45 results about "Sialon" patented technology

A method of making a carbon-carbon composite may comprise forming a Silicon-Aluminum-Oxygen-Nitrogen (SiAlON) precursor suspension and infiltrating a fibrous preform with the SiAlON precursor suspension. A SiAlON forming heating treatment may be performed on the fibrous preform to form SiAlON particles. The fibrous preform may be densified using chemical vapor infiltration to form a densified fibrous preform.

In an X-ray photoelectron spectrum obtained using Al-Kα radiation as an excitation X-ray source, this β-sialon phosphor satisfies the relationship 2.5>Y / X, where X is the photoelectron intensity at a binding energy of 103.5 eV and Y is the photoelectron intensity at a binding energy of 102.0 eV.

To provide blue light-emitting transparent sialon ceramics that are transparent and blue fluorescent, and can increase the productivity while having durability comparable to or higher than the prior art.SOLUTION: Such blue light-emitting transparent sialon ceramics have a main phase of α-sialon having general formula Mx(Si,Al)12(N,O)16 (where M is at least one selected from the group consisting of dysprosium, holmium, erbium, thulium, ytterbium and lutetium, and 0.3≤x≤1) in which some M are substituted with Ce, so that a luminescent center ion is at least Ce3+.SELECTED DRAWING: Figure 1

This SiAlON powder satisfies at least one of the following (1) and (2). (1) The powder is Cam / 2Si12-(m+n)Al(m+n)OnN16-n, in which m is less than 1.0. (2) The value of Ca / (Si+Al) determined by inductively coupled plasma (ICP) optical emission spectrometry is less than 0.0595.

Provided is a silicon nitride sintered body exhibiting excellent durability even when used in an environment in which torque changes. According to an embodiment, in XRD analysis results of an arbitrary cross section of a silicon nitride sintered body, the strongest peak intensities corresponding to a hexagonal alpha-SiAlON crystal detected at 20.5 + / -0.3 DEG, 22.8 + / -0.3 DEG, 34.3 + / -0.3 DEG, and 38.7 + / -0.3 DEG are respectively set as I20.5 DEG, I22.8 DEG, I34.3 DEG, and I38.7 DEG, and the strongest peak intensities corresponding to a beta-Si3N4 crystal detected at 33.6 + / -0.3 DEG and 36.1 + / -0.3 DEG are respectively set as I33.6 DEG and I36.1 DEG. When the strongest peak intensities corresponding to the R2Si3O3N4 crystal (R is a rare earth element) detected at 31.8 + / -0.3 DEG and 37.2 + / -0.3 DEG are respectively set as I31.8 DEG and I37.2 DEG, 0.001 < = (I20.5 DEG + I22.8 DEG + I34.3 DEG + I38.7 DEG) / (I33.6 DEG + I36.1 DEG) / < = 0.300 is satisfied, and 0.002 < = (I31.8 DEG + I37.2 DEG) / (I33.6 DEG + I36.1 DEG) / < = 0.100 is satisfied.

The application belongs to the technical field of refractory materials, and discloses a multi-scale pore carbon-based microsphere and a preparation method thereof. The application prepares a premix by grinding walnut shell powder, aluminum powder and an additive into fine powder, takes polystyrene balls as spherical supports, adds a silica sol solution, and forms a shape in a granulator and sieves. After drying, heat treatment and other steps, a multi-scale pore carbon-based microsphere is synthesized at low temperature. In the carbon skeleton hole formed by the walnut shell powder, a Sialon-SiC composite ceramic phase is generated in situ, filling part of the pores, so that pores of different scales are formed. The application uses cheap and easily available raw materials, has the characteristics of low cost and simple preparation process, and the prepared multi-scale pore carbon microsphere has excellent high-temperature resistance.

The invention relates to Mg-SiAlON-coated MgO core-shell composite powder with a fish scale space structure and a preparation method thereof. According to the technical scheme, MgSiN2 powder and Al powder are activated through the radio frequency plasma technology, then plasma ball milling mixing is conducted, and a ball milling material is obtained; then putting the mixture into an atmosphere furnace for pretreatment to obtain a treated material; preparing slurry from the treated material, polyvinylpyrrolidone and ethanol; mixing the fused magnesia particles and the fused magnesia fine powder to obtain a mixture II, putting the mixture II into a water chestnut type coating machine, and spraying the slurry onto the surface of the mixture II by using a spray gun to obtain a mixture III; and finally, putting into a high-temperature atmosphere furnace, heating to 1350-1500 DEG C in a nitrogen atmosphere, preserving heat for 2-5 hours, cooling along with the furnace, crushing and screening to obtain the Mg-SiAlON-coated MgO core-shell composite powder with the fish scale space structure. The prepared product is uniform in phase distribution, high in density and strong in interface bonding, and the magnesium refractory material prepared from the powder is excellent in mechanical property and good in erosion resistance.

The present invention provides a silicon nitride sintered body that exhibits excellent durability even when used in an environment where torque changes. According to an embodiment, in an XRD analysis result of an arbitrary cross section of a silicon nitride sintered body, when the highest peak intensities corresponding to a hexagonal α-SiAlON crystal that are detected at 20.5±0.3°, 22.8±0.3°, 34.3±0.3°, and 38.7±0.3° are represented respectively by I20.5°, I22.8°, I34.3°, and I38.7°, the highest peak intensities corresponding to a β-Si3N4 crystal that are detected at 33.6±0.3° and 36.1±0.3° are represented respectively by I33.6° and I36.1°, and the highest peak intensities corresponding to an R2Si3O3N4 crystal (where R is a rare earth element) that are detected at 33.6±0.3° and 36.1±0.3° are represented respectively by I31.8° and I37.2°, 0.001 ≤ (120.5°+122.8°+134.3°+138.7°) / (133.6°+136.1°) ≤ 0.300 is satisfied, and 0.002 ≤ (I31.8°+I37.2°) / (I33.6°+I36.1°) ≤ 0.100 is satisfied.

本发明公开了兼具高硬度高韧性的α‑SiAlON / TiN复相陶瓷材料、制备方法及其应用，属于合金切削刀具技术领域。该制备方法采用放电等离子烧结工艺对制备好的原料粉末进行烧结，最终制得的α‑SiAlON / TiN复相陶瓷材料由TiN和α‑SiAlON两相组成，两相间界面结合良好，界面表现出阶梯状结构。本发明将TiN颗粒添加到α‑SiAlON陶瓷中，实现了较高强度的两相界面及显著延长的裂纹扩展路径，合成了性能优异的α‑SiAlON / TiN复相陶瓷材料，硬度大于20GPa，断裂韧性大于6.5 MPa·m1 / 2。

The application discloses an aluminum nitride-based composite ceramic carrier and a preparation method thereof, and belongs to the technical field of composite ceramic material preparation. The carrier is prepared from aluminum nitride as a base material, and a specific proportion of beta-Sialon precursor powder and Y2O3-ZrO2 composite sintering aids. The preparation method comprises the following steps: treating raw materials by adopting a high-speed and low-speed ball milling process, and then performing two-stage composite sintering of electric discharge plasma sintering and hot-press sintering in sequence. Through the synergistic design of the material formula and the process, the columnar beta-Sialon grain network and the metastable tetragonal phase ZrO2 generated in situ are utilized to construct a multi-stage toughening system while the super-high thermal conductivity of the aluminum nitride base is maintained, so that the material has high fracture toughness and excellent thermal shock resistance, and is especially suitable for an automobile exhaust treatment system with strict requirements on rapid ignition and long-term reliability.

The invention belongs to the technical field of refractory materials, and particularly relates to an integral forming preparation method of a Sialon combined silicon carbide blast furnace taphole mud sleeve. Silicon carbide coarse, medium and fine particles, silicon carbide micro powder, aluminum oxide micro powder, metal silicon powder and metal aluminum powder are used as main raw materials, uniformly dispersed slurry is obtained through ball milling, the slurry is poured into a pre-assembled mold with an inner cavity integrally communicated, an integrated mud sleeve blank is obtained through a gel injection molding method, and the integrated mud sleeve is manufactured. A sialon binding phase is formed through an in-situ reaction in a nitrogen atmosphere, and then the sintering temperature is further increased, so that the sialon-bound silicon carbide blast furnace taphole mud sleeve is obtained. The prepared iron notch mud sleeve can replace existing mud sleeves of castable, prefabricated parts and the like, is used for a blast furnace iron notch, and effectively solves the problems that the existing mud sleeve is short in service life, frequent in maintenance, high in labor intensity, prominent in potential safety hazards and the like.

The invention discloses a rare earth ion doped beta-SiAlON / h-BN composite ceramic and a preparation method thereof, and relates to the technical field of ceramic materials, the original powder of the composite ceramic comprises hexagonal boron nitride (h-BN) powder, alpha-silicon nitride (alpha-Si3N4) powder, rare earth oxide (Re2O3) powder (Re = Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Sc) and aluminum oxide (Al2O3) powder, the volume ratio range of h-BN to alpha-Si3N4 is 8: 2-5: 5, and the volume ratio range of alpha-SiAlON / h-BN is 1: 2-3: 5. And 5-15 vol% of Re2O3-Al2O3 (the molar ratio is 3: 5) is additionally added. The preparation method comprises the following steps: weighing the raw materials according to the proportion, carrying out ball milling and mixing on the raw materials, zirconium oxide balls and absolute ethyl alcohol, then drying, loading into a graphite mold, and carrying out hot pressed sintering at 1700-1900 DEG C and 10-40MPa in a nitrogen atmosphere to obtain a finished product. According to the method, the rare earth ion doped beta-SiAlON phase is generated in situ in the sintering process, interface bonding with an h-BN matrix is improved, the problems that traditional h-BN is difficult to sinter and low in mechanical property are effectively solved, and the composite ceramic has excellent characteristics of the rare earth ion doped beta-SiAlON and the h-BN and is suitable for the field of ceramic materials with advanced structures.

The invention relates to the field of LED luminescent materials, solves the problems of harsh synthesis conditions and high production cost of narrow-band green fluorescent powder in the prior art, and provides a narrow-band green fluorescent powder preparation method based on composite nucleation and an LED package. The method comprises the following steps: weighing raw materials according to a first preset ratio; preparing a nucleating agent according to a second preset ratio; uniformly mixing the pretreated raw materials with the nucleating agent to obtain a mixture; putting the mixture into a double-layer crucible; a reaction atmosphere is established in the reaction furnace, and the pressure in the reaction furnace is controlled to reach the target pressure; applying a microwave field in the reaction furnace according to a preset microwave frequency range to sinter the mixture, heating to a first target temperature interval, and preserving heat to obtain a sintered material; and quickly cooling the sintered material to obtain the narrow-band green nitrogen oxide fluorescent powder. The preparation difficulty and production cost of beta-Sialon: Eu are reduced, and the method is suitable for industrial production.

A phosphor plate includes a plate-like composite including a base material and an α-type sialon phosphor present in the base material, in which, in an X-ray diffraction analysis pattern using a Cu-Kα ray, in a case in which peak intensity corresponding to the α-type sialon phosphor having a diffraction angle 2θ in a range of 30.2° or more and 30.4° or less is defined as Iα and peak intensity of a peak having a diffraction angle 2θ in a range of 26.6° or more and 26.8° or less is defined as Iβ, Iα, and Iβ satisfy 0<Iβ / Iα≤10.

Fluorescent ceramic containing a first component which emits in the range from ≥ 500 to ≤ 650 nm and a second component which absorbs in the range from ≥ 500 to ≤ 650 nm and emits in the range from ≥ 900 to ≤ 1000 nm; wherein the first component is a material selected from the group consisting of (M I 1-x-y M II x M III y )3(M IV 1-z M V z )5O 12 with M I = Y, Lu, Tb; M II = Gd, Yb; M III = Ce, Pr, Yb; M IV = Al; M V = Ga, Sc and 0.0 ≤ x ≤ 1.0; 0.0 ≤ y ≤ 0.1; 0.0 ≤ z ≤ 1.0 or (La 1-x Y x )3Si6N 11 :Ce, ß-SiAlON:Eu, (Ca 1-x Sr x )Sc2O4:Ce, La(Ba 1-x Sr x )2AlO5:Ce 3+ (Ba 1-x Sr x )(Y 1-x Lu x )2Al4SiO 12 :Ce 3+ , (Ba 1-x Si x )2SiO4:Eu 2+, Li2BaSiO4:Eu 2+ , RbLi(Li3SiO4)2:Eu 2+ , (Ba 1-x-y ,Sr x Ca y )Si2O2N2:Eu 2+ , Ca7(PO4)2(SiO4)2:Eu 2+ , Ca2BO3Cl:Eu 2+ , Ba2LiSi7N 11 :Eu 2+ , (Ba 1-x-y Sr x Ca y )LnSi4N7:Eu 2+ (Ln = Y, La, Gd, Lu), Ca2Al3O6F:Eu 2+ , Ba2LiSi7AlN 12 :Eu 2+ or Ca3Si2O4N2:Eu 2+ with x = 0.0 - 1.0 and y = 0.0 - 1.0 and mixtures thereof; and wherein the second component is a material selected from the group consisting of Mg2SiO4:Cr, (Y 1-x-y Gd x Lu y )Al3(BO3)4:Cr, (Y 1-x-y-z La x Gd y Lu z )3(Al 1- a Ga a )5O 12 :Cr, (Ca 1-x Sr x )Sc2O4:Cr, Ca3(Sc 1-x Ga x )2Si3O 12 :Cr, La3Ga5GeO 14 :Cr, (Y 1-x- y Gd x La y )AlO3:Cr, (Ca 1-x- ySr y Bay )CuSi4O 10 or (Ca 1-x-y Sr y Ba y )CuGe4O 10 , La2MgZrO6:Cr 3+ , Mg3Ga2GeO8:Cr 3+ , BaZrSi3O9:Cr 3+ , K2Ga2Sn6O 16 :Cr 3+ , Mg 14 Ge5O 24 :Cr 3+ ,Cr 4+ , LiScP2O7:Cr 3+ , Ca2LuZr2Al3O 12 :Cr 3+ , K3LuSi2O7:Eu 2+ , LaMgGa 11 O 19 :Cr 3+ , Ca2LuScGa2Ge2O 12 :Cr 3+ , Ba3(PO4)2:Mn 5+ , LiInSiO4:Cr 3+ , ScBO3:Cr 3+ or MgAl2O4:Mn 2+ with x, y, z, a = 0.0 - 1.0 and mixtures thereof.

The invention discloses an antibacterial rock plate and a production process thereof, and belongs to the technical field of ceramics. The antibacterial rock plate comprises a green body, a cover glaze layer, a decorative pattern layer and an antibacterial dry particle layer located on the outermost layer which are sequentially arranged. The antibacterial dry particle layer comprises frits, quartz, potassium feldspar, coloring materials, antibacterial materials and ammonium chloride, the antibacterial materials and the ammonium chloride are dispersed in the coloring materials, the antibacterial materials are silver-containing composite powder, and the silver-containing composite powder is prepared from filler through aluminosilicate precursor solution coating, hydrothermal crystallization and silver ion exchange treatment; the filler is at least one of beta-SiAlON and fluoride; and the fluoride is at least one of CaF2, YF3, CeF3 and AlF3. The invention also provides a preparation method of the composition. Compared with the prior art, the prepared antibacterial rock plate has high antibacterial rate and antibacterial durability, keeps good bending strength, wear resistance, household chemical resistance and acid and alkali resistance, and is suitable for being popularized and used in kitchens, toilets and other application scenes needing long-term cleaning and antibacterial.

The invention discloses a Yb-alpha-beta-Sialon composite ceramic and a preparation method thereof, and belongs to the technical field of ceramic processing, and the Yb-alpha-beta-Sialon composite ceramic comprises the following components: Si3N4, Al2O3, AlN, Yb2O3, Lu2O3, nano SiC whisker, Ti3SiC2, a liquid metal gallium indium tin alloy, a bonding aid and a sintering aid. Double rare earth stabilizers (ytterbium and lutetium) are introduced, the radius of ytterbium ions is large, and an alpha-Sialon phase is mainly stabilized; the lutetium ions are small in radius and mainly stabilize the beta-Sialon phase, the combination can more effectively enter lattice vacancies of different crystal phases, the grain boundary migration speed is restrained, and excessive growth of grains is hindered.

The invention relates to alpha sialon ceramic taking manganese as stable ions and a preparation method thereof. The alpha-SiAlON ceramic with the manganese as the stable ion is represented by a general formula Mnm / 2Si < 12-m-n > Al < m + n > OnN < 16-n >, m ranges from 1 to 3.6, and n ranges from 0 to 3. The novel alpha-SiAlON ceramic is prepared from Si3N4, AlN, MnO and other powder as raw materials through spark plasma sintering, air pressure sintering or hot pressed sintering and other methods, and the preparation method is simple and convenient. The alpha-SiAlON ceramic taking manganese as stable ions has high hardness and excellent fracture toughness, and is expected to be widely applied to various occasions with relatively high requirements on mechanical properties such as ceramic hardness and toughness.

The invention discloses an impact-resistant composite refractory brick and a preparation method thereof, and relates to the technical field of refractory materials, the refractory brick sequentially comprises a compact working layer, a transition buffer layer and a porous tough inner core from outside to inside; the transition buffer layer contains a plastic phase matrix and a beta-sialon ceramic three-dimensional network, and the thermal expansion coefficient of the transition buffer layer is between that of the other two layers; the porous tough inner core is a lightweight aggregate frame, and pores are filled with an aerogel and ceramic fiber mixture. The preparation method comprises the steps of porous tough inner core prefabrication, transition buffer layer blank preparation, isostatic pressing composite molding and segmented firing, a ceramic network is generated through a reducing atmosphere, and metallurgical bonding is achieved through a weak oxidizing atmosphere. Through the synergistic effect of a composite structure, the problems of poor impact resistance, thermal stress cracking and the like of a traditional refractory brick are solved, and the refractory brick has high-temperature resistance, stable structure and heat insulation performance and is suitable for high-temperature impact working conditions.

Connected body (15A), comprising: a support substrate (1) comprising a metal oxide; a substrate made of a piezoelectric material (4A); a connecting layer (2B) provided between the support substrate (1) and the substrate made of a piezoelectric material (4A), wherein the connecting layer (2B) has a composition of Si (1-x) O x [0.008 ≤ x ≤ 0.408] exhibits; and an amorphous layer (10) provided between the connecting layer (2B) and the support substrate (1), where the oxygen content of the amorphous layer (10) is higher than the oxygen content of the support substrate (1), wherein the metal oxide is selected from the group consisting of sialon, sapphire, cordierite, mullite and aluminum oxide, and wherein the substrate is selected from a piezoelectric material (4A) from the group consisting of lithium niobate, lithium tantalate and a solid solution of lithium niobate-lithium tantalate.

The application relates to a light repairing material for a working layer of a rolling steel heating furnace lining, and belongs to the technical field of refractory materials. The light repairing material for the working layer of the rolling steel heating furnace lining comprises the following raw materials in parts by mass: 3-5 parts of fine powder material prepared by mixing magnesite and silica powder, 7-10 parts of light aggregate prepared by mixing magnesite and silica powder, 5-10 parts of light composite ceramic and 3-5 parts of a binder. The preparation method of the light composite ceramic is as follows: SiAlON powder, zirconium dioxide powder and CoCrFeNiTi powder are mixed to obtain mixed powder, a solvent is added into the mixed powder, ball milling is uniformly carried out, then expanded vermiculite and a foaming agent are added and uniformly mixed to obtain slurry, the slurry is spray dried and granulated, green bodies are obtained after compression molding, and the green bodies are vacuum sintered to obtain the light composite ceramic. The light repairing material for the working layer of the rolling steel heating furnace lining has a low heat preservation coefficient, heat emission in the rolling steel heating furnace is avoided, energy saving is achieved, and cost is saved.

The invention relates to the technical field of blast furnace ironmaking, and discloses a construction method of a blast furnace bosh refractory material structure based on a sialon phase material, which comprises the following steps: an in-furnace synchronous pouring construction method and an out-furnace pouring construction method. According to the construction method of the blast furnace bosh refractory material structure based on the sialon phase material, the sialon corundum castable is adopted, a compact refractory material layer is formed, direct contact between furnace slag and a cooling wall is effectively blocked, the service life of the cooling wall in a traditional bricklaying process is only 1-2 years, the service life can be prolonged to 3 years or above through the construction method, heat transfer is accelerated through the high heat conductivity (larger than 200 W / mK) of AlN, and the service life of the cooling wall is prolonged. The hot surface temperature of the cooling wall is reduced by 300-500 DEG C, material cracking caused by temperature fluctuation is reduced due to the thermal shock resistance (capable of bearing rapid cooling and rapid heating at the temperature of 2200 DEG C) of BN, the cooling wall is prevented from being damaged due to thermal stress, and the service life of the cooling wall is remarkably prolonged.

A sintered body having β-SiAlON as a main phase, the half-value width of a peak corresponding to β phase (101) in an X-ray diffraction (XRD) spectrum being 0.20 or lower.

The invention relates to the field of LED luminescent materials, solves the problems of harsh synthesis conditions and high production cost of narrow-band green fluorescent powder in the prior art, and provides a method for preparing narrow-band green fluorescent powder under a micro-positive pressure condition and an LED package. The method comprises the following steps: uniformly mixing raw materials and an oxygen trapping agent according to a preset proportion to obtain a mixture; filling the mixture into a crucible with an oxygen isolation structure, and placing the crucible into a reaction furnace; establishing a reaction atmosphere in the reaction furnace, and controlling the pressure in the reaction furnace to be within a preset micro-positive pressure range; under the reaction atmosphere, controlling the reaction furnace to perform staged sintering to obtain a sintered material; and after the staged sintering is completed, carrying out rapid cooling treatment on the sintered material according to a preset cooling rate and a preset cooling time to obtain the narrow-band green nitrogen oxide fluorescent powder. The preparation difficulty and production cost of beta-Sialon: Eu are reduced, and the method is suitable for industrial production.

The application relates to the technical field of ceramics, in particular to an injection molding process of large SiAlON ceramics, an injection molding process of large SiAlON ceramics, which comprises the following steps: A, ceramic powder preparation; B, feed preparation; C, injection molding; D, solvent debinding; E, thermal debinding and pre-sintering; and F, sintering. The large SiAlON ceramics produced by the injection molding process has high size precision, the size tolerance of the finished product after sintering can be controlled within 0.1%, the surface finish can reach 3-5 microns, the required machining allowance is extremely small, the cost required for the size precision machining in the later stage is greatly reduced, the production cycle is short, and the production efficiency is greatly improved.

The invention belongs to the technical field of high-performance structural ceramics, and discloses a high-toughness ZrN-SiAlON composite ceramic as well as a preparation method and application thereof. The method comprises the following steps: performing ball milling on Si3N4, AlN, Al2O3, Yb2O3 and ZrN powder to obtain slurry, drying the slurry, and sieving the slurry to obtain composite powder; and carrying out spark plasma sintering at the temperature of between 1,800 and 1,850 DEG C and the axial pressure of between 27 and 33 MPa in a nitrogen atmosphere, so as to obtain the ZrN-SiAlON composite ceramic. The composite ceramic is composed of alpha-SiAlON, beta-SiAlON and ZrN, the fracture toughness of the composite ceramic is 6.2-6.6 MPa.m < 1 / 2 >, the hardness of the composite ceramic is 19-20 GPa, and the fracture toughness of the composite ceramic is nearly doubled while the hardness of the composite ceramic is not remarkably reduced compared with that of SiAlON ceramic. The composite ceramic disclosed by the invention has high toughness and excellent comprehensive performance, and is suitable for the fields of aerospace, armor protection, cutting tools and the like.

The invention provides a gradient pore sialon-based composite ceramic material, which comprises a substrate and a plating layer on the surface of the substrate, the substrate is a sialon ceramic material embedded with boron nitride particles and ceramic fibers, and the interior of the substrate is provided with a gradient pore structure of which the pore diameter is gradually reduced from inside to outside; the plating layer comprises a bottom surface layer and a surface layer, the bottom surface layer comprises an inner layer, a transition layer and an outer layer, and the surface layer is of a multi-layer structure formed by alternately arranging silicon carbonitride and silicon carbide. The invention further provides a preparation method of the gradient pore sialon-based composite ceramic material. The preparation method comprises the steps of raw material treatment, forming, segmented sintering, gradient coating and circulating coating. The invention further provides application of the gradient pore sialon-based composite ceramic material. The gradient pore structure is utilized, stress on an interface is transmitted to other internal pores, the stress is buffered into the whole base body, breakage caused by overlarge local stress is avoided, and the whole film layer has high strength and high abrasion resistance in a high-temperature environment due to the multi-layer film coating structure, is tightly combined with the base body and is difficult to fall off.

A sintered refractory product comprising: - a granule consisting of all particles larger than 100 μm, or "grains", the granule representing between 55% and 85% by mass of the product, the maximum grain size being less than 3.5 mm, and - a matrix binding said grains together and consisting of particles smaller than or equal to 100 μm, or "fine particles", said matrix comprising at least one crystallized SiAlON phase of formula SixAlyOuNv, wherein - x is greater than or equal to 0, greater than 0.05, greater than 0.1 or greater than 0.2, and less than or equal to 1, less than or equal to 0.8 or less than or equal to 0.4; - y is greater than 0, or greater than 0.1, greater than 0.3 or greater than 0.5, and less than or equal to 1; - u is greater than or equal to 0, greater than 0.1 or greater than 0.2, and less than or equal to 1 or less than or equal to 0.7; - v is greater than 0, greater than 0.1, greater than 0.2 or greater than 0.5, or greater than 0.7, and less than or equal to 1;at least one of the stoichiometric indices x, y, uyv is equal to 1, and the volume of the pore fraction with a size between 10 and 100 microns is greater than 4% of the total pore volume.;

The invention discloses a SiAlON / C nanowire composite material with electromagnetic absorption and mechanical toughening functions and a preparation method of the SiAlON / C nanowire composite material, and belongs to the technical field of nanocomposite materials. The preparation method comprises the steps of ball milling, high-pressure sintering, ultrasonic dispersion and drying; the step of ball milling comprises the following steps: mixing Si3N4 and aluminum powder, adding water, and carrying out ball milling and drying; the step of high-pressure sintering comprises the following steps: mixing the dried ball-milled product with graphene in a crucible, then putting the crucible into a tubular furnace, carrying out high-pressure sintering, and unsealing the crucible. The SiAlON / C nanowire composite material is obtained by doping graphene into preparation of beta-SiAlON nanowires, the graphene serves as a carbon source, and the adding amount of the graphene can be adjusted according to experimental requirements to control the thickness of a carbon layer and generation of a SiC intermediate layer at an interface, so that the composite material with excellent electromagnetic wave absorption performance is obtained.

To provide a method for producing a β sialon phosphor having excellent thermal deterioration resistance.SOLUTION: A method for producing a β sialon phosphor includes a preparation step for mixing raw material powder containing silicon, aluminum and europium and firing the mixture, to prepare a β sialon phosphor with europium dissolved therein, and an alkali treatment step for heating the β sialon phosphor with a solid basic substance attached to its surface.SELECTED DRAWING: None