C04B2235/5216

Formulations with active functional additives for 3D printing of preceramic polymers, and methods of 3D-printing the formulations

This invention provides resin formulations which may be used for 3D printing and pyrolyzing to produce a ceramic matrix composite. The resin formulations contain a solid-phase filler, to provide high thermal stability and mechanical strength (e.g., fracture toughness) in the final ceramic material. The invention provides direct, free-form 3D printing of a preceramic polymer loaded with a solid-phase filler, followed by converting the preceramic polymer to a 3D-printed ceramic matrix composite with potentially complex 3D shapes or in the form of large parts. Other variations provide active solid-phase functional additives as solid-phase fillers, to perform or enhance at least one chemical, physical, mechanical, or electrical function within the ceramic structure as it is being formed as well as in the final structure. Solid-phase functional additives actively improve the final ceramic structure through one or more changes actively induced by the additives during pyrolysis or other thermal treatment.

KR desulfurization stirring paddle casting material and preparation method therefor

Provided are a Kanbara Reactor (KR) desulfurization stirring paddle casting material and a preparation method therefor. The casting material consists of a base material and an additive; the base material consists of the following raw materials in weight percentages: M70 sintered mullite 60-80%, flint clay 5-20%, fine powder 5-20%, and pure calcium aluminate cement 1-5%. The percentages of each component of the additive based on the weight of the base material are as follows: water reducing agent 0.05-0.2%, and heat-resistant stainless steel fiber 1-5%. The main raw materials are M70 sintered mullite and a small amount of flint clay so as to ensure good thermal shock resistance; the medium temperature and high temperature strength are controlled at 100-180 MPa so as to ensure good erosion resistance; the content of Al.sub.2O.sub.3 in the casting material is 60-70% so as to ensure good corrosion resistance; the ratio of high temperature strength to medium temperature strength is controlled at 1-1.2, which further improves the thermal shock resistance and peeling resistance of the casting material, thereby extending the service life of the stirring paddle. The casting material is lower in cost and has a good practical furnace usage effect; in addition, a paddle blade has less chance of cracking and peeling, while a bottom portion of the stirring paddle is less eroded, thus the frequency of paddle blade repair is low, and service life is significantly improved.

DRY REFRACTORY COMPOSITIONS WITH REDUCED LEVELS OF RESPIRABLE CRYSTALLINE SILICA
20210331982 · 2021-10-28 ·

A silica-based dry refractory composition (“DRC”) comprising, by weight, about 95% to about 99.9% silica, and about 0.1 to about 5% binder, wherein the silica comprises about 40% to about 80% quartz and about 20% to about 60% fused silica, and the DRC has less than about 5% crystalline silica having a size less than 10 μm. A method of forming a refractory lining is also provided.

Short-Fiber-Reinforced Oriented MAX-Phase Ceramic-Based Composite and Preparation Method Therefor
20210323875 · 2021-10-21 ·

The present invention relates to the field of MAX-phase ceramic-based composites, specifically to a short-fiber-reinforced oriented MAX-phase ceramic-based composite and a preparation method therefor. By using a new process with a fiber, a nano lamellar MAX-phase ceramic powder, other additives, etc., for preparing a fiber-reinforced MAX-phase ceramic-based composite, a novel ternary composite is prepared, wherein a matrix is composed of a highly oriented lamellar MAX-phase ceramic, the fiber is distributed parallel to the lamellar MAX-phase ceramic in an axial direction, and a granulate ceramic phase enhancement phase is dispersed in the matrix. Thus, the problems of a MAX-phase ceramic-based composite matrix material prepared by an existing method, such as coarse grains, multiple internal defects and a low strength, and a poor fracture toughness; and a reaction sintering temperature being too high such that fibers are chemically and physically damaged in a substrate, resulting in performance degradation, are solved. Fibers prepared by the method are suitable for large-scale industrial preparation and have properties that are far superior to those of any existing known fiber MAX-phase composite.

CERAMIC HONEYCOMB BODY FOR LIGHTWEIGHT STRUCTURES AND CORRESPONDING PRODUCTION METHOD

A honeycomb body made of a composite material for fire-resistant lightweight structures including honeycomb cells having a cross section is provided. The cell walls of the honeycomb cells are produced from a composite material. The composite material has at least one carrier, for example a woven fabric or a laid fabric made of fibers, and a matrix into which the carrier is embedded. The matrix includes a silicon-based ceramic material, of which the proportion by mass in the matrix along the cell walls is at least 30 wt. %. A method for producing such a ceramic honeycomb body and a honeycomb tube as an intermediate product for the same are also provided. A flat semi-finished product as a curable intermediate product for the production of fire-resistant fiber composite lightweight structures, which has a matrix mixture including dispersed silicon particles, is also provided.

Electromagnetic coil

An electromagnetic coil with improved insulation properties at high temperatures. A bobbin is insulated by a thin ceramic composite layer that is produced by winding a glass or ceramic fiber over the support structure and impregnating it with a pre-ceramic polymer. The pre-ceramic polymer is then modified to form a ceramic SiO.sub.2 matrix around the fibrous layer. The ceramic matrix secures the glass or ceramic fibers in place and produces a dense layer. A ceramic coated magnet wire is then wound around the insulated support structure. The magnet wire is a conductor that is spiral-wrapped with a glass fiber impregnated with a pre-ceramic polymer.

Articles for creating hollow structures in ceramic matrix composites

The present disclosure relates to a method of fabricating a ceramic composite components. The method may include providing at least a first layer of reinforcing fiber material which may be a pre-impregnated fiber. An additively manufactured component may be provided on or near the first layer. A second layer of reinforcing fiber, which may be a pre-impregnated fiber may be formed on top the additively manufactured component. A precursor is densified to consolidates at least the first and second layer into a densified composite, wherein the additively manufactured material defines at least one cooling passage in the densified composite component.

Ceramic composition and method of making the composition

A method of making a ceramic composite comprises forming a wet ceramic composition comprising a plurality of discrete ceramic components and a fluxing agent dissolved in a solvent. At least a portion of the solvent is removed from the wet ceramic composition to form a dried ceramic composition comprising the plurality of discrete ceramic components coated with the fluxing agent. The dried ceramic composition is sintered to form the ceramic composite, the sintering being carried out at a sinter temperature sufficient to fuse the discrete ceramic components at bridging sites formed where two or more of the discrete ceramic components coated with fluxing agent are in physical contact.

COLD ISOSTATIC PRESSING OF FUSED FILAMENT FABRICATED COMPONENTS

A method may include cold isostatic pressing a fused filament fabricated component comprising a plurality of roads and channels between at least some roads of the plurality of roads. The plurality of roads may include a sacrificial binder and a powder including a metal or alloy. The cold isostatic pressing reduces a presence of the channels between the at least some roads to form a compacted fused filament fabricated component. The method also may include removing substantially all the sacrificial binder from the compacted fused filament fabricated component and leave a powder component; and sintering the powder component to form a sintered component.

Method for the production of a part made from a composite material

A method of fabricating a composite part, includes forming a fiber preform for the part that is to be obtained by depositing a plurality of fiber structures impregnated with a thermoplastic polymer onto a surface, with deposition being performed by automated fiber placement; eliminating the thermoplastic polymer present in the preform by dissolution with a solvent; and injecting a liquid impregnation composition into the pores of the fiber preform after eliminating the thermoplastic polymer in order to form a matrix in the pores of the fiber preform.