Method of preparing an electrical contact material, and a method of manufacturing a contact element incorporating such a material
US4971754A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1989 |
| Grant date | Nov 20, 1990 |
| Priority date | — |
| Expiry date | Nov 22, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB22F2998/10
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
The method concerns preparing a contact material constituted by silver and tin oxide. According to the invention the method comprises the following steps: PA1 preparing an aqueous solution containing dissolved silver nitrate and tin oxide particles in suspension, with the size of said particles measured in terms of specific surface area using the BET method lying between about 2 m.sup.2 /g and 6 m.sup.2 /g; PA1 causing silver nitrate to precipitate in silver hydroxide by rapidly adding a strong base and stirring, with silver hydroxide being unstable and transforming progressively into silver oxide; PA1 eliminating the ions from the solution and then the water in order to obtain a dry product; and PA1 heating the dry product to a temperature of about 200.degree. C. to 500.degree. C. in order to reduce the silver oxide to metallic silver. PA1 The invention is applicable to manufacturing electrical contacts for opening and closing in electromechanical apparatuses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.