The New Student's Reference Work/Alloy
Alloy', a mixture of two or more metals melted together. Some of the metals, when combined with other metals, are rendered more serviceable for certain uses. Thus copper alone is not fit for castings, and is too tough to be easily worked by tools, but when alloyed with zinc, forming brass, it can be cast, rolled or turned. Gold and silver, also, when pure are very soft and easily worn out. They are hardened by alloying them with other metals in different proportions. The silver coins of the United States are made up of nine parts of silver and one of copper, while the gold coins consist of nine parts gold and the other part is divided into one-quarter silver and three-quarters copper. Alloys are generally harder and much more fusible than would be indicated by the hardness and fusibility of the component metals. Besides the alloys that have been mentioned, some important ones are bell-metal and bronze consisting of copper and tin; type-metal, containing lead and antimony and sometimes tin also; German-silver, composed of copper, nickel and zinc; and solder, which is ordinarily made of lead and tin. Alloys of which one metal is mercury are called amalgams.