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Phosphor-bronze

This bronze, according to the purposes for which it is intended, contains from 3 to 15 parts tin to 100 copper, with an addition of from 1/4 to 2 1/2 per cent of phosphorus. This alloy can be remelted any number of times without altering its quality, which is as fine as cast steel, and may be made as hard as that metal or as tough as wrought iron; in fact, it can be made to any degree of hardness, toughness, or elasticity. It is somewhat difficult to introduce the phosphorus into the crucible, and very much of it is lost in the operation. for which allowance must be made. The action of phosphorus on bronze alloy is to drive out the oxides, and cause the tin to adopt a crystalline structure, which gives the alloy a higher degree of homogeneousness than in common bronze. Another important feature is that any degree of hardness may be obtained by increasing the quantity of phosphorus, exclusive of any further addition of tin, the latter metal being sure to separate when used in too large proportions. The more advanced method of introducing the phosphorus is by adding phosphor copper, or phosphor tin, specially prepared for the purpose. See PHOSPHOR-COPPER; PHOSPHOR-TIN; BRONZE; COPPER.

Phosphor-copper is made by lining a crucible with a mixture composed of bone-ash, 18, silica 14, and powdered carbon 4, which is made into a daubing or lining by adding glue-water containing 4 parts each of powdered glass and carbonate of soda. Granulated copper is charged after the lining has been thoroughly dried, and covered with some of the lining mixture; after which the lid is luted on and the copper melted, when it will be found to contain about 0.52 per cent of phosphorus. The silicic acid acts on the phosphate, the phosphoric acid is reduced, and taken up as freed by the copper. Another phosphor copper, containing about 9 per cent of phosphorus, can be produced by first making a phosphorous mass by mixing superphosphate of lime with 20 per cent of charcoal and dehydrating the mixture at a dull-red heat. Six hundred parts of this mass are mixed with 975 of copper turnings and 75 of charcoal, and kept at copper-fusion heat for sixteen hours in a graphite crucible. The phosphor copper is obtained in the form of detached granules, which are picked out, re-fused, and cast into cast-iron ingot-moulds. The introduction of phosphorus into the metal is better effected by means of these rich phosphor coppers than by any of the methods adopted for pushing it under the metal in a crude state. See PHOSPHOR-BRONZE.

Phosphor-tin is a phosphide of tin used as a medium for introducing phosphorus into bronze alloys, and sometimes used in conjunction with phosphor-copper for that purpose. It is made by heating 6 parts of phosphorus with 94 parts of moist tin-sponge prepared from the chloride by reduction with zinc. The sticks of phosphorus are first placed in the crucible and the tin sponge pressed hard down. A gentle heat is sufficient for this operation, which ends when the burning phosphorus ceases to give forth flame, and a coarse, white, crystalline substance has formed, which is the phosphor-tin. See PHOSPHOR-BRONZE.

Phosphorus is one of the non-metallic elements, and is found in nature only in combination--chiefly as the phosphate of lime. It would appear that plants require it, as more or less is found concentrated in their seeds. The bodies of animals contain it in a large degree, being present in the nervous tissues, the urine, the blood, the hair, and in the bones, which contain a large proportion of the phosphate of lime. The earthy phosphates are important, as they aid in giving stiffness and inflexibility to the bony skeleton. Phosphorus was discovered in urine by Brandt of Hamburg, 1669. It is chiefly made from bones; when pure it appears like bleached wax, and is soft and flexible at common temperatures, melts at 44 deg. and boils at 289 deg. Phosphorus, in its combining relation, is more closely connected with the metals arsenic and antimony than with any of the members of the sulphur group, in which it is commonly placed. See ARSENIC; ANTIMONY; PHOSPHOR-BRONZE.