The Influence of the Applied Load on the Friction Coefficient of the Sintered Iron-Base Bearings

Abstract

In the recent years the iron base sintered bearings production was considerable increased at the expense of the copper based ones, due to the low cost and availability of the iron powders as well as the higher strength. The mechanical properties of a part are strongly related to the composition of the materials. For tribological applications, the properties of the surface are related to the different metallic and intermetallic phases formed in the material. The friction nature of the bearing type couple having the bearing bush made from sintered material is a function of pores size, applied load, velocity, temperature, the quality and quantity of the stored oil and can appear as hydrodynamic, mixed and limit friction. The tribological features of the selected iron-copper based materials have been studied using an experimental device for wear testing of the sliding bearings. The friction coefficient and wear resistance have been analyzed in dry friction conditions. The influence of the applied load and p x v values on the friction coefficient was studied. Also, the dependence of the functioning time until the failure of the bearing (seizing) with the friction coefficient for the applied forces was analyzed.