Long-Term Behaviour of Plug-in Connectors with Copper Beryllium Contact Lamellas Depending on Stress Relaxation

Plug-in connectors with contact lamellas, so-called Multilams, are distinguished by multifaceted application possibilities and various dimensions. The Multilams investigated in this paper are used for high current applications and consist of age-hardened copper beryllium (CuBe2) characterised by high mechanical strength, great spring properties and also good electrical conductivity. The ageing of electrical connectors with Multilams depending on stress relaxation is researched by long-term studies and FEM-calculations along with various material investigations. Experimental setups consist each of two plain and bolted pressure plates with inlaid strips of Multilams. The spring deflection is adjusted by ceramic spacers and can be assumed as constant. These samples are aged by electrical current or thermal heating at several temperatures up to 115°C. The joint resistances and the remaining spring forces are measured time-dependent to evaluate the influence of stress relaxation on the long-term behaviour of plug-in connectors with copper beryllium contact lamellas.