layer is sequentially formed by applying a mixture to a surface of an underlying layer and heating the mixture. The mixture includes a plurality of ultra-high melting point refractory ceramic particles and a pre-ceramic polymer. The mixture is heated to a heat treatment temperature to pyrolyze the pre-ceramic polymer and form the overcoat layer in an inert atmosphere or under vacuum. As a result, the overcoat layer includes a crystallized ultra-high melting point polymer-derived ceramic matrix that includes the plurality of ultra-high melting point refractory ceramic particles.