Location, location & size: defects close to surfaces dominate fatigue crack initiation

• DOI: 10.1038/srep45239
• Publication Date: 2017-03-27T09:59:33Z
• Authors: Itziar Serrano-Munoz; Jean-Yves Buffiere; Rajmund Mokso; Catherine Verdu; Yves Nadot
• Keywords: Shrinkage; Fatigue cracking; Fatigue limit

Abstract Metallic cast components inevitably contain defects such as shrinkage cavities which are inherent to the solidification process. Those known significantly alter fatigue life of components. Yet very little is known, quantitatively, on dangerosity internal casting compared surface ones. In this study, specimens containing controlled (shrinkage pores) used foster cracking. situ tests monitored by X ray synchrotron tomography revealed that nucleation and propagation cracks was systematically overran cracking initiated at castings up ten times smaller than These findings indicate presence in can be tolerated a larger extent allowed nowadays standards