Abstract: A die or piston of a spark plasma sintering apparatus, wherein the die or piston is made from graphite and the outer surfaces of the die or piston are coated with a silicon carbide layer with a thickness of 1 to 10 micrometres, the silicon carbide layer being further optionally coated with one or more other layer(s) made from a carbide other than silicon carbide chosen from hafnium carbide, tantalum carbide and titanium carbide, the other layer(s) each having a thickness of 1 to 10 micrometres. A spark plasma sintering (SPS) apparatus comprising the die and two of the pistons, defining a sintering, densification or assembly chamber capable of receiving a powder to be sintered, a part to be densified, or parts to be assembled. A method of sintering a powder, densifying a part, or assembling two parts by means of a method of spark plasma sintering (SPS) in an oxidising atmosphere, using the spark plasma sintering (SPS) apparatus.

Abstract: A die or piston of a spark plasma sintering apparatus, wherein the die or piston is made from graphite and the outer surfaces of the die or piston are coated with a silicon carbide layer with a thickness of 1 to 10 micrometres, the silicon carbide layer being further optionally coated with one or more other layer(s) made from a carbide other than silicon carbide chosen from hafnium carbide, tantalum carbide and titanium carbide, the other layer(s) each having a thickness of 1 to 10 micrometres. A spark plasma sintering (SPS) apparatus comprising the die and two of the pistons, defining a sintering, densification or assembly chamber capable of receiving a powder to be sintered, a part to be densified, or parts to be assembled. A method of sintering a powder, densifying a part, or assembling two parts by means of a method of spark plasma sintering (SPS) in an oxidising atmosphere, using the spark plasma sintering (SPS) apparatus.

Abstract: A die or piston of a spark plasma sintering apparatus, wherein the die or piston is made from graphite and the outer surfaces of the die or piston are coated with a silicon carbide layer with a thickness of 1 to 10 micrometres, the silicon carbide layer being further optionally coated with one or more other layer(s) made from a carbide other than silicon carbide chosen from hafnium carbide, tantalum carbide and titanium carbide, the other layer(s) each having a thickness of 1 to 10 micrometres. A spark plasma sintering (SPS) apparatus comprising the die and two of the pistons, defining a sintering, densification or assembly chamber capable of receiving a powder to be sintered, a part to be densified, or parts to be assembled. A method of sintering a powder, densifying a part, or assembling two parts by means of a method of spark plasma sintering (SPS) in an oxidising atmosphere, using the spark plasma sintering (SPS) apparatus.

Abstract: Method for the preparation, by means of a heating technique, of a composite material composed of a matrix of at least a first oxide of at least one metal and/or at least one metalloid reinforced by reinforcements in at least a second oxide of at least one metal and/or at least one metalloid, characterised in that the following successive steps are carried out: the reinforcements are placed in at least one liquid precursor of the first oxide of at least one metal and/or at least one metalloid; said reinforcements and the liquid precursor are heated so as to form the first oxide by means of the thermal decomposition of said liquid precursor, and to deposit the first oxide thus formed around the reinforcements and between the reinforcements thus forming the matrix.

Abstract: A method for manufacturing a part from a first ceramic or from carbon, consolidated by a second ceramic, having a determined geometry, that involves carrying out the following sequence of steps: a) manufacturing a preform made from an organic polymer; b) impregnating the preform made from an organic polymer with a resin that is a precursor of the first ceramic or a resin that is a precursor of carbon; c) crosslinking and/or polymerising, then pyrolysing the resin that is a precursor of the first ceramic or the resin that is a precursor of carbon; to obtain a part made from a first ceramic or from carbon having the same geometry as the part to be manufactured; e) depositing the second ceramic on the part made from a first ceramic or from carbon by means of a chemical vapour deposition or CVD process or a chemical vapour infiltration or CVI process.

Abstract: A composite material consisting of a matrix made of at least one aluminosilicate notably selected from barium aluminosilicate BAS, barium and strontium aluminosilicate BSAS, strontium aluminosilicate SAS, and mixtures thereof, reinforced by reinforcements made of at least one metal or metalloid oxide, the expansion coefficient of which is close to that of said at least one aluminosilicate. A method for preparing said composite material. A composite material according to the invention notably finding its application in the aeronautical or aerospace field, for example for the manufacture of radomes.

Abstract: Method for the preparation, by means of a heating technique, of a composite material composed of a matrix of at least a first oxide of at least one metal and/or at least one metalloid reinforced by reinforcements in at least a second oxide of at least one metal and/or at least one metalloid, characterised in that the following successive steps are carried out: the reinforcements are placed in at least one liquid precursor of the first oxide of at least one metal and/or at least one metalloid; said reinforcements and the liquid precursor are heated so as to form the first oxide by means of the thermal decomposition of said liquid precursor, and to deposit the first oxide thus formed around the reinforcements and between the reinforcements thus forming the matrix.

Abstract: The invention relates to a method for preparing a material based on an aluminosilicate selected from barium aluminosilicate BAS, barium-strontium aluminosilicate BSAS, and strontium aluminosilicate SAS, said aluminosilicate consisting of aluminosilicate with a hexagonal structure, characterised in that it includes a single sintering step in which a mixture of powders of precursors of said aluminosilicate, including an aluminium hydroxide Al(OH)3 powder, are sintered by a hot-sintering technique with a pulsed electric field SPS; whereby a material based on an aluminosilicate, said aluminosilicate consisting of an aluminosilicate with a hexagonal structure is obtained. The material based on an aluminosilicate prepared by said method can be used in a method for preparing a composite material consisting of an aluminosilicate matrix reinforced by reinforcements made of metalloid or metal oxide.

Abstract: A method preparing a metals carbides multilayer coating on at least one surface of a first carbon layer of a substrate, or under the surface inside the first carbon layer, by a reactive melt infiltration technique, includes: a) putting the surface into contact with a solid metal disilicide MSi2, M is selected from hafnium, titanium, and tantalum; b) heating the substrate and the metal disilicide to above the melting temperature of the metal disilicide; c) observing a plateau at the temperature for a sufficient duration so that the metal disilicide reacts with the carbon and forms a first multilayer coating including a dense and continuous layer of SiC, fully covered by a dense and continuous layer of MC; d) cooling the part with the first multilayer coating; and then, at the end of d), optionally e) depositing a second carbon layer at the surface of the first multilayer coating.

Abstract: A die or piston of a spark plasma sintering apparatus, wherein the die or piston is made from graphite and the outer surfaces of the die or piston are coated with a silicon carbide layer with a thickness of 1 to 10 micrometres, the silicon carbide layer being further optionally coated with one or more other layer(s) made from a carbide other than silicon carbide chosen from hafnium carbide, tantalum carbide and titanium carbide, the other layer(s) each having a thickness of 1 to 10 micrometres. A spark plasma sintering (SPS) apparatus comprising the die and two of the pistons, defining a sintering, densification or assembly chamber capable of receiving a powder to be sintered, a part to be densified, or parts to be assembled. A method of sintering a powder, densifying a part, or assembling two parts by means of a method of spark plasma sintering (SPS) in an oxidising atmosphere, using the spark plasma sintering (SPS) apparatus.

Abstract: The invention relates to a method for preparing a material based on an aluminosilicate selected from barium aluminosilicate BAS, barium-strontium aluminosilicate BSAS, and strontium aluminosilicate SAS, said aluminosilicate consisting of aluminosilicate with a hexagonal structure, characterised in that it includes a single sintering step in which a mixture of powders of precursors of said aluminosilicate, including an aluminium hydroxide Al(OH)3 powder, are sintered by a hot-sintering technique with a pulsed electric field SPS; whereby a material based on an aluminosilicate, said aluminosilicate consisting of an aluminosilicate with a hexagonal structure is obtained. The material based on an aluminosilicate prepared by said method can be used in a method for preparing a composite material consisting of an aluminosilicate matrix reinforced by reinforcements made of metalloid or metal oxide.

Abstract: A method is disclosed for coating, by means of a chemical vapor deposition (CVD) technique, a part with a coating (PAO) for protecting against oxidation. The method enables the preparation of a refractory coating for protecting against oxidation, having a three-dimensional microstructure, which ensures the protection against oxidation at a high temperature, generally at a temperature above 1200° C., for materials that are sensitive to oxidation, such as composite materials, and in particular carbon/carbon composite materials.

Abstract: A method for preparing a protective coating against oxidation on at least one surface of at least one part made of at least one material capable of being oxidized, wherein the following successive steps are carried out: a) each of the particles of a powder made of a first ceramic selected from refractory ceramics and ceramics which resist oxidation, is coated with at least one layer selected from layers made of a refractory ceramic, layers made of a ceramic which resist oxidation, and layers made of a refractory metal, provided that the coating comprises at least one ceramic which resists oxidation, and at least one refractory ceramic or metal; b) the powder is deposited onto the surface to be coated of the part; c) sintering of the powder is achieved on the surface of the part by a Spark Plasma Sintering (SPS) Method; d) the part is cooled; e) the cooled part, coated on at least one of its surfaces with a protective refractory monolayer coating against oxidation, with a three-dimensional microstructure, i

Abstract: A method preparing a metals carbides multilayer coating on at least one surface of a first carbon layer of a substrate, or under the surface inside the first carbon layer, by a reactive melt infiltration technique, includes: a) putting the surface into contact with a solid metal disilicide MSi2, M is selected from hafnium, titanium, and tantalum; b) heating the substrate and the metal disilicide to above the melting temperature of the metal disilicide; c) observing a plateau at the temperature for a sufficient duration so that the metal disilicide reacts with the carbon and forms a first multilayer coating including a dense and continuous layer of SiC, fully covered by a dense and continuous layer of MC; d) cooling the part with the first multilayer coating; and then, at the end of d), optionally e) depositing a second carbon layer at the surface of the first multilayer coating.

Abstract: A composite material consisting of a matrix made of at least one aluminosilicate notably selected from barium aluminosilicate BAS, barium and strontium aluminosilicate BSAS, strontium aluminosilicate SAS, and mixtures thereof, reinforced by reinforcements made of at least one metal or metalloid oxide, the expansion coefficient of which is close to that of said at least one aluminosilicate. A method for preparing said composite material. A composite material according to the invention notably finding its application in the aeronautical or aerospace field, for example for the manufacture of radomes.

Abstract: The invention relates to a process for manufacturing at least one elementary electrochemical cell comprising a first and a second electrode between which an electrolyte is intercalated, said first and second electrodes and said electrolyte being in the form of layers, which process is characterized in that it comprises: a) producing at least one structure comprising a layer of a powder of a first electrode material and a layer of a powder of a second electrode material between which a layer of a powder of an electrolyte material is intercalated; and b) simultaneously sintering all the powder layers by an electric field sintering. Applications: manufacture of energy- or hydrogen-producing electrochemical systems, in particular solid oxide fuel cells (SOFCs) or high temperature electrolysers cells (HTEs).

Abstract: A process for joining, by spark plasma sintering, at least two refractory ceramic parts, each of the parts having at least one surface to be joined by spark plasma sintering, in which surfaces to be joined are brought into contact without addition of any sort between the surfaces. Then, a joining pressure of 1 to 200 MPa is applied to the ceramic parts. A pulsed electric current having an intensity of 500 A to 8000 A is applied to the ceramic parts so as to raise the temperature of the parts to a joining temperature of at least 1300° C. Then, the electric current is terminated simultaneously with the pressure, and the parts are cooled, and the joined parts are recovered.

Abstract: The invention relates to a method for coating, by means of a chemical vapour deposition (CVD) technique, a part with a coating (PAO) for protecting against oxidation. The method enables the preparation of a refractory coating for protecting against oxidation, having a three-dimensional microstructure, which ensures the protection against oxidation at a high temperature, generally at a temperature above 1200° C., for materials that are sensitive to oxidation, such as composite materials, and in particular carbon/carbon composite materials.

Abstract: A method for preparing a protective coating against oxidation on at least one surface of at least one part made of at least one material capable of being oxidized, wherein the following successive steps are carried out: a) each of the particles of a powder made of a first ceramic selected from refractory ceramics and ceramics which resist oxidation, is coated with at least one layer selected from layers made of a refractory ceramic, layers made of a ceramic which resist oxidation, and layers made of a refractory metal, provided that the coating comprises at least one ceramic which resists oxidation, and at least one refractory ceramic or metal; b) the powder is deposited onto the surface to be coated of the part; c) sintering of the powder is achieved on the surface of the part by a Spark Plasma Sintering (SPS) Method; d) the part is cooled; e) the cooled part, coated on at least one of its surfaces with a protective refractory monolayer coating against oxidation, with a three-dimensional microstructure, i

Abstract: The invention relates to a process for manufacturing at least one elementary electrochemical cell comprising a first and a second electrode between which an electrolyte is intercalated, said first and second electrodes and said electrolyte being in the form of layers, which process is characterized in that it comprises: a) producing at least one structure comprising a layer of a powder of a first electrode material and a layer of a powder of a second electrode material between which a layer of a powder of an electrolyte material is intercalated; and b) simultaneously sintering all the powder layers by an electric field sintering. Applications: manufacture of energy- or hydrogen-producing electrochemical systems, in particular solid oxide fuel cells (SOFCs) or high temperature electrolysers cells (HTEs).