Structure changes of powder composites surface layers in sliding under electric current and Pb-Sn melt in the contact space

Abstract

The tribotechnical behavior of a sintered powder composites based on steels of different classes against quenched AISI steel 1045 was studied in the presence of Pb-Sn melt in the friction zone under high density electric current. Some increase in the electrical conductivity of the contact and the wear resistance of the composites was observed. It was noted that the Pb-Sn melt does not provide a satisfactory separation of the contact surfaces. This is comparable to the separation from FeO appearing during dry slip with current collection. Pb-Sn melt does not prevent the formation of a tribolayer with a thickness of about 20 µm in the composite based on low-alloyed bearing steel. The same melt leads to the formation of brittle cracks in the friction zone of the composite based on high-alloyed Hadfield steel.