NDLI: Effect of Current Crowding on Microstructural Evolution at Rail-Armature Contacts in Railguns

Content Provider	IEEE Xplore Digital Library
Author	Chen, T. Long, X. Dutta, I. Persad, C.
Copyright Year	1965
Abstract	During firing of a railgun, the armature typically undergoes melting at the rail-armature contact and deposits melt on the rail, thereby reducing rail life. This melting starts at the trailing edge of the armature, and can be attributed to current crowding and localized Joule heating. This paper reports on dual laboratory-scale armature tests, one with current and one without, and by microstructural analysis of the two armatures, demonstrates that localized Joule heating due to current crowding is the principal source of melting, with frictional heating playing a much smaller role. The paper reports on microstructural changes in the armature due to Joule heating, along with associated degradation of the rail surface. It evaluates the impact of skin effect in the rail and the electrical contact conductance at the rail-armature interface on current crowding at the points of entry and exit of the current into and from the armature. In general, reduction of current crowding decreases the peak temperature at the rail-armature interface. But while reducing interfacial contact conductance reduces current crowding, it enhances the peak temperature and causes more melting.
Sponsorship	IEEE Magnetics Society
Starting Page	3278
Ending Page	3286
Page Count	9
File Size	2968413
File Format	PDF
ISSN	00189464
Volume Number	43
Issue Number	7
Language	English
Publisher	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Publisher Date	2007-07-01
Publisher Place	U.S.A.
Access Restriction	One Nation One Subscription (ONOS)
Rights Holder	Institute of Electrical and Electronics Engineers, Inc. (IEEE)
Subject Keyword	Proximity effect Railguns Rails Heating Contacts Temperature Laboratories Testing Degradation Skin effect railgun Armature current crowding model and microstructural analysis
Content Type	Text
Resource Type	Article
Subject	Electronic, Optical and Magnetic Materials Electrical and Electronic Engineering

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1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
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7	National Digital Library of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
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