Abstract:
A coated component, along with methods of its formation and use, is provided. The coated component may include a substrate having a surface with a plurality of cavities defined therein, a bond coating (e.g., including a silicon material) on the surface of the substrate within the cavities, and an environmental barrier coating over the surface of the substrate and encasing the bond coating within the cavities such that the bond coating, when melted, is contained within the cavities. Such a coated component may be, in one embodiment, a turbine component, such as a CMC component for use in a hot gas path of a gas turbine engine.
Abstract:
A ceramic matrix composite article includes a chemical vapor infiltration ceramic matrix composite base portion including ceramic fiber reinforcement material in a ceramic matrix material having between 0% and 5% free silicon. The ceramic matrix composite article further includes a melt infiltration ceramic matrix composite covering portion including a ceramic fiber reinforcement material in a ceramic matrix material having a greater percentage of free silicon than the chemical vapor infiltration ceramic matrix composite base portion.
Abstract:
A coated component, along with method of forming the same, is provided. The coated component may include a substrate having a surface, a silicon-based bond coating on the surface of the substrate, and an EBC on the silicon-based bond coating. The silicon-based bond coating may include a silicon-phase contained within a refractory phase. The silicon-phase, when melted, is contained within the refractory phase and between the surface of the substrate and an inner surface of the environmental barrier coating. Such a coated component may be, in particular embodiments, a turbine component.
Abstract:
Methods for forming a ceramic matrix composite (CMC) are generally provided. The method may include melt infiltrating a silicon mixture into a ceramic matrix composite preform, with the silicon mixture including SiGa, SiIn, or a mixture thereof. The silicon mixture may include silicon metal in combination with SiGa, SiIn, or the mixture thereof. Additionally, the silicon mixture may further include B within the SiGa, SiIn, or the mixture thereof (e.g., in the form of SiBGa, SiBIn, or a mixture thereof).
Abstract:
A process for producing a silicon-containing CMC article. The process entails depositing one or more coating layers on silicon carbide (SiC) fibers, drawing the coated SiC fibers through a slurry to produce slurry-coated fiber material, and then processing the slurry-coated SiC fiber material to form unidirectional prepreg tapes. The tapes are stacked and then fired to yield a porous preform. The porous preform is then further densified by infiltrating the porosity therein to yield a CMC article. Infiltration can be achieved by a series of polymer infiltration and pyrolysis (PIP) steps, by melt infiltration (MI) after filling the porosity in the preform with carbon or one or more refractory metal, by chemical vapor infiltration (CVI), or by a combination of these infiltration techniques.