Beryllium Copper Strip
Performance of Beryllium Copper
(5) Electrical Conductivity and Tolerance to Heat Generation
High current (up to 30A) passes through the contact springs in automotive components and relays. Because of its high electrical conductivity, beryllium copper can minimize heat generation caused by resistivity of a contact spring, even if it carries a high current.
Fig. 7 Rise in Temperature by Resistance Heating,
Beryllium Copper vs. Phosphor Bronze
Fig. 7 shows the rise in temperature when a current of 20A is passed through test pieces in beryllium copper or phosphor bronze (test piece in 0.2mm x 10mm x 75mm).
After 500 seconds the temperature rises up to 80/90°C in alloy 25, approx. 701 for alloy 7 and approx. 601 for alloy 11, while it reaches more than 120'C in phosphor bronze. Since the internal heat generated by the resistivity of a given material may cause stress relaxation in service, the selection of high conductive material is essential for switches or relays subject to high amperage load.