Abstract
Electric contacts are the essential components of electric equipment. In the past, the silver-cadmium oxide is used as the materials contacts. However, because it generates the poison cadmium gas during the service, which causes the cancer, the silver-cadmium oxide will be prohibited in the near future. Now the silver-tin oxide is often used as the materials of the electrical contacts. To oxidize pure tin more easily,¡AIn2O3 is usually added as the auxiliary oxide agent. However, In2O3 is expensive. Hence, in this study, the other metal oxide agents are added to the silver-tin oxide to investigate the agent effect on the erosion characteristics (such as the erosion amount, the contact resistance, the arc energy, etc).
This study uses the powder metallurgy to produce the electrical contacts, where the sizes of pure silver powder and tin oxide powder are 2~3£gm and 4~5£gm, respectively. The doping agents are made of 3~4£gm tungsten oxide and 3~5£gm molybdenum oxide, respectively. The powder are mixed in a suitable proportion to produce electrical contacts. The effect of metal oxide on the erosion of electrical contacts is investigated under different electric conditions.
Results show that when the tin oxide powder is added to the pure sil-ver, the splashing of material can be prevented efficiently, and the erosion of electrical contacts can be reduced. Among the materials of silver-tin oxide, the contacts have the minimum erosion at the concen-tration of 5wt%. In order to reduce the cost of electrical con-tacts, the concentration of tin oxide is increased to 10wt% to investigate the influence of the doping agent. Results show that the addition of 0.3wt%WO3 has the minimum erosion. This electrical contact has lower erosion than the commercial ones.
Furthermore, the regions, where the electrical contact has lower erosion than the commercial pure silver contacts and the silver-cadmium oxide, respectively, are established. These re-gions will be the best usable regions of silver tin oxide, and it will be the basis for the choice and the application of silver-tin oxide electrical contacts.
| Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0731103-150630 |
| Date | 31 July 2003 |
| Creators | Shih, Chun-Hao |
| Contributors | Jen-Fin Lin, none, none, Chiou Yuang-Cherng |
| Publisher | NSYSU |
| Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
| Language | Cholon |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0731103-150630 |
| Rights | unrestricted, Copyright information available at source archive |
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