Composite material
A composite material includes: a first member containing tungsten as a primary component; a second member containing copper as a primary component, the second member being joined to the first member; and a metal containing at least one metal selected from a group consisting of titanium, zirconium, and hafnium, the metal being present in the second member, wherein a concentration of the metal is more than 0 atomic % and less than or equal to 5.0 atomic % at a location of 5 μm from a joining interface between the first member and the second member toward the second member side.
1 . A composite material comprising:
a first member containing tungsten as a primary component;
a second member containing copper as a primary component, the second member being joined to the first member; and
a metal containing at least one selected from a group consisting of titanium, zirconium, and hafnium, the metal being present in the second member, wherein
the first member and the second member being directly jointed to each other, a concentration of the metal is more than 0 atomic % and less than or equal to 5.0 atomic % at a location of 5 μm from a joining interface between the first member and the second member toward the second member side,
the atomic % is calculated by a spot analysis in which a spectrum of a characteristic X-ray when irradiated with an electron beam having an acceleration voltage of 15 kV, a beam current of 50 nA, and a spot diameter of 10 μm is divided to calculate a constituent ratio of elements in the metal using a ZAF method,
a joining strength of the composite material is 146 MPa and less than or equal to 239 MPa, and
a thickness of the second member is more than or equal to 10 mm.
2 . The composite material according to claim 1 , wherein the metal is titanium.
3 . The composite material according to claim 1 , wherein the concentration of the metal is more than or equal to 0.1 atomic % at the location of 5 μm from the joining interface between the first member and the second member toward the second member side,
wherein the atomic % is calculated by the spot analysis in which the spectrum of the characteristic X-ray when irradiated with the electron beam having the acceleration voltage of 15 kV, the beam current of 50 nA, and the spot diameter of 10 μm is divided to calculate the constituent ratio of elements in the metal using the ZAF method.
4 . The composite material according to claim 1 , wherein the concentration of the metal is less than or equal to 1.0 atomic % at the location of 5 μm from the joining interface between the first member and the second member toward the second member side,
wherein the atomic % is calculated by the spot analysis in which the spectrum of the characteristic X-ray when irradiated with the electron beam having the acceleration voltage of 15 kV, the beam current of 50 nA, and the spot diameter of 10 μm is divided to calculate the constituent ratio of elements in the metal using the ZAF method.
5 . The composite material according to claim 1 , wherein the second member includes a pure-copper-based layer provided on a side close to the first member, and a layer that has a strength higher than a strength of pure copper, that has a composition different from a composition of the pure-copper-based layer, and that is provided on a side far from the first member.
6 . The composite material according to claim 5 , wherein a thickness of the pure-copper-based layer is more than or equal to 0.2 mm and less than 1.5 mm.
7 . The composite material according to claim 1 , wherein the second member has:
a rod shape having a length, corresponding to the thickness, of more than or equal to 10 mm and less than or equal to 50 mm, or
a flat plate shape having the thickness equal to 15 mm.
8 . The composite material according to claim 1 , wherein the metal contains at least one of zirconium or hafnium.