Читать книгу Henley's Formulas, Recipes and Processes (Applied Chemistry) - Various - Страница 165

—These alloys are usually supported by bearings of brass, into which it is poured after they have been tinned, and heated and put together with an exact model of the axle, or other working piece, plastic clay being previously applied, in the usual manner, as a lute or outer mold. Soft gun metal is also excellent, and is much used for bearings. They all become less heated in working than the {51} harder metals, and less grease or oil is consequently required when they are used.

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.

V.—Lead, 1 part; tin, 2 parts; zinc, 4 parts; copper, 68 parts. Used when the metal is exposed to heat.

VI.—Tin, 48 to 50 parts; antimony, 5 parts; copper, 1 part.

VII.—(Fenton’s.) Tin, with some zinc, and a little copper.

VIII.—(Ordinary.) Tin, or hard pewter, with or without a small portion of antimony or copper. Without the last it is apt to spread out under the weight of heavy machinery. Used for the bearings of locomotives, etc.

The following two compositions are for motor and dynamo shafts: 100 pounds tin; 10 pounds copper; 10 pounds antimony.

83 ¹/₂ pounds tin; 8 ¹/₄ pounds antimony; 8 ¹/₄ pounds copper.

IX.—Lead, 75 parts; antimony, 23 parts; tin, 2 parts.

X.—Magnolia Metal.—This is composed of 40 parts of lead, 7 ¹/₂ parts of antimony, 2 ¹/₂ of tin, ¹/₈ of bismuth, ¹/₈ of aluminum, and ¹/₄ of graphite. It is used as an anti-friction metal, and takes its name from its manufacturer’s mark, a magnolia flower.

ARGENTAN: See German Silver, under this title.