Fabricable, High Strength, Oxidation Resistant Ni-Cr-Co-Mo-Al Alloys
Ni—Cr—Co—Mo—Al based alloys are disclosed which contain 15 to 20 wt. % chromium, 9.5 to 20 wt. % cobalt, 7.25 to 10 wt. % molybdenum, 2.72 to 3.9 wt. % aluminum, along with typical impurities, a tolerance for up to 10.5 wt. % iron, minor element additions and a balance of nickel. These alloys are readily fabricable, have high creep strength, and excellent oxidation resistance up to as high as 2100° F. (1149° C.). This combination of properties is useful for a variety of gas turbine engine components, including, for example, combustors.
1 . A nickel-chromium-cobalt-molybdenum-aluminum based alloy having a composition comprised in weight percent of:
15 to 20
chromium
9.5 to 20
cobalt
7.25 to 10
molybdenum
2.72 to 3.9
aluminum
up to 10.5
iron
present up to 0.15
carbon
up to 0.015
boron
up to 0.75
titanium
up to 1.5
tantalum
up to 1
hafnium
up to 1
manganese
up to 0.6
silicon
up to 0.06
zirconium
with a balance of nickel and impurities, the alloy further satisfying the following compositional relationship defined with elemental quantities being in terms of weight percent:
Al+0.56Ti+0.29Nb+0.15Ta≦3.9.
2 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , containing hafnium, tantalum, or a combination of hafnium and tantalum, where the sum of the two elements is between 0.2 wt. % and 1.5 wt. %.
3 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , containing titanium, from 0.2 to 0.75 wt. %.
4 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , containing at least one of the elements hafnium and tantalum at a level ranging from 0.2 wt. % up to 1 and 1.5 wt. %, respectively.
5 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , containing traces of at least one of magnesium, calcium, and any rare earth elements up to 0.05 wt. %.
6 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , containing at least one of the following impurities: copper up to 0.5 wt. %, sulfur up to 0.015 wt. %, and phosphorous up to 0.03 wt. %.
7 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 wherein the alloy contains in weight percent:
16 to 20
chromium
15 to 20
cobalt
7.25 to 9.75
molybdenum
2.9 to 3.7
aluminum
8 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , wherein the alloy contains in weight percent:
17 to 20
chromium
17 to 20
cobalt
7.25 to 9.25
molybdenum
2.9 to 3.6
aluminum
9 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , wherein the alloy contains in weight percent:
17.5 to 19.5
chromium
17.5 to 19.5
cobalt
7.25 to 8.25
molybdenum
3.0 to 3.5
aluminum
10 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , wherein the alloy contains in weight percent:
up to 5
iron
present up to 0.12
carbon
up to 0.008
boron
up to 0.5
silicon
up to 0.04
zirconium
11 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , wherein the alloy contains in weight percent:
up to 2
iron
0.02 to 0.12
carbon
present up to 0.005
boron
0.2 to 0.5
titanium
up to 0.5
manganese
up to 0.4
silicon
present up to 0.04
zirconium
12 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , wherein the alloy has oxidation resistance such that the average metal affected has a value not greater than 2.5 mils/side when tested in flowing air at 2100° F. (1149° C.) for 1008 hours.
13 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , wherein the alloy has modified CHRT test ductility values greater than 7%.
14 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 1 , wherein the alloy has a creep-rupture life of at least 325 hours when tested at 1800° F. (982° C.) under a load of 2.5 ksi (17 MPa).
15 . A nickel-chromium-cobalt-molybdenum-aluminum based alloy having a composition comprised in weight percent of:
15 to 20
chromium
9.5 to 20
cobalt
7.25 to 10
molybdenum
2.72 to 3.9
aluminum
up to 5
iron
present up to 0.15
carbon
up to 0.015
boron
up to 0.75
titanium
up to 1
niobium
up to 1.5
tantalum
up to 1
hafnium
up to 2
tungsten
up to 1
manganese
up to 0.6
silicon
up to 0.06
zirconium
with a balance of nickel and impurities, the alloy further satisfying the following compositional relationship defined with elemental quantities being in terms of weight percent:
Al+0.56Ti+0.29Nb+0.15Ta≦3.9.
16 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 15 , containing hafnium, tantalum, or a combination of hafnium and tantalum, where the sum of the two elements is between 0.2 wt. % and 1.5 wt. %.
17 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 15 , containing at least one of hafnium, tantalum, and niobium, where the sum of these elements is between 0.2 wt. % and 1.5 wt. %.
18 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 15 , containing titanium, from 0.2 to 0.75 wt. %.
19 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 15 , containing at least one of the elements niobium, hafnium, and tantalum at a level ranging from 0.2 wt. % up to 1, 1, and 1.5 wt. %, respectively.
20 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 15 , containing traces of at least one of magnesium, calcium, and any rare earth elements up to 0.05 wt. %.
21 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 15 , containing at least one of: copper up to 0.5 wt. %, sulfur up to 0.015 wt. %, and phosphorous up to 0.03 wt. %.
22 . A nickel-chromium-cobalt-molybdenum-aluminum based alloy having a composition comprised in weight percent of:
15.3 to 19.9
chromium
9.7 to 20.0
cobalt
7.5 to 10.0
molybdenum
2.72 to 3.78
aluminum
0.1 to 10.4
iron
0.085 to 0.120
carbon
up to 0.005
boron
up to 0.49
titanium
up to 1.0
tantalum
up to 0.48
hafnium
up to 0.49
silicon
up to 0.02
yttrium
up to 0.04
zirconium
with a balance of nickel and impurities, the alloy further satisfying the following compositional relationship defined with elemental quantities being in terms of weight percent:
Al+0.56Ti+0.29Nb+0.15Ta≦3.89.
23 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 22 , containing up to 4.5 wt. % iron and at least one of tungsten or niobium at a level of up to 1.94 wt. % tungsten and up to 0.91 wt. % niobium.
24 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 22 , containing traces of at least one of magnesium, calcium, and any rare earth elements up to 0.05 wt. %.
25 . The nickel-chromium-cobalt-molybdenum-aluminum based alloy of claim 22 , containing one or more of the following impurities: niobium up to 0.2 wt. %, tungsten up to 0.5 wt. %, copper up to 0.5 wt. %, sulfur up to 0.015 wt. %, and phosphorous up to 0.03 wt. %.