Abstract: A method for impregnating an oxide fibre roving with a matrix of alumina and silica includes a introducing an oxide fibre roving into an impregnation bath, wherein the impregnation bath is prepared by sol-gel process and includes a silica precursor in the form of a hybrid polymeric sol, an alumina precursor in the form of a colloidal sol and ceramic particles.

Abstract: A turbine engine part coated in at least a first ceramic layer forming a thermal barrier and including a ceramic material with first ceramic fibers dispersed in the first layer. The first layer may have a chemical composition gradient between a material for forming a thermal barrier and a material for providing protection against calcium and magnesium aluminosilicates, which is present at a greater content in an outer zone of the first layer, and/or the first layer may be porous and may present a porosity gradient such that an outer portion of the first layer presents lower porosity.

Abstract: A method for coating a turbomachine part includes depositing a paint by electrophoresis on the part, a voltage between the part and a counter electrode being controlled during the deposition by imposing a sequence of pulsed voltage cycles, each cycle having: (i) a first voltage stabilization phase during which a first potential difference is imposed between the part and the counter electrode, and a second voltage stabilization phase during which a second potential difference is imposed, an absolute value of the first potential difference being between 0.1 V and 30 V, and an absolute value of the second potential difference being less than the absolute value of the first potential difference, the second potential difference being not equal to zero or being equal to zero, and (ii) a ratio R [duration of the first phase]/[duration of the first phase+duration of the second phase] between 1:10 and 1:3.

Abstract: A process for manufacturing an abradable layer, includes compressing a powder composition including at least micrometric ceramic particles having a number-average form factor greater than or equal to 3, a mass content of said micrometric ceramic particles in the powder composition being greater than or equal to 85%, the form factor of a particle being defined as the ratio [largest dimension of the particle]/[largest cross-sectional dimension of the particle], and sintering the powder composition thus compressed to obtain the abradable layer, wherein a temperature imposed during sintering, the sintering time and the compression pressure applied are selected so as to obtain a volume porosity rate of the abradable layer greater than or equal to 20%.

Abstract: A turbine engine part coated in at least a first ceramic layer forming a thermal barrier and including a ceramic material with first ceramic fibers dispersed in the first layer. The first layer may have a chemical composition gradient between a material for forming a thermal barrier and a material for providing protection against calcium and magnesium aluminosilicates, which is present at a greater content in an outer zone of the first layer, and/or the first layer may be porous and may present a porosity gradient such that an outer portion of the first layer presents lower porosity.

Abstract: A method of localized repair to a damaged thermal barrier, the method including subjecting a part coated in a damaged thermal barrier to electrophoresis treatment, the part being made of an electrically conductive material, the damaged thermal barrier including a ceramic material and presenting at least one damaged zone that is to be repaired, the part being present in an electrolyte including a suspension of particles in a liquid medium, the ceramic coating being deposited by electrophoresis in the damaged zone in order to obtain a repaired thermal barrier for use at temperatures higher than or equal to 1000° C., the particles being made of a material different from the ceramic material present in the damaged thermal barrier.

Abstract: A method of localized repair to a damaged thermal barrier, the method including subjecting a part coated in a damaged thermal barrier to electrophoresis treatment, the part being made of an electrically conductive material, the damaged thermal barrier including a ceramic material and presenting at least one damaged zone that is to be repaired, the part being present in an electrolyte including a suspension of particles in a liquid medium, the ceramic coating being deposited by electrophoresis in the damaged zone in order to obtain a repaired thermal barrier for use at temperatures higher than or equal to 1000° C., the particles being made of a material different from the ceramic material present in the damaged thermal barrier.

Abstract: The invention relates to a method for manufacturing a thermal barrier protection covering a superalloy metal substrate and comprising at least one metal sublayer (13) and a ceramic layer (14) based on zirconia stabilized with yttrium having a column structure defining pores. The following steps are applied: impregnation of a portion of the pores of the ceramic layer (14) with a sol based on zirconia is achieved via a sol-gel route and this in order to form an anchoring sublayer (22), on said ceramic layer topped with said anchoring sub-layer (22), a continuous protective layer (20) based on oxide, is formed via a sol-gel route, and a heat treatment is carried out, whereby an outer protection layer is formed against the attack of the thermal barrier (11) by CMASes. Application to the protection of aeronautical protection parts.

Abstract: An anticorrosion treatment process in which applied to an oxidizable surface of a solid metal substrate is a liquid solution, referred to as treatment solution, including: at least one alkoxysilane, and at least one cerium (Ce) cation; in a liquid aqueous-alcoholic composition, the treatment solution being suitable for being able to form, at the surface of the solid metal substrate, a hybrid matrix by hydrolysis/condensation of each alkoxysilane(s) and of each cerium (Ce) cation; the treatment solution having a molar ratio (Si/Ce) of silicon element of the alkoxysilane(s) with respect to the cerium (Ce) cation(s) of between 50 and 500; characterized in that the cerium (Ce) cation(s) has(have) a concentration between 0.005 mol/L and 0.015 mol/L in the treatment solution.

Abstract: The present invention relates to a method for manufacturing a metal-oxide-based ceramic, including, in order, the step of inserting, into a flash sintering device, a nanocrystalline powder comprising crystallites and crystallite agglomerates of a ceramic of formula, Zr1-xMxO2, where M is chosen from yttrium, scandium and cerium, or Ce1-xM?xO2, where M? is chosen from gadolinium, scandium, samarium and yttrium, where x lies between 0 and 0.2, the powder having an average crystallite size of between 5 and 50 nm, an average crystallite agglomerate size of between 0.5 and 20 ?m, and a specific surface area of between 20 and 100 m2/g. The invention further includes the step of flash sintering the powder by applying a pressure of between 50 and 150 MPa, at a temperature of between 850° C. and 1400° C., for a time of between 5 and 30 minutes.

Abstract: The invention relates to a method for manufacturing a thermal barrier protection covering a superalloy metal substrate and comprising at least one metal sublayer (13) and a ceramic layer (14) based on zirconia stabilized with yttrium having a column structure defining pores. The following steps are applied: impregnation of a portion of the pores of the ceramic layer (14) with a sol based on zirconia is achieved via a sol-gel route and this in order to form an anchoring sublayer (22), on said ceramic layer topped with said anchoring sub-layer (22), a continuous protective layer (20) based on oxide, is formed via a sol-gel route, and a heat treatment is carried out, whereby an outer protection layer is formed against the attack of the thermal barrier (11) by CMASes. Application to the protection of aeronautical protection parts.

Abstract: The present invention relates to a method for manufacturing a metal-oxide-based ceramic, including, in order, the step of inserting, into a flash sintering device, a nanocrystalline powder comprising crystallites and crystallite agglomerates of a ceramic of formula, Zr1-xMxO2, where M is chosen from yttrium, scandium and cerium, or Ce1-xM?xO2, where M? is chosen from gadolinium, scandium, samarium and yttrium, where x lies between 0 and 0.2, the powder having an average crystallite size of between 5 and 50 nm, an average crystallite agglomerate size of between 0.5 and 20 ?m, and a specific surface area of between 20 and 100 m2/g. The invention further includes the step of flash sintering the powder by applying a pressure of between 50 and 150 MPa, at a temperature of between 850° C. and 1400° C., for a time of between 5 and 30 minutes.

Abstract: A gas electrode includes a plurality of stacked layers (2, 3, 4), wherein the first layer (2) is in contact with a solid substrate (1) while the last layer (4) has a free outer surface to be contacted with a gas, each layer being made of at least one mixed oxide selected from the group including perovskites and Ruddlesden-Popper phases, the micro-structure of the first layer (2) being different from that of the last layer (4), the porosity of the different layers (2, 3, 4) increasing from the first layer (2) towards the last layer (4), and the different layers stacked on each other defining a network of a solid interconnected material between the free outer surface of the last layer (4) and the solid substrate with a total thickness higher than 1 ?m. A method for making such an electrode and its use in an electrochemical cell are disclosed.

Abstract: Method of preparing a metal oxide layer on a substrate, in which the following successive steps are carried out: a) a metal oxide powder is dispersed in a liquid medium comprising a dispersion solvent and a dispersant, the said liquid medium containing neither plasticizer nor binder, by means of which a suspension A of the said metal oxide powder in the said liquid medium is obtained; b) a solution of at least one polymer in a solvent is added to the said suspension A, by means of which a suspension B is obtained; c) suspension B is deposited on the substrate by a dip coating method, by means of which a green layer is obtained; d) the green layer obtained in step c) is dried; and e) the dried layer obtained in step d) is calcined.