Advances in material development for high power, vacuum interrupter contacts

This paper reviews the development of contact materials for vacuum interrupters. During the past 15 years, chromium-copper (Cr-Cu) has gradually become the dominant contact material for use in medium-voltage, high-current vacuum interrupters. The manufacturing methods for this material are discussed. Other materials such a tungsten-copper (W-Cu), tungsten carbide-silver (WC-Ag), and copper alloys are briefly described. The performance of the vacuum interrupter contacts under operating conditions is reviewed. This review shows that Cr-Cu continues to be the best contact material for vacuum interrupters used in vacuum circuit breakers.>