FRETTING IN NI-COATED ALUMINUM CONDUCTORS

The degradation of nickel-coated aluminum conductors in contact with aluminum, copper, nickel, and tin under fretting conditions has been studied. In addition to contact resistance measurements, scanning electron microscopy (SEM) and X-ray fluorescence (EDX) analysis were used to study the processes involved. The fretting tests were carried out with a simulated connector configuration at a frequency of oscillation of 1 Hz and contact loads of 2 and 10 N. The effects of fretting slip amplitude, contact load, and lubrication were 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 were reduced to some extent 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.