Experimental evidence and physical models of fatigue crack initiation

0465497 - ÚFM 2017 RIV GB eng J - Journal Article
Polák, Jaroslav - Man, Jiří
Experimental evidence and physical models of fatigue crack initiation.
International Journal of Fatigue. Roč. 91, OCT (2016), s. 294-303. ISSN 0142-1123. E-ISSN 1879-3452
R&D Projects: GA ČR(CZ) GA13-23652S; GA ČR GA13-32665S; GA MŠMT(CZ) ED1.1.00/02.0068
Institutional support: RVO:68081723
Keywords : Crack initiation * Persistent slip band * Point defects * Extrusions * Intrusions
Subject RIV: JL - Materials Fatigue, Friction Mechanics
Impact factor: 2.899, year: 2016

Results of the study of the early fatigue damage in a number of model and structural crystalline materials using modern experimental techniques are presented. The dislocation structure of the persistent slip bands and the evolution of the surface relief resulting in the formation of persistent slip markings during cyclic loading are documented. The dislocation mechanisms leading to production of point defects in cyclic loading are described and point defect production and annihilation rates are derived. The kinetics of point defect migration is characterized. The physically based models of the surface relief formation describing the formation of extrusions and intrusions are presented. The models are confronted with experimental evidence. It is concluded that intrusions representing sharp surface crack-like defects play the principal role in the initiation of fatigue cracks.
Permanent Link: http://hdl.handle.net/11104/0264041