Material optimization for high electric current, high speed applications
Abstract
Studies of electrical contacts carrying high currents have been carried out at speeds in the range 1.5 to 13 m/sec, and current densities in the range 1 to 3 amp/sq mm. As regards the wear of graphite brushes, it was shown that the wear rates were low when the ring metals were metallurgically incompatible with graphite. When silver-graphite brushes were used, low wear was associated with ring materials that were compatible both with silver and with carbon. An expression was developed for the temperature rise at the interface between sliding electrical contacts. This equation was tested indirectly using wear measurements and directly using a thermocouple technique. The agreement between theory and practice was reasonable, but more work is needed to define one key variable, namely the number of junctions formed at any one time.
- Publication:
-
Massachusetts Inst. of Tech. Report
- Pub Date:
- September 1982
- Bibcode:
- 1982mit..rept.....R
- Keywords:
-
- Electric Contacts;
- Electric Current;
- Graphite;
- Optimization;
- Sliding Friction;
- Compatibility;
- Current Density;
- Electrical Resistivity;
- Gold;
- High Speed;
- Silver;
- Thermocouples;
- Wear;
- Electronics and Electrical Engineering