Damage Initiation and Evolution in Silicon Nitride under Rolling Contact Fatigue and Cyclic Contact Fatigue

0435048 - ÚFM 2015 RIV DE eng O - Ostatní výsledky
Raga, R. - Khader, I. - Kailer, A. - Chlup, Zdeněk
Damage Initiation and Evolution in Silicon Nitride under Rolling Contact Fatigue and Cyclic Contact Fatigue.
2014
GRANT EU: European Commission(XE) 263476 - ROLICER
Institucionální podpora: RVO:68081723
Klíčová slova: Silicon nitride * Contact fatigue * Damage
Kód oboru RIV: JL - Únava materiálu a lomová mechanika

This study focuses on the damage mechanisms in silicon nitride undergoing non-conforming contact. The study arose in order to understand the damage involved in hybrid contact (e.g., ceramic-metal contact in hybrid bearings). Two distinct cases were investigated, namely, rolling contact fatigue (RCF) and cyclic contact fatigue (CCF). In rolling contact loading any point on the contact surface undergoes alternating cyclic tension-compression stress fields; whereas in cyclic contact loading a compression dominated stress field is generated underneath the contact and tensile stress regions emerge outside the contact zone. Understanding damage under different loading conditions is essential in order to prevent premature failure of the material in service. A rolling contact experiment was designed in order to mimic the contact conditions appearing in hybrid bearings at contact pressures ranging from 3 to 5GPa; the experiments were run without slip and under different lubrication conditions. Additionally, cyclic contact experiments under different media were carried out. Following the experiments, high resolution microscopy was carried out to analyse the samples. The rolling contact experiments showed considerable wear under dry conditions even without gross slip between the contact partners. The cyclic contact fatigue tests showed remarkable distinction between the experiment running in air and under lubrication
Trvalý link: http://hdl.handle.net/11104/0239595