The Impact of the Environment on the Contact Potential Difference of Metal Machine Parts

Abstract

In this paper we consider the influence of environmental parameters on the electrons work function and the contact potential difference of metal parts of machines. Experimental studies have been carried out, including measurements of the contact potential difference on samples from Al, Ti and Ni by the Kelvin-Zisman method at different temperatures, pressures and relative humidity, as well as in non-equilibrium and equilibrium environmental conditions. Measurements of the contact potential difference were carried out by the device "Surface-11". Atmospheric parameters were measured by the digital meteorological station HAMA EWS-800. The results of measurements of the contact potential difference of metals were processed by methods of mathematical statistics. The results of experimental studies have shown a direct effect of changes in ambient temperature on the contact potential difference and the electrons work function of metal samples, which has an average correlation. It is found that atmospheric pressure and relative humidity have a weak effect on the contact potential difference and the electrons work function of the metals under study, their influence can be neglected. The effect of equilibrium and non-equilibrium environmental parameters on the contact potential difference and electrons work function of metal samples is studied. The results confirming the reduction of the contact potential difference (increase in the electrons work function) of metals, as well as an increase in the mean square deviation of the measurement results under non-equilibrium environmental conditions are obtained. On the basis of the research it is recommended to measure the contact potential difference of metals in the laboratory.

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