Part 14

«Arsenic.»—Alloys which contain small quantities of arsenic are very ductile, have a beautiful white color, and were formerly used in England in the manufacture of tableware. They are not, however, suitable for this purpose, on account of the poisonous character of the arsenic. They are composed usually of 49 parts of silver, 49 of copper, and 2 of arsenic.

«China Silver.»—Copper, 65.24 per cent; tin, 19.52 per cent; nickel, 13.00 per cent; silver, 2.05 per cent.

«Copper-Silver.»—When silver is alloyed with copper only one proportion is known which will give a uniform casting. The proportion is 72 per cent silver to 28 per cent copper. With more silver than 72 per cent the center of a cast bar will be {76} richer than the outside, which chills first; while with a less percentage than 72 per cent the center of the bar will be poorer and the outside richer than the average. This characteristic of silver-copper alloys is known to metallurgists as “segregation.”

When nickel is added to the silver and copper, several good alloys may be formed, as the following French compositions:

I II III Silver 33 40 20 Copper 37–42 30–40 45–55 Nickel 25–30 20–30 25–35

The whitening of alloys of silver and copper is best accomplished by annealing the alloy until it turns black on the surface. Cool in a mixture of 20 parts, by weight, of concentrated sulphuric acid to 1,000 parts of distilled water and leave therein for some time. In place of the sulphuric acid, 40 parts of potassium bisulphate may be used per 1,000 parts of liquid. Repeat the process if necessary.

«Copper, Silver, and Cadmium Alloys.»—Cadmium added to silver alloys gives great flexibility and ductility, without affecting the white color; these properties are valuable in the manufacture of silver-plated ware and wire. The proportions of the metals vary in these alloys. Some of the most important varieties are given below.

Silver Copper Cadmium I. 980 15 5 II. 950 15 35 III. 900 18 82 IV. 860 20 180 V. 666 25 309 VI. 667 50 284 VII. 500 50 450

In preparing these alloys, the great volatility of cadmium must be taken into account. It is customary to prepare first the alloy of silver and copper, and add the cadmium, which, as in the case of the alloys of silver and zinc, must be wrapped in paper. After putting it in, the mass is quickly stirred, and the alloy poured immediately into the molds. This is the surest way to prevent the volatilization of the cadmium.

«Silver, Copper, Nickel, and Zinc Alloys.»—These alloys, from the metals contained in them, may be characterized as argentan or German silver with a certain percentage of silver. They have been used for making small coins, as in the older coins of Switzerland. Being quite hard, they have the advantage of wearing well, but soon lose their beautiful white color and take on a disagreeable shade of yellow, like poor brass. The silver contained in them can be regained only by a laborious process, which is a great drawback to their use in coinage. The composition of the Swiss fractional coins is as follows:

20 centimes 10 centimes 5 centimes Silver 15 10 5 Copper 50 55 60 Nickel 25 25 25 Zinc 10 10 10

«Mousset’s Alloy.»—Copper, 59.06; silver, 27.56; zinc, 9.57; nickel, 3.42. This alloy is yellowish with a reddish tinge, but white on the fractured surface. It ranks next after Argent-Ruolz, which also contains sometimes certain quantities of zinc, and in this case may be classed together with the alloy just described. The following alloys can be rolled into sheet or drawn into wire:

I II III Silver 33.3 34 40.0 Copper 41.8 42 44.6 Nickel 8.6 8 4.6 Zinc 16.3 16 10.8

«Japanese (Gray) Silver.»—An alloy is prepared in Japan which consists of equal parts of copper and silver, and which is given a beautiful gray color by boiling in a solution of alum, to which copper sulphate and verdigris are added. The so-called “mokum,” also a Japanese alloy, is prepared by placing thin plates of gold, silver, copper, and the alloy just described over each other and stretching them under the hammer. The cross sections of the thin plates obtained in this way show the colors of the different metals, which give them a peculiar striped appearance. Mokum is principally used for decorations upon gold and silver articles.

«Silver-Zinc.»—Silver and zinc have great affinity for each other, and alloys of these two metals are therefore easily made. The required quantity of zinc, wrapped in paper, is thrown into the melted and strongly heated silver, the mass is thoroughly stirred with an iron rod, and at once poured out into molds. Alloys of silver and zinc can be obtained which are both ductile and flexible. An alloy consisting of 2 parts of zinc and 1 of silver closely resembles silver in color, and is quite ductile. With a larger proportion of zinc the alloy becomes brittle. In preparing the alloy, a somewhat larger quantity of zinc must be taken than the {77} finished alloy is intended to contain, as a small amount always volatilizes.

«Imitation Silver Alloys.»—There are a number of alloys, composed of different metals, which resemble silver, and may be briefly mentioned here.

I.—Warne’s metal is composed of tin 10 parts, bismuth 7, and cobalt 3. It is white, fine-grained, but quite difficult to fuse.

II.—Tonca’s metal contains copper 5 parts, nickel 4, tin 1, lead 1, iron 1, zinc 1, antimony 1. It is hard, difficult to fuse, not very ductile, and cannot be recommended.

III.—Trabuk metal contains tin 87.5, nickel 5.5, antimony 5, bismuth 5.

IV.—Tourun-Leonard’s metal is composed of 500 parts of tin and 64 of bell metal.

V.—Silveroid is an alloy of copper, nickel, tin, zinc, and lead.

VI.—Minargent. Copper, 100 parts; nickel, 70 parts; tungsten, 5 parts; aluminum, 1 part.

VII.—Nickel, 23 parts; aluminum, 5 parts; copper, 5 parts; iron, 65 parts; tungsten, 4 parts.

VIII.—Argasoid. Tin, 4.035; lead, 3.544; copper, 55.780; nickel, 13.406; zinc, 23.198; iron, trace.

SOLDERS: See Solders.

«STEEL ALLOYS: See also Steel.»

«For Locomotive Cylinders.»—This mixture consists of 20 per cent steel castings, old steel springs, etc.; 20 per cent No. 2 coke iron, and 60 per cent scrap. From this it is stated a good solid metal can be obtained, the castings being free from honeycombing, and finishing better than the ordinary cast-iron mixture, over which it has the advantage of 24 per cent greater strength. Its constituents are: Silicon, 1.51; manganese, 0.33; phosphorus, 0.65; sulphur, 0.068; combined carbon, 0.62; graphite, 2.45.

Nickel steel is composed of nickel 36 per cent, steel 64 per cent.

Tungsten steel is crucible steel with 5 to 12 per cent tungsten.

«STEREOTYPE METAL.»

Lead 2 parts Tin 3 parts Bismuth 5 parts

The melting point of this alloy is 196° F. The alloy is rather costly because of the amount of bismuth which it contains. The following mixtures are cheaper:

I II III IV Tin 1 3 1 2 Lead 1 5 1.5 2 Bismuth 2 8 3 5 Antimony — — — 1

«TIN ALLOYS:»

«Alloys for Dentists’ Molds and Dies.»—I.—Very hard. Tin, 16 parts; antimony, 1 part; zinc, 1 part.

II.—Softer than the former. Tin, 8 parts; zinc, 1 part; antimony, 1 part.

III.—Very hard. Tin, 12 parts; antimony, 2 parts; copper, 1 part.

«Cadmium Alloy, about the Hardness of Zinc.»—Tin, 10 parts; antimony, 1 part; cadmium, 1 part.

«Tin-Lead.»—Tin is one of those metals which is not at all susceptible to the action of acids, while lead, on the other hand, is very easily attacked by them. In such alloys, consequently, used for cooking utensils, the amount of lead must be limited, and should properly not exceed 10 or 15 per cent; but cases have been known in which the so-called tin contained a third part, by weight, of lead.

Alloys containing from 10 to 15 per cent of lead have a beautiful white color, are considerably harder than pure tin, and much cheaper. Many alloys of tin and lead are very lustrous, and are used for stage jewelry and mirrors for reflecting the light of lamps, etc. An especially brilliant alloy is called “Fahlun brilliants.” It is used for stage jewelry, and consists of 29 parts of tin and 19 of lead. It is poured into molds faceted in the same way as diamonds, and when seen by artificial light, the effect is that of diamonds. Other alloys of tin and lead are employed in the manufacture of toys. These must fill the molds well, and must also be cheap, and therefore as much as 50 per cent of lead is used. Toys can also be made from type metal, which is even cheaper than the alloys of tin and lead, but has the disadvantage of readily breaking if the articles are sharply bent. The alloys of tin and lead give very good castings, if sharp iron or brass molds are used.

Lead 19 parts Tin 29 parts

This alloy is very bright and possesses a permanent sheen. It is well adapted for the making of artificial gems for stage use. It is customary in carrying out the process to start with two parts of tin and one part of lead. Tin is added until a sample drop which is allowed to fall upon an iron plate forms a mirror. The artificial gems are produced by {78} dipping into the molten alloy pieces of glass cut to the proper shape. The tin coating of metal which adheres to the glass cools rapidly and adheres tenaciously. Outwardly these artificial gems appear rough and gray, but inwardly they are highly reflective and quite deceptive when seen in artificial light.

If the reflective surfaces be coated with red, blue, or green aniline, various colored effects can be obtained. Instead of fragile glass the gems may be produced by means of well-polished pieces of steel or bronze.

«Other Tin-Lead Alloys.»—Percentage of lead and specific gravity.

P. C. S. G. 0 7.290 1 7.316 2 7.342 3 7.369 4 7.396 5 7.423 6 7.450 7 7.477 8 7.505 9 7.533 10 7.562 11 7.590 12 7.619 13 7.648 14 7.677 15 7.706 16 7.735 17 7.764 18 7.794 19 7.824 20 7.854 21 7.885 22 7.916 23 7.947 24 7.978 25 8.009 26 8.041 27 8.073 28 8.105 29 8.137 30 8.169 31 8.202 32 8.235 33 8.268 34 8.302 35 8.336 36 8.379 37 8.405 38 8.440 39 8.476 40 8.512 41 8.548 42 8.584 43 8.621 44 8.658 45 8.695 46 8.732 47 8.770 48 8.808 49 8.846 50 8.884 60 9.299 70 9.736 80 10.225 90 10.767 100 11.370

«Tin Statuettes, Buttons, etc.»—

I.—Tin 4 parts Lead 3 parts

This is a very soft solder which sharply reproduces all details.

Another easily fusible alloy but somewhat harder, is the following:

II.—Tin. 8 parts Lead 6 parts Antimony 0.5 part

«Miscellaneous Tin Alloys.»—I.—Alger Metal.—Tin, 90 parts; antimony, 10 parts. This alloy is suitable as a protector.

II. Argentine Metal.—Tin, 85.5 per cent; antimony, 14.5 per cent.

III.—Ashberry metal is composed of 78 to 82 parts of tin, 16 to 20 of antimony, 2 to 3 of copper.

IV. Quen’s Metal.—Tin, 9 parts; lead, 1 part; antimony, 1 part; bismuth, 1 part.

«Type Metal.»—An alloy which is to serve for type metal must be readily cast, fill out the molds sharply, and be as hard as possible. It is difficult to satisfy all these requirements, but an alloy of antimony and lead answers the purpose best. At the present day there are a great many formulas for type metal in which other metals besides lead and antimony are used, either to make the alloy more readily fusible, as in the case of additions of bismuth, or to give it greater power of resistance, the latter being of especial importance for types that are subjected to constant use. Copper and iron have been recommended for this purpose, but the fusibility of the alloys is greatly impaired by these, and the manufacture of the types is consequently more difficult than with an alloy of lead and antimony alone. In the following table some alloys suitable for casting type are given:

Lead Antimony Copper Bismuth Zinc Tin Nickel I 3 1 — — — — — II 5 1 — — — — — III 10 1 — — — — — IV 10 2 — 1 — — — V 70 18 2 — — 10 — VI 60 20 — — — 20 — VII 55 25 — — — 20 — VIII 55 30 — — — 15 — IX 100 30 8 2 — 20 8 X 6 — 4 — 90 — —

The French and English types contain a certain amount of tin, as shown by the following analyses:

English Types French Types I II III Lead 69.2 61.3 55.0 55 Antimony 19.5 18.8 22.7 30 Tin 9.1 20.2 22.1 15 Copper 1.7 — — —

Ledebur gives the composition of type metal as follows:

I II III IV Lead 75 60 80 82 Antimony 23 25 20 14.8 Tin 22 15 — 3.2

WATCHMAKERS’ ALLOYS: See Watchmakers’ Formulas.

«WHITE METALS.»

The so-called white metals are employed almost exclusively for bearings. (See Anti-friction Metals under Alloys.) In the technology of mechanics an accurate distinction is made between the different kinds of metals for bearings; and they may be classed in two groups, red brass and white metal. The {79} red-brass bearings are characterized by great hardness and power of resistance, and are principally used for bearings of heavily loaded and rapidly revolving axles. For the axles of large and heavy flywheels, revolving at great speed, bearings of red brass are preferable to white metal, though more expensive.

In recent years many machinists have found it advantageous to substitute for the soft alloys generally in use for bearings a metal almost as hard as the axle itself. Phosphor bronze (q. v.) is frequently employed for this purpose, as it can easily be made as hard as wrought or cast steel. In this case the metal is used in a thin layer, and serves only, as it were, to fill out the small interstices caused by wear on the axle and bearing, the latter being usually made of some rather easily fusible alloy of lead and tin. Such bearings are very durable, but expensive, and can only be used for large machines. For small machines, running gently and uniformly, white-metal bearings are preferred, and do excellent work, if the axle is not too heavily loaded. For axles which have a high rate of revolution, bearings made of quite hard metals are chosen, and with proper care—which, indeed, must be given to bearings of any material—they will last for a long time without needing repair.

WHITE METAL FOR BEARING. ──────+───────────────────────+──────+────────+──────+──────+──────+────── │ │ Tin │Antimony│ Zinc │ Iron │ Lead │Copper ──────+───────────────────────+──────+────────+──────+──────+──────+────── I │German, light loads │ 85.00│ 10.00 │ — — │ — — │ — — │ 5.00 II │German, light loads │ 82.00│ 11.00 │ — — │ — — │ — — │ 7.00 III │German, light loads │ 80.00│ 12.00 │ — — │ — — │ — — │ 8.00 IV │German, light loads │ 76.00│ 17.00 │ — — │ — — │ — — │ 7.00 V │German, light loads │ 3.00│ 1.00 │ 5.00│ — — │ 3.00│ 1.00 VI │German, heavy loads │ 90.00│ 8.00 │ — — │ — — │ — — │ 2.00 VII │German, heavy loads │ 86.81│ 7.62 │ — — │ — — │ — — │ 5.57 VIII │English, heavy loads │ 17.47│ — — │ 76.14│ — — │ — — │ 5.62 IX │English, medium loads │ 76.70│ 15.50 │ — — │ — — │ — — │ 7.80 X │English, medium loads │ 72.00│ 26.00 │ — — │ — — │ — — │ 2.00 XI │For mills │ 15.00│ — — │ 40.00│ — — │ 42.00│ 3.00 XII │For mills │ — — │ 1.00 │ 5.00│ — — │ 5.00│ — — XIII │For mills │ — — │ 1.00 │ 10.00│ — — │ 2.00│ — — XIV │Heavy axles │ 72.70│ 18.20 │ — — │ — — │ — — │ 9.10 XV │Heavy axles │ 38.00│ 6.00 │ 47.00│ — — │ 4.00│ 1.00 XVI │Rapidly revolving axles│ 17.00│ 77.00 │ — — │ — — │ — — │ 6.00 XVII │Very hard metal │ 55.00│ — — │ — — │ 70.00│ — — │ 2.50 XVIII │Very hard metal │ 12.00│ 82.00 │ 2.00│ — — │ — — │ 4.00 XIX │Cheap metal │ 2.00│ 2.00 │ 88.00│ — — │ — — │ 8.00 XX │Cheap metal │ 1.50│ 1.50 │ 90.00│ — — │ — — │ 7.00 ──────+───────────────────────+──────+────────+──────+──────+──────+──────

Other white bearing metals are:

XXI.—Tin, 8.5; antimony, 10; copper, 5 parts.

XXII.—Tin, 42; antimony, 16; lead, 42 parts.

XXIII.—Tin, 72; antimony, 26; copper, 2 parts.

XXIV.—Tin, 81; antimony, 12.5; copper, 6.5 parts.

«White Metals Based on Copper.»—

I.—Copper, 65 parts; arsenic, 55 parts.

II.—Copper, 64 parts; arsenic, 50 parts.

III.—Copper, 10 parts; zinc, 20 parts; nickel, 30 parts.

IV.—Nickel, 70 parts; copper, 30 parts; zinc, 20 parts.

V.—Nickel, 60 parts; copper, 30 parts; zinc, 30 parts.

VI.—Copper, 8 parts; nickel, 4 parts; zinc, 4 parts.

VII.—Copper, 10 parts; nickel, 5 parts; zinc, 5 parts.

VIII.—Copper, 8 parts; nickel, 3 parts; zinc, 4 parts.

IX.—Copper, 50 parts; nickel, 25 parts; zinc, 25 parts.

X.—Copper, 55 parts; nickel, 24 parts; zinc, 21 parts.

XI.—Copper, 55 parts; nickel, 24 parts; zinc, 16 parts; iron, 2 parts; tin, 3 parts.

IX, X, and XI are suitable for tableware.

XII.—Copper, 67 parts, and arsenic, 53 parts.

XIII.—Copper, 63 parts, and arsenic, 57 parts.

XII and XIII are bright gray, unaffected by the temperature of boiling water; they are fusible at red heat.

«White Metals Based on Platinum.»—

I.—Platinum, 1 part; copper, 4 parts; or platinum, 1 1⁠/⁠2 parts; copper, 3 1⁠/⁠2 parts.

II.—Platinum, 10 parts; tin, 90 parts; or platinum, 8 parts; tin, 92 parts.

III.—Platinum, 7 parts; copper, 13 parts; tin, 80 parts.

IV.—Platinum, 2 parts; steel, 98 parts.

V.—Platinum, 2.5 parts; steel, 97.5 parts.

IV and V are for gun metal.

«Miscellaneous White-Metal Alloys.»—

I.—For lining cross-head slides: Lead, 65 parts; antimony, 25 parts; copper, 10 parts. Some object to white metal containing lead or zinc. It has been found, however, that lead and zinc have properties of great use in these alloys.

II.—Tin, 85 parts; antimony, 7 1⁠/⁠2 parts; copper, 7 1⁠/⁠2 parts.

III.—Tin, 90 parts; copper, 3 parts; antimony, 7 parts. {80}

«ZINC ALLOYS:»

«Bidery Metal.»—This is sometimes composed of 31 parts of zinc, 2 parts of copper, and 2 parts of lead; the whole is melted on a layer of rosin or wax to avoid oxidation. This metal is very resistive; it does not oxidize in air or moisture. It takes its name from the town of Bider, near Hyderabad (India), where it was prepared for the first time industrially for the manufacture of different utensils.

Other compositions of Indian Bidery metal (frequently imitated in England) are about as follows:

P.C. P.C. P.C. Copper 3.5 11.4 16 Zinc 93.4 84.3 112 Tin — 1.4 2 Lead 3.1 2.9 4

Erhardt recommends the following as being both ductile and hard:

Zinc 89 to 93 Tin 9 to 6 Lead 2 to 4 Copper 2 to 4

The tin is first melted, and the lead, zinc, and copper added successively.

«Zinc-Nickel.»—Zinc, 90 parts; nickel, 10 parts. Used in powder form for painting and cloth printing purposes.

«Platine for Dress Buttons.»—Copper, 43 parts; zinc, 57 parts.

«UNCLASSIFIED ALLOYS:»

«Alloys for Drawing Colors on Steel.»—Alloys of various composition are successfully used for drawing colors on steel. To draw to a straw color use 2 parts of lead and 1 part of tin, and melt in an iron ladle. Hold the steel piece to be drawn in the alloy as it melts and it will turn to straw color. This mixture melts at a temperature of about 437° F. For darker yellow use 9 parts of lead to 4 parts of tin, which melts at 458° F. For purple, use 3 parts of lead to 1 part of tin, the melting temperature being 482° F. For violet, use 9 parts of lead to 2 parts of tin, which melts at 494° F. Lead without any alloy will draw steel to a dark blue. The above apply to steel only since iron requires a somewhat greater heat and is more or less uncertain in handling.

«Alloy for Pattern Letters and Figures.»—A good alloy for casting pattern letters and figures and similar small parts of brass, iron, or plaster molds, is made of lead 80 parts, and antimony 20 parts. A better alloy will be lead 70 parts, antimony and bismuth each 15 parts. To insure perfect work the molds should be quite hot by placing them over a Bunsen burner.

«Alloy for Caliper and Gage-Rod Castings.»—A mixture of 30 parts zinc to 70 parts aluminum gives a light and durable alloy for gage rods and caliper legs; the gage rods must be steel tipped, for the alloy is soft and wears away too rapidly for gage points.

«Alloys for Small Casting Molds.»—Tin, 75 parts, and lead, 22 parts; or 75 parts of zinc and 25 parts of tin; or 30 parts of tin and 70 parts of lead; or 60 parts of lead and 40 parts of bismuth.

ALLOYS FOR METAL FOIL: See Metal Foil.

ALMOND COLD CREAM: See Cosmetics.

ALMOND LIQUEURS: See Wines and Liquors.

ALTARS, TO CLEAN: See Cleaning Preparations and Methods.

«ALUM:»

«Burnt Alum.»—I.—Heat the alum in a porcelain dish or other suitable vessel till it liquefies, then raise and continue the heat, not allowing it to exceed 400°, till aqueous vapor ceases to be disengaged, and the salt has lost 47 per cent of its weight. Reduce the residue to powder, and preserve it in a well-stoppered bottle.—_Cooley._

II.—Heat ordinary alum (alumina alum) with constant stirring in an iron pan in which it will first melt quietly, and then commence to form blisters. Continue heating until a dry white mass of a loose character remains, which is powdered and kept in well-closed glasses.

ALUM BATH: See Photography.

«Aluminum and its Treatment»

«HOW TO COLOR ALUMINUM:»

«Blanching of Aluminum.»—Aluminum is one of the metals most inalterable by air; nevertheless, the objects of aluminum tarnish quickly enough without being {81} altered. They may be restored to their mat whiteness in the following manner: Immerse the aluminum articles in a boiling bath of caustic potash; next plunge them quickly into nitric acid, rinse and let dry. It must be understood that this method is applicable only to pieces entirely of aluminum.

«Decolorized Aluminum.»—Gray or unsightly aluminum may be restored to its white color by washing with a mixture of 30 parts of borax dissolved in 1,000 parts of water, with a few drops of ammonia added.

«Mat Aluminum.»—In order to impart to aluminum the appearance of mat silver, plunge the article into a hot bath composed of a 10-per-cent solution of caustic soda saturated with kitchen salt. Leave it in the bath for 15 to 20 seconds, then wash and brush; put back into the bath for half a minute, wash anew and dry in sawdust.