Henley's Twentieth Century Formulas, Recipes and Processes. Various

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СКАЧАТЬ 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

      {65}

      These alloys are prepared СКАЧАТЬ