Importance of contact geometry for experimental tribological research of austenitic cast iron at high temperatures

This publication focuses on the influence of the contact geometry and especially the particle ejection on the tribological behaviour of unlubricated, thermally highly loaded contacts by a systematic comparison of a system and a model test. Moreover, the influence of temperature and the influence of an exhaust gas atmosphere on the tribological system behaviour of an austenitic cast iron was analysed in depth. Between the system and model experiments, the dominant tribological mechanisms are broadly comparable, and the corresponding temperature regimes of the wear behaviour show excellent agreement. However, the wear rates and atmospheric effects are significantly different. By using grooved bushings, the influence of the particle ejection and thus the contact geometry on the tribological behaviour was analysed. For lower temperatures, comparable wear rates and atmospheric influences between the tests are only determined with grooved bushings. • Systematic comparison between model & system experiments regarding contact geometry. • Differing wear rates and atmospheric effects between contact systems determined. • Formation of a third body mainly affected by particle ejection and contact geometry. • Tribological characterisation of Cr-plated steel - cast iron as shaft-bushing.