| Copper | 85.00 |
| Manganese | 6.00 |
| Zinc | 5.00 |
5 per cent. of cupro-manganese = manganese 1.00 remaining in the metal.
The best method of procedure is first to melt the copper in a crucible, and then to add the tin and the zinc; finally the cupro-manganese is added just at the moment of pouring, as in the Manhès process; then the reaction on the oxides is very effective, there is a boiling with scintillation similar to the action produced in the Bessemer and Martin process when ferro-manganese is added to the bath of steel.
The following are some of the results obtained from thirteen alloys obtained in this manner. These samples were taken direct from the casting and were tested with the machine at Friedrich-Wilhelms-hütte, and with the one at the shops of the Rhine Railroad. Their resistance was considerably increased, as with the other alloys, by rolling or hammering.
| Numbers. | Nature of mould. | Copper | Tin. | Zinc. | Cupro- manganese. | Limit of elasticity in kilos per mm. | Weight of fracture in kilos per mm. | Elongation, percentage. |
|---|---|---|---|---|---|---|---|---|
| 1 | Sand | 85.00 | 6.00 | 5.00 | — | 11.30 | 16.00 | — |
| 2 | — | 85.00 | 6.00 | 5.00 | 4.00 | 13.00 | 16.10 | 2.00 |
| 3 | Cast. | 87.00 | 8.70 | 4.30 | 4.00 | — | 19.40 | — |
| 4 | — | 85.00 | 6.90 | 5.00 | 6.00 | — | 18.80 | 6.00 |
| 5 | — | 85.00 | 6.00 | 5.00 | 6.00 | — | 19.75 | 7.00 |
| 6 | — | 85.00 | 6.00 | 5.00 | 10.00 | — | 17.15 | 4.00 |
| 7 | Sand | 87.00 | 5.20 | 4.33 | 3.47 | — | 19.70 | 8.70 |
| 8 | — | 87.00 | 5.20 | 4.33 | 3.47 | — | 19.70 | 8.90 |
| 9 | — | 85.00 | 6.00 | 5.00 | 3.00 | 16.80 | 22.00 | — |
| 10 | — | 74.00 | 10.00 | 5.00 | 3.30 | 13.80 | 18.70 | — |
| 11 | — | 78.70 | 8.00 | (7.66 Pb) ( 8 Pb) | 3.30 | 13.80 | 20.70 | — |
| 12 | — | 82.00 | 9.80 | 4.90 | 3.30 | 14.75 | 19.75 | — |
| 13 | — | 86.20 | 16.50 | — | 3.30 | 14.30 | 24.70 | — |
The results of the tests of ductility which are here given, with reference to the cupro-manganese, manganese bronze, the alloys with zinc and tin, are taken from M.C. Hensler's very valuable communication to the Berlin Society for the Advancement of the Industrial Arts.
These various alloys, as well as the phosphorus bronze, of which we make no mention here, are at present very largely used in the manufacture of technical machines, as well as for supports, valves, stuffing-boxes, screws, bolts, etc., which require the properties of resistance and durability. They vastly surpass in these qualities the brass and like compounds which have been used hitherto for these purposes.—Bull. Soc. Chim., Paris, xxxvi. p. 184.
See Engineering, May 27, 1881