Kobe Steel, Ltd.

Akira Fugono

Yasuhiro Aruga

Katsura Kajihara

Takeshi Kudo

Hisao Shishido

Hiroshi Sakamoto

Yuya Sumino

The present invention relates to a copper alloy having high strength, high electrical conductivity, and excellent bendability, the copper alloy containing, in terms of mass %, 0.4 to 4.0% of Ni; 0.05 to 1.0% of Si; and, as an element M, one member selected from 0.005 to 0.5% of P, 0.005 to 1.0% of Cr, and 0.005 to 1.0% of Ti, with the remainder being copper and inevitable impurities, in which an atom number ratio M/Si of elements M and Si contained in a precipitate having a size of 50 to 200 nm in a microstructure of the copper alloy is from 0.01 to 10 on average, the atom number ratio being measured by a field emission transmission electron microscope with a magnification of 30,000 and an energy dispersive analyzer.

Copper alloy having high strength, high electric conductivity and excellent bending workability

To provide a copper alloy sheet excellent in the balance of strength and electroconductivity and excellent in the balance of strength and bending workability also. A copper alloy contains predetermined amount of Cr, Ti, and Si so as to satisfy a mass ratio of the Cr to the Ti: 1.0&#x2266;(Cr/Ti)&#x2266;30, and a mass ratio of the Cr to the Si: 3.0&#x2266;(Cr/Si)&#x2266;30, the remainder including copper and unavoidable impurities, in which 70% or more out of total amount of Cr, Ti and Si contained in the copper alloy is precipitated, a number of piece of precipitates with 300 nm or more circle equivalent diameter observed by a SEM in a region of 25 &#x3bc;m in the thickness direction from the surface of the copper alloy&#xd7;40 &#x3bc;m in the cross-sectional direction in a cross section in the width direction of the copper alloy is 50 pieces or less, and an average circle equivalent diameter of precipitates with less than 300 nm circle equivalent diameter observed by a TEM on the surface of the copper alloy is 15 nm or less.

Copper alloy

Disclosed is a Cu&#x2014;Ni&#x2014;Si copper alloy sheet that excels in strength and formability and is used in electrical and electronic components. The copper alloy sheet contains, by mass, 1.5% to 4.5% Ni and 0.3% to 1.0% of Si and optionally contains at least one member selected from 0.01% to 1.3% of Sn, 0.005% to 0.2% of Mg, 0.01% to 5% of Zn, 0.01% to 0.5% of Mn, and 0.001% to 0.3% of Cr, with the remainder being copper and inevitable impurities. The average size of crystal grains is 10 &#x3bc;m or less, the standard deviation &#x3c3; of crystal grain size satisfies the condition: 2&#x3c3;&#x3c;10 &#x3bc;m, and the number of dispersed precipitates lying on grain boundaries and having a grain size of from 30 to 300 nm is 500 or more per millimeter.

Copper alloy sheet excellent in strength and formability for electrical and electronic components

A copper alloy having high strength, high electrical conductivity, and excellent bendability, the copper alloy containing, in terms of mass %, 0.4 to 4.0% of Ni; 0.05 to 1.0% of Si; and, as an element M, one member selected from 0.005 to 0.5% of P, 0.005 to 1.0% of Cr, and 0.005 to 1.0% of Ti, with the remainder being copper and inevitable impurities, in which an atom number ratio M/Si of elements M and Si contained in a precipitate having a size of 50 to 200 nm in a microstructure of the copper alloy is from 0.01 to 10 on average, the atom number ratio being measured by a field emission transmission electron microscope with a magnification of 30,000 and an energy dispersive analyzer. According to the invention, it is possible to provide a copper alloy having high strength, high electrical conductivity, and excellent bendability.

The present invention relates to a copper alloy having high strength, high electrical conductivity, and excellent bendability, the copper alloy containing, in terms of mass %, 0.4 to 4.0% of Ni; 0.05 to 1.0% of Si; and, as an element M, one member selected from 0.005 to 0.5% of P, 0.005 to 1.0% of Cr, and 0.005 to 1.0% of Ti, with the remainder being copper and inevitable impurities, in which an atom number ratio M/Si of elements M and Si contained in a precipitate having a size of 50 to 200 nm in a microstructure of the copper alloy is from 0.01 to 10 on average, the atom number ratio being measured by a field emission transmission electron microscope with a magnification of 30,000 and an energy dispersive analyzer. According to the invention, it is possible to provide a copper alloy having high strength, high electrical conductivity, and excellent bendability.

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Shimonoseki, Japan

Akira Fugono