Describing different operating regimes of journal-bearing materials by pressure velocity diagrams derived from ring-on-disc model testing

Abstract

The loading capacity of metallic journal-bearing materials is investigated in this study under lubricated conditions using a ring-on-disc test configuration. The materials investigated are AlSn20Cu, AlSn40, SnSb7.5Cu3.5, PbSn18Cu2, and AlSn20Cu-Sputter, mated against polished steel counterparts. The loading capacity for different sliding speeds ranging from 0.14 to 2.82 m/s was determined using seizure test procedure. Microscopic analysis of the tested specimen was carried out and the load limits were plotted in pv-diagrams. The results show that for tribomaterials with a load-bearing matrix, as in AlSn-based materials, an increase in the content of soft phase improves fault tolerance. It also increases the loading capacity at low speeds, where adhesion effects dominate. Materials composed of a soft matrix such as Sn-or Pb-based material possess excellent sliding performance but fail due to thermo-mechanical breakdown.