Metal material, connection terminal and metal material manufacturing method

Abstract

A metal materialis provided with a base material, an intermediate layercontaining at least Ni and covering a surface of the base material, and an In covering layermade of In or In alloy not containing Ni other than as unavoidable impurities, covering a surface of the intermediate layerand exposed on an outermost surface. In is contained more than 7/3 times of Ni in an atomic ratio in the sum of the intermediate layer and the In covering layer. Further, a connection terminal is configured to contain the metal material, and the intermediate layerand the In covering layerare formed on the surface of the base materialat least in a contact point portion to be brought into electrical contact with a mating electrically conductive member.