Henley's Twentieth Century Formulas, Recipes and Processes. VariousЧитать онлайн книгу.
parts
Arguzoid.—
| Copper | 55.78 parts |
| Zinc | 23.198 parts |
| Nickel | 13.406 parts |
| Tin | 4.035 parts |
| Lead | 3.544 parts |
Silver white, almost ductile, suited for artistic purposes. {71}
Ferro-argentan.—
| Copper | 70.0 parts |
| Nickel | 20.0 parts |
| Zinc | 5.5 parts |
| Cadmium | 4.5 parts |
Resembles silver; worked like German silver.
Silver Bronze.
—Manganese, 18 per cent; aluminum, 1.2 per cent; silicium, 5 per cent; zinc, 13 per cent; copper, 67.5 per cent. The electric resistance of silver bronze is greater than that of German silver, hence it ought to be highly suitable for rheostats.
Instrument Alloys.
—The following are suitable for physical and optical instruments, metallic mirrors, telescopes, etc.:
I.—Copper, 62 parts; tin, 33 parts; lead, 5 parts.
II.—Copper, 80; antimony, 11; lead, 9.
III.—Copper, 10; tin, 10; antimony, 10; lead, 40.
IV.—Copper, 30; tin, 50; silver, 2; arsenic, 1.
V.—Copper, 66; tin, 33.
VI.—Copper, 64; tin, 26.
VII.—Steel, 90; nickel, 10.
VIII.—Platinum, 60; copper, 40.
IX.—Platinum, 45; steel, 55.
X.—Platinum, 55; iron, 45.
XI.—Platinum, 15; steel, 85.
XII.—Platinum, 20; copper, 79; arsenic, 1.
XIII.—Platinum, 62; iron, 28; gold, 10.
XIV.—Gold, 48; zinc, 52.
XV.—Steel, 50; rhodium, 50.
XVI.—Platinum, 12; iridium, 88.
XVII.—Copper, 89.5; tin, 8.5; zinc, 2.
Lead Alloys.
The following alloys, principally lead, are used for various purposes:
Bibra Alloy.
—This contains 8 parts of bismuth, 9 of tin, and 38 to 40 of lead.
Metallic Coffins.
—Tin, 40 parts; lead, 45 parts; copper, 15 parts.
Plates For Engraving.
—I.—Lead, 84 parts; antimony, 16 parts.
II.—Lead, 86 parts; antimony, 14 parts.
III.—Lead, 87 parts; antimony, 12 parts; copper, 1 part.
IV.—Lead, 81 parts; antimony, 14 parts; tin, 5 parts.
V.—Lead, 73 parts; antimony, 17 parts; zinc, 10 parts.
VI.—Tin, 53 parts; lead, 43 parts; antimony, 4 parts.
Hard lead is made of lead, 84 parts; antimony, 16 parts.
Sheet Metal Alloy.—
| Tin | 35 parts |
| Lead | 250 parts |
| Copper | 2.5 parts |
| Zinc | 0.5 part |
This alloy has a fine white color, and can be readily rolled into thin sheets. For that reason it is well adapted for lining tea chests and for the production of tobacco and chocolate wrappers. The copper and zinc are used in the form of fine shavings. The alloy should be immediately cast into thin plates, which can then be passed through rolls.
Magnetic Alloys.
Alloys which can be magnetized most strongly are composed of copper, manganese, and aluminum, the quantities of manganese and aluminum being proportional to their atomic weights (55.0 to 27.1, or about 2 to 1). The maximum magnetization increases rapidly with increase of manganese, but alloys containing much manganese are exceedingly brittle and cannot be wrought. The highest practicable proportion of manganese at present is 24 per cent.
These magnetic alloys were studied by Hensler, Haupt, and Starck, and Gumlich has recently examined them at the Physikalisch—technische Reichsanstalt, with very remarkable and interesting results.
The two alloys examined were composed as follows:
Alloy I.—Copper, 61.5 per cent; manganese, 23.5 per cent; aluminum, 15 per cent; lead, 0.1 per cent, with traces of iron and silicon.
Alloy II.—Copper, 67.7 per cent; manganese, 20.5 per cent; aluminum, 10.7 per cent; lead, 1.2 per cent, with traces of iron and silicon.
Alloy II could be worked without difficulty, but alloy I was so brittle that it broke under the hammer. A bar 7 inches long and 1/4 inch thick was obtained by grinding. This broke in two during the measurements, but, fortunately, without invalidating them. Such a material is evidently unsuited to practical uses.
The behavior of magnetic alloys at high temperatures is very peculiar. Alloy I is indifferent to temperature changes, which scarcely affect its magnetic properties, but the behavior of alloy II is very different. Prolonged heating to 230° F. produces a great increase in its capability of magnetization, which, after 544 hours’ heating, rises from 1.9 to 3.2 kilogauss, {72} approaching the strength of alloy I. But when alloy II is heated to 329° F., its capability of magnetization fails again and the material suffers permanent injury, which can be partly, but not wholly, cured by prolonged heating.
Another singular phenomenon was exhibited by both of these alloys. When a bar of iron is magnetized by an electric current, it acquires its full magnetic strength almost instantaneously on the closure of the circuit. The magnetic alloys, on the contrary, do not attain their full magnetization for several minutes. In some of the experiments a gradual increase was observed even after the current had been flowing five minutes.
In magnetic strength alloy I proved far superior to alloy II, which contained smaller proportions of manganese and aluminum. Alloy I showed magnetic strengths up to 4.5 kilogauss, while the highest magnetization obtained with alloy II was only 1.9 kilogauss. But even alloy II may be called strongly magnetic, for its maximum magnetization is about one-tenth that of good wrought iron (18 to 20 kilogauss), or one-sixth that of cast iron (10 to 12 kilogauss). Alloy I is nearly equal in magnetic properties to nickel, which can be magnetized up to about 5 kilogauss.
Manganese Alloys:
Manganese Bronze
is a bronze deprived of its oxide by an admixture of manganese. The manganese is used as copper manganese containing 10 to 30 per cent manganese and added to the bronze to the amount of 0.5 to 2 per cent.
Manganese Copper.
—The alloys of copper with manganese have a beautiful silvery color, considerable ductility, great hardness and tenacity, and are more