The present invention relates to the general field of nickel-based superalloys for turbomachines, in particular for fixed blades, also called distributors or rectifiers, or mobile blades, or even ring segments.

Prior art

Nickel-based superalloys are generally used for the hot parts of turbomachines, that is, the parts of turbomachines located downstream of the combustion chamber.

The main advantages of nickel-based superalloys are that they combine high creep resistance at temperatures between 650 ° C and 1200 ° C, as well as resistance to oxidation and corrosion.

The high temperature resistance is mainly due to the microstructure of these materials, which is composed of a face-centered cubic crystal structure (CFC) g-Ni matrix and ordered hardening precipitates y'-Ni3AI of structure L12.

Certain grades of nickel-based superalloys are used in the manufacture of monocrystalline parts.

Disclosure of the invention

The object of the present invention is to provide compositions of nickel-based superalloys which make it possible to improve the mechanical strength, and in particular the resistance to creep.

Another object of the present invention is to provide superalloy compositions which make it possible to improve resistance to the environment, and in particular corrosion resistance and oxidation resistance.

Another object of the present invention is to provide superalloy compositions which have a reduced density.

According to a first aspect, the invention provides a nickel-based superalloy comprising, in percentages by weight, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.2% of hafnium, 0.5 to 4% molybdenum, 3.5 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.1% silicon, the remainder being made up of nickel and inevitable impurities.

The term “nickel-based alloy” is defined as an alloy in which the percentage by mass of nickel is predominant.

Unavoidable impurities are defined as those elements which are not intentionally added to the composition and which are supplied with other elements. Among the inevitable impurities, mention may in particular be made of carbon (C) or sulfur (S).

The nickel-based superalloy according to the invention has good microstructural stability in temperature, thus making it possible to obtain high mechanical characteristics in temperature.

The nickel-based superalloy according to the invention has corrosion resistance and improved oxidation resistance.

The nickel-based superalloy according to the invention reduces the susceptibility to foundry defect formation.

The nickel-based superalloy according to the invention provides a density of less than 8.4 g. cm 3.

According to one possible variant, the superalloy may comprise, in percentages by mass, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% of chromium, 0 to 0.2% of hafnium, 0.5 to 4 % molybdenum, 3.5 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.05% silicon, the remainder being nickel and inevitable impurities.

Furthermore, the superalloy may comprise, in percentages by mass, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.15% hafnium, 0.5 to 4% of molybdenum, 3.5 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.1% silicon, the remainder being nickel and impurities inevitable.

According to one possible variant, the superalloy may comprise, in percentages by mass, 6.5 to 7.5% aluminum, 12 to 15% cobalt, 4.5 to 7.5% chromium, 0 to 0.2% hafnium, 0.5 to 3.5% molybdenum, 3.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0 to 1 , 5% tungsten, 0 to 0.1% silicon, the remainder being nickel and inevitable impurities.

According to one possible variant, the superalloy may also comprise, in percentages by mass, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 4.5 to 5.5% chromium, 0 to 0.2 % hafnium, 1.5-2.5% molybdenum, 4.5-5.5% rhenium, 4.5-5.5% tantalum, 1.5-2.5% titanium, 0, 5 to 1.5% tungsten, the remainder being nickel and inevitable impurities.

According to one possible variant, the superalloy may comprise, in percentages by mass, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 4.5 to 5.5% chromium, 0 to 0.15% hafnium, 1.5-2.5% molybdenum, 4.5-5.5% rhenium, 4.5-5.5% tantalum, 1.5-2.5% titanium, 0.5 1.5% tungsten, the remainder being nickel and inevitable impurities.

According to one possible variant, the superalloy may comprise, in percentages by mass, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 4.5 to 5.5% chromium, 0 to 0.1% hafnium, 1.5-2.5% molybdenum, 4.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0.5 to 1.5% tungsten, the remainder being of nickel and inevitable impurities.

According to one possible variant, the superalloy may comprise, in percentages by weight, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 4.5 to 5.5% chromium, 1, 5 to 2, 5% molybdenum, 4.5-5.5% rhenium, 4.5-5.5% tantalum, 1.5-2.5% titanium, 0.5-1.5% tungsten, 0 0.1% silicon, the remainder being nickel and inevitable impurities.

According to one possible variant, the superalloy may comprise, in percentages by mass, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 4.5 to 5.5% chromium, 0 to 0.1% hafnium, 1.5-2.5% molybdenum, 4.5-5.5% rhenium, 4.5-5.5% tantalum, 1.5-2.5% titanium, 0.5 at 1.5% tungsten, 0-0.1% silicon, the remainder being nickel and inevitable impurities.

The superalloy may further comprise, in percentages by weight, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 4.5 to 5.5% chromium, 0 to 0.2% hafnium, 0.5 to 1.5% molybdenum, 4.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

According to one possible variant, the superalloy may comprise, in percentages by mass, 6.5 to 7.5% aluminum, 12 to 14% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% hafnium, 1.5 to 2.5% molybdenum, 4.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being consisting of nickel and inevitable impurities.

According to another possible variant, the superalloy may comprise, in weight percentages, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 5.5 to 6.5% chromium, 0 to 0.2 % hafnium, 1.5 to 2.5% molybdenum, 4.5 to 5.5% rhenium,

4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

According to another possible variant, the superalloy may comprise, in percentages by mass: 6.5 to 7.5% aluminum, 12 to 14% cobalt, 6.5 to 7.5% chromium, 0 to 0.2 % hafnium, 0.5 to 1.5% molybdenum, 4.5 to 5.5% rhenium,

4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

According to another possible variant, the superalloy may comprise, in percentages by mass: 6.5 to 7.5% aluminum, 13 to 15% cobalt, 6.5 to 7.5% chromium, 0 to 0.2 % hafnium, 1.5 to 2.5% molybdenum, 3.5 to 4.5% rhenium,

4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

According to one possible variant, the superalloy may comprise, in percentages by mass: 6.5 to 7.5% aluminum, 13 to 15% cobalt, 5.5 to 6.5% chromium, 0 to 0.2% hafnium, 2.5 to 3.5% molybdenum, 3.5 to 4.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being consisting of nickel and inevitable impurities.

According to a second aspect, the invention provides a nickel-based superalloy turbomachine part according to any one of the preceding characteristics.

The part may be an element of an aircraft turbomachine turbine, for example a high-pressure turbine or a low-pressure turbine, or else a compressor element, and in particular a high-pressure compressor.

According to an additional characteristic, the turbine or compressor part may be a blade, said blade possibly being a moving blade or a fixed blade, or else a ring sector.

According to another characteristic, the turbomachine part is monocrystalline, preferably with a crystalline structure oriented in a crystallographic direction <001>.

According to a third aspect, the invention provides a method of manufacturing a nickel-based superalloy turbomachine part according to any one of the preceding characteristics by foundry.

According to an additional characteristic, the method comprises a directed solidification step to form a monocrystalline part.

Description of the embodiments

The superalloy according to the invention comprises a nickel base with which major addition elements are associated.

Major addition elements include: cobalt Co, chromium Cr, molybdenum Mo, tungsten W, aluminum Al, tantalum Ta, titanium Ti, and rhenium Re.

The superalloy can also include minor addition elements, which are addition elements whose maximum percentage in the superalloy does not exceed 1% by weight percent.

Minor addition elements include: hafnium Hf and silicon Si.

The nickel-based superalloy comprises, in percentages by mass, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.2% hafnium, 0.5 to 4% of molybdenum, 3 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.1% silicon, the remainder being of nickel and inevitable impurities.

The nickel-based superalloy can also advantageously comprise, in percentages by weight, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.2% hafnium, 0, 5 to 4% molybdenum, 3 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.05% silicon, the remainder being nickel and inevitable impurities.

The nickel-based superalloy can also advantageously comprise, in percentages by weight, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.1% hafnium, 0, 5 to 4% molybdenum, 3 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.1% silicon, the remainder being nickel and inevitable impurities.

The nickel-based superalloy can also advantageously comprise, in percentages by mass, 6 to 8% of aluminum, 12 to 15% of cobalt,

4 to 8% chromium, 0 to 0.05% hafnium, 0.5 to 4% molybdenum, 3 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.1% silicon, the remainder being nickel and inevitable impurities.

The nickel-based superalloy can also advantageously comprise, in percentages by weight, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.1% hafnium (preferably 0 to 0.05% hafnium), 0.5 to 4% molybdenum, 3 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0 .05% silicon, the remainder being nickel and inevitable impurities.

The superalloy can also advantageously comprise, in percentages by mass, 6.5 to 7.5% aluminum, 12 to 15% cobalt, 4.5 to 7.5% chromium, 0 to 0.2% hafnium, 0.5 to 3.5% molybdenum, 3.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0 to 1 , 5% tungsten, 0 to 0.1% silicon, the remainder being nickel and inevitable impurities.

Advantageously, the superalloy may comprise, in weight percentages, 6.5 to 7.5% aluminum, 12 to 15% cobalt, 4.5 to 7.5% chromium, 0 to 0.2% of hafnium, 0.5 to 3.5% molybdenum, 3.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0 to 1, 5% tungsten, 0 to 0.05% silicon, the remainder being nickel and inevitable impurities.

The superalloy can also advantageously comprise, in percentages by weight, 6.5 to 7.5% aluminum, 12 to 15% cobalt, 4.5 to 7.5% chromium, 0 to 0.1% hafnium, 0.5 to 3.5% molybdenum, 3.5 to 5.5% rhenium,

4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0 to 1.5% tungsten, 0 to 0.1% silicon, the remainder being nickel and inevitable impurities.

Preferably, the superalloy may comprise, in weight percentages, 6.5 to 7.5% aluminum, 12 to 15% cobalt, 4.5 to 7.5% chromium, 0 to 0.05% of hafnium, 0.5 to 3.5% molybdenum, 3.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0 to 1, 5% tungsten, 0 to 0.1% silicon, the remainder being nickel and inevitable impurities.

Preferably, the superalloy may comprise, in weight percentages, 6.5 to 7.5% aluminum, 12 to 15% cobalt, 4.5 to 7.5% chromium, 0 to 0.1% of hafnium (preferably 0 to 0.05% hafnium), 0.5 to 3.5% molybdenum,

3.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0 to 1.5% tungsten, 0 to 0.05% silicon, the remainder being made up of nickel and inevitable impurities.

Claims

[Claim 1] Nickel-based superalloy comprising, in weight percentages, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.2% hafnium, 0.5 to 4 % molybdenum, 3.5 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.1% silicon, the remainder being nickel and inevitable impurities.

[Claim 2] The superalloy of claim 1, wherein said superalloy comprises, in weight percentages, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.2% hafnium , 0.5 to 4% molybdenum, 3.5 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.05% silicon, the remainder being made up of nickel and inevitable impurities.

[Claim 3] A superalloy according to claim 1, wherein said superalloy comprises, in weight percentages, 6 to 8% aluminum, 12 to 15% cobalt, 4 to 8% chromium, 0 to 0.15% hafnium. , 0.5 to 4% molybdenum, 3.5 to 6% rhenium, 4 to 6% tantalum, 1 to 3% titanium, 0 to 2% tungsten, 0 to 0.1% silicon, the remainder being made up of nickel and inevitable impurities.

[Claim 4] The superalloy of claim 1, wherein said superalloy comprises, in weight percentages, 6.5-7.5% aluminum, 12-15% cobalt, 4.5-7.5% chromium, 0 to 0.2% hafnium, 0.5 to 3.5% molybdenum, 3.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0 to 1.5% tungsten, 0 to 0.1% silicon, the remainder being nickel and inevitable impurities.

[Claim 5] A superalloy according to claim 4, wherein said superalloy comprises, in weight percentages, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 4.5 to 5.5% chromium, 0 to 0.2% hafnium, 1.5 to 2.5% molybdenum, 4.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, 0.5 to 1.5% tungsten, the remainder being nickel and inevitable impurities.

[Claim 6] The superalloy of claim 4, wherein said superalloy comprises, in weight percentages, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 4.5 to 5.5% chromium, 0 to 0.2% hafnium, 0.5 to 1.5% molybdenum, 4.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

[Claim 7] A superalloy according to claim 4, wherein said superalloy comprises, in weight percentages, 6.5-7.5% aluminum, 12-14% cobalt, 5.5-6.5% chromium, 0 to 0.2% hafnium, 1.5 to 2.5% molybdenum, 4.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

[Claim 8] A superalloy according to claim 4, wherein said superalloy comprises, in weight percentages, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 5.5 to 6.5% chromium, 0 to 0.2% hafnium, 1.5 to 2.5% molybdenum, 4.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

[Claim 9] A superalloy according to claim 4, wherein said superalloy comprises, in weight percentages, 6.5-7.5% aluminum, 12-14% cobalt, 6.5-7.5% chromium, 0 to 0.2% hafnium, 0.5 to 1.5% molybdenum, 4.5 to 5.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

[Claim 10] The superalloy of claim 4, wherein said superalloy comprises, in weight percentages, 6.5-7.5% aluminum, 13-15% cobalt, 6.5-7.5% chromium, 0 to 0.2% hafnium, 1.5 to 2.5% molybdenum, 3.5 to 4.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

[Claim 11] A superalloy according to claim 4, wherein said superalloy comprises, in weight percentages, 6.5 to 7.5% aluminum, 13 to 15% cobalt, 5.5 to 6.5% chromium, 0 to 0.2% hafnium, 2.5 to 3.5% molybdenum, 3.5 to 4.5% rhenium, 4.5 to 5.5% tantalum, 1.5 to 2.5% titanium, the remainder being nickel and inevitable impurities.

[Claim 12] A nickel-based superalloy turbomachine part according to any one of claims 1 to 11.

[Claim 13] A part according to claim 12, wherein said part is monocrystalline.

[Claim 14] A method of manufacturing a nickel-based superalloy turbomachine part according to any one of claims 1 to 11 by foundry.