Understanding the fretting failure mechanisms in gold-plated contact materials

Using an electro-dynamic-shaker-based test setup, experiments were performed on gold-plated contacts under a variety of fretting conditions, including different vibration frequencies, vibration amplitudes and different environment temperatures. The variations in contact resistance with fretting cycles are recorded explicitly. The fretted surface is examined using a scanning electron microscope, energy-dispersive X-ray spectroscopy, and a con-focal laser scanning microscope to assess the surface morphology, extent of oxidation and elemental distribution across the fretted zone. It was found that fretting damage is a complex phenomenon for electrical contact applications. Different fretting regimes, including the infinite electrical contact life, the oxidation-dominated failure, and the transient unstable conductivity failure are determined. Finally, the degradation mechanisms of gold-plated contacts are proposed.