Methods for repairing composite component voids are provided. For example, one method comprises locating a void in a composite component and subjecting the composite component to a process for repair. The process for repair includes creating a flow path through the void, applying a filler material to the composite component at the flow path, and processing the composite component having the filler material. In some embodiments, the flow path has a first opening on a first side of the composite component and a second opening on a second, opposite side of the composite component. In other embodiments, at least one portion of the flow path extends at a first angle with respect to a lateral direction defined by the CMC component, and at least another portion extends at a second angle with respect to the lateral direction.

Methods for repairing composite component voids are provided. For example, one method comprises locating a void in a composite component and subjecting the composite component to a process for repair. The process for repair includes creating a flow path through the void, applying a filler material to the composite component at the flow path, and processing the composite component having the filler material. In some embodiments, the flow path has a first opening on a first side of the composite component and a second opening on a second, opposite side of the composite component. In other embodiments, at least one portion of the flow path extends at a first angle with respect to a lateral direction defined by the CMC component, and at least another portion extends at a second angle with respect to the lateral direction.

Methods for repairing composite component voids are provided. For example, one method comprises locating a void in a composite component and subjecting the composite component to a process for repair. The process for repair includes creating a flow path through the void, applying a filler material to the composite component at the flow path, and processing the composite component having the filler material. In some embodiments, the flow path has a first opening on a first side of the composite component and a second opening on a second, opposite side of the composite component. In other embodiments, at least one portion of the flow path extends at a first angle with respect to a lateral direction defined by the CMC component, and at least another portion extends at a second angle with respect to the lateral direction.

A new class of multi-component rare earth multi-silicate materials has been created for use in harsh environments such as gas turbine engines. Moreover, by combining two-or-more rare earth disilicates the properties (for example, thermal expansion, thermal conductivity, etc.) can be tailored to fit specific applications, such as having a matching thermal expansion with that of silicon-based composites and a low thermal conductivity close to that of 1 W/m K. Applications can be extended for use with other material classes such as MCrAlY, MAX-phase, and refractory metal alloys, utilizing a thermal expansion of up to about 15−10.sup.−6 /° C. By mixing of specific sets of rare earth disilicates it is possible to obtain a high entropy or entropy stabilized mixture, and utilize features such as “sluggish diffusion”, and more.

A new class of multi-component rare earth multi-silicate materials has been created for use in harsh environments such as gas turbine engines. Moreover, by combining two-or-more rare earth disilicates the properties (for example, thermal expansion, thermal conductivity, etc.) can be tailored to fit specific applications, such as having a matching thermal expansion with that of silicon-based composites and a low thermal conductivity close to that of 1 W/m K. Applications can be extended for use with other material classes such as MCrAlY, MAX-phase, and refractory metal alloys, utilizing a thermal expansion of up to about 15−10.sup.−6 /° C. By mixing of specific sets of rare earth disilicates it is possible to obtain a high entropy or entropy stabilized mixture, and utilize features such as “sluggish diffusion”, and more.

A power module includes a power wiring line provided with a power element, a glass ceramic multilayer substrate provided with a control element to control the power element, and a highly heat-conductive ceramic substrate made of a ceramic material having higher thermal conductivity than a glass ceramic contained in the glass ceramic multilayer substrate. The power wiring line is disposed on the highly heat-conductive ceramic substrate, and the glass ceramic multilayer substrate is disposed directly on the highly heat-conductive ceramic substrate.

A composite ceramic multilayer substrate includes a glass ceramic insulating layer including a wiring layer and a highly thermally conductive ceramic insulating layer made of a ceramic material having a higher thermal conductivity than the glass ceramic insulating layer. The glass ceramic insulating layer is provided on at least one main surface of the highly thermally conductive ceramic insulating layer directly and/or with a wiring layer interposed therebetween. When viewed in a direction perpendicular or substantially perpendicular to a main surface of the composite ceramic multilayer substrate, the composite ceramic multilayer substrate includes at least one heat generating element-mounting portion surrounded by the glass ceramic insulating layer and at which a heat generating element-mounting wiring line provide on the main surface of the highly thermally conductive ceramic insulating layer is exposed.

A coated substrate is provided that comprises: a substrate; and a barrier coating comprising a compound having the formula: Ln.sub.2ABO.sub.8, where Ln comprises scandium, yttrium, lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, or mixtures thereof; A comprises Si, Ti, Ge, Sn, Ce, Hf, Zr, or a combination thereof; and B comprises Mo, W, or a combination thereof. In one embodiment, B comprises Mo. A gas turbine is also provided that comprises the coated substrate described above.

An article comprises a substrate comprising a ceramic matrix composite; a first layer disposed over the substrate, the first layer comprising a substantially interconnected silicon source material, and a secondary material; and a second layer disposed over the first layer, the second layer comprising a membrane material in mass transfer communication with the silicon source material.

An article comprises a substrate comprising a ceramic matrix composite; a first layer disposed over the substrate, the first layer comprising a substantially interconnected silicon source material, and a secondary material; and a second layer disposed over the first layer, the second layer comprising a membrane material in mass transfer communication with the silicon source material.