Provided herein are methods for making a freeze-cast material having a internal structure, the methods comprising steps of: determining the internal structure of the material, the internal structure having a plurality of pores, wherein: each of the plurality of pores has directionality; and the step of determining comprises: selecting a temperature gradient and a freezing front velocity to obtain the determined internal structure based on the selected temperature gradient and the selected freezing front velocity; directionally freezing a liquid formulation to form a frozen solid, the step of directionally freezing comprising: controlling the temperature gradient and the freezing front velocity to match the selected temperature gradient and the selected freezing front velocity during directionally freezing; wherein the liquid formulation comprises at least one solvent and at least one dispersed species; and subliming the at least one solvent out of the frozen solid to form the material.

Scalable 3D-printing of ceramics includes dispensing a preceramic polymer at the tip of a moving nozzle into a gel that can reversibly switch between fluid and solid states, and subsequently thermally cross-linking the entire printed part “at-once” while still inside the same gel. The solid gel, including mineral oil and silica nanoparticles, converts to fluid at the tip of the moving nozzle, allows the polymer solution to be dispensed, and quickly returns to a solid state to maintain the geometry of the printed polymer both during printing and the subsequent high temperature (160° C.) cross-linking. The cross-linked part is retrieved from the gel and converted to ceramic by high temperature pyrolysis. This scalable process opens new opportunities for low-cost, high-speed production of complex 3-dimensional ceramic parts, and will be widely used for high temperature and corrosive environment applications, including electronics and sensors, microelectromechanical systems, energy, and structural applications.

Solid or liquid N—H free, C-free, and Si-rich perhydropolysilazane compositions comprising units having the following formula [—N(SiH.sub.3).sub.x(SiH.sub.2—).sub.y], wherein x=0, 1, or 2 and y=0, 1, or 2 when x+y=2; and x=0, 1 or 2 and y=1, 2, or 3 when x+y=3 are disclosed. Also disclosed are synthesis methods and applications for the same.

Methods and ceramic matrix composite articles formed thereby, as well as systems for making such ceramic matrix composite articles and carrying out such methods are disclosed herein. The methods include preparing a ceramic matrix composite by steps including (a) providing reinforcing fiber, such as carbon fiber, for impregnation; (b) heat treating the reinforcing fiber; (c) impregnating the heat treated reinforcing fiber with a composition comprising a ceramic forming polymer to form a fiber reinforced, ceramic forming polymer pre-preg; and (d) heat molding the fiber reinforced, ceramic forming polymer pre-preg to form a molded ceramic matrix composite article.

An optically clear resin for additive manufacturing includes an optically clear ceramic precursor having a pre-defined refractive index. Each molecule of the ceramic precursor has at least two photopolymerizable functional groups, at least one of the photopolymerizable functional groups being functionalized with a refractive index-tuning group thereby causing the ceramic precursor to have the pre-defined refractive index.

Organosilicon chemistry, polymer derived ceramic materials, and methods. Such materials and methods for making polysilocarb (SiOC) and Silicon Carbide (SiC) materials having 3-nines, 4-nines, 6-nines and greater purity. Processes and articles utilizing such high purity SiOC and SiC.

Silicon (Si) based high temperature coatings and base materials and methods of making those materials. More specifically, methods and materials having silicon, oxygen and carbon containing polymer derived ceramic liquids that form filled and unfiled coatings, including high temperature crack resistant coatings.

Organosilicon chemistry, polymer derived ceramic materials, and methods. Such materials and methods for making polysilocarb (SiOC) and Silicon Carbide (SiC) materials having 3-nines, 4-nines, 6-nines and greater purity. Processes and articles utilizing such high purity SiOC and SiC.

Organosilicon chemistry, polymer derived ceramic materials, and methods. Such materials and methods for making polysilocarb (SiOC) and Silicon Carbide (SiC) materials having 3-nines, 4-nines, 6-nines and greater purity. Processes and articles utilizing such high purity SiOC and SiC.

Metal containing polymer compositions, useful for the production of high temperature metal carbide ceramics are described, including poly(carbohafnocene) compositions and related poly(carbometallocene) compositions, as well as compositions formed from the reaction of hafnium chloride and 2-butyne-1,4-diol. Methods of synthesizing such compositions are provided.