Abstract: The present invention concerns a turbine part comprising a substrate made of nickel-based monocrystalline superalloy, comprising chromium and at least one element chosen among rhenium and ruthenium, the substrate having a ?-?? phase, an average mass fraction of rhenium and of ruthenium greater than or equal to 4% and an average mass fraction of chromium less than or equal to 5% and preferably less than or equal to 3%, a sub-layer covering at least a part of a surface of the substrate, characterised in that the sublayer has a ?-?? phase and an average atomic fraction of chromium greater than 5%, of aluminium between 10% and 20% and of platinum between 15% and 25%.

Abstract: A process for coating a refractory alloy part is provided and includes coating an area of a refractory alloy part by means of a treatment composition including a type of preceramic polymer and a solvent, and heat treating the part coated with the treatment composition. The heat treating partially converts the preceramic polymer and forms a ceramic coating obtained by conversion, the ceramic coating protecting the refractory alloy from oxidation. The treatment composition also includes active fillers to form an alloy coating on a surface of the part by solid diffusion in addition to the ceramic coating obtained by conversion, and the alloy coating generates a protective oxide layer when subjected to oxidizing conditions.

Abstract: The invention relates to a nickel-based superalloy comprising, in percentages by mass, 4.0 to 5.5% rhenium, 1.0 to 3.0 ruthenium, 2.0 to 14.0% cobalt, 0.3 to 1.0% molybdenum, 3.0 to 5.0% chromium, 2.5 to 4.0% tungsten, 4.5 to 6.5% aluminum, 0.50 to 1.50% titanium, 8.0 to 9.0% tantalum, 0.15 to 0.30% hafnium, 0.05 to 0.15% silicon, the balance being nickel and unavoidable impurities. The invention also relates to a single-crystal blade (20A, 20B) comprising such an alloy and a turbomachine (10) comprising such a blade (20A, 20B).

Abstract: A turbomachine part includes a nickel-based superalloy substrate including, in mass content, 5.0% to 8.0% cobalt, 6.5% to 10% chromium, 0.5% to 2.5% molybdenum, 5.0% to 9.0% tungsten, 6.0% to 9.0% tantalum, 4.5% to 5.8% aluminum, hafnium in a mass content between 500 ppm and 1100 ppm, and optionally including niobium in a mass content less than or equal to 1.5%, and optionally at least one of carbon, zirconium and boron each in a mass content less than or equal to 100 ppm, the remainder being composed of nickel and unavoidable impurities.

Abstract: A turbomachine part includes (i) a nickel-based superalloy substrate including, in mass content, 5.0% to 8.0% cobalt, 6.5% to 10% chromium, 0.5% to 2.5% molybdenum, 5.0% to 9.0% tungsten, 6.0% to 9.0% tantalum, 4.5% to 5.8% aluminum, hafnium in a mass content greater than or equal to 2000 ppm, and optionally including niobium in a mass content less than or equal to 1.5%, and optionally at least one of carbon, zirconium and boron each in a mass content less than or equal to 100 ppm, the remainder being composed of nickel and unavoidable impurities; and (ii) a ?-structured nickel aluminide coating covering the substrate.

Abstract: A process for coating a part by chemical vapor diffusion is provided and includes placing a powder mixture in a chamber, immersing the part partially in the powder mixture, and applying a heat treatment to the part. The powder mixture includes a first component and a second component forming a gaseous compound during the heat treatment so as to allow deposition of the second component on the part. The part includes a metal refractory allow and the second component forms a solid diffusion alloy by solid diffusion with a metal species of the refractory metal alloy to generate a coating. The solid diffusion allow generates a passivating oxide layer when subjected to oxidizing conditions.

Abstract: The invention relates to a nickel-based superalloy comprising, in percentages by mass, 4.0 to 5.5% rhenium, 1.0 to 3.0 ruthenium, 2.0 to 14.0% cobalt, 0.3 to 1.0% molybdenum, 3.0 to 5.0% chromium, 2.5 to 4.0% tungsten, 4.5 to 6.5% aluminum, 0.50 to 1.50% titanium, 8.0 to 9.0% tantalum, 0.15 to 0.30% hafnium, 0.05 to 0.15% silicon, the balance being nickel and unavoidable impurities. The invention also relates to a single-crystal blade (20A, 20B) comprising such an alloy and a turbomachine (10) comprising such a blade (20A, 20B).

Abstract: A process for protecting a part made of a hafnium-free nickel-based single-crystal superalloy against corrosion and oxidation includes manufacturing a part made of a hafnium-free nickel-based single-crystal superalloy, depositing successively on the part, a first layer including hafnium, then a mixed layer of stacked layers of an undercoat of an alloy having 10 atomic % or more of aluminum and a second layer including hafnium or a mixed layer of an alloy of aluminum and hafnium, and then a third layer including hafnium, and diffusing and performing an oxidation treatment so as to obtain a hafnium-doped alumina layer.

Abstract: A nickel-based superalloy comprises, in percentages by mass, 4.0 to 5.5% rhenium, 1.0 to 3.0 ruthenium, 2.0 to 14.0% cobalt, 0.3 to 1.0% molybdenum, 3.0 to 5.0% chromium, 2.5 to 4.0% tungsten, 4.5 to 6.5% aluminum, 0.50 to 1.50% titanium, 8.0 to 9.0% tantalum, 0.15 to 0.30% hafnium, 0.05 to 0.15% silicon, the balance being nickel and unavoidable impurities. A single-crystal blade comprises such an alloy and a turbomachine comprising such a blade.

Abstract: A mold for producing a ceramic core by injecting a ceramic composition, the mold having a body in which a casting core cavity is formed, the cavity having a primary cavity and a secondary cavity connected by a plurality of segments, the mold being characterized in that it includes a primary arm configured in such a way as to allow an injection of ceramic composition into the primary cavity, and a secondary arm configured in such a way as to allow an injection of ceramic composition into the secondary cavity, and in that the ratio of the volume of the primary cavity to the volume of the secondary cavity is equal, plus or minus 15%, to the ratio of the volume of the primary arm to the volume of the secondary arm.

Abstract: The invention concerns a turbine component, such as a turbine blade or a distributor fin, for example, comprising a substrate made from single-crystal nickel superalloy, and a metal sublayer covering the substrate, characterised in that the metal sublayer comprises at least two elementary layers, including a first elementary layer and a second elementary layer, the first elementary layer being arranged between the substrate and the second elementary layer, each elementary layer comprising a ??-Ni3Al phase, and optionally a ?-Ni phase, and in that the average atomic fraction of aluminum in the second elementary layer is strictly greater than the average atomic fraction of aluminum in the first elementary layer.

Abstract: A turbine component includes a substrate made from monocrystalline nickel-based superalloy including rhenium, which has a ?-?? Ni phase, and an average weight faction of chromium of less than 0.08, a sublayer made from nickel-based metal superalloy covering the substrate, in which the sublayer made from metal superalloy includes at least aluminium, nickel, chromium, silicon, hafnium and has, predominantly by volume, a ??-Ni 3 Al phase.

Abstract: A nickel-based superalloy comprises, in percentages by mass, 4.0 to 5.5% rhenium, 3.5 to 12.5% cobalt, 0.30 to 1.50% molybdenum, 3.5 to 5.5% chromium, 3.5 to 5.5% tungsten, 4.5 to 6.0% aluminum, 0.35 to 1.50% titanium, 8.0 to 10.5% tantalum, 0.15 to 0.30% hafnium, 0.05 to 0.15% silicon, the balance being nickel and unavoidable impurities. A single-crystal blade comprises such an alloy and a turbomachine comprising such a blade.

Abstract: The present invention concerns a turbine part comprising a substrate made of nickel-based monocrystalline superalloy, comprising chromium and at least one element chosen among rhenium and ruthenium, the substrate having a ?-?? phase, an average mass fraction of rhenium and of ruthenium greater than or equal to 4% and an average mass fraction of chromium less than or equal to 5% and preferably less than or equal to 3%, a sub-layer covering at least a part of a surface of the substrate, characterised in that the sublayer has a ?-?? phase and an average atomic fraction of chromium greater than 5%, of aluminium between 10% and 20% and of platinum between 15% and 25%.

Abstract: A turbine part, such as a turbine blade or a distributor fin, for example, including a substrate made of superalloy based on monocrystalline nickel, including rhenium and/or ruthenium, and having a ??-NisAI phase that is predominant by volume and a ?-Ni phase, the part also including a sublayer made of metal superalloy based on nickel covering the substrate, wherein the sublayer has a ??-NisAI phase that is predominant by volume and wherein the sublayer has an average atomic fraction of aluminium of between 0.15 and 0.25, of chromium of between 0.03 and 0.08, of platinum of between 0.01 and 0.05, of hafnium of less than 0.01 and of silicon of less than 0.01. A process for manufacturing a turbine part including a step of vacuum deposition of a sublayer made of a superalloy based on nickel having predominantly by volume a ??-NisAI phase, on a substrate made of superalloy based on nickel including rhenium and/or ruthenium.

Abstract: A nickel-based superalloy comprises in mass percent: 4.0% to 6.0% chromium; 0.4% to 0.8% molybdenum; 2.5% to 3.5% rhenium; 6.2% to 6.6% tungsten; 5.2% to 5.7% aluminum; 0.0 to 1.6% titanium; 6.0% to 9.9% tantalum; 0.0 to 0.7% hafnium; and 0.0 to 0.3% silicon; the balance being constituted by nickel and any impurities. A monocrystalline blade comprises such an alloy and a turbomachine including such a blade.

Abstract: A process for coating a refractory alloy part is provided and includes coating an area of a refractory alloy part by means of a treatment composition including a type of preceramic polymer and a solvent, and heat treating the part coated with the treatment composition. The heat treating partially converts the preceramic polymer and forms a ceramic coating obtained by conversion, the ceramic coating protecting the refractory alloy from oxidation. The treatment composition also includes active fillers to form an alloy coating on a surface of the part by solid diffusion in addition to the ceramic coating obtained by conversion, and the alloy coating generates a protective oxide layer when subjected to oxidizing conditions.

Abstract: A process for coating a part by chemical vapor diffusion is provided and includes placing a powder mixture in a chamber, immersing the part partially in the powder mixture, and applying a heat treatment to the part. The powder mixture includes a first component and a second component forming a gaseous compound during the heat treatment so as to allow deposition of the second component on the part. The part includes a metal refractory allow and the second component forms a solid diffusion alloy by solid diffusion with a metal species of the refractory metal alloy to generate a coating. The solid diffusion allow generates a passivating oxide layer when subjected to oxidizing conditions.

Abstract: A nickel-based superalloy comprises, in percentages by mass, 4.0 to 5.5% rhenium, 1.0 to 3.0 ruthenium, 2.0 to 14.0% cobalt, 0.3 to 1.0% molybdenum, 3.0 to 5.0% chromium, 2.5 to 4.0% tungsten, 4.5 to 6.5% aluminum, 0.50 to 1.50% titanium, 8.0 to 9.0% tantalum, 0.15 to 0.30% hafnium, 0.05 to 0.15% silicon, the balance being nickel and unavoidable impurities. A single-crystal blade comprises such an alloy and a turbomachine comprising such a blade.

Abstract: The invention relates to a process for manufacturing a part made of nickel-based monocrystalline superalloy containing hafnium. This process is noteworthy in that it comprises the following successive steps consisting in: —manufacturing a nickel-based monocrystalline superalloy that is not doped with hafnium, —manufacturing a part from this superalloy, —directly depositing on said part a layer of hafnium having a thickness of between 50 nm and 800 nm, —carrying out a diffusion treatment of the hafnium so as to form an interdiffusion layer at the surface of said part and to thus obtain a part made of nickel-based monocrystalline superalloy containing hafnium.