A method for the joining of ceramic pieces with a hermetically sealed joint comprising brazing a layer of joining material between the two pieces. The wetting and flow of the joining material is controlled by the selection of the joining material, the joining temperature, the joining atmosphere, and other factors. The ceramic pieces may be aluminum nitride and the pieces may be brazed with an aluminum alloy under controlled atmosphere. The joint material is adapted to later withstand both the environments within a process chamber during substrate processing, and the oxygenated atmosphere which may be seen within the shaft of a heater or electrostatic chuck.

One aspect of the present disclosure includes a turbine vane assembly comprising a vane made from ceramic matrix composite material having an outer wall extending between a leading edge and a trailing edge and between a first end and an opposing second end; an endwall made at least partially from a ceramic matrix composite material configured to engage the first end of the vane; and a retaining region including corresponding bi-cast grooves formed adjacent the first end of the vane and a receiving aperture formed in the endwall; wherein a bond is formed in the retaining region to join the vane and endwall together.

A method of forming an integral fastener for a ceramic matrix composite component comprises the steps of forming a fiber preform with an opening, forming a fiber fastener, inserting the fiber fastener into the opening, and infiltrating a matrix material into the fiber preform and fiber fastener to form a ceramic matrix composite component with an integral fastener. A gas turbine engine is also disclosed.

A method for the joining of ceramic pieces with a hermetically sealed joint comprising brazing a layer of joining material between the two pieces. The wetting and flow of the joining material is controlled by the selection of the joining material, the joining temperature, the joining atmosphere, and other factors. The ceramic pieces may be on a non-diffusable type, such as aluminum nitride, alumina, beryllium oxide, and zirconia, and the pieces may be brazed with an aluminum alloy under controlled atmosphere. The joint material is adapted to later withstand both the environments within a process chamber during substrate processing, and the oxygenated atmosphere which may be seen within the shaft of a heater or electrostatic chuck.

A method of forming an integral fastener for a ceramic matrix composite component comprises the steps of forming a fiber preform with an opening, forming a fiber fastener, inserting the fiber fastener into the opening, and infiltrating a matrix material into the fiber preform and fiber fastener to form a ceramic matrix composite component with an integral fastener. A gas turbine engine is also disclosed.

A preform CMC article is disclosed comprising an interior ply structure having at least one interior CMC ply including at least one longitudinal CMC ply disposed along the article length, an exterior shell ply forming an article surface and having at least one exterior CMC ply substantially surrounding the interior ply structure, and at least one wicking portion in which the interior ply structure penetrates the exterior ply shell with an exposed edge of the longitudinal CMC ply disposed at the article surface. A CMC article is disclosed including the interior ply structure and the exterior ply shell, wherein the longitudinal CMC ply includes an exposed edge disposed at the surface of the CMC article. A method for forming the CMC article is disclosed including wicking a melt infiltration agent into the article through the wicking portion into the interior ply structure along the longitudinal CMC ply.

Methods for forming a unitary ceramic component are provided. The method may include: positioning a braze reactant layer in a contact area between a first densified ceramic component and a second densified ceramic component; positioning a pack material around at least a portion of the first densified ceramic component or the second densified ceramic component; positioning at least one infiltrate source in fluid communication with the braze reactant layer; and thereafter, heating the at least one infiltrate source, the pack material, the first densified ceramic component, and the second densified ceramic component to a braze temperature that is at or above a melting point of at least one phase of the infiltrate composition such that at least one phase of infiltrate composition melts and flows into the braze reactant layer and reacts with a ceramic precursor compound therein to form a ceramic material.

The disclosure describes techniques for forming a surface layer of an article including a CMC using a cast. In some examples, the surface layer includes three-dimensional surface features, which may increase adhesion between the CMC and a coating on the CMC. In some examples, the surface layer may include excess material, with or without three-dimensional surface features, which is on the CMC. The excess material may be machined to remove some of the excess material and facilitate conforming the article to dimensional tolerances, e.g., for fitting the article to another component. The excess material may reduce a likelihood that the CMC (e.g., reinforcement material in the CMC) is damaged by the machining.

Methods of forming a cutting element include sintering diamond particles at a temperature of at least about 1400 C. under a pressure of at least about 10 GPa in the absence of a metal solvent catalyst so as to form a polycrystalline diamond compact (PDC), providing a barrier material over at least a portion of the PDC, providing a carbide material and a metal binder comprising at least one transition metal element over the barrier material and the PDC, and performing a second sintering process comprising sintering the carbide material, the metal binder, the barrier material, and the PDC at a temperature of at least about 1400 C. under a pressure of at least about 5 GPa to form the cutting element. At least a portion of the PDC proximate an exposed exterior surface of the PDC may be at least substantially free of the metal binder.

Composite components and methods for adding a composite material to a composite component are provided. For example, a method comprises positioning a composite material segment against the composite component to form a component layup; applying an insulating material around at least a portion of the component layup to form an insulated layup; and densifying the insulated layup, where the composite component was previously densified before positioning the composite material segment against the composite component. In some embodiments, the composite material is ceramic matrix composite (CMC) and the composite material segment is a plurality of CMC plies. The composite component may be a CMC gas turbine engine component that comprises an original CMC component and a new CMC material segment joined to the original CMC component through the transfer of silicon between the original CMC component and the new CMC material segment during melt infiltration.