Powdered metallurgical process for forming vacuum interrupter contacts
US3960554A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 3, 1974 |
| Grant date | Jun 1, 1976 |
| Priority date | — |
| Expiry date | Jun 3, 1994 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1216
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A powdered metallurgical procedure for forming chromium copper contacts used in vacuum interrupters, wherein by adding a small amount of copper powder to the difficult-to-press chromium powder, superior pressed properties are attained and a resulting chromium compact having higher green strength is produced. By practicing the teaching of this invention, vacuum interrupter contacts can be pressed to complex shapes. It is desirable to have a vacuum interrupter contact having an approximately 50% chromium composition. The low compacting pressure necessary to produce a 40% to 60% chromium powder concentrations yields a compact having a very low green strength which cannot be ejected from a die without falling apart; by adding a small amount of copper powder to the chromium powder before pressing a compact having a much higher green strength, which can be readily handled, is obtained. Using the disclosed process a press to shape contact having a variable density can be attained. This process can be used to produce a desirable chromium compact having a high density on the peripheral areas which decreases to a lower density in the center contact area.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.