|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Fatigue in Materials: Fundamentals, Multiscale Modeling and Prevention
||Ultra Small Scale High Cycle Fatigue Testing by Micro-cantilevers
|On-Site Speaker (Planned)
A new method will be presented for testing (very) high cycle fatigue properties using micro-cantilevers cut by focused ion beam into the surface a bulk sample block. A high power 20kHz ultrasonic generator is used to vibrate the sample block causing cyclic deflections in the cantilever. Sample shapes were designed to achieve stress amplitudes of several hundred MPa even in Ti using finite element modelling.
S-N curves have been obtained for 2Ám wide single crystal Ti micro-cantilevers using a step test protocol which show a systematic decrease in stress amplitude for failure from 10<sup>5</sup> to 10<sup>8</sup> cycles. The strong dependence on crystal orientation and sample size will be discussed and compared to our previous measurements of static strength measured on micro-cantilevers of similar size using a nanoindenter. Due to the small specimen size, it is suggested that the results reflect the behaviour of fatigue nucleation rather than propagation.
||Planned: Publication Outside of TMS (Indicate publication title and publisher if known.)