Fretting in nickel-coated aluminium conductors

The degradation of nickel-coated aluminium conductors in contact with aluminum, copper, nickel, and tin under fretting conditions is studied. In addition to contact resistance measurements, scanning electron microscopy (SEM) and X-ray fluorescence (EDX) analysis are used to study the processes involved. The fretting tests are carried out with a simulated connector configuration at a frequency of oscillation of 1 Hz and contact loads of 2 N and 10 N. The effects of fretting slip amplitude, contact load, and lubrication are evaluated. The results showed that fretting adversely affects the contact resistance of nickel-coated aluminum conductors, which shows a rapid increase and substantial fluctuations with fretting time. The effects of fretting are reduced by decreasing the slip amplitude and increasing the contact load and lubrication. SEM and EDX analysis revealed that considerable damage of the contact zones resulted from the fretting action and substantial exchange of material occurred in nonlubricated joints.