Читать книгу Henley's Formulas, Recipes and Processes (Applied Chemistry) - Various - Страница 292
Zinc Alloys: Bidery Metal.
Оглавление—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.
