Experimental and numerical investigation of crack initiation and propagation in silicon nitride ceramic under rolling and cyclic contact

0506664 - ÚFM 2020 RIV GB eng C - Conference Paper (international conference)
Raga, R. - Khader, I. - Chlup, Zdeněk - Kailer, A.
Experimental and numerical investigation of crack initiation and propagation in silicon nitride ceramic under rolling and cyclic contact.
Journal of Physics Conference Series. In: 6TH INTERNATIONAL CONFERENCE ON FRACTURE FATIGUE AND WEAR (FFW). Bristol: IOP Publishing, 2017, č. článku 012030. Journal of Physics Conference Series, 843. ISSN 1742-6588.
[FFW 2017 - International Conference on Fracture Fatigue and Wear /6./. Porto (PT), 26.07.2017-27.07.2017]
EU Projects: European Commission(XE) 263476 - ROLICER
Institutional support: RVO:68081723
Keywords : finite-element-analysis * wear * friction
OECD category: Ceramics

The focus of the work was to investigate crack initiation and propagation mechanisms in silicon nitride undergoing non-conforming hybrid contact under various tribological conditions. In order to understand the prevailing modes of damage in silicon nitride, two distinct model experiments were proposed, namely, rolling contact and cyclic contact experiments. The rolling contact experiment was designed in order to mimic the contact conditions appearing in hybrid bearings at contact pressures ranging from 3 to 6 GPa. On the other hand, cyclic contact experiments with stresses ranging from 4 to 15 GPa under different media were carried out to study damage under localised stresses. In addition, the experimentally observed cracks were implemented in a finite element model to study the stress redistribution and correlate the generated stresses with the corresponding mechanisms. Crack propagation under rolling contact was attributed to two different mechanisms, namely, fatigue induced fracture and lubricant driven crack propagation. The numerical simulations shed light on the tensile stress driven surface and subsurface crack propagation mechanisms. On the other hand, the cyclic contact experiments showed delayed crack formation for lubricated cyclic contact. Ceramographic cross-sectional analysis showed crack patterns similar to Hertzian crack propagation under cyclic contact load.
Permanent Link: http://hdl.handle.net/11104/0300118