Effect of adsorbed chlorine and oxygen on the shear strength of iron and copper junctions

Abstract

Static friction experiments were performed in ultrahigh vacuum at room temperature on copper, iron, and steel contacts selectively contaminated with oxygen and chlorine in submonolayer amounts. The concentration of the adsorbates was determined with Auger electron spectroscopy and was measured relative to the saturation concentration of oxygen on iron (concentration 1. 0). The coefficient of static friction decreased with increasing adsorbate concentration. It was independent of the metal and the adsorbate. The results compared satisfactorily with an extension of the junction growth theory to heterogeneous interfaces. The reduction in interfacial shear strength was measured by the ratio Sa/sm, where sa is the shear strength of the interface with an adsorbate concentration of 1. 0, and s m is the strength of the clean metal interface. This ratio was 0.835±0. 012 for all the systems tested. SUMMARYStatic friction experiments were performed in ultrahigh vacuum at room temperature on copper, iron, and steel contacts selectively contaminated with oxygen and chlorine in submonolayer amounts. The concentration of the adsorbates was determined with Auger electron spectroscopy and was measured relative to the saturation concentration of oxygen on iron (concentration 1. 0). The coefficient of static friction decreased with increasing adsorbate concentration. It was independent of the metal and the adsorbate.The results compared satisfactorily with an extension of the junction growth theory to heterogeneous interfaces. The reduction in interfacial shear strength was measured by the ratio sa/s m , where s a is the shear strength of the interface with an adsorbate concentration of 1. 0, and sm is the strength of the clean metal interface. This ratio was 0. 835±0. 012 for all the systems tested.

The Effect of Grain Orientation on Micro Frictional of Medium Carbon Steel

“…The higher atomic density planes, or the lower surface energy planes, are expected to have lower friction coefficient. [6,7]. On the other hand, slip and shear takes place most often on these planes.…”