Abstract
Deterioration of an electric contact is closely related to phenomena occurring in the microscopic contact spots in the contact interface. Contact spots in idealized aluminum-aluminum contact interfaces, that have passed heavy alternating currents, have been carefully examined by scanning electron microscopy and metallographic imaging techniques. Small cracks are observed in the contact spot regions, and have to a great extent impaired the current-carrying ability of the area. The temperature in the contact spots cycles with twice the power frequency, and in heavily stressed contacts the maximum temperature reaches several hundred degrees centigrade. The associated local thermal expansion and contraction in and around the immediate vicinity of the contact spot generates cyclic mechanical forces of substantial magnitudes. Indications that this repetitive stress causes the observed cracks are found. It is suggested that the resistance increase observed in practical aluminum connectors being subjected to short-circuit currents can have a similar origin
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: IEEE Transactions on Components and Packaging Technologies
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
