comprises 20 parts of silver, 50 of copper, 30 of nickel. These proportions may, however, vary.
Tissier’s Metal.
—This alloy contains arsenic, is of a beautiful tombac red color, and very hard. Its composition varies a great deal, but the peculiar alloy which gives the name is composed of copper, 97 parts; zinc, 2 parts; arsenic, 1 or 2. It may be considered a brass with a very high percentage of copper, and hardened by the addition of arsenic. It is sometimes used for axle bearings, but other alloys are equally suitable for this purpose, and are to be preferred on account of the absence of arsenic, which is always dangerous.
File Alloys.
—Many copper-tin alloys are employed for the making of files which, in distinction from the steel files, are designated composition files. Such alloys have the following compositions:
Geneva Composition Files.—
| I | II | |
|---|---|---|
| Copper | 64.4 | 62 |
| Tin | 18.0 | 20 |
| Zinc | 10.0 | 10 |
| Lead | 7.6 | 8 |
Vogel’s Composition Files.—
| III | IV | V | |
|---|---|---|---|
| Copper | 57.0 | 61.5 | 73.0 |
| Tin | 28.5 | 31.0 | 19.0 |
| Zinc | 78.0 | — | 8.0 |
| Lead | 7.0 | 8.5 | 8.0 |
VI.—Another alloy for composition files is copper, 8 parts; tin, 2; zinc, 1, and lead, 1—fused under a cover of borax.
Easily Fusible Or Plastic Alloys.
(These have a fusing point usually below 300° F.)
(See also Solders.)
I. Rose’s Alloy.—Bismuth, 2 parts; lead, 1 part; tin, 1 part. Melting point, 200° F.
II. Darcet Alloy.—This is composed of 8 parts of bismuth, 5 of lead, and 3 of tin. It melts at 176° F. To impart greater fusibility, 1/16 part of mercury is added; the fusing is then lowered to 149° F.
III.—Newton alloy melts at 212° F., and is composed of 5 parts of bismuth, 2 of lead, and 3 of tin.
IV.—Wood’s Metal.—
| Tin | 2 parts |
| Lead | 4 parts |
| Bismuth | 5 to 8 parts |
This silvery, fine-grained alloy fuses between 151° and 162° F., and is excellently adapted to soldering.
V.—Bismuth, 7 parts; lead, 6 parts; cadmium, 1 part. Melting point, 180° F.
VI.—Bismuth, 7 to 8 parts; lead, 4; tin, 2; cadmium, 1 to 2. Melting point, 149° to 160° F.
Other Easily Fusible Alloys:
| VII | VIII | IX | |
|---|---|---|---|
| Lead | 1 | 2 | 3 |
| Tin | 1 | 2 | 3 |
| Bismuth | 1 | 1 | 1 |
| Melting Point | 258° F. | 283° | 311° |
Fusible Alloys For Electric Installations.
—These alloys are employed in electric installations as current interrupters. Serving as conductors on a short length of circuit, they melt as soon as the current becomes too strong. Following is the composition of some of these alloys.
| Fusing temperature | Lead | Tin | Bismuth | Cadmium | |
|---|---|---|---|---|---|
| I | 203° F. | 250 | 500 | 500 | — |
| II | 193° F. | 397 | — | 532 | 71 |
| III | 168° F. | 344 | 94 | 500 | 62 |
| IV | 153° F. | 260 | 148 | 522 | 70 |
| V | 150° F. | 249 | 142 | 501 | 108 |
| VI | 145° F. | 267 | 136 | 500 | 100 |
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These alloys are prepared
