Arc erosion reduction on electrical contacts using transverse current injection

Electrical contact lifetime is often directly determined by are erosion, A method for reducing are erosion was developed consisting of injecting from an external current source an additional electrical current flowing parallel to the contact surface, This method was examined in three are environments using the additional transverse electrical current with a density less than 1 A/mm(2): 1) automobile ignition contacts; 2) pulsed air are; and 3) low pressure (P = 100 mTorr) are in nitrogen. SEM and X-ray examination showed that application of a transverse current in a contact during arcing changed the phase composition and microstructure of the contact surface, Under optimal conditions, the microstructure which is formed is significantly more erosion resistant than without the transverse current injection.