Alloy
. Alloy, substance composed of two or more metals. Alloys, like pure metals, possess metallic luster and conduct heat and electricity well, although not generally as well as do the pure metals of which they are formed. Compounds that contain both a metal or metals and certain nonmetals, particularly those containing carbon, are also called alloys. The most important of these is steel. Simple carbon steels consist of about 0.5 percent manganese and up to 0.8 percent carbon, with the remaining material being iron. An alloy may consist of an intermetallic compound, a solid solution, an intimate mixture of minute crystals of the constituent metallic elements, or any combination of solutions or mixtures of the foregoing. Intermetallic compounds, such as NaAu2, CuSn, and CuAl2, do not follow the ordinary rules of valency. They are generally hard and brittle; although they have not been important in the past where strength is required, many new developments have made such compounds increasing...