II.—A silver aluminum that is easily worked into various articles contains about one-fourth silver and three-fourths of aluminum.
Aluminum-tin.
Aluminum-tungsten.
Aluminum-zinc.
AMALGAMS: See Fusible Alloys.
Anti-friction Bearing Or Babbitt Metals.
I.—An anti-friction metal of excellent quality and one that has been used with success is made as follows: 17 parts zinc; 1 part copper; 1 1/2 parts antimony; prepared in the following way: Melt the copper in a small crucible, then add the antimony, and lastly the zinc, care being taken not to burn the zinc. Burning can be prevented by allowing the copper and antimony to cool slightly before adding the zinc. This metal is preferably cast into the shape desired and is not used as a lining metal because it requires too great a heat to pour. It machines nicely and takes a fine polish on bearing surfaces. It has the appearance of aluminum when finished. Use a lubricating oil made from any good grade of machine oil to which 3 parts of kerosene have been added.
II.—Copper, 6 parts; tin, 12 parts; lead, 150 parts; antimony, 30 parts; wrought iron, 1 part; cast iron, 1 part. For certain purposes the composition is modified as follows: Copper, 16 parts; tin, 40 parts; lead, 120 parts; antimony, 24 parts; wrought iron, 1 part; cast iron, 1 part. In both cases the wrought iron is cut up in small pieces, and in this state it will melt readily in fused copper and cast iron. After the mixture has been well stirred, the tin, lead, and antimony are added; these are previously melted in separate crucibles, and when mingled the whole mass is again stirred thoroughly. The product may then be run into ingots, to be employed when needed. When run into the molds the surface should be well skimmed, for in this state it oxidizes rapidly. The proportions may be varied without materially affecting the results.
III.—From tin, 16 to 20 parts; antimony, 2 parts; lead, 1 part; fused together, and then blended with copper, 80 parts. Used where there is much friction or high velocity.
IV.—Zinc, 6 parts; tin, 1 part; copper, 20 parts. Used when the metal is exposed to violent shocks.