A method of making a ceramic matrix composite (CMC) part such as armor, in which a mixture, including a preceramic polymer, particles such as ceramic microparticles and/or nanoparticles, and organic compounds such as a surfactant and a solvent, are mixed to form a paste and printed or molded. The part is then cured and densified by polymer infiltration and pyrolysis (PIP) using the preceramic polymer with a varying amount and size of ceramic particles and different temperatures in some of the cycles. The CMC can contain silicon carbide, boron carbide, boron suboxide, alumina, or any other ceramic. The process is compatible with sacrificial materials, enabling the creation of parts with hollow portions or overhangs. The mixture preferably has a high loading of particles, for example between 70 wt % and 90 wt % of the mixture, in order to minimize shrinkage. Curing and pyrolyzing the part can be performed by microwaving. Two such CMC parts can be joined together by using the paste, having the same or a different concentration of particles, as an adhesive.

According to an embodiment, a silicon nitride sintered body includes silicon nitride crystal grains and a grain boundary phase. In a case where Raman spectroscopy of a 20 μm×20 μm region at any cross section of the silicon nitride sintered body is performed, seven or more peaks are detected within a range of not less than 400 cm.sup.−1 and not more than 1200 cm.sup.−1, and the most intense peak of the seven or more peaks is not in a range of not less than 515 cm.sup.−1 and not more than 525 cm.sup.−1. Favorably, at least three of the seven or more peaks exist within a range of not less than 530 cm.sup.−1 and not more than 830 cm.sup.−1. It is favorable for at least one of the seven or more peaks to be within a range of not less than 440 cm.sup.−1 and not more than 460 cm.sup.−1.

According to an embodiment, a silicon nitride sintered body includes silicon nitride crystal grains and a grain boundary phase. In a case where Raman spectroscopy of a 20 μm×20 μm region at any cross section of the silicon nitride sintered body is performed, seven or more peaks are detected within a range of not less than 400 cm.sup.−1 and not more than 1200 cm.sup.−1, and the most intense peak of the seven or more peaks is not in a range of not less than 515 cm.sup.−1 and not more than 525 cm.sup.−1. Favorably, at least three of the seven or more peaks exist within a range of not less than 530 cm.sup.−1 and not more than 830 cm.sup.−1. It is favorable for at least one of the seven or more peaks to be within a range of not less than 440 cm.sup.−1 and not more than 460 cm.sup.−1.

The friction stir welding tool member according to the present invention is made of a silicon nitride sintered body, wherein the silicon nitride sintered body contains 15% by mass or less of additive components except silicon nitride in such a manner that the additive components include at least one element selected from lanthanoid elements and at least one element selected from Mg, Ti, Hf, and Mo. In addition, it is preferable that the additive components further include at least one element selected from Al, Si, and C. According to the above-described configuration, a friction stir welding tool member having an excellent durability can be provided.

The friction stir welding tool member according to the present invention is made of a silicon nitride sintered body, wherein the silicon nitride sintered body contains 15% by mass or less of additive components except silicon nitride in such a manner that the additive components include at least one element selected from lanthanoid elements and at least one element selected from Mg, Ti, Hf, and Mo. In addition, it is preferable that the additive components further include at least one element selected from Al, Si, and C. According to the above-described configuration, a friction stir welding tool member having an excellent durability can be provided.

An airfoil includes a ceramic matrix composite airfoil core that defines an airfoil portion and a root portion. The ceramic matrix composite airfoil core is subject to core thermal growth. A platform includes a ceramic matrix composite that wraps around the root portion. The platform is subject to platform thermal growth. A buffer layer is located between the root portion and the platform. The buffer layer absorbs a mismatch between the core thermal growth and the platform thermal growth.

The present disclosure provides a method of making a non-oxide ceramic part. The method includes obtaining a photopolymerizable slurry; selectively curing the photopolymerizable slurry to obtain a gelled article; drying the gelled article to form an aerogel article or a xerogel article; heat treating the aerogel article or the xerogel article to form a porous ceramic article; and sintering the porous ceramic article to obtain a sintered ceramic article. The photopolymerizable slurry includes non-oxide ceramic particles; at least one radiation curable monomer; a solvent; a photoinitiator; an inhibitor; and at least one sintering aid. Further, aerogels, xerogels, porous ceramic articles, and non-oxide ceramic articles are provided. In addition, methods are provided, including receiving, by a manufacturing device having one or more processors, a digital object comprising data specifying an article; and generating, with the manufacturing device by an additive manufacturing process, the article based on the digital object. A system is also provided, including a display that displays a 3D model of an article; and one or more processors that, in response to the 3D model selected by a user, cause a 3D printer to create a physical object of an article.

According to an example, a green body may include from about 1 wt. % to about 20 wt. % of a metal nanoparticle binder and a build material powder, wherein the metal nanoparticle binder is selectively located within an area of the green body to impart a strength greater than about 3 MPa.

A method for manufacturing active metal-brazed a nitride ceramics substrate having excellent joining strength, includes: a step of preparing a mixed raw material; a step of forming a green sheet of the mixed raw material by a tape casting method; a step of removing a binder by performing degreasing; a step of performing sintering; a step of forming an aluminum nitride sintered substrate by performing gradual cooling; and a step of printing a conductive wiring pattern with active metal paste on the aluminum nitride sintered substrate.

A method for manufacturing active metal-brazed a nitride ceramics substrate having excellent joining strength, includes: a step of preparing a mixed raw material; a step of forming a green sheet of the mixed raw material by a tape casting method; a step of removing a binder by performing degreasing; a step of performing sintering; a step of forming an aluminum nitride sintered substrate by performing gradual cooling; and a step of printing a conductive wiring pattern with active metal paste on the aluminum nitride sintered substrate.