Platinum Metals Review - Volume 7, Issue 2, 1963

Although the 10 per cent rhodium-platinum alloy has been used extensively for high-temperature applications in the glass and chemical industries for many years, little precise information on its mechanical properties under suck conditions has hitherto been available. Experiments in specially designed high-temperature creep furnaces have provided accurate design data to ensure useful life at high temperature.

This paper outlines the nature of the various classes of electrical discharges—the high voltage capacitative spark discharge, the normal arc discharge, and the low voltage arc that occurs at electrical contacts—and discusses the physical processes that determine the dependence of the rate of electrode erosion on the physical properties of the metal. It is concluded that the most important properties conducive to low erosion rates are high boiling point, high thermal conductivity and high density, so providing the physical reason for the low erosion rates observed for the platinum metals when used as electrodes and electrical contacts.