Office National D'etudes Et De Recherches Aerospatiales

Centre National De La Recherche Scientifique

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Université Pierre Et Marie Curie (paris 6)

Electricite De France - Service National

Paris Sciences Et Lettres

Université Pierre Et Marie Curie

Ecole Nationale Superieure De Chimie De Paris

Daniel Morvan

Marie-Pierre Bacos

Frederic Rousseau

Jean-Paul Garandet

Jacques Amouroux

Odile Lavigne

Frédéric Prima

Malek Benmansour

Catherine Rio

Olivier Lesage

Jonathan Cramer

Frédéric Rousseau

Rafik Benrabbah

Marie-Helene Vidal-Setif

Marie-Hélène Vidal-Setif

The invention relates to a process for selectively and continuously extracting a series of desired species from a matrix, comprising the steps of:&#x2014;injecting a plasma () in an extraction chamber by means of a plasma torch,&#x2014;continuously monitoring () the excited elements extracted from the matrix and contained in the plasma by optical emission spectroscopy, and for each species of the series,&#x2014;setting a distance () between the support and the plasma torch, and the composition of the injected plasma as a function of the monitored excited elements so that only one desired species of the series of species is being extracted from the matrix under molecular form, and&#x2014;providing () a plate in the extraction chamber, exterior to the plasma, causing collection of molecules comprising said desired species by deposition onto the surface of the plate.

Process and system for plasma-induced selective extraction and recovery of species from a matrix

The invention relates to a method for repairing a thermal barrier of a component comprising a substrate coated with such a thermal barrier, said substrate being made of a high-performance alloy, said thermal barrier being adhered to the alloy and having lower thermal conductivity than the alloy, the thermal barrier including at least one ceramic, one region of the thermal barrier being a region to be repaired, wherein said method includes the following steps: a) defining the region to be repaired, using a mask which protects the other regions of the thermal barrier; b) injecting a carrier gas loaded with droplets of ceramic precursor into a plasma discharge inside a plasma chamber of a plasma reactor containing the component to be repaired, while making the concentration of ceramic precursor in the carrier gas dependent on at least one parameter of the reactor selected from among: the pressure of the plasma chamber, the power of the plasma generator and the diameter of the precursor droplets, in order to control the state&#x2014;liquid, gel or solid&#x2014;of the ceramic precursor having an effect on the region to be repaired; c) injecting a gas not loaded with ceramic precursor into a plasma discharge within the plasma chamber, steps b) and c) being repeated.

Method for locally repairing thermal barriers

The invention relates to a method and system for forming a layer of oxide on a pervious component made of a material or a stack of materials that are stable at 400&#xb0; C., said component including an outer surface to be coated and at least one pore with a diameter of 50 to 1000 &#x3bc;m leading onto said outer surface. Said method includes the following steps: a) injecting a carrier gas loaded with droplets of at least one precursor of the oxide into a low-pressure plasma inside an enclosure of a plasma reactor housing the component to be coated, and injecting a fluid passing through the pervious component and flowing in gaseous state through said at least one pore with a flow opposite to that of the carrier gas in the plasma chamber in order to avoid the clogging of the pore, the pressure and the mass flow of said fluid upstream of the pervious component being such that the pressure of the gas at the outlet of the at least one pore is higher than the pressure in the plasma chamber, and the injection mass flow of the fluid passing through the pervious component is: &#x3b1;) less than or equal to the mass low of the carrier gas loaded with precursor of the oxide injected into the plasma chamber, and &#x3b2;) greater than or equal to the product of the mass flow of the carrier gas loaded with precursors of the oxide injected into the plasma chamber by the ration between the total surface of the open pores of the pervious component and the surface of the passage section of the plasma chamber, thus, the speed of the gas at the outlet of the at least one pore is no lower than the intake speed of the carrier gas loaded with at least one precursor of the oxide in, non-preferentially, the liquid, gel or solid state thereof, on the outer surface of the component; b) injecting a carrier gas not loaded with a precursor of the oxide into a plasma inside the plasma chamber, wherein the injection of the fluid passing through the pervious component is maintained and steps a) and b) are repeated, such as to form said oxide on the outer surface, the diameter of the at least one pore being preserved.

Method and system for depositing oxide on a porous component

A device for analyzing at least one oxidizable molten metal using a LIBS technique, including: a LIBS analyzer; a mechanical rotary mechanism stirring a liquid bath of the at least one oxidizable molten metal, and including a central section, to be positioned above the liquid bath of the at least one oxidizable molten metal, including an internal cavity forming an analysis chamber, the central section including a first end connected to the LIBS analyzer, and a plurality of mechanical stirring paddles to be partially submerged in the liquid bath of the at least one oxidizable molten metal and that are connected to a second end of the central section opposite the first end of the central section, the LIBS analyzer configured to allow the surface of the at least one oxidizable molten metal located in the portion plumb with the internal cavity of the central portion to be analyzed.

Device for analysing an oxidisable molten metal using a libs technique

Boron is removed from silicon by zone melting purification. A jet of hot plasma obtained by high frequency excitation is directed on a zone of a bar of silicon to be purified. The plasma is formed from a mixture of a plasma-producing gas, such as argon, and an amount of oxygen which is sufficiently low to avoid oxidization of silicon.

Zone purification of silicon in a reactive plasma

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Paris, France

Daniel Morvan