Abstract: A copper alloy material having: 1.0 to 5.0 mass % of Ni; 0.2 to 1.0 mass % of Si; 1.0 to 5.0 mass % of Zn; 0.1 to 0.5 mass % of Sn; 0.003 to 0.3 mass % of P; and the balance consisting of Cu and an unavoidable impurity. The mass ratio between Ni and each of Si, Zn and Sn is to be Ni/Si=4 to 6, Zn/Ni=0.5 or more, and Sn/Ni=0.05 to 0.2.

Abstract: A radiator plate includes a core having core surfaces and holes whose hole axes are directed in a direction along a normal direction of the core surface, and heat transfer plates joined to the core surfaces and filled in the holes. A multilayer radiator plate includes a first radiator plate including a first core having first core surfaces and first holes whose hole axes are directed in a direction along a normal direction of the first core surface and first heat transfer plates joined to the first core surfaces and filled in the first holes, a second radiator plate including a second core having second core surfaces and second holes whose hole axes are directed in a direction along a normal direction of the second core surface and second heat transfer plates joined to the second core surfaces and filled in the second holes, and the first radiator plate and the second radiator plate are joined to each other.

Abstract: A copper alloy material having: 1.0 to 5.0 mass % of Ni; 0.2 to 1.0 mass % of Si; 1.0 to 5.0 mass % of Zn; 0.1 to 0.5 mass % of Sn; 0.003 to 0.3 mass % of P; and the balance consisting of Cu and an unavoidable impurity. The mass ratio between Ni and each of Si, Zn and Sn is to be Ni/Si=4 to 6, Zn/Ni=0.5 or more, and Sn/Ni=0.05 to 0.2.

Abstract: A copper alloy material having: 1.0 to 5.0 mass % of Ni; 0.2 to 1.0 mass % of Si; 1.0 to 5.0 mass % of Zn; 0.1 to 0.5 mass % of Sn; 0.003 to 0.3 mass % of P; and the balance consisting of Cu and an unavoidable impurity. The mass ratio between Ni and each of Si, Zn and Sn is to be Ni/Si=4 to 6, Zn/Ni=0.5 or more, and Sn/Ni=0.05 to 0.2.

Abstract: A copper alloy material for electric parts having: 1.0 to 5.0 mass % of Ni; 0.2 to 1.0 mass % of Si; 0.05 to 2.0 mass % of Sn; 0.1 to 5.0 mass % of Zn; 0.01 to 0.3 mass % of P; 0.05 to 1.0 mass % of at least one of Fe and Co; and the balance consisting of Cu and an unavoidable impurity. The ratio, (Ni+Fe+Co)/(Si+P), between the total mass of Ni, Fe and Co and the total mass of Si and P is 4 or more and 10 or less.