A process for preparing a composite material comprising an electride compound and an additive, said process comprising (i) providing a composition comprising the additive and a precursor compound of the electride compound, wherein the precursor compound comprises an oxidic compound of the garnet group, and wherein the additive has a boiling temperature which is higher than the melting temperature of the precursor compound; (ii) heating the composition provided in (i) under plasma forming conditions in a gas atmosphere to a temperature above the Httig temperature of the precursor compound and below the boiling temperature of the additive, obtaining the composite material.

The present invention relates to a flame-resistant composite material, in particular a composite material comprising an inorganic matrix and an organic matrix.

The present invention also relates to the method of production of the organic matrix and to the organic matrix, which exhibits a particular resistance to oxidative environments.

Therefore, the composite material according to the present invention finds application where there is a strong oxidation, characteristic of high temperature environments, typically over 700 C., as heat-resistant material, of a fire barrier, or as a material for manufacturing all those artefacts. with operating temperatures between 55 C. and 1200 C. and, for example, with life cycle according to international aeronautical regulations.

A composite sintered body is a ceramic composite sintered body which includes metal oxide which is a main phase, and silicon carbide which is a sub-phase, in which crystal grains of the silicon carbide are dispersed in crystal grains of the metal oxide and at crystal grain boundaries of the metal oxide, and a proportion of the crystal grains of the silicon carbide dispersed in the crystal grains of the metal oxide is 25% or more in an area ratio with respect to a total crystal grains of the silicon carbide.

Provided is a SiC sintered body which contains nitrogen atoms, wherein a ratio R.sub.max/R.sub.ave of a maximum volume resistivity R.sub.max of the sintered body to an average volume resistivity R.sub.ave of the sintered body is 1.5 or lower; a ratio R.sub.min/R.sub.ave of a minimum volume resistivity R.sub.min of the sintered body to the average volume resistivity R.sub.ave is 0.7 or higher; and a relative density of the sintered body is 98% or higher.

A method of manufacturing a silicon carbide (SiC) sintered body and a SiC sintered body obtained by the method are provided. The method includes: preparing a composite powder by subjecting a SiC raw material and a sintering aid raw material to mechanical alloying; and sintering the composite powder, wherein the sintering aid is at least one selected from the group consisting of an AlC-based material, an AlBC-based material, and a BC-based material. Accordingly, a SiC sintered body that can be sintered at low temperature, can be densified, and has high strength and high electrical conductivity can be prepared.

This composite sintered body is a ceramic composite sintered body which includes aluminum oxide which is a main phase, and silicon carbide which is a sub-phase, the composite sintered body including an interface layer which includes, as a forming material, a material other than the aluminum oxide and the silicon carbide, at an interface between a crystal grain of the aluminum oxide and a crystal grain of the silicon carbide in a grain boundary.

A composite sintered body including: a metal oxide as a main phase; silicon carbide as a sub-phase; and silicate of a metal element that is included in the metal oxide, in which the average aggregation diameter of the silicate in the field of view of 600 ?m.sup.2 at a magnification of 1000 times is 5 ?m or lower.

A method of producing a component of a composite of diamond and a binder, wherein a Hot Isostatic gas Pressure process (HIP) is used, includes the step of enclosing a de-bound green body having compacted diamond particles in an infiltrant. The method includes the further steps of enclosing the de-bound green body and the infiltrant in a Zr-capsule that has Zirconium as a main constituent and sealing the Zr-capsule, and applying a predetermined pressure-temperature cycle on the unit formed by the de-bound green body, infiltrant and capsule in which the infiltrant infiltrates the de-bound green body and the de-bound green body is further densified in the sense that the volume thereof is decreased.

A polycrystalline sintered ceramic material of very low electrical resistivity includes by mass more than 95% silicon carbide (SiC), less than 1.5% silicon in another form than SiC, less than 2.5% carbon in another form than SiC, less than 1% oxygen (O), less than 0.5% aluminum (Al), less than 0.5% of the elements Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu, less than 0.5% alkali elements, less than 0.5% alkaline earth, between 0.1 and 1.5% nitrogen (N), the other elements forming the complement to 100%, wherein the grains of the above material have a median equivalent diameter of between 0.5 and 5 micrometers, the mass ratio of SiC alpha (?)/SiC beta (?) is less than 0.1, and the total porosity represents less than 15% by volume of the material.

A polycrystalline silicon carbide sintered material includes silicon carbide grains having a median equivalent diameter of between 1 and 10 microns, the material having a total porosity of less than 2% by volume of the material, and a silicon carbide mass content of at least 99%, except for the free carbon, wherein in the material the mass ratio of the content of SiC having a beta-type crystallographic form to the content of SiC having an alpha-type crystallographic form is less than 2.