The present disclosure discloses use of a copper-chromium alloy in a medical biopsy puncture needle. The copper-chromium alloy used as a material for a needle core and/or needle tube of the puncture needle. The copper-chromium alloy includes the following components by mass: 10≤Cr≤20, 0.04≤Zr≤0.1, and the balance of Cu. According to the present disclosure, a copper alloy with designed components is obtained by combining a diamagnetic material Cu with paramagnetic Cr and Zr, and compared with existing medical stainless steel and titanium alloy, the copper alloy has greatly reduced magnetic susceptibility, and specifically, the artifact area and volume are also significantly reduced. In addition, the blank of use of the copper alloy in medical biopsy paracentesis is filled.

A method for making a three-dimensional hierarchical layered porous copper, the method includes providing a copper-zinc alloy precursor being composed of a β′ phase and a γ phase, and treating the copper-zinc alloy precursor by electrochemical dealloying. The present application further provides a three-dimensional hierarchical layered porous copper including a first surface layer, an intermediate layer, and a second surface layer stacked in that order. The first surface layer includes a plurality of micron-scale pores and a plurality of first nanoscale pores. The intermediate layer includes a plurality of second nanoscale pores. The second surface layer includes the plurality of micron-scale pores and the plurality of first nanoscale pores.

A method for making a three-dimensional hierarchical layered porous copper, the method includes providing a copper-zinc alloy precursor being composed of a β′ phase and a γ phase, and treating the copper-zinc alloy precursor by electrochemical dealloying. The present application further provides a three-dimensional hierarchical layered porous copper including a first surface layer, an intermediate layer, and a second surface layer stacked in that order. The first surface layer includes a plurality of micron-scale pores and a plurality of first nanoscale pores. The intermediate layer includes a plurality of second nanoscale pores. The second surface layer includes the plurality of micron-scale pores and the plurality of first nanoscale pores.

A high strength/highly conductive copper alloy plate material of the present invention contains silver in a range of 4% by mass or more and 13% by mass or less, and balancing copper and unavoidable impurities. In the high strength/highly conductive copper alloy plate material, a minimum value of a tensile strength (UTS) is 600 MPa or more and 1250 MPa or less, and a conductivity (% IACS) is 60% or more and 90% or less.

A high strength/highly conductive copper alloy plate material of the present invention contains silver in a range of 4% by mass or more and 13% by mass or less, and balancing copper and unavoidable impurities. In the high strength/highly conductive copper alloy plate material, a minimum value of a tensile strength (UTS) is 600 MPa or more and 1250 MPa or less, and a conductivity (% IACS) is 60% or more and 90% or less.

A pure copper sheet of the present invention has a composition including 99.96 mass % or more of Cu, 0.01 mass ppm or more and 3.00 mass ppm or less of P, 3.0 mass ppm or more of a total content of Ag and Fe, and inevitable impurities as a balance, in which an average crystal grain size of crystal grains on a rolled surface is 10 μm or more, and, in a case where a measurement area of 1 mm.sup.2 or more is measured by an EBSD method at measurement intervals of 5 μm steps, a measurement point where a CI value analyzed with data analysis software OIM is 0.1 or less is excluded, and a boundary where an orientation angle between adjacent pixels is 5° or more is regarded as a crystal grain boundary, a Kernel average misorientation (KAM) value is 1.50 or less.

A pure copper sheet of the present invention has a composition including 99.96 mass % or more of Cu, 0.01 mass ppm or more and 3.00 mass ppm or less of P, 3.0 mass ppm or more of a total content of Ag and Fe, and inevitable impurities as a balance, in which an average crystal grain size of crystal grains on a rolled surface is 10 μm or more, and, in a case where a measurement area of 1 mm.sup.2 or more is measured by an EBSD method at measurement intervals of 5 μm steps, a measurement point where a CI value analyzed with data analysis software OIM is 0.1 or less is excluded, and a boundary where an orientation angle between adjacent pixels is 5° or more is regarded as a crystal grain boundary, a Kernel average misorientation (KAM) value is 1.50 or less.

A pure copper sheet has a composition including 99.96 mass% or more of Cu, 9.0 mass ppm or more and less than 100.0 mass ppm of a total content of Ag, Sn, and Fe, and inevitable impurities as a balance, in which an average crystal grain size of crystal grains on a rolled surface is 10 .Math.m or more, the pure copper sheet has crystals in which crystal planes parallel to the rolled surface are a {022} plane, a {002} plane, a {113} plane, a {111} plane, and a {133} plane, and diffraction peak intensities of the individual crystal planes that are obtained by X-ray diffraction measurement by a 2θ/θ method on the rolled surface satisfy I {022}/(I {022} + I {002} + I {113} + I {111} + I {133}) ≤ 0.15, I {002}/I {111} ≥ 10.0, and I {002}/I {113} ≥ 15.0.

A copper foil having high fracture energy after heat treatment to be strong against breakage is disclosed. Also disclosed are an electrode for secondary batteries and a secondary battery exhibiting, by including the copper foil, excellent characteristics in terms of, for example, cycle lifespan, safety, and workability.

A copper foil having high fracture energy after heat treatment to be strong against breakage is disclosed. Also disclosed are an electrode for secondary batteries and a secondary battery exhibiting, by including the copper foil, excellent characteristics in terms of, for example, cycle lifespan, safety, and workability.