Copper-beryllium alloy with high strength

Abstract

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.