ULTRA HIGH STRENGTH COPPER-NICKEL-TIN ALLOYS
The present disclosure relates to ultra high strength wrought copper-nickel-tin alloys and processes for improving the yield strength of the copper-nickel-tin alloy such that the resulting 0.2% offset yield strength is at least 175 ksi. The alloy includes about 14.5 wt % to about 15.5% nickel, about 7.5 wt % to about 8.5% tin, and the remaining balance is copper. The steps include cold working the copper-nickel-tin alloy wherein the alloy undergoes between 50%-75% plastic deformation. The alloy is heat treated at elevated temperatures between about 740° F. and about 850° F. for a time period of about 3 minutes to 14 minutes.
1 . An ultra-high strength wrought alloy comprising copper, nickel, and tin, and having a 0.2% offset yield strength of at least 175 ksi, wherein the alloy is produced by:
performing a first mechanical cold working step on the alloy to a percentage of cold working (%CW) of about 50% to about 75%; and
heat treating the alloy.
2 . The alloy of claim 1 , wherein the heat treating step is performed at a temperature of about 740° F. to about 850° F. for a period of about 3 minutes to 14 minutes.
3 . The alloy of claim 2 , wherein the heat treating step is performed at a temperature of about 740° F. to about 800° F.
4 . The alloy of claim 1 , wherein the heat treating step is performed by running the alloy in strip form through a furnace at a rate of about 5 ft/min to about 20 ft/mm.
5 . The alloy of claim 1 , wherein the alloy has a 0.2% offset yield strength of 175 to 190 ksi.
6 . The alloy of claim 1 , wherein the alloy has an ultimate tensile strength of at least 180 ksi.
7 . The alloy of claim 1 , wherein the alloy has a % elongation at break of at least 1%.
8 . The alloy of claim 1 , wherein the alloy has a Young's modulus of at least 16 million psi.
9 . The alloy of claim 1 , wherein the alloy has a 0.2% offset yield strength of at least 175 ksi and an ultimate tensile strength of at least 180 ksi.
10 . The alloy of claim 1 , wherein the alloy includes from about 14.5 wt % to about 15.5 wt % nickel, and from about 7.5 wt % to about 8.5% tin; and with the remaining balance being copper.
11 . The alloy of claim 1 , wherein the heat treating step is performed at a temperature of about 740° F. to about 850° F. while running the alloy in strip form through a conveyor furnace apparatus at a rate of about 5 ft/min to about 20 ft/min.
12 . The alloy of claim 1 , having a 0.2% offset yield strength of at least 175 ksi; an ultimate tensile strength of at least 180 ksi; a % elongation at break of at least 1%; and a Young's modulus of at least 16 million psi.
13 . An ultra-high strength wrought alloy comprising copper, nickel, and tin, and having a 0.2% offset yield strength of at least 175 ksi.
14 . The alloy of claim 13 , wherein the alloy comprises:
about 9.0 wt % to about 15.5 wt % nickel;
about 6.0 wt % to about 9.0% tin; and
copper.
15 . The alloy of claim 13 , wherein the alloy has a 0.2% offset yield strength of at least 175 ksi and an ultimate tensile strength of at least 180 ksi.
16 . The alloy of claim 13 , wherein the alloy has a 0.2% offset yield strength of at least 175 ksi; an ultimate tensile strength of at least 180 ksi; a % elongation at break of at least 1%; and a Young's modulus of at least 16 million psi.
17 . The alloy of claim 13 , wherein the alloy is made by:
performing a first mechanical cold working step on the alloy to a percentage of cold working (%CW) of about 50% to about 75%; and
heat treating the alloy.
18 . The alloy of claim 17 , wherein the heat treating step is performed at a temperature of about 740° F. to about 850° F. for a period of about 3 minutes to 14 minutes.
19 . The alloy of claim 17 , wherein the heat treating step is performed by running the alloy in strip form through a furnace at a rate of about 5 ft/min to about 20 ft/mm.
20 . The alloy of claim 17 , wherein the heat treating step is performed at a temperature of about 740° F. to about 850° F. while running the alloy in strip form through a furnace at a rate of about 5 ft/min to about 20 ft/min.