Abstract: The invention relates to a multilayer tubular part (1) comprising a metal layer forming a metal tubular body (3) and two layers in ceramic matrix composite material covering the metal tubular body, wherein one of the two layers in ceramic matrix composite material covers the inner surface of the metal tubular body to form an inner tubular body (4), whilst the other of the two layers in ceramic matrix composite material covers the outer surface of the metal tubular body to form an outer tubular body (2), the metal tubular body therefore being sandwiched between the inner and outer tubular bodies. The metal tubular body is in metal or metal alloy. Finally, the metal tubular body has a mean thickness smaller than the mean thicknesses of the inner and outer tubular bodies. A said part is useful in particular for producing nuclear fuel claddings.

Abstract: A device for tensioning a preform made from interlaced fibers is applied to tension the preform used in a process for fabricating a part made from a ceramic matrix composite material. During this process, the preform is tensioned before and during its densification using the tensioning device (100), which comprises a main body (2), a first assembly element (3) and a second assembly element (4) and a control rod, rotation of the control rod causing translation of the second assembly element, separation of the first and second assembly elements from each other and tensioning of the preform along the longitudinal direction.

Abstract: A method for producing a part made of ceramic matrix and ceramic fibers composite material. It comprises: the formation of a fibrous preform by intertwining threads constituted of ceramic material fibers on a contact surface of a support element reproducing the internal and/or external shape of the part to be produced; the partial densification of the fibrous preform at a temperature below the melting temperature of the material of the support element and below the melting temperature of the material of the fibers of the preform, said partial densification resulting in a consolidated fibrous preform comprising a matrix volume fraction above 5% and at the most equal to 40% of the matrix volume of the part to be produced; the removal of the support element from the consolidated fibrous preform by chemical attack of the contact surface of the material of the support element; the densification of the consolidated preform, carried out at a temperature below the melting temperature of the fibers of said preform.

Abstract: The invention relates to a multilayer tubular part (1) comprising a metal layer forming a metal tubular body (3) and two layers in ceramic matrix composite material covering the metal tubular body, wherein one of the two layers in ceramic matrix composite material covers the inner surface of the metal tubular body to form an inner tubular body (4), whilst the other of the two layers in ceramic matrix composite material covers the outer surface of the metal tubular body to form an outer tubular body (2), the metal tubular body therefore being sandwiched between the inner and outer tubular bodies. The metal tubular body is in metal or metal alloy. Finally, the metal tubular body has a mean thickness smaller than the mean thicknesses of the inner and outer tubular bodies. A said part is useful in particular for producing nuclear fuel claddings.

Abstract: A method for producing a part made of ceramic matrix and ceramic fibres composite material. It comprises: the formation of a fibrous preform by intertwining threads constituted of ceramic material fibres on a contact surface of a support element reproducing the internal and/or external shape of the part to be produced; the partial densification of the fibrous preform at a temperature below the melting temperature of the material of the support element and below the melting temperature of the material of the fibres of the preform, said partial densification resulting in a consolidated fibrous preform comprising a matrix volume fraction above 5% and at the most equal to 40% of the matrix volume of the part to be produced; the removal of the support element from the consolidated fibrous preform by chemical attack of the contact surface of the material of the support element; the densification of the consolidated preform, carried out at a temperature below the melting temperature of the fibres of said preform.

Abstract: The invention relates to a device for tensioning a preform made from interlaced fibres and a process for fabricating a part made from a ceramic matrix composite material, using this preform. During this process, the preform is tensioned before and during its densification using the tensioning device (100), which comprises a main body (2), a first assembly element (3) and a second assembly element (4) and a control rod, rotation of the control rod causing translation of the second assembly element, separation of the first and second assembly elements from each other and tensioning of the preform along the longitudinal direction.

Abstract: A method for manufacturing a contact temperature sensor to be used at a temperature of use, including a) supplying a carbon fiber; b) heat treating of the fiber at a temperature higher than 800° C. and higher than the temperature of use; c) full layer depositing on the fiber, at a deposition temperature, an electrically insulating ceramic coating layer stable at the temperature of use, the ceramic material chosen among silica (SiO2), zirconia (ZrO2), and alumina (Al2O3); d) heat treating of the fiber, coated with the coating layer, at a temperature higher than the deposition temperature of the coating layer and higher than the temperature of use, or (c?) full layer depositing on the fiber a first coating layer of silicon carbide; d?) full layer depositing the first coating layer a second coating layer of boron nitride; e?) heat treating the fiber thereby obtained at a temperature above the deposition temperatures and the temperature of use of the sensor.

Abstract: A method for manufacturing a contact temperature sensor to be used at a temperature of use, including a) supplying a carbon fiber; b) heat treating of the fiber at a temperature higher than 800° C. and higher than the temperature of use; c) full layer depositing on the fiber, at a deposition temperature, an electrically insulating ceramic coating layer stable at the temperature of use, the ceramic material chosen among silica (SiO2), zirconia (ZrO2), and alumina (Al2O3); d) heat treating of the fiber, coated with the coating layer, at a temperature higher than the deposition temperature of the coating layer and higher than the temperature of use, or (c?) full layer depositing on the fiber a first coating layer of silicon carbide; d?) full layer depositing the first coating layer a second coating layer of boron nitride; e?) heat treating the fiber thereby obtained at a temperature above the deposition temperatures and the temperature of use of the sensor.