Copper alloy for electronic devices, method of manufacturing copper alloy for electronic devices, copper alloy plastic working material for electronic devices, and component for electronic devices
A copper alloy for electronic devices has a low Young's modulus, high proof stress, high electrical conductivity and excellent bending formability and is appropriate for a component for electronic devices including a terminal, a connector, a relay and a lead frame. Also a method of manufacturing a copper alloy utilizes a copper alloy plastic working material for electronic devices, and a component for electronic devices. The copper alloy includes Mg at 3.3 to 6.9 at %, with a remainder substantially being Cu and unavoidable impurities. When a concentration of Mg is X at %, an electrical conductivity σ (% IACS) is in a range of σ≤{1.7241/(−0.0347×X 2 +0.6569×X+1.7)}×100, and an average grain size is in a range of 1 μm-100 μm. In addition, an average grain size of a copper material after an intermediate heat treatment and before finishing working is in a range of 1 μm-100 μm.
1. A copper alloy for electronic devices, consisting of:
a binary alloy of Cu and Mg,
wherein the binary alloy consists of Mg at a content of 3.3 at % or more and 6.9 at % or less, and a remainder of Cu and unavoidable impurities,
when a concentration of Mg is given as X at %, an electrical conductivity of the copper alloy (% IACS) satisfies σ≤{1.7241/(−0.0347×X 2 +0.6569×X+1.7)}×100,
an average grain size is in a range of 1 μm or greater and 100 μm or smaller,
the copper alloy is a Cu—Mg solid solution alloy supersaturated with Mg, and
a Young's modulus is in a range of 125 GPa or less, and a 0.2% proof stress σ 0.2 is in a range of 400 MPa or more.
2. The copper alloy for electronic devices according to claim 1 ,
wherein a ratio of a region having a CI value of 0.1 or less is in a range of 80% or less as a measurement result according to an SEM-EBSD method.
3. The copper alloy for electronic devices according to claim 1 ,
wherein an average number of intermetallic compounds having grain sizes of 0.1 μm or greater and mainly containing Cu and Mg is in a range of 1 piece/μm 2 or less during observation by a scanning electron microscope.
4. The copper alloy for electronic devices according to claim 1 ,
wherein an amount of Sn as an unavoidable impurity is in a range of less than 0.1 mass %, and an amount of Zn as an unavoidable impurity is in a range of less than 0.01 mass %.
5. A copper alloy for electronic devices, consisting of:
a binary alloy of Cu and Mg,
wherein the binary alloy consists of Mg at a content of 3.3 at % or more and 6.9 at % or less, and a remainder of Cu and unavoidable impurities,
when a concentration of Mg is given as X at %, an electrical conductivity of the copper alloy (% IACS) satisfies σ≤{1.7241/(−0.0347×X 2 +0.6569×X+1.7)}×100,
an average grain size of a copper material after an intermediate heat treatment and before finishing working is in a range of 1 μm or greater and 100 μm or smaller,
the copper alloy is a Cu—Mg solid solution alloy supersaturated with Mg, and
a Young's modulus is in a range of 125 GPa or less, and a 0.2% proof stress σ 0.2 is in a range of 400 MPa or more.
6. The copper alloy for electronic devices according to claim 5 ,
wherein a ratio of a region having a CI value of 0.1 or less is in a range of 80% or less as a measurement result according to an SEM-EBSD method.
7. The copper alloy for electronic devices according to claim 5 ,
wherein an average number of intermetallic compounds having grain sizes of 0.1 μm or greater and mainly containing Cu and Mg is in a range of 1 piece/μm 2 or less during observation by a scanning electron microscope.
8. The copper alloy for electronic devices according to claim 5 ,
wherein an amount of Sn as an unavoidable impurity is in a range of less than 0.1 mass %, and an amount of Zn as an unavoidable impurity is in a range of less than 0.01 mass %.
9. A copper alloy plastic working material for electronic devices, consisting of the copper alloy for electronic devices according to claim 1 ,
wherein a Young's modulus E is in a range of 125 GPa or less, and a 0.2% proof stress σ 0.2 is in a range of 400 MPa or more.
10. The copper alloy plastic working material for electronic devices according to claim 9 ,
wherein the copper alloy plastic working material is used as a copper material included in a component for electronic devices such as a terminal including a connector, a relay, and a lead frame.
11. A component for electronic devices, comprising the copper alloy for electronic devices according to claim 1 .
12. A terminal comprising the copper alloy for electronic devices according to claim 1 .
13. A copper alloy plastic working material for electronic devices, consisting of the copper alloy for electronic devices according to claim 5 ,
wherein a Young's modulus E is in a range of 125 GPa or less, and a 0.2% proof stress σ 0.2 is in a range of 400 MPa or more.
14. The copper alloy plastic working material for electronic devices according to claim 13 ,
wherein the copper alloy plastic working material is used as a copper material included in a component for electronic devices such as a terminal including a connector, a relay, and a lead frame.
15. A component for electronic devices, comprising the copper alloy for electronic devices according to claim 5 .
16. A terminal comprising the copper alloy for electronic devices according to claim 5 .