Effect of Ni addition on the contact resistance of Ag-WC electrical contacts

In this work, Ni was used as an additive in Ag-WC (60-40 wt.%) metal matrix composites employed as electrical contacts. Increasing the Ni content from 1 to 3 wt.% resulted in an increase in the mean electrical contact resistance (Rc) from ~2 to ~3 mΩ. However, further addition of Ni up to 10 wt.% resulted in the formation of a silver layer on the contact surface after switching, which strongly reduced the Rc from ~3 to ~1.5 mΩ. The influence of Ni addition on the microstructural changes in the contact material was investigated and the mechanism for the transfer of silver from the bulk composite material to the surface as a consequence of thermal cycling during switching was elucidated.publisher: Elsevier articletitle: Effect of Ni addition on the contact resistance of Ag-WC electrical contacts journaltitle: Journal of Alloys and Compounds articlelink: http://dx.doi.org/10.1016/j.jallcom.2016.02.037 content_type: article copyright: Copyright © 2016 Elsevier B.V. All rights reserved.status: publishe