The method for producing non-core beta silicon carbide fibers includes four steps. The first step is spinning of multifilament polymeric fiber by melt-extrusion of polycarbosilane. The second step is thermooxidative cross-linking for which the produced spun polymeric fibers are cured in an oxidation furnace at a temperature of 175-250 degrees C. at a heating rate of 3-10 degrees C./h until their weight is increased by 6-15%. The third step is carbonization of the produced cured polymeric fibers with the conversion into the ceramic phase. The fourth step is finishing of the produced beta silicon carbide fiber. The effect of the invention is producing non-core silicon carbide fibers, improving their strength performance, improving resistance to high temperatures and their high creep resistance, stable fiber properties, optimal average diameter of fibers, absence of foreign impurities in the fiber composition.

The method for producing non-core beta silicon carbide fibers includes four steps. The first step is spinning of multifilament polymeric fiber by melt-extrusion of polycarbosilane. The second step is thermooxidative cross-linking for which the produced spun polymeric fibers are cured in an oxidation furnace at a temperature of 175-250 degrees C. at a heating rate of 3-10 degrees C./h until their weight is increased by 6-15%. The third step is carbonization of the produced cured polymeric fibers with the conversion into the ceramic phase. The fourth step is finishing of the produced beta silicon carbide fiber. The effect of the invention is producing non-core silicon carbide fibers, improving their strength performance, improving resistance to high temperatures and their high creep resistance, stable fiber properties, optimal average diameter of fibers, absence of foreign impurities in the fiber composition.

The present invention relates to methods for preparing silicon carbide powder and single crystal silicon carbide and, more particularly, to a method for preparing silicon carbide powder including: providing a precursor gas onto a fibrous carbon body in a reactor to deposit silicon carbide (SiC) on the fibrous carbon body; recovering the silicon carbide deposited on the fibrous carbon body to obtain a first silicon carbide powder; and oxidizing the first silicon carbide powder, wherein a molecule of the precursor gas include a silicon atom and a carbon atom.

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.

A method for manufacturing predominantly amorphous silicon-containing particles includes a chemical compound of formula: Si.sub.(1−x)C.sub.x, where 0.005≤x<0.05. The particles, when subjected to XRD analysis applying unmonochromated CuKα radiation, exhibit one peak at around 28° and one peak at around 52°. Both peaks have a Full Width at Half Maximum of at least 5° when using Gaussian peak fitting. The method includes forming a homogeneous gas mixture of a first precursor gas of a silicon containing compound and at least one second precursor gas of a substitution element M containing compound, injecting the homogeneous gas mixture of the first and second precursor gases into a reactor space where the precursor gases are heated to a temperature in the range of from 700 to 900° C. so that the precursor gases react and form particles, and collecting and cooling the particles to a temperature in the range of from ambient temperature up to about 350° C. The relative amounts of the first and the second precursor gases are adapted such that the formed particles obtain an atomic ratio C: Si in the range of [0.005, 0.05).

A method for manufacturing predominantly amorphous silicon-containing particles includes a chemical compound of formula: Si.sub.(1−x)C.sub.x, where 0.005≤x<0.05. The particles, when subjected to XRD analysis applying unmonochromated CuKα radiation, exhibit one peak at around 28° and one peak at around 52°. Both peaks have a Full Width at Half Maximum of at least 5° when using Gaussian peak fitting. The method includes forming a homogeneous gas mixture of a first precursor gas of a silicon containing compound and at least one second precursor gas of a substitution element M containing compound, injecting the homogeneous gas mixture of the first and second precursor gases into a reactor space where the precursor gases are heated to a temperature in the range of from 700 to 900° C. so that the precursor gases react and form particles, and collecting and cooling the particles to a temperature in the range of from ambient temperature up to about 350° C. The relative amounts of the first and the second precursor gases are adapted such that the formed particles obtain an atomic ratio C: Si in the range of [0.005, 0.05).

Provided is a polycrystalline SiC molded body wherein the resistivity is not more than 0.050 Ωcm and, when the peak strength in a wave number range of 760-780 cm.sup.−1 in a Raman spectrum is regarded as “A” and the peak strength in a wave number range of 790-800 cm.sup.−1 in the Raman spectrum is regarded as “B”, then the peak ratio (A/B) is not more than 0.100.

Provided is a polycrystalline SiC molded body wherein the resistivity is not more than 0.050 Ωcm and, when the diffraction peak strength in a diffraction angle 2θ range of 33-34° in an X-ray diffraction pattern is regarded as “A” and the diffraction peak strength of the SiC(111) plane in the X-ray diffraction pattern is regarded as “B”, then the ratio (A/B) is not more than 0.018.

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. Vapor deposition processes and articles formed by those processes utilizing such high purity SiOC and SiC.