COPPER-BERYLLIUM ALLOY WITH HIGH STRENGTH
A process for producing a copper-beryllium alloy product. The process comprises preparing a base alloy having 0.15 wt %-4.0 wt % beryllium and having grains and an initial cross section area. The process further comprises cold working the base alloy to a percentage of cold reduction of area (CRA) greater than 40%, based on the initial cross section area, and heat treating the cold worked alloy to produce the copper-beryllium alloy product. The grain structure of the copper-beryllium alloy product has an orientation angle of less than 45° when viewed along the direction of the cold working. The copper-beryllium alloy product demonstrates a fatigue strength of at least 385 MPa after 10 6 cycles of testing.
1 .- 20 . (canceled)
21 . A copper-beryllium alloy product, comprising:
0.15-4.0 wt % beryllium; and
copper;
and having grains and a grain structure;
wherein the grains of the copper-beryllium alloy product are generally elongated or flattened in a common direction and the grain structure has an orientation angle of less than 45° when viewed along the direction of the grain elongation.
22 . The copper-beryllium alloy product of claim 21 , further comprising from 0 wt % to 2.7 wt % of cobalt, nickel, or zirconium, or combinations thereof.
23 . The copper-beryllium alloy product of claim 21 , further comprising 0.5 wt % or less of titanium, tin, lead, or zinc, or combinations thereof.
24 . The copper-beryllium alloy product of claim 21 , wherein the grain structure orientation angle is less than 15°.
25 . The copper-beryllium alloy product of claim 21 , wherein the copper-beryllium alloy product demonstrates a fatigue strength of at least 385 MPa after 10 6 cycles of testing.
26 . The copper-beryllium alloy product of claim 21 , wherein the copper-beryllium alloy product demonstrates an ultimate tensile strength transverse to the direction of the grain elongation and an ultimate tensile strength in the direction of the grain elongation.
27 . The copper-beryllium alloy product of claim 26 , wherein the ultimate tensile strength transverse to the direction of the grain elongation is greater than the ultimate tensile strength in the direction of the grain elongation by from 5% to 10%.
28 . The copper-beryllium alloy product of clam 21 , wherein the copper-beryllium alloy product demonstrates a 0.2% offset yield strength transverse to the direction of the grain elongation and a 0.2% offset yield strength in the direction of the grain elongation.
29 . The copper-beryllium alloy product of claim 28 , wherein the 0.2% offset yield strength transverse to the direction of the grain elongation is greater than the 0.2% offset yield strength in the direction of the grain elongation by from 5% to 10%.
30 . The copper-beryllium alloy product of claim 21 , wherein the copper-beryllium alloy product has fatigue initiation sites, and wherein the amount of fatigue initiation sites is less than the amount of fatigue initiation sites in the base alloy by 1% to 35%.
31 . The copper-beryllium alloy product of claim 21 , wherein the copper-beryllium alloy product has been cold worked to a thickness of less than 0.01 inches.
32 . The copper-beryllium alloy product of claim 21 , wherein the copper-beryllium alloy product has been cold worked to achieve a percentage of cold reduction of area (CRA) greater than 40%, based on an initial cross section area of a base alloy.
33 . The copper-beryllium alloy product of claim 21 , wherein the copper-beryllium alloy product has been cold worked to achieve a percentage of cold reduction of area (CRA) of 70% to 80%, based on an initial cross section area of a base alloy.
34 . The copper-beryllium alloy product of claim 32 , wherein the cold worked copper-beryllium alloy product has been heat treated at a temperature of 600° F. to 700° F. for a period of 1 minutes to 5 minutes.
35 . The copper-beryllium alloy product of claim 34 , wherein the heat treated cold worked copper-beryllium alloy product has been subjected to solution annealing and aging.
36 . The copper-beryllium alloy product of claim 35 , wherein the solution annealing is performed at a temperature of 1350° F. to 1450° F. for a period of 0.5 minutes to 5 minutes.
37 . The copper-beryllium alloy product of claim 35 , wherein the aging is performed at a temperature of 450° F. to 650° F. for a period of 2 hours to 4 hours.