阅读说明：本技术 在高温下具有高机械强度和环境稳定性的低密度镍基超合金 (Low density nickel-based superalloys having high mechanical strength and environmental stability at high temperatures ) 是由 J·拉姆 E·梅诺 C·德斯格兰杰斯 F·谭克瑞特 于 2020-01-14 设计创作，主要内容包括：本发明涉及镍基超合金,按重量百分比,镍基超合金包含：6％至8％铝、12％至15％钴、4％至8％铬、0％至0.2％铪、0.5％至4％钼、3.5％至6％铼、4％至6％钽、1％至3％钛、0％至2％钨、0％至0.1％硅,其余部分则由镍和不可避免的杂质组成。(The invention relates to a nickel-based superalloy, comprising, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.2% of hafnium, 0.5% to 4% of molybdenum, 3.5% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.)

1. A nickel-based superalloy comprising, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.2% of hafnium, 0.5% to 4% of molybdenum, 3.5% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

2. The superalloy of claim 1, wherein the superalloy comprises, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.2% of hafnium, 0.5% to 4% of molybdenum, 3.5% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.05% of silicon, the remainder consisting of nickel and unavoidable impurities.

3. The superalloy of claim 1, wherein the superalloy comprises, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.15% of hafnium, 0.5% to 4% of molybdenum, 3.5% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

4. The superalloy of claim 1, wherein the superalloy comprises, in weight percent: 6.5% to 7.5% of aluminium, 12% to 15% of cobalt, 4.5% to 7.5% of chromium, 0% to 0.2% of hafnium, 0.5% to 3.5% of molybdenum, 3.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

5. The superalloy of claim 4, wherein the superalloy comprises, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.2% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, the remainder consisting of nickel and unavoidable impurities.

6. The superalloy of claim 4, wherein the superalloy comprises, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 4.5 to 5.5% of chromium, 0 to 0.2% of hafnium, 0.5 to 1.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

7. The superalloy of claim 4, wherein the superalloy comprises, in weight percent: 6.5 to 7.5% of aluminium, 12 to 14% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

8. The superalloy of claim 4, wherein the superalloy comprises, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

9. The superalloy of claim 4, wherein the superalloy comprises, in weight percent: 6.5 to 7.5% of aluminium, 12 to 14% of cobalt, 6.5 to 7.5% of chromium, 0 to 0.2% of hafnium, 0.5 to 1.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

10. The superalloy of claim 4, wherein the superalloy comprises, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 6.5 to 7.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 3.5 to 4.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

11. The superalloy of claim 4, wherein the superalloy comprises, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 2.5 to 3.5% of molybdenum, 3.5 to 4.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

12. The nickel-base superalloy turbomachine component of any of claims 1 to 11.

13. The component of claim 12, wherein the component is monocrystalline.

14. A method of manufacturing a turbomachinery component of the nickel-base superalloy of any of claims 1 to 11 by casting.

Technical Field

The present invention relates to the general field of nickel-based superalloys for turbomachines, in particular blades (vanes), also known as distributors or rectifiers (rectifiers) or blades (blades) or ring segments.

Prior Art

Nickel-based superalloys are commonly used in high temperature components of turbomachinery, i.e., turbomachine components located downstream of the combustor.

The main advantage of nickel-based superalloys is that they combine high creep resistance at temperatures of 650 ℃ to 1200 ℃ with oxidation and corrosion resistance.

The high temperature resistance is mainly due to the microstructure of these materials, which consists of a gamma-Ni matrix of Face Centered Cubic (FCC) crystal structure and L1₂Structural order gamma' -Ni₃Al hardening precipitates.

Some grades of nickel-based superalloys are used to make single crystal components.

Disclosure of Invention

It is an object of the present invention to provide nickel-based superalloy compositions that provide improved mechanical strength, particularly creep resistance.

It is another object of the present invention to provide superalloy compositions that provide improved environmental resistance, particularly oxidation and corrosion resistance.

It is another object of the present invention to provide superalloy compositions having reduced density.

According to a first aspect, the present invention provides a nickel-base superalloy comprising, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.2% of hafnium, 0.5% to 4% of molybdenum, 3.5% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

A nickel-based alloy is defined as an alloy based on the weight of nickel.

Unavoidable impurities are defined as elements that are not intentionally added to the composition but are brought along with other elements. Among the unavoidable impurities, particular mention may be made of carbon (C) or sulfur (S).

The nickel-based superalloy according to the present invention has good microstructural stability at a certain temperature, and thus can obtain high mechanical properties at a certain temperature.

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

The nickel-based superalloys according to the invention have reduced susceptibility to casting defect formation.

The nickel-based superalloys according to the invention provide less than 8.4g.cm^-3The density of (c).

In a possible alternative, the superalloy may comprise, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.2% of hafnium, 0.5% to 4% of molybdenum, 3.5% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.05% of silicon, the remainder consisting of nickel and unavoidable impurities.

Further, the superalloy may comprise, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.15% of hafnium, 0.5% to 4% of molybdenum, 3.5% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

According to a possible alternative, the superalloy may comprise, in weight percent: 6.5% to 7.5% of aluminium, 12% to 15% of cobalt, 4.5% to 7.5% of chromium, 0% to 0.2% of hafnium, 0.5% to 3.5% of molybdenum, 3.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

According to a possible alternative, the superalloy may also comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.2% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, the remainder consisting of nickel and unavoidable impurities.

According to a possible alternative, the superalloy may comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.15% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, the remainder consisting of nickel and unavoidable impurities.

According to a possible alternative, the superalloy may comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.1% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, the remainder consisting of nickel and unavoidable impurities.

According to a possible alternative, the superalloy may comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

According to a possible alternative, the superalloy may comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.1% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 4.5 to 5.5% of chromium, 0 to 0.2% of hafnium, 0.5 to 1.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

According to a possible alternative, the superalloy may comprise, in weight percent: 6.5 to 7.5% of aluminium, 12 to 14% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

According to another possible alternative, the superalloy may comprise, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

According to another possible alternative, the superalloy may comprise, in weight percent: 6.5 to 7.5% of aluminium, 12 to 14% of cobalt, 6.5 to 7.5% of chromium, 0 to 0.2% of hafnium, 0.5 to 1.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

According to another possible alternative, the superalloy may comprise, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 6.5 to 7.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 3.5 to 4.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

According to a possible alternative, the superalloy may comprise, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 2.5 to 3.5% of molybdenum, 3.5 to 4.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

According to a second aspect, the invention provides a turbomachine component comprising a nickel-base superalloy according to any of the preceding features.

The component may be a component of an aircraft turbomachinery turbine (e.g. a high pressure turbine or a low pressure turbine), or a compressor component, in particular a high pressure compressor.

According to other features, the turbine or compressor component may be a blade, which can be a moving blade or a blade, or an annular segment.

According to another feature, the turbomachine component is monocrystalline, preferably having a crystalline structure oriented along a crystallographic direction <001 >.

According to a third aspect, the invention provides a method for manufacturing a turbomachine component of a nickel-base superalloy according to any of the preceding features by casting.

According to another feature, the method comprises a step of directional solidification to form the monocrystalline component.

Description of the embodiments

The superalloy according to the present invention comprises a nickel substrate and associated primary additive elements.

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

The superalloy may also include minor additions that are up to a maximum percentage of 1 wt% of the superalloy.

The secondary added elements include: hafnium Hf and silicon Si.

The nickel-based superalloy comprises, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.2% of hafnium, 0.5% to 4% of molybdenum, 3% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

The nickel-base superalloy may also advantageously comprise, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.2% of hafnium, 0.5% to 4% of molybdenum, 3% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.05% of silicon, the remainder consisting of nickel and unavoidable impurities.

The nickel-base superalloy may also advantageously comprise, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.1% of hafnium, 0.5% to 4% of molybdenum, 3% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

The nickel-base superalloy may also advantageously comprise, in weight percent: 6% to 8% of aluminium, 12% to 15% of cobalt, 4% to 8% of chromium, 0% to 0.05% of hafnium, 0.5% to 4% of molybdenum, 3% to 6% of rhenium, 4% to 6% of tantalum, 1% to 3% of titanium, 0% to 2% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

The nickel-base superalloy may also advantageously comprise, in weight percent: 6% to 8% aluminium, 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 consisting of nickel and unavoidable impurities.

The superalloy may also advantageously comprise, in weight percent: 6.5% to 7.5% of aluminium, 12% to 15% of cobalt, 4.5% to 7.5% of chromium, 0% to 0.2% of hafnium, 0.5% to 3.5% of molybdenum, 3.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

The superalloy may advantageously comprise, in weight percent: 6.5% to 7.5% of aluminium, 12% to 15% of cobalt, 4.5% to 7.5% of chromium, 0% to 0.2% of hafnium, 0.5% to 3.5% of molybdenum, 3.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0% to 1.5% of tungsten, 0% to 0.05% of silicon, the remainder consisting of nickel and unavoidable impurities.

The superalloy may also advantageously comprise, in weight percent: 6.5% to 7.5% of aluminium, 12% to 15% of cobalt, 4.5% to 7.5% of chromium, 0% to 0.1% of hafnium, 0.5% to 3.5% of molybdenum, 3.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

Preferably, the superalloy may comprise, in weight percent: 6.5% to 7.5% of aluminium, 12% to 15% of cobalt, 4.5% to 7.5% of chromium, 0% to 0.05% of hafnium, 0.5% to 3.5% of molybdenum, 3.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

Preferably, the superalloy may comprise, in weight percent: 6.5% to 7.5% aluminium, 12% to 15% cobalt, 4.5% to 7.5% chromium, 0% to 0.1% 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 consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.2% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.15% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.1% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0% to 0.1% of hafnium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, 0% to 0.1% of silicon, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, 0.5% to 1.5% of tungsten, the remainder consisting of nickel and unavoidable impurities.

The superalloy may also include, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 4.5 to 5.5% of chromium, 0 to 0.2% of hafnium, 0.5 to 1.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 4.5% to 5.5% of chromium, 0.5% to 1.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may also include, in weight percent: 6.5 to 7.5% of aluminium, 12 to 14% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 12% to 14% of cobalt, 5.5% to 6.5% of chromium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may also include, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 5.5% to 6.5% of chromium, 1.5% to 2.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may also include, in weight percent: 6.5 to 7.5% of aluminium, 12 to 14% of cobalt, 6.5 to 7.5% of chromium, 0 to 0.2% of hafnium, 0.5 to 1.5% of molybdenum, 4.5 to 5.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 12% to 14% of cobalt, 6.5% to 7.5% of chromium, 0.5% to 1.5% of molybdenum, 4.5% to 5.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may also include, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 6.5 to 7.5% of chromium, 0 to 0.2% of hafnium, 1.5 to 2.5% of molybdenum, 3.5 to 4.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 6.5% to 7.5% of chromium, 1.5% to 2.5% of molybdenum, 3.5% to 4.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may also include, in weight percent: 6.5 to 7.5% of aluminium, 13 to 15% of cobalt, 5.5 to 6.5% of chromium, 0 to 0.2% of hafnium, 2.5 to 3.5% of molybdenum, 3.5 to 4.5% of rhenium, 4.5 to 5.5% of tantalum, 1.5 to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

The superalloy may further comprise, in weight percent: 6.5% to 7.5% of aluminium, 13% to 15% of cobalt, 5.5% to 6.5% of chromium, 2.5% to 3.5% of molybdenum, 3.5% to 4.5% of rhenium, 4.5% to 5.5% of tantalum, 1.5% to 2.5% of titanium, the remainder consisting of nickel and unavoidable impurities.

Cobalt, chromium, tungsten, molybdenum and rhenium are mainly involved in the hardening of the gamma phase, which is the austenitic matrix of the FCC structure.

Aluminum, titanium and tantalum promote the precipitation of the gamma' phase, which is L1₂Hardened Ni of ordered cubic structure₃(Al, Ti, Ta) phase.

In addition, rhenium slows down the diffusion process and limits coalescence of the gamma' phase, thereby improving high temperature creep resistance. However, the rhenium content should not be too high to negatively affect the mechanical properties of the superalloy component.

The refractory elements (i.e., molybdenum, tungsten, rhenium, and tantalum) also slow the diffusion-controlled mechanism, thereby increasing the creep resistance of the superalloy component.

In addition, chromium and aluminum improve the oxidation and corrosion resistance at high temperatures (especially about 900 ℃ for corrosion and about 1100 ℃ for oxidation).

Silicon and hafnium can also be added by adding Al₂O₃Adhesion of alumina layer to optimize the thermal oxidation resistance of the superalloy, said Al₂O₃An aluminum oxide layer is formed on the superalloy surface at high temperatures in an oxidizing environment.

In addition, chromium and cobalt help to lower the gamma prime solution temperature of the superalloy.

Cobalt is an element chemically related to nickel that partially replaces nickel to form a solid solution in the gamma phase, thereby strengthening the gamma matrix, reducing susceptibility to precipitation of topologically dense phases, particularly the mu, P, R and sigma phases and the Laves phase, and reducing susceptibility to Secondary Reaction Zone (SRZ) formation.

The superalloy composition improves the mechanical properties at high temperatures (650 ℃ to 1200 ℃) of components made from the superalloy.

In particular, the superalloy composition makes it possible to obtain a minimum breaking stress of 250MPa at 950 ℃ for 1100 hours, a minimum breaking stress of 150MPa at 1050 ℃ for 550 hours and a minimum breaking stress of 55MPa at 1200 ℃ for 510 hours.

The mechanical properties are due in particular to the microstructure comprising the gamma phase and the gamma' phase and to a maximum topologically dense phase content of 6% in mole percent. Topological compact phases include the μ, P, R and σ phases, as well as the Laves phase. The microstructure may also include the following carbides: MC, M₆C、M₇C₃And M₂₃C₆。

Furthermore, these mechanical properties of creep resistance at temperature are obtained due to the better stability of the microstructure between 650 ℃ and 1200 ℃.

The superalloy composition also improves oxidation and corrosion resistance of components made from the superalloy. The corrosion and oxidation resistance is achieved by providing at least 9.5 atomic percent of aluminum in the gamma phase at 1200 c and at least 7.5 atomic percent of chromium in the gamma phase at 1200 c, thereby ensuring the formation of a protective layer of aluminum oxide on the surface of the material.

In addition, such superalloy compositions simplify the manufacturing process of the component. This simplification is ensured by obtaining a difference of at least 10 ℃ between the solvus temperature of the γ 'precipitate and the solidus temperature (solidus temperature) of the superalloy, thereby facilitating the implementation of the re-dissolution step of the γ' precipitate during the manufacture of the component.

Furthermore, the superalloy composition allows for improved manufacturing by reducing the risk of defect formation during component manufacturing, in particular the risk of "freckle" -type parasitic grains forming during directional solidification.

In fact, the superalloy composition reduces the susceptibility of the component to form "freckle" parasitic grains. The susceptibility of the part to the formation of "freckle" parasitic grains was evaluated using the Konter standard, denoted NFP, given by the following equation (1):

[ mathematical equation 1]

Wherein,% Ta is the tantalum content of the superalloy in weight percent; % Hf is the hafnium content of the superalloy in weight percent; % Mo is the molybdenum content of the superalloy in weight percent; % Ti is the titanium content of the superalloy in weight percent; % W is the tungsten content of the superalloy in weight percent; % Re is the rhenium content of the superalloy in weight percent.

The superalloy composition makes it possible to obtain an NFP parameter greater than or equal to 0.7, above which the formation of "freckle" parasitic grains will be greatly reduced.

Furthermore, the superalloy compositions allow for reduced densities, in particular below 8.4g/cm³The density of (c).

Table 1 below shows the composition (in weight percent) of seven examples of superalloys according to the invention (examples 1 to 11) and of commercial or reference superalloys (examples 12 to 16). Example 12 corresponds toSuperalloy, example 13 corresponds toSuperalloy, example 14 corresponding to CMSX-4Mod C superalloys, example 15 corresponding toSuperalloy, and example 16 corresponds to CMSX-10A superalloy.

[ Table 1]

TABLE 1

Table 2 gives the estimated properties of the superalloys listed in table 1. The properties given in table 2 are density, Konter standard (NFP), and creep rupture stress at 950 ℃ for 1100 hours, 1050 ℃ for 550 hours, and 1200 ℃ for 510 hours, with the creep rupture stress being designated CRF in table 2.

[ Table 2]

TABLE 2

Table 3 gives the estimated properties of the superalloys listed in table 1. The characteristics given in table 3 are the different transition temperatures (solvus, solidus and liquidus), the mole fractions of the gamma' phase at 900 ℃, 1050 ℃ and 1200 ℃, and the mole fractions of the topologically dense phase (TCP) at 900 ℃ and 1050 ℃.

[ Table 3]

TABLE 3

As shown in table 3, for the superalloys of examples 1 to 11, the mole fraction of the γ' phase at 1200 ℃ is higher (35 to 40% in mole percent), reflecting the high stability of the hardened precipitates, thus improving the mechanical properties at high temperatures. Furthermore, for the superalloys of examples 1 to 11, the molar fraction of topologically dense phases is low at 900 ℃ (5%) and negligible (< 0.5%) at 1050 ℃, which also reflects the high stability of the microstructure, thus improving the mechanical properties at high temperatures.

Table 4 gives the estimated properties of the superalloys listed in table 1. The properties given in table 4 are the chromium activity in the gamma phase at 900 c and the aluminum activity in the gamma phase at 1100 c. The activities of chromium and aluminum in the gamma matrix are indicators of corrosion resistance and oxidation resistance, the higher the activities of chromium and aluminum in the matrix, the higher the corrosion resistance and oxidation resistance.

[ Table 4]

TABLE 4

	Gamma phase Cr activity	Activity of gamma-phase Al
			Alloy (I)	900℃	1100℃
Example 1	2,6E-3	1,94E-07
			Example 2	2,4E-3	1,60E-07
Example 3	3,0E-3	1,96E-07
			Example 4	2,9E-3	2,06E-07
Example 5	3,4E-3	2,10E-07
			Example 6	3,0E-3	1,89E-07
Example 7	3,1E-3	2,07E-07
			Example 8	2,6E-3	1,95E-07
Example 9	2,6E-3	1,96E-07
			Example 10	2,6E-3	2,05-07
Example 11	2,6E-3	2,07-07
			Example 12	3,10E-3	1,29E-07
Example 13	3,02E-3	1,27E-07
			Example 14	1,50E-3	1,02E-07
Example 15	1,79E-3	1.47E-07
			Example 16	5,21E-4	4,23E-08

As shown in tables 2, 3 and 4, the superalloys according to the invention have mechanical properties at high temperatures that are superior to prior art alloys, while exhibiting lower density and excellent corrosion and oxidation resistance.

The properties given in tables 3 and 4 were estimated using the CALPHAD (phase diagram calculation) method.

The nickel-base superalloy component may be prepared by casting.

Casting of the part is accomplished by melting the superalloy, pouring the liquid superalloy into a mold, cooling and solidifying. For example, the casting of the component may be performed by a lost wax technique, in particular to manufacture the blade.

Furthermore, for the manufacture of monocrystalline components, in particular blades, the method may comprise a directional solidification step. Directional solidification is performed by controlling the solidification rate and temperature gradient of the superalloy, by introducing single crystal grains or using a grain selector to avoid new grains before the solidification front.

In particular, directional solidification may allow the manufacture of single crystal blades with a crystal structure oriented along a crystallographic direction <001> parallel to the longitudinal direction of the blade, i.e. along the radial direction of the turbomachine, which orientation provides better mechanical properties.