ARC EROSION BEHAVIOR OF CU-15-PERCENT-NB AND CU-15-PERCENT-CR IN-SITUCOMPOSITES

The are erosion behavior of Cu-15%Nb and Cu-15%Cr in situ composites w as studied for both low-energy make-and-break contact and a high-energ y stationary arcing gap configuration. For low-energy make-and-break c ontacts, a computerized test set-up was developed, while the high-ener gy pulsed power stationary arcing tests were performed in the Mark VI facility at Texas Tech University, Lubbock, TX. The study dealt with v ariation in contact resistance for make-and-break contacts, are erosio n at both energy levels, and materials response to are erosion. The su rface films formed in the make-and-break operation were analyzed by an X-ray diffraction technique, and the eroded surfaces and are erosion mechanisms were studied by scanning electron microscopy. It was conclu ded that in low-energy contacts, oxidation was the major cause of dete rioration of electrical contacts, while melting was the major failure mode in high-energy contacts. The contact resistance of Cu-15%Nb was m uch lower than that of Cu-15%Cr. The are erosion resistance of Cu-15%N b and Cu-15%Cr was higher than that of the commercially used Cu-W comp osite in stationary are erosion tests. (C) 1997 Elsevier Science S.A.