A composite material containing a matrix and a fibrous reinforcement, in particular a textile embedded in the matrix. The matrix includes a geopolymer of the poly(phospho-sialate) type having the following formula I: (1) (—P—O—Si—O—Al—O—).sub.n in which n is greater than 2. The matrix further includes zirconium covalently bonded to the matrix, especially in the —ZrO form and/or in the —O—Zr—O form. The matrix has a melting temperature greater than 700° C., especially equal to or greater than 1200° C.

The invention concerns a method for coating a core (1) for producing a turbomachine part (2) by isostatic compacting, for example a leading-edge shield of a blade, the coating method comprising the steps of:—S1: covering the core (1) by means of a first solution comprising a first refractory component configured to oppose the diffusion of species, the first component comprising a metal oxide,—S2: covering the core (1) by means of a second solution comprising a second component designed to bind the first component in such a way as to form a homogeneous layer, the second component comprising a mineral binder;—S3: applying a heat treatment to the covered core (1) in such a way as to dry the solution and solidify the coating.

A preparation method for a ceramic composite material, a ceramic composite material, and a wavelength converter. The preparation method comprises: preparing an aluminium salt solution and a fluorescent powder; dispersing the fluorescent powder into a buffer solution having a pH 4.5-5.5 to obtain a suspension; titrating the suspension with the aluminium salt solution to obtain a fluorescent powder coated with Al.sub.2O.sub.3 hydrate film; calcining the fluorescent powder coated with Al.sub.2O.sub.3 hydrate film to obtain a Al.sub.2O.sub.3-coated fluorescent powder; mixing aluminium oxide powder with a particle size of 0.1 μm-1 μm and aluminium oxide powder with a particle size of 1 μm-10 μm to obtain mixed aluminium oxide powder; mixing the Al.sub.2O.sub.3-coated fluorescent powder and the mixed aluminium oxide powder to obtain mixed powder, the Al.sub.2O.sub.3-coated fluorescent powder being present in 40%-90% by weight of the mixed powder; and pre-pressing and sintering the mixed powder to obtain the ceramic composite material.

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.

The invention provides a bright white refractory roofing granule, comprising a ceramic material formed from a substantially homogenous mixture of a ceramic-forming clay, sintering material, and optionally comprising silica particles, and other potential additives, said bright white refractory roofing granule having a total solar reflectance of at least 0.80 and a Hunter Color Lvalue of at least 85.0, together with processes for making and using the same.

A method of additively manufacturing a ceramic matrix composite material includes providing a ceramic fiber and a powdery base material for a ceramic matrix composite and layer-by-layer building up the ceramic matrix material for the ceramic matrix composite by irradiating of a powder bed formed by the base material with an energy beam according to a predetermined geometry, wherein the base material is melted, solidified and adhesively joined to the ceramic fiber in that parameters of the energy beam are locally chosen such that in the contact region of the ceramic fiber and the powder bed, the ceramic fiber is only partly melted.

A refractory article includes a body having a first portion defining at least a portion of a first exterior surface of the body, the first portion including a carbide, and further including a second portion defining at least a portion of a second exterior surface of the body opposite the first exterior surface, the second portion including an oxide, and a thermal conductivity difference (ΔTC) of at least 10 W/mK between the first exterior surface and the second exterior surface, and an average Shell Temperature of not greater than 400° C.

A non-spray-drying, dry-granulation process for making a ceramic particulate mixture including from 4 wt % to 9 wt % water. At least 90 wt % of the particles have a particle size of from 80 μm to 600 μm. The process includes the steps of: (a) forming a precursor material; (b) subjecting the precursor material to a compaction step to form a compacted precursor material; (c) subjecting the compacted precursor material to a crushing step to form a crushed precursor material; and (d) subjecting the crushed precursor material to at least two air classification steps. One air classification step removes at least a portion of the particles having a particle size of greater than 600 μm from the crushed precursor material, and the other air classification step removes at least a portion of the particles having a particle size of less than 80 μm from the crushed precursor material.

A part for an aircraft turbojet engine nacelle is made of a composite material and includes at least one outer face (S1), a fibrous preform including fiber locks and having a surface(s) delimiting depressions between fiber locks, a covering material which at least partially covers the surface(s) of the fibrous preform and in particular the depressions, and a matrix which binds entirely the covering material and the fibrous preform. The covering material is a fibrous mat and the outer face (S1) is smooth. A method for manufacturing such a part includes manufacturing the fibrous preform, providing a fibrous mat, depositing the fibrous preform and fibrous mat in a mold, dispersing the matrix between the fibers of the preform and mat and consolidating the fibrous preform and mat.

Ceramic photoresin compositions include an ethylenically unsaturated UV curable composition and at least about 70 wt % of a ceramic composition and optionally a photoinitiator, a formulation additive, and/or UV absorbing agent. The composition may be useful for 3D printing applications.