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alloys, manganese

Значение термина alloys, manganese в knolik

alloys, manganese - Alloys, Manganese
alloys, manganese -

Manganesian iron

Manganesian iron is mixed with copper, melted in a reverberatory furnace, and run into pigs. An alloy capable of being rolled is made by melting this together with zinc and copper. For a bronze capable of being forged, protoxide of manganese and protoxide of iron, together with sufficient coal-dust to reduce the two oxides, are added to copper. After melting, the product is similar to aluminium bronze. ('Jl. Soc. Chem. Ind.')

Copper, Tin and Zinc

These alloys are very numerous, and have been given a variety of names, according to the proportions in which the metals composing them are combined; but they may be classified under 3 heads: (1) Those composed of copper and tin (gun-metal); (2) copper, tin, and zinc (bronze); (3) copper and zinc(brass).

To obtain the best effects, the ferro-manganese to be used in the gun-metal alloys should be richer in manganese than that for the brass, while that for the bronze may be between the two, and regulated as conveniently as can be by the proportions of tin and zinc employed: that is to say, if little zinc is used in the bronze alloy, the ferro-manganese employed may be nearly as rich in manganese as in the gun-metal alloys; while if the zinc predominates, the ferro-manganese employed may be a trifle richer in manganese than that used in the brass alloys; and if the zinc and tin are about equal, the quantity of manganese contained in the ferro-manganese may be between that used for the gun-metal and that used for brass alloys. The ferro-manganese used to mix with the gun-metal alloys should contain 10 to 40 per cent, of metallic manganese, while that used to mix with the brass alloys should contain about 5 to 20 per cent.; and that used for the bronze alloys should be between the two, according to the proportions of tin and zinc employed. In selecting the ferro-manganese to be used, it should contain as little silicon as possible; when spiegd-eisen can be obtained of the best quality, containing but a minute quantity of silicon, and 5 to 10 per cent, of manganese, it will be suitable to mix with the brass alloys, and it may even be used with the gun-metal alloys; but it will be found advantageous to apply for both, as well as the bronze, a ferro-manganese made as follows: Procure ferro-manganese (as now manufactured for and used in steel-works) rich in metallic manganese, containing 50 to 60, or even 70 per cent.; melt this in a crucible under powdered charcoal, along with the requisite proportion of the purest wrought-iron scrap, to bring down the quantity of metallic manganese to any of the proportions before named. Supposing it is desired to employ a ferro-manganese, to mix with any of the before-named alloys, containing 20 per cent, of manganese, and a ferro-manganese, containing 60 per cent, of metallic manganese and say 1 per cent, of silicon, is melted with wrought-iron scrap in the proportion of 100 of ferro-manganese to 200 of wrought-iron scrap, a ferro-manganese containing the desired quantity of metallic manganese (20 per cent.) will be obtained, containing only ⅓| per cent, of silicon instead of 1 per cent., and so on for any other proportions required; not only this, but a still further portion of the silicon is eliminated, and the metal is refined by this second melting in a crucible as described. The quantity of ferro-manganese to be employed will vary both with the nature of the alloy and with the quality required in each particular alloy, and this will also, to a certain extent, have to be regulated by the quality of the copper, tin, and zinc employed. The purer these metals, the larger may be the quantity of ferro-manganese employed, and therefore no precise quantities can be specified; but generally, for ordinary gun-metal (composed of about 90 per cent, copper and 10 per cent, tin), ½ to 1½ per cent, ferro-manganese may be added, containing say 20 per cent, metallic manganese; and as the tin is' increased, the ferro-manganese should contain more manganese and less iron.

The quantity of ferro-manganese employed should be regulated according to the purposes for which the alloy is intended to be used; generally the effect produced is with the smaller quantities named to increase the strength of the alloy and the hardness slightly; and as the quantity of ferro-manganese is increased, the hardness is also increased, but at the same time the alloy becomes more brittle. A similar effect is produced by the addition of the ferro-manganese to the brass and bronze alloys. With the brass alloys, ½ to 5 per cent, of the ferro-manganese maybe employed with advantage for general purposes; and for the bronze alloys, any proportions between those for gun-metal and brass alloys may be advantageously used, these proportions being adjusted according to the quantities of tin and zinc used: that is to say, the more tin used, the less should be the quantity of ferro-manganese.

Manganese and Copper

Berthier made several alloys of manganese protoxide and metallic copper in the proportions of 1 to 8, 1 to 4, 1 to 2, and with the manganese slightly in excess of the copper. These alloys were all ductile, the first being perfectly so, while the last, still very ductile, was also very tenacious and capable of taking a fine polish.

Experiments have been made in Paris with a new alloy having a white colour, yet containing no nickel. It is said to be very strong and malleable. It is made of copper and ferro-manganese, the proportions being varied according to the purpose to which the alloy is to be employed. An alloy of 40 parts copper and 60 of ferro-manganese, with a suitable quantity of some appropriate flux, produces a metal of such tenacity that it surpasses the best steel armour-plates. The melted mixture is cast in blocks, and is perfectly malleable. To obtain a white metal that can be rolled out in sheets, the above alloy is melted again, and 20 or 25 per cent, of zinc or white metal added, which imparts to it the desired quality. A plate of the first-named alloy, 2 in. thick, was found by experiment to offer more resistance to a cannon-ball than a steel armour-plate of the same thickness. This new kind of " white bronze " is not to be confounded with the alloy used in America under the same name for gravestones and monuments, and which consists principally of zinc. ('Polyt. Notiz.')

Manganese German silver

"Manganese German silver" was made from 70 copper, 15 manganese, and 15 zinc; but as this alloy proved rather brittle in the rollers, the proportions were altered to 80 copper, 15 manganese, and 5 zinc, when a beautiful white and ductile metal was obtained, which would take a high polish.

Manganese tin and zinc bronzes

Of far greater importance are the "manganese tin and zinc bronzes," which were perhaps among the first upon which experiments were made on a large scale. They were obtained by adding to an alloy of copper, tin, and zinc, a certain quantity of " manganese copper," viz. the combination of 70 copper with 30 manganese as above described, by which an increase of at least 9 per cent, of strength is obtained over the ordinary alloy. This seems to be greatly due, as in the case of the refined tough copper, to a chemical action of the manganese; for all ordinary bronzes contain more or less of copper and tin oxides, which are reduced to metal by the action of the manganese. An addition of manganese seems, however, to have also physically a strengthening effect, and an addition of 3 to 6 per cent, of manganese copper has been experimentally found to suit the purpose best.

Manganese and tin combine as readily as manganese and copper; tin, however, shows, as in ordinary bronzes, a tendency to separate itself in the middle of thick castings from the other alloys, because it remains longest in a fluid condition, and under the process of solidification it seems to get squeezed out of those parts of a casting which retain the heat longest.

An important series of experiments made at Isabelle-Hutte have shown that the strongest "manganese tin bronze" is obtained by alloying 85 copper with 6 tin, 5 zinc, and 5 manganese copper, so that the cooled product retains something above 1 per cent, manganese. The best mode of procedure is first to melt the copper in a crucible, then to add successively tin and zinc, but manganese copper only at the last moment, when the metals are well stirred up with a rod made from gas retort graphite; a reaction upon the oxides of the metallic bath is clearly noticed, as it begins to boil and to emit sparks after the addition of manganese, of which a portion is carried into the slag. See table of trials made with a series of rough ingots of the metal.

The absolute strength of these alloys is considerably enhanced when the ingots are subjected to judicious forging or rolling.

Delatot's white metal

Delatot's white metal is composed of 80 parts red copper, 2 manganese oxide, 18 zinc, 1 lime phosphate, fused together. To the melted copper is added the manganese in very small instalments; when this is dissolved, the lime phosphate is similarly introduced, and after the reduction has lasted ½ hour, the scum is removed from the surface of the bath, and the zinc is added about 10 minutes before running out. This alloy is said to equal gun-metal in tenacity and resistance, excel it in obviating friction, and cost much less. The fusion of the manganese oxide may be hastened by using a flux composed of 2 parts charcoal, 1 calcium fluoride, 1 sodium borate.

No	Cast in	Copper	Tin	Zinc	Manganese Copper	Breaking Strength, tons per sq.in.	Limit of Elasticity, tons per sq.in.	Elongation per cent
1	sand	85	6	5	..	10.3	7.24	..
2	sand	85	6	5	4	10.34	8.4	2
3	iron	87	8.7	4.3	4	12.51	..	..
4	iron	85	6.9	5	6	12.13	..	6
5	iron	85	6	5	6	12.7	..	7
6	iron	85	6	5	10	11.05	..	5
7	sand	87	5.20	4.33	3.47	12.63	..	8.7
8	sand	87	5.20	4.33	3.47	12.7	..	8.9
9	sand	85	6	5	3	14.09	10.8
10	sand	74	10	5 (7.66 lead)	3.3	12.06	8.9	..
11	sand	78.7	8	(8 lead)	3.3	13.33	8.9	..
12	sand	82	9.8	4.9	3.3	12.7	9.5	..
13	sand	86.2	16.5	..	3.3	15.87	9.2	..

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