Copper alloy, copper alloy plate, and process for producing the same

Abstract

A copper alloy with an excellent stress relaxation resistance including Ni: 0.1 through 3.0 mass %, Sn: 0.01 through 3.0 mass %, P: 0.01 through 0.3 mass % and remainder copper and inevitable impurities, and the Ni content in extracted residues separated and left on a filter having filter mesh size of 0.1 μm by using an extracted residues method accounting for 40 mass % or less of the Ni content in the copper alloy, wherein the extracted residues method requires that 10 g of the copper alloy is immersed in 300 ml of a methanol solution which contains 10 mass % of ammonium acetate, and using the copper alloy as the anode and platinum as the cathode, constant-current electrolysis is performed at the current density of 10 mA/cm 2 , and the solution in which the copper alloy is thus dissolved is subjected to suction filtration using a membrane filter of polycarbonate whose filter mesh size is 0.1 μm, thereby separating and extracting undissolved residues on said filter, and the Ni content in the extracted residues is identified through analysis by ICP after dissolving said undissolved residues separated and left on said filter into a solution prepared by mixing aqua regia and water at the ratio of 1:1.

1 : A copper alloy with an excellent stress relaxation resistance comprising:
 Ni: 0.1 through 3.0 mass %;   Sn: 0.01 through 3.0 mass %;   P: 0.01 through 0.3 mass %; and   remainder copper and inevitable impurities, and the Ni content in extracted residues separated and left on a filter having filter mesh size of 0.1 μm by using an extracted residues method accounting for 40 mass % or less of the Ni content in the copper alloy, wherein   said extracted residues method requires that 10 g of the copper alloy is immersed in 300 ml of a methanol solution which contains 10 mass % of ammonium acetate, and using the copper alloy as the anode and platinum as the cathode, constant-current electrolysis is performed at the current density of 10 mA/cm 2 , and the solution in which the copper alloy is thus dissolved is subjected to suction filtration using a membrane filter of polycarbonate whose filter mesh size is 0.1 μm, thereby separating and extracting undissolved residues on said filter, and   the Ni content in said extracted residues is identified through analysis by ICP after dissolving said undissolved residues separated and left on said filter into a solution prepared by mixing aqua regia and water at the ratio of 1:1.   
   
   
       2 : The copper alloy of  claim 1 , further comprising:
 Fe: 0.5 mass % or less;   Zn: 1 mass % or less;   Mn: 0.1 mass % or less;   Si: 0.1 mass % or less; and   Mg: 0.3 mass % or less.   
   
   
       3 : The copper alloy of  claim 1 , further comprising one or more elements selected from the group consisting of Ca, Zr, Ag, Cr, Cd, Be, Ti, Co, Au and Pt in the total amount of 1.0 mass % or less. 
   
   
       4 : The copper alloy of  claim 1 , further comprising one or more elements selected from the group consisting of Hf, Th, Li, Na, K, Sr, Pd, W, S, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B and misch metals in the total amount of 0.1 mass % or less. 
   
   
       5 : A copper alloy comprising:
 Ni: 0.4 through 1.6 mass %;   Sn: 0.4 through 1.6 mass %;   P: 0.027 through 0.15 mass %,   Fe: 0.0005 through 0.15 mass %; and   the remainder part having Cu and impurities, the ratio Ni/P of the Ni content to the P content being lower than 15, wherein   precipitates are dispersed in the copper alloy, and   said precipitates have diameters of 60 nm or smaller, and twenty or more precipitates having the diameters of 5 nm to 60 nm are observed within a scope of 500 nm×500 nm.   
   
   
       6 : The copper alloy of  claim 5 , further comprising one or more elements selected from the group consisting of:
 Zn: 1 mass % or less;   Mn: 0.1 mass % or less;   Si: 0.1 mass % or less; and   Mg: 0.3 mass % or less.   
   
   
       7 : The copper alloy of  claim 5 , further comprising one or more elements selected from the group consisting of Cr, Co, Ag, In, Be, Al, Ti, V, Zr, Mo, Hf, Ta and B in the total amount of 0.1 mass % or less. 
   
   
       8 : A copper alloy plate for electric connection components made of the copper alloy of  claim 1 . 
   
   
       9 : A method of making a copper alloy plate of the copper alloy of  claim 1 , wherein while the copper alloy plate is being made through casting, hot rolling, cold rolling and annealing of the copper alloy, the time since the completion of addition of alloy elements into melting furnace until the start of casting is 1200 seconds or shorter and the time since ejection of an ingot from an ingot heating furnace until the end of hot rolling is 1200 seconds or shorter. 
   
   
       10 : A copper alloy plate for electric connection components made of the copper alloy of  claim 5 .