Evaluation of Copper-Beryllium Contacts for High Current Density Pulsed Applications

• Published in: IEEE transactions on plasma science Vol. 47; no. 8; pp. 4048 - 4051
• Main Authors: Lindero-Hernandez, Miguel, Ramos-Lopez, Gonzalo, Nieto-Perez, Martin
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum; Beryllium; Beryllium base alloys; Capacitors; Contact pressure; Contacts; Copper; Copper base alloys; copper–beryllium; Current density; Current pulses; Electric contacts; High current; Melting; Metals; Motors; Oxidation; pulsed power; Railguns; RLC circuits; Silver; Springs
• ISSN: 0093-3813; 1939-9375
• DOI: 10.1109/TPS.2019.2925382

Low-resistance metal-to-metal contacts, both static and sliding contacts, are of interest to many scientific and technical applications as magnetic confinement fusion, railguns, and electrical motors. In fusion applications, silver-coated copper contacts and low-current-density designs are preferred, while in other applications, high current densities are required. For high-pressure high-current-density sliding contacts, contact pairs such as aluminum/copper are preferred as in railguns, while for electrical motors, copper-copper alloys are preferred. Copper-beryllium alloy, C172, is investigated as static contacts for high-current-density pulsed-power applications. To subject the contacts to suitable current pulses and pressures, a special electrical contact assembly has been developed allowing contact pressures from 0 to 66 MPa and current densities from 62 to 263 kA/cm 2 . The contacts were studied under different current density pressure combinations with repeated 60-<inline-formula> <tex-math notation="LaTeX">\mu \text{s} </tex-math></inline-formula> pulses in air, while current evolution and surface modifications were followed. Besides some surface oxidation, no evidence of other surface modifications like welding or surface melting were found.