Study of minimum fretting for connectors used in automotive applications

• Published in: Electrical engineering 2013-09, Vol.95 (3), p.201-208
• Main Authors: Bouzera, A., Carvou, E., El Abdi, R., Benjemâa, N., Tristani, L., Zindine, E. M.
• Format: Article
• Language: English
• Subjects: Economics and Management; Electrical Engineering; Electrical Machines and Networks; Energy Policy; Engineering; Original Paper; Physics; Power Electronics
• ISSN: 0948-7921; 1432-0487
• DOI: 10.1007/s00202-012-0254-6

For automotive applications, the mechanical behaviour of the contact area under vibration is one of the key factors for connector reliability. Such vibrations on the bulk contact device are typically in the range of 10–2,000 Hz and result in displacements of only a few microns at the contact interface. In the present study, a bench test has been developed to control motions down to 1  m. The objective is to determine the minimum amplitude for fretting-corrosion degradation based on the evolution of contact resistance and to study the effects of the material, the contact force, the coating, for these low displacement amplitudes. To obtain the limit of the appearance of fretting, a sub-micrometer incrementing displacement amplitude methodology was applied on a high stiffness bench test including a double piezoelectric actuator. It was found that the fretting degradation starts to occur from 2 to 6  m when the contact force is from 0.5 to 2.5 N with a tin-coated terminal. Moreover, pure copper, tin and nickel have similar amplitude fretting limits while noble metals confirm the absence of fretting up to 10  m amplitude and for a large number of operations (10 cycles). Best fitting of the obtained minimum fretting amplitude data to the Mindlin equation is discussed and improved by a correction factor.