All substances added to iron,.according to Kirk, make it more fusible. Lead added in small quantity makes iron soft and tough, but in excess renders it " extreme coldshort." Copper induces "extreme red-short "-ness, and over 1 Per cent. will make the iron "cold-short," but small quantities increase the strength of iron when cold. Arsenic imparts a silvery whiteness, but renders the iron brittle. Tin also whitens iron, and in about equal proportions makes it as hard as steel, but the alloy cannot be forged. The chromium alloy of iron is as hard as bort, but difficult to make. Tungsten "steel, containing 6 to 8 per cent. of the former metal, is excessively hard and tough, but requires much care in manufacture. Silver renders iron hard, brittle, and very liable to corrosion. Gold produces toughness, and a yellow colour; this alloy is used for small iron castings. Carbon increases the fusibility; 1 to 2 per cent. makes hard cast iron, 5 to 6 foundry iron, less than 1 per cent. renders the iron very hard and brittle, and over 6 per cent. causes extreme brittleness. Sulphur causes iron to be both hard and brittle, when either hot or cold, and it makes molten iron "short-lived;" fuel containing sulphur should not be used for melting iron in contact with the fuel.
Phosphorus is very injurious to iron; 1/2 per cent. will cause iron to be very hard and brittle when cold, but it imparts a brilliant and white colour to iron more perfectly than any other metal. Silicon makes iron brittle and hard; it has a similar effect to phosphorus, but it is not so injurious. All cast iron contains more or less carbon, sulphur, phosphorus, and silicon, and, as these substances predominate, they form hard or soft, strong or brittle irons; and as all anthracite coal and coke contain more or less of these substances, anthracite or coke iron is less pure and more variable than charcoal iron, and, on account of the uncertain amount of these impurities contained in cast iron, it is very difficult to make an alloy of iron and other metals with any certainty as to the result: for this reason, alloyed iron is very little used.
Faraday and Stodart made a nickel-iron alloy by adding 3 per cent. of nickel to a good iron, and exposing in a crucible to a high temperature during several hours. The metals were melted; and on examining the button, the nickel was found combined with the iron. The alloy appeared to be as malleable and easily worked as pure iron; its colour was tolerably white when polished; the specific gravity was 7.804. On melting horse-shoe nails with 10 per cent. of nickel, the metals were found perfectly combined, but the alloy was less malleable, and easily broken under the hammer. Polished, it had a yellow tinge; its specific gravity was 7.849. This alloy was affected very slightly by humidity, compared to what would have happened had the iron been pure. According to Berthier, the alloy, consisting of-charcoal, is semi-ductile, very tenacious, and has a granular fracture, slightly lamellar.
Iron.... 0.917 12 at.
Nickel . . 0083 1 „ which is obtained by reducing a mixture of the 2 oxides in a crucible lined with Iron in all states (malleable, cast, and sheet) unites with gold in any proportion by fusion :-3 parts iron and 1 of gold enter into fusion together at a temperature inferior to that necessary for melting iron; equal parts of the 2 metals give, by fusion, a greyish mass, somewhat brittle, and attracted by the magnet; with 6 parts gold and 1 of iron, a white alloy is obtained, which is attracted by the magnet, ductile while cold, and at a moderate heat becomes yellow, red, and blue; 9 of iron and 1 of gold form an alloy which resists the file, unless previously subjected to a red heat; with 28 of iron and 8 of gold, the alloy is as white as pure silver, and more yielding under the fire and hammer than ductile' iron. According to Hatchett, the alloy formed with 11 parts gold and 1 of iron is very ductile, of great resisting power, and harder than gold. Without any preparation, it can readily be cut into blocks, laminated, or struck into medals. This alloy is of a pale yellowish-grey colour, approaching dirty white.
Its specific gravity is 16.885.
Iron combines with tungsten by heating to the proper point, in a crucible, a mixture of 100 parts iron, 50 of the yellow oxide of tungsten, and a sufficient quantity of charcoal. After fusion and cooling, there is found a perfect button of a brownish-white colour, hard, rough to the touch, and of an even fracture. Has-senfratz obtained an alloy of the 2 metals, which forged easily enough, although slightly brittle; it was ductile, cracked in the tempering, and assumed in forging a partially fibrous partially granular texture. Karsten concludes from these experiments, that tungsten (in this respect resembling titanium) only increases the hardness of iron. The alloy, composed of Iron .... 0.63 6 at. Tungsten . . 0.37 1 „ is, according to Berthier, of a whiter grey than iron, shining, hard, more brittle than ordinary cast-iron, and of lamellar structure.
The union of iron and antimony is readily effected by fusion, and it would seem that it may take place in all proportions. These metals have a great affinity for each other. Their alloys are much more fusible than iron, and are white, hard, and very brittle. Their specific gravity is less than the mean of that of the 2 metals. According to Dr. Thompson, this alloy may be obtained by fusing in a crucible 2 parts antimony sulphide and 1 of iron. This alloy was formerly called regulus martialis, used in medicine for the preparation called "Mars' saffron," or " aperient antimony." The magnetic character of iron is much more diminished by its alloy with antimony than by almost any other metal. The iron is also rendered harder, much more fusible, and brittle, like cast-iron. Antimony, in uniting with iron, becomes harder and less fusible. Karsten added to cast-iron, after liquefaction, 1 per cent. of antimony; notwithstanding its volatility, this metal exercised on iron a worse influence than even tin.