Arc erosion behavior of Cu-15%Nb and Cu-15%Cr in situ composites

Abstract

The arc erosion behavior of Cu-15%Nb and Cu-15%Cr in situ composites was studied for both low-energy make-and-break contact and a high-energy stationary arcing gap configuration. For low-energy make-and-break contacts, a computerized test set-up was developed, while the high-energy pulsed power stationary arcing tests were performed in the Mark VI facility at Texas Tech University, Lubbock, TX. The study dealt with variation in contact resistance for make-and-break contacts, are erosion at both energy levels, and materials response to arc erosion. The surface films formed in the make-and-break operation were analyzed by an X-ray diffraction technique, and the eroded surfaces and arc erosion mechanisms were studied by scanning electron microscopy. It was concluded that in low-energy contacts, oxidation was the major cause of deterioration of electrical contacts, while melting was the major failure mode in high-energy contacts. The contact resistance of Cu-15%Nb was much lower than that of Cu-15%Cr. The arc erosion resistance of Cu-15Nb and Cu-%Cr was higher than that of the commercially used CuW composite in stationary arc erosion tests.