Cobalt Silicide-Containing Copper Alloy

Abstract

The present invention discloses copper alloy containing cobalt and silicon, which comprises (in percentage of weight): 69% to 92% of copper; 6.5% to 30.5% of zinc; 0.01% to 3% of cobalt; and 0.01% to 0.5% of silicon; wherein the total content of copper and zinc is greater than 95%, and the content of inevitable impurities is less than 0.2%. Preferably, the copper alloy comprises matrix phases of copper-zinc α solid solution and Co x Si y precipitated phases; the Co x Si y precipitated phases are dispersedly distributed on a matrix phase; the percentage of the matrix phases by area is greater than or equal to 95%; and, the percentage of the Co x Si y precipitated phases by area is 0.01% to 5%.

1 . A copper alloy containing cobalt and silicon comprising (in percentage of weight):
 69% to 92% of copper;   6.5% to 30.5% of zinc;   0.01% to 3% of cobalt; and   0.01% to 0.5% of silicon;   wherein the total content of copper and zinc is greater than 95%, and the content of inevitable impurities is less than 0.2%.   
     
     
         2 . The copper alloy of  claim 1 , wherein the copper alloy comprises matrix phases of copper-zinc α solid solution and Co x Si y  precipitated phases;
 the Co x Si y  precipitated phases are dispersedly distributed on a matrix phase; 
 the percentage of the matrix phases by area is greater than or equal to 95%; and, 
 the percentage of the Co x Si y  precipitated phases by area is 0.01% to 5%. 
 
     
     
         3 . The copper alloy of  claim 2 , wherein the percentage of the Co x Si y  precipitated phases having a particle size between 10 nm and 200 nm is greater than or equal to 90%, and the percentage of the Co x Si y  precipitated phases having a particle size above 200 nm is less than or equal to 10%. 
     
     
         4 . The copper alloy of  claim 3 , wherein an atomic ratio of copper to zinc (Cu/Zn) is 2.3 to 15.8, and a mass fraction of copper and zinc satisfies 0.65≦([Cu]/3+1)/([Zn]+5)≦3.5. 
     
     
         5 . The copper alloy of  claim 4 , wherein a yield strength/tensile strength of the copper alloy is greater than or equal to 85%; and
 a stress relaxation rate under an initial stress at a yield strength of 50% at 100° C. for 1000 H is less than or equal to 15%.   
     
     
         6 . The copper alloy of  claim 1 , wherein the copper alloy further comprises (in percentage of weight) at least one of 0.01% to 3.5% of Sn, 0.01% to 4.0% of Al and 0.01% to 3% of Ni. 
     
     
         7 . The copper alloy of  claim 1 , wherein the copper alloy further comprises (in percentage of weight) 0.01% to 0.35% of P. 
     
     
         8 . The copper alloy of  claim 7 , wherein the copper alloy further comprises Co m P n  precipitated phases, and a percentage of the Co m P n  precipitated phases by area is 0.01% to 5%. 
     
     
         9 . The copper alloy of  claim 6 , wherein the copper alloy further comprises (in percentage of weight) 0.01% to 0.35% of P. 
     
     
         10 . The copper alloy of  claim 9 , wherein the copper alloy further comprises Co m P n  precipitated phases, and a percentage of the Co m P n  precipitated phases by area is 0.01% to 5%. 
     
     
         11 . The copper alloy of  claim 6 , wherein further comprises A having a total content of 0.0001% to 2%, and the A is at least one selected from a group comprises (in percentage of weight) 0.01% to 1.5% of Mn, 0.01% to 1.5% of Fe, 0.001% to 0.3% of Cr, 0.001% to 0.2% of Zr, 0.001% to 0.5% of Mg, 0.001% to 0.8% of Ti, 0.0005% to 0.3% of B and 0.0001% to 0.1% of Re. 
     
     
         12 . The copper alloy of  claim 7 , wherein the copper alloy further comprises A having a total content of 0.0001% to 2%, and the A is at least one selected from a group comprises (in percentage of weight) 0.01% to 1.5% of Mn, 0.01% to 1.5% of Fe, 0.001% to 0.3 of Cr, 0.001% to 0.2% of Zr, 0.001% to 0.5% of Mg, 0.001% to 0.8% of Ti, 0.0005% to 0.3% of B, and 0.0001% to 0.1% of Re.