Abstract: According to one embodiment of the invention, a Cu—Ga alloy material has an average composition consisting of not less than 32% and not more than 53% by mass of gallium (Ga) as well as the balance consisting of copper (Cu) and an inevitable impurity. In the Cu—Ga alloy material, a region containing less than 47% by mass of copper accounts for 2% or less by volume of the whole Cu—Ga alloy material.

Abstract: A Cu—Ga alloy includes a plurality of phases, and not less than 40 wt % and not more than 60 wt % of gallium (Ga) and a balance consisting of copper and an inevitable impurity. The plurality of phases include a segregation phase including not less than 80 wt % of gallium (Ga), and a rate of a volume of the segregation phase to a total volume of the Cu—Ga alloy is not more than 1%. The plurality of phases include particles including not less than 40 wt % and not more than 60 wt % of gallium (Ga), the particles include a diameter of not less than 0.1 ?m and not more than 30 ?m, and a rate of a volume of the particles to the total volume of the Cu—Ga alloy is not less than 90%.