About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
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Symposium
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Materials for High Temperature Applications: Next Generation Superalloys and Beyond
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Presentation Title |
Crack Initiation Anisotropy of Ni-based Single-crystal Superalloys in the VHCF Regime |
Author(s) |
Alice Cervellon, Chris J. Torbet, Tresa M. Pollock |
On-Site Speaker (Planned) |
Alice Cervellon |
Abstract Scope |
The influence of the crystal primary orientation on the transition from crack initiation to crack propagation in Ni-base single-crystals superalloys has been studied in the very high cycle fatigue regime. Ni-based SX superalloys solidified in three orientations close to the <001>, <110> and <111> directions have been tested under fully-reversed conditions (R = -1) at 20 kHz and 750°C.
Fracture surface observations and longitudinal cuts intercepting the main crack initiation site have been performed in order to characterize the active slip systems for each orientation. When the number of cycles exceeds 10^7 cycles, the topography of the facets is less planar at the vicinity of the crack initiation site and evidences a dominant micro-crack propagation stage in the total fatigue life. The localization of the plastic deformation and the first stages of crack propagation will be detailed for each orientation. The implications on the resultant fatigue life will be discussed. |
Proceedings Inclusion? |
Planned: |