and makes it very hard and brittle. Before German silver was known,
these alloys were sometimes used for the manufacture of such cast
articles as were not to come in contact with iron. When exposed to the
air, they soon lose their whiteness and take on a brownish shade. On
account of this, as well as the poisonous character of the arsenic,
they are very little used at the present time. Alloys of copper and
arsenic are best prepared by pressing firmly into a crucible a mixture
of 70 parts of copper and 30 of arsenic (the copper to be used in the
form of fine shavings) and fusing this mixture in a furnace with a good
draught, under a cover of glass.
«Copper Iron.»—The alloys of copper and iron are little used in the
industries of the present day, but it would seem that in earlier times
they were frequently prepared for the purpose of giving a considerable
degree of hardness to copper; for in antique casts, consisting
principally of copper, we regularly find large quantities of iron,
which leads to the supposition that they were added intentionally.
These alloys, when of a certain composition, have considerable strength
and hardness. With an increase in the quantity of the iron the hardness
increases, but the solidity is lessened. A copper and iron alloy of
considerable strength, and at the same time very hard, is made of
copper, 66 parts; iron, 34. These alloys acquire, on exposure to air,
an ugly color inclining toward black, and are therefore not adapted for
articles of art.
«Copper Nickel.»—A. Morrell, of New York, has obtained a patent on
a nickel-copper alloy which he claims is valuable on account of its
noncorrosive qualities, therefore making it desirable for ships, boiler
tubes, and other uses where the metal comes much in contact with water.
The process of making the metal is by smelting ore containing sulphide
of nickel and copper, and besemerizing the resultant matter. This
is calcined in order to obtain the nickel and copper in the form of
oxides. The latter are reduced in reverberating furnace with carbon, or
the like, so as to produce an alloy which preferably contains 2 parts
of nickel and 1 part of copper.
«Delta Metal.»—An alloy widely used for making parts of machinery,
and also for artistic purposes, is the so-called Delta metal. This is
a variety of brass hardened with iron; some manufacturers add small
quantities of tin and lead; also, in some cases, nickel. The following
analysis of Delta metal (from the factory at Düsseldorf) will show its
usual composition:
──────────+───────+───────+───────+─────+─────
│ I │ II │ III │ IV │ V
──────────+───────+───────+───────+─────+─────
Copper │ 55.94 │ 55.80│ 55.82│54.22│58.65
Zinc │ 41.61 │ 40.07│ 41.41│42.25│38.95
Lead │ 0.72 │ 1.82│ 0.76│ 1.10│ 0.67
Iron │ 0.87 │ 1.28│ 0.86│ 0.99│ 1.62
Manganese │ 0.81 │ 0.96│ 1.38│ 1.09│ —
Nickel │traces.│traces.│ 0.06│ 0.16│ 0.11
Phosphorus│ 0.013│ 0.011│traces.│ 0.02│ —
──────────+───────+───────+───────+─────+─────
I is cast, II hammered, III rolled, and IV hot-stamped metal. Delta
metal is produced by heating zinc very strongly in crucibles (to about
1600° F.), and adding ferromanganese or “spiegeleisen,” producing an
alloy of 95 per cent zinc and 5 per cent of iron. Copper and brass and
a very small amount of copper phosphate are also added. {64}
«Gong Metal.»—A sonorous metal for cymbals, gongs, and tam-tams
consists of 100 parts of copper with 25 parts tin. Ignite the piece
after it is cast and plunge it into cold water immediately.
«Production of Minargent.»—This alloy consists of copper, 500 parts;
nickel, 350; tungsten, 25, and aluminum, 5. The metal obtained
possesses a handsome white color and greatly resembles silver.
«Minofor.»—The so-called Minofor metal is composed of copper, tin,
antimony, zinc, and iron in the following proportions:
I II
Copper 3.26 4
Tin 67.53 66
Antimony 17.00 20
Zinc 8.94 9
Iron — 1
Minargent and Minofor are sometimes used in England for purposes in
which the ordinary Britannia metal, 2 parts tin and 1 part antimony,
might equally well be employed; the latter surpasses both of them in
beauty of color, but they are, on the other hand, harder.
«Retz Alloy.»—This alloy, which resists the corrosive action of
alkalies and acids, is composed of 15 parts of copper, 2.34 of tin,
1.82 of lead, and 1 of antimony. It can be utilized in the manufacture
of receivers, for which porcelain and ebonite are usually employed.
«Ruoltz Metal.»—This 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 by melting the lead in a stearine bath and
adding successively, and during the cooling, first, the cadmium;
second, the bismuth; third, the tin. It is absolutely necessary to
proceed in this manner, since these metals fuse at temperatures ranging
from 850° F. (for lead), to 551° F. (for tin).
«Fusible Safety Alloys for Steam Boilers.»—
───────+───────+────+────+────────+────────
│ │ │ │ Melting│ Atmos.
│Bismuth│Lead│Zinc│ point │pressure
───────+───────+────+────+────────+────────
I. │ 8 │ 5 │ 3 │ 212° F.│ 1
II. │ 8 │ 8 │ 4 │ 235° F.│ 1.5
III. │ 8 │ 8 │ 3 │ 253° F.│ 2
IV. │ 8 │ 10 │ 8 │ 266° F.│ 2.5
V. │ 8 │ 12 │ 8 │ 270° F.│ 3
VI. │ 8 │ 16 │ 14 │ 280° F.│ 3.5
VII. │ 8 │ 16 │ 12 │ 285° F.│ 4
VIII. │ 8 │ 22 │ 24 │ 309° F.│ 5
IX. │ 8 │ 32 │ 36 │ 320° F.│ 6
X. │ 8 │ 32 │ 28 │ 330° F.│ 7
XI. │ 8 │ 30 │ 24 │ 340° F.│ 8
───────+───────+────+────+────────+────────
«Lipowitz Metal.»—This amalgam is prepared as follows: Melt in a dish,
cadmium, 3 parts, by weight; tin, 4 parts; bismuth, 15 parts; and
lead, 8 parts, adding to the alloy, while still in fusion, 2 parts
of quicksilver previously heated to about 212° F. The amalgamation
proceeds easily and smoothly. The liquid mass in the dish, which
should be taken from the fire immediately upon the introduction of the
mercury, is stirred until the contents solidify. While Lipowitz alloy
softens already at 140° F. and fuses perfectly at 158°, the amalgam has
a still lower fusing point, which lies around 143 3/5° F.
This amalgam is excellently adapted for the production of impressions
of various objects of nature, direct impressions of leaves, and other
delicate parts of plants having been made with its aid which, in point
of sharpness, are equal to the best plaster casts and have a very
pleasing appearance. The amalgam has a silver-white color and a fine
gloss. It is perfectly constant to atmospheric influences. This amalgam
has also been used with good success for the making of small statuettes
and busts, which are hollow and can be readily gilt or bronzed by
electro-deposition. The production of small statues is successfully
carried out by making a hollow gypsum mold of the articles to be cast
and heating the mold evenly to about 140° F. A corresponding quantity
of the molten amalgam is then poured in and the mold moved rapidly to
and fro, so that the alloy is thrown against the sides all over. The
shaking should be continued until it is certain that the amalgam has
solidified. When the mold has cooled off it is taken apart and the
seams removed by means of a sharp knife. If the operation is carried on
correctly, a chasing of the cast mass becomes unnecessary, since the
alloy fills out the finest depressions of the mold with the greatest
sharpness.
«Amalgam for Plaster.»—Tin, 1 part; bismuth, 1 part; mercury, 1 part.
Melt the bismuth and the tin together, and when the two metals are in
fusion add the mercury while stirring. For use, rub up the amalgam with
a little white of egg and brush like a varnish on the plaster articles.
«Plastic Metal Composition.»—I. Copper oxide is reduced by means of
hydrogen or copper sulphate by boiling a solution of the same in water
with some zinc filings in order to obtain entirely pure copper. Of the
copper powder obtained in this manner, 20, 30, or 36 parts, by weight,
according to the degree of hardness desired for the composition (the
greater the quantity of copper used the harder will the composition
become), are thoroughly moistened in a cast-iron or porcelain mortar
with sulphuric acid of 1.85 specific gravity; 70 parts, by weight,
of mercury are then added to this paste, the whole being constantly
stirred. When all the copper has been thoroughly amalgamated with the
mercury, the sulphuric acid is washed out again with boiling water,
and in 12 hours after it has become cold the composition will be
so hard that it can be polished. It is impervious to the action of
dilute acids, alcohol, ether, and boiling water. It contains the same
specific gravity, alike in the soft or the hard condition. When used
as a cement, it can at any time be rendered soft and plastic in the
following manner: If applied while hot and plastic to the deoxidized
surfaces of two pieces of metal, these latter will unite so firmly that
in about 10 or 12 hours the metal may be subjected to any mechanical
process. The properties of this composition render it very useful for
various purposes, and it forms a most effective cement for fine metal
articles which cannot be soldered in fire.
II.—Bismuth, 5.5 parts; lead, 3; tin, 1.5.
III. Alloy d’Homburg.—Bismuth, {66} 3 parts; lead, 3; tin, 3. This
alloy is fusible at 251° F., and is of a silvery white. It is employed
for reproductions of medals.
IV. Alloy Valentine Rose.—Bismuth, 4 to 6 parts; lead, 2 parts; tin, 2
to 3 parts. This alloy fuses at 212° to 250° F.
V. Alloy Rose père.—Bismuth, 2 parts; lead, 2; tin, 2. This alloy fuses
at 199° F.
The remainder are plastic alloys for reproducing cuts, medals, coins,
etc.:
VI.—Bismuth, 4 parts; lead, 2 parts; tin, 1 part.
VII.—Bismuth, 3 parts; lead, 3 parts; tin, 2 parts.
VIII.—Bismuth, 4 parts; lead, 2 parts; tin, 2 parts.
IX.—Bismuth, 5 parts; lead, 2 parts; tin, 3 parts.
X.—Bismuth, 2 parts; lead, 2 parts; tin, 2 parts.
«Quick-Water.»—That the amalgam may easily take hold of bronze objects
and remain there, it is customary to cover the perfectly cleansed
and shining article with a thin coat of mercury, which is usually
accomplished by dipping it into a so-called quick-water bath.
In the form of minute globules the mercury immediately separates itself
from the solution and clings to the bronze object, which thereupon
presents the appearance of being plated with silver. After it has been
well rinsed in clean water, the amalgam may be evenly and without
difficulty applied with the scratch brush.
This quick-water (in reality a solution of mercurous nitrate), is made
in the simplest manner by taking 10 parts of mercury and pouring over
it 11 parts of nitric acid of a specific gravity equal to 1.33; now
let it stand until every part of the mercury is dissolved; then, while
stirring vigorously, add 540 parts of water. This solution must be kept
in closed flasks or bottles to prevent impurities, such as dust, etc.,
from falling into it.
The preparatory work on the object to be gilded consists mainly in
cleansing it from every trace of oxidation. First, it must be well
annealed by placing it in a bed of glowing coal, care being exercised
that the heating be uniform. When cooled, this piece is plunged into a
highly diluted sulphuric-acid bath in order to dissolve in a measure
the oxide. Next it is dipped in a 36° nitric-acid bath, of a specific
gravity equal to 1.33, and brushed off with a long brush; it is now
dipped into nitric acid into which a little lampblack and table salt
have been thrown. It is now ready for washing in clean water and drying
in unsoiled sawdust. It is of the greatest importance that the surface
to be gilded should appear of a pale yellow tint all over. If it be too
smooth the gold will not take hold easily, and if it be too dull it
will require too much gold to cover it.
«GOLD ALLOYS:»
«Colored Gold Alloys.»—The alloys of gold with copper have a reddish
tinge; those of gold with silver are whiter, and an alloy of gold,
silver, and copper together is distinguished by a greenish tone.
Manufacturers of gold ware make use of these different colors, one
piece being frequently composed of several pieces of varying color.
Below are given some of these alloys, with their colors:
──────+──────+──────+──────+─────+───────
│ Gold │Silver│Copper│Steel│Cadmium
──────+──────+──────+──────+─────+───────
I. │ 2.6 │ 1.0 │ — │ — │ —
II. │ 75.0 │ 16.6 │ — │ — │ 8.4
III. │ 74.6 │ 11.4 │ 9.7 │ — │ 4.3
IV. │ 75.0 │ 12.6 │ — │ — │ 12.5
V. │ 1.0 │ 2.0 │ — │ — │ —
VI. │ 4.0 │ 3.0 │ 1.0 │ — │ —
VII. │ 14.7 │ 7.0 │ 6.0 │ — │ —
VIII. │ 14.7 │ 9.0 │ 4.0 │ — │ —
IX. │ 3.0 │ 1.0 │ 1.0 │ — │ —
X. │ 10.0 │ 1.0 │ 4.0 │ — │ —
XI. │ 1.0 │ — │ 1.0 │ — │ —
XII. │ 1.0 │ — │ 2.0 │ — │ —
XIII. │ 30.0 │ 3.0 │ — │ 2.0 │ —
XIV. │ 4.0 │ — │ — │ 1.0 │ —
XV. │ 29.0 │ 11.0 │ — │ — │ —
XVI. │ 1.3 │ — │ — │ 1.0 │ —
──────+──────+──────+──────+─────+───────
Nos. I, II, III, and IV are green gold; No. V is pale yellow; Nos.
VI, VII, and VIII bright yellow; Nos. IX and X pale red; Nos. XI and
XII bright red; Nos. XIII, XIV, and XV gray; while No. XVI exhibits a
bluish tint. The finished gold ware, before being put upon the market,
is subjected to a special treatment, consisting either in the simple
pickling or in the so-called coloring, which operation is conducted
especially with alloys of low degree of fineness, the object being to
give the layers a superficial layer of pure gold.
The presence of silver considerably modifies the color of gold, and the
jeweler makes use of this property to obtain alloys of various shades.
The following proportions are to be observed, viz.: {67}
Gold Silver Copper
Color of Gold per per per
1,000 1,000 1,000
I. Green 750 250 —
II. Dead leaves 700 300 —
III. Sea green 600 400 —
IV. Pink 750 200 50
V. English yellow 750 125 125
VI. English white 750 150 100
VII. Whiter 750 170 80
VIII. Less white 750 190 60
IX. Red 750 — 250
Other colored gold alloys are the following:
X. Blue.—Fine gold, 75; iron, 25.
XI. Dark Gray.—Fine gold, 94; iron, 6.
XII. Pale Gray.—Fine gold, 191; iron, 9.
XIII. Cassel Yellow.—Fine gold, 75; fine silver, 12 1/2; rose copper,
12 1/2.
The above figures are understood to be by weight.
The gold solders, known in France under the names of _soudures au
quart_ (13 1/2 carat), _au tiers_ (12 carat), and _au deux_ (9
carat), are composed of 3, 2, or 1 part of gold respectively, with 1
part of an alloy consisting of two-thirds silver and one-third copper.
Gold also forms with aluminum a series of alloys of greatly varying
coloration, the most curious of them, composed of 22 parts of aluminum
for 88 parts of gold, possessing a pretty purple shade. But all these
alloys, of a highly crystalline base, are very brittle and cannot be
worked, for which reason their handsome colorings have not yet been
capable of being utilized.
«Enameling Alloys.»—I. Transparent.—This alloy should possess the
property of transmitting rays of light so as to give the highest
possible effect to the enamel. The alloy of gold for transparent green
should be pale; a red or copper alloy does not do for green enamel,
the copper has a tendency to darken the color and thus take away a
part of its brilliancy. The following alloy for transparent green
possesses about the nearest print, in color, to the enamel—which
should represent, as near as possible, the color and brilliancy of the
emerald—that can be arrived at:
ozs. dwts. grs.
Fine gold 0 18 8
Fine silver 0 1 6
Fine copper 0 0 10
No borax must be used in the melting of this alloy, it being of a more
fusible nature than the ordinary alloy, and will not take so high a
heat in enameling.
II. Red Enamel.—The enamel which forms this color being of a higher
fusing point, if proper care be not taken, the gold will melt first,
and the work become ruined. In the preparation of red enamel, the
coloring matter is usually an oxide of gold, and this so raises the
temperature at which it melts that, in order to prevent any mishap, the
gold to be enameled on should be what is called a 22-carat red, that
is, it should contain a preponderance of copper in the alloying mixture
so as to raise the fusing point of the gold. The formula is:
ozs. dwts. grs.
Fine gold 0 18 8
Fine silver 0 0 10
Fine copper 0 1 6
«Gold-leaf Alloys.»—All gold made into leaf is more or less alloyed.
The gold used by the goldbeater is alloyed according to the variety
of color required. Fine gold is commonly supposed to be incapable of
being reduced to thin leaves. This, however, is not the case, although
its use for ordinary purposes is undesirable on account of its greater
cost. It also adheres by contact of one leaf with another, thus causing
spoiled material and wasted labor; but for work exposed to the weather
it is much preferable, as it is more durable and does not tarnish or
change color.
The following is a list of the principal classes of leaf recognized
and ordinarily prepared by beaters with the proportion of alloy they
contain:
Gold Silver Copper
grs. grs. grs.
I. Red gold 456–460 — 20–24
II. Pale red 464 — 16
III. Extra deep 456 12 12
IV. Deep 444 24 12
V. Citron 440 30 10
VI. Yellow 408 72 —
VII. Pale yellow 384 96 —
VIII. Lemon 360 120 —
IX. Green or pale 312 168 —
X. White 240 240 —
«Gold-Plate Alloys.»—Gold, 92 parts; copper, 8 parts.
II.—Gold, 84 parts; copper, 16 parts.
III.—Gold, 75 parts; copper, 25 parts.
«IMITATION GOLD.»
I.—One hundred parts, by weight, of copper of the purest quality; 14
of zinc or tin; 6 of magnesia; 3/6 of sal ammoniac, limestone, and
cream of tartar. The copper is first melted, then the magnesia, sal
ammoniac, limestone, and cream of tartar in powder are added separately
and gradually. The whole mass is kept stirred for a half hour, the zinc
or tin being dropped in piece by piece, the {68} stirring being kept up
till they melt. Finally the crucible is covered and the mass is kept
in fusion 35 minutes and, the same being removed, the metal is poured
into molds, and is then ready for use. The alloy thus made is said to
be fine-grained, malleable, takes a high polish, and does not easily
oxidize.
II.—An invention, patented in Germany, covers a metallic alloy, to
take the place of gold, which, even if exposed for some time to the
action of ammoniacal and acid vapors, does not oxidize or lose its gold
color. It can be rolled and worked like gold and has the appearance of
genuine gold without containing the slightest admixture of that metal.
The alloy consists of copper and antimony in the approximate ratio of
100 to 6, and is produced by adding to molten copper, as soon as it has
reached a certain degree of heat, the said percentage of antimony. When
the antimony has likewise melted and entered into intimate union with
the copper, some charcoal ashes, magnesium, and lime spar are added to
the mass when the latter is still in the crucible.
III. Aluminum Gold.—This alloy, called Nuremberg gold, is used for
making cheap gold ware, and is excellent for this purpose, as its color
is exactly that of pure gold, and does not change in the air. Articles
made of Nuremberg gold need no gilding, and retain their color under
the hardest usage; even the fracture of this alloy shows the pure gold
color. The composition is usually 90 parts of copper, 2.5 of gold, and
7.5 of aluminum.
IV.—Imitation gold, capable of being worked and drawn into wire,
consists of 950 parts copper, 45 aluminum, and 2 to 5 of silver.
V.—Chrysochalk is similar in composition to Mannheim gold:
I II
Copper 90.5 58.68
Zinc 7.9 40.22
Lead 1.6 1.90
In color it resembles gold, but quickly loses its beauty if exposed to
the air, on account of the oxidation of the copper. It can, however, be
kept bright for a long time by a coating of colorless varnish, which
excludes the air and prevents oxidation. Chrysochalk is used for most
of the ordinary imitations of gold. Cheap watch chains and jewelry are
manufactured from it, and it is widely used by the manufacturers of
imitation bronze ornaments.
«Mannheim Gold or Similor.»—Mannheim gold is composed of copper, zinc,
and tin, in proportions about as follows:
I II
Copper 83.7 89.8
Zinc 9.3 9.9
Tin 7.0 0.6
It has a fine yellow color, and was formerly much used in making
buttons and pressed articles resembling gold. Later alloys, however,
surpass it in color, and it has fallen somewhat into disuse. One
variety of Mannheim gold, so called, contains 1.40 parts of brass
(composition 3 Cu_〈2〉 1 Zn) to 10 of copper and 0.1 of zinc.
«Mosaic Gold.»—This is an alloy composed—with slight deviations—of 100
parts of copper and 50 to 55 of zinc. It has a beautiful color, closely
resembling that of gold, and is distinguished by a very fine grain,
which makes it especially suitable for the manufacture of castings
which are afterwards to be gilded. The best method of obtaining a
thoroughly homogeneous mixture of the two metals is first to put into
the crucible one-half of the zinc to be used, place the cover upon it,
and fuse the mixture under a cover of borax at as low a temperature as
possible. Have ready the other half of the zinc, cut into small pieces
and heated almost to melting, and when the contents of the crucible are
liquid throw it in, a small portion at a time, stirring constantly to
effect as intimate a mixture of the metals as possible.