摘要:
A thermal barrier coating for a superalloy part used, in particular, in turbomachines comprises a ceramic coating and a sub-layer interposed between the superalloy substrate and the ceramic coating, the sub-layer being composed of a nickel and/or cobalt aluminide containing at least one platinum-like metal and at least one metal for promoting the formation of a layer of oxide constituted by the alpha-allotropic variety of alumina.
摘要:
The invention relates to a method of producing and joining superalloy balls by means of brazing and to objects produced with such joints. According to one aspect of the invention, an alloy powder covered with a brazing solder is bonded to a spherical core and subsequently transformed into a continuous alloy layer by means of brazing.
摘要:
A structural element used for attenuating aviation turbine noise is provided with pores (1, 2) embodied in the form of cylindrical channels which are open on the first ends inside the turbine housing and closed on the opposite ends thereof, wherein the diameter (D) of each channel ranges approximately from 0.1 to 0.3 mm, each channel is remote at least along one part of the length thereof from the closest neighbours at a minimum distance ranging approximately from 0.02 to 0.3 mm and the ratio between the channel length and diameter thereof is of the order of 102.
摘要:
Hollow metal spheres are heated in a high vacuum in the presence of an organic substance, at a temperature at least equal to the melting point of a eutectic between carbon and the metallic constituents of the said spheres.
摘要:
In order to protect a monocrystalline superalloy rich in rhenium against corrosion whilst avoiding the formation of progressive secondary reaction zones, a layer (3) formed of tungsten and cobalt is deposited on its surface before aluminisation treatment.
摘要:
The sealing composition contains powders composed, by weight, of 70 to 90% of aluminium, 5 to 25% of silicon, 0 to 5% of silica and 0.1 to 5% of moderating metal, which are dispersed in a vehicle comprising an organic binder dissolved in a solvent and a mineral binder. It is applied to the faces to be assembled of a ceramic part and of a refractory alloy or superalloy part and the whole is heated in order to eliminate said vehicle and form between the two parts a layer of mullite syncrystallized with the ceramic.
摘要:
Method, apparatus, and system for preparing a cellular material based on hollow metal beads. According to the description, at least one bead chain in which said hollow metal beads are linked to one another in pairs by means of an articulation is used as elementary structure constituting the cellular material.
摘要:
The invention relates to a method for forming a protective coating against high-temperature oxidation on a surface of a refractory composite material based on silicon and niobium, wherein chromium present on the surface to be protected is reacted with a reactive gas which contains silicon and oxygen in order to produce a composite coating having two phases, a first phase of which is an oxide phase based on silica which has viscoplastic properties and a second phase of which is based on silicon, chromium and oxygen, and wherein the first phase and second phase are coalesced at high temperature, which allows a protective coating to be formed in which the second phase acts as a reservoir to reform, during operation, the first phase by means of reaction with an oxidising gas. The invention is preferably used in the field of aeronautical engines.
摘要:
The invention relates to a method for forming a protective coating against high-temperature oxidation on a surface of a refractory composite material based on silicon and niobium, wherein chromium present on the surface to be protected is reacted with a reactive gas which contains silicon and oxygen in order to produce a composite coating having two phases, a first phase of which is an oxide phase based on silica which has viscoplastic properties and a second phase of which is based on silicon, chromium and oxygen, and wherein the first phase and second phase are coalesced at high temperature, which allows a protective coating to be formed in which the second phase acts as a reservoir to reform, during operation, the first phase by means of reaction with an oxidising gas. The invention is preferably used in the field of aeronautical engines.
摘要:
The invention relates to a method of brazing a Ti—Al alloy. According to the invention, a layer of nickel (2) is disposed between a part (1) which is made from titanium aluminide and a brazing sheet (3), such as to enable: the aforementioned part (1) to be brazed to another metallic material (4) without the aluminium diffusing from one to the other; and a stable link with good mechanical strength to be produced. The invention can be used for the assembly of aircraft engine parts which are made from titanium aluminide and nickel-based superalloy.