A metal alloy composite comprising a phase of a highly-conductive base metal in the from of a matrix and a phase of another metal positioned within the matrix, the base metal being present in a major amount and the other metal being present in a minor amount, the metal alloy composite being capable of being formed into a very thin wire for use in a semiconductor application which includes a terminal assembly comprising an electrically conductive terminal in conductive contact with a conductive member and another electrically conductive terminal in conductive contact with a semiconductor, said terminals being joined by said alloy composite wire, examples of the base metal being gold, copper, and aluminum.