The present disclosure provides a method of making a ceramic article. The method includes (a) obtaining a photopolymerizable slurry or sol including a plurality of ceramic particles distributed in the photopolymerizable slurry or sol and (b) selectively polymerizing the photopolymerizable slurry or sol using actinic radiation and continuous movement of a build substrate through the photopolymerizable slurry or sol to form a gelled article. The method also includes (c) extracting solvent from the gelled article to form an aerogel article or a xerogel article; (d) heat treating the aerogel article or the xerogel article to form a porous ceramic article; and (e) sintering the porous ceramic article to form a sintered ceramic article. The sintered ceramic article exhibits a particular density. Further, additive manufactured ceramic articles are provided that exhibit a particular density, opacity, or both. Preferably, all cross-sectional portions of an interior of the ceramic article having selected dimensions are free of a frequency analysis signal maxima larger than a background signal.

A prepreg including a support with, for more than 90% of the weight thereof, of ceramic fibers, and a thermoreversible liquefiable gel covering, at least in part, at least one portion of the ceramic fibers. The liquefiable gel including: 20% to 60% of ceramic particles and 0% to 10% of metal particles, both as percentage by volume based on the volume of the liquefiable gel; 0.2% to 10% of a thermoreversible hydrocolloid and 0% to 7% of one or more other constituents, both as a percentage by weight on the basis of the total weight of the ceramic particles and metal particles; the balance to 100% being water. It being possible for the ceramic particles and the metal particles to be replaced, partially or completely, by precursors of ceramic particles and of metal particles, respectively, capable of forming, by heat treatment above 200° C., ceramic particles and metal particles, respectively.

Compositions comprising preceramic resins and fumed alumina are described. The compositions can also include fillers, such as silicon carbide whiskers or zirconium diboride particles. The compositions can be used as three-dimensional printable inks for preparing ceramic composites, e.g., composites having complex geometry. Inclusion of fumed alumina as a rheology modifier in the composition can provide improved printing properties for the inks compared to preceramic resin inks that do not include fumed alumina.

A metal boride aerogel includes a three-dimensional aerogel structure comprising metal boride particles having an average diameter of less than one micron. A method is disclosed for forming a metal boride aerogel including dispersing boron nanoparticles in a solution of a metal salt, forming a boron-loaded metal oxide precursor gel using the dispersed boron nanoparticles in the solution of the metal salt, drying the boron-loaded metal oxide precursor gel to form a boron-loaded metal oxide precursor aerogel, and heating the boron-loaded metal oxide precursor aerogel to form a metal boride aerogel. The metal boride aerogel is essentially free of metal oxide.

Systems for and methods for improving mechanical properties of ceramic material are provided. The system comprises a heat source for heating the ceramic material to a temperature greater than a brittle-to-ductile transition temperature of the ceramic material; a probe for mounting the ceramic material and configured to extend the ceramic material into the heat source; a plasma-confining medium and a sacrificial layer disposed between the ceramic material and the plasma-confining medium; and an energy pulse generator such as a laser pulse generator. The sacrificial layer is utilized to form plasma between the ceramic material and the plasma-confining medium. The method comprises heating ceramic material to a temperature greater than a brittle-to-ductile transition temperature of the ceramic material and subjecting the ceramic material to energy pulses via a sacrificial layer and a plasma-confining medium whereby a plasma of the sacrificial coating forms between the ceramic material and a plasma-confining medium.

Systems for and methods for improving mechanical properties of ceramic material are provided. The system comprises a heat source for heating the ceramic material to a temperature greater than a brittle-to-ductile transition temperature of the ceramic material; a probe for mounting the ceramic material and configured to extend the ceramic material into the heat source; a plasma-confining medium and a sacrificial layer disposed between the ceramic material and the plasma-confining medium; and an energy pulse generator such as a laser pulse generator. The sacrificial layer is utilized to form plasma between the ceramic material and the plasma-confining medium. The method comprises heating ceramic material to a temperature greater than a brittle-to-ductile transition temperature of the ceramic material and subjecting the ceramic material to energy pulses via a sacrificial layer and a plasma-confining medium whereby a plasma of the sacrificial coating forms between the ceramic material and a plasma-confining medium.

diboride-silicon carbide (SiC) multiphase ceramic, including: (S1) mixing a transition metal oxide mixed powder, nano carbon black and a silicon hexaboride (SiB.sub.6) powder to obtain a precursor powder; and (S2) subjecting the precursor powder to pressureless sintering to obtain the high-entropy carbide-high-entropy diboride-SiC multiphase ceramic with a relative density of 96% or more.

Disclosed is a blade for a turbomachine, comprising an outer shell and an inner core which is at least partially enclosed by the outer shell and has a higher porosity than the outer shell. The outer shell is formed by a ceramic body or a body made of a ceramic matrix composite material, and the inner core is formed by a fiber-reinforced ceramic or a fiber-reinforced ceramic matrix composite material.

A composite composed of one or a plurality of principal strengthening compounds and at least one principal cemented refractory metal that is prepared by combining a suitable binary to senary borides and/or carbides with a unitary to binary principal refractory metal is disclosed. As compared with the conventional sintered cemented carbides, the composite of the disclosure not only possess high hardness and high toughness but also has various ratios of principal components since it is not prepared with equal mole during the process.

A method for producing a cermet composition, including mixing a first predetermined amount of a yttria stabilized zirconia powder with between 2 and 8 weight percent mu-metal powder to define a homogeneous admixture, oxidizing the mu-metal in the admixture, forming the homogeneous admixture into a green body, calcining the green body in a first reducing atmosphere to remove oxygen from the oxidized mu-metal to yield a calcined body, and sintering the calcined body in a second reducing atmosphere to yield a densified body having no more than 0.8% porosity. The densified body has a plurality of mu-metal particles distributed therethrough, a hardness of at least 1450 HV, flexural strength of at least 200 kPSI, and a relative permeability μ/μ.sub.o of at least 850.