Abstract
The Mechanisms of fatigue failure in Ti-6Al-2Sn-4Zr-6Mo forged discs are investigated: the effects of forging and machining operations on fatigue are decoupled. A four-point bend fatigue testing approach enabled the crack initiation and propagation characteristics to be studied at multiple locations around the disc periphery. Fatigue performance variation (of ~60%) at different positions, and crack initiation and propagation behaviour were linked to the heterogeneous crystallographic texture - developed during upstream forging. Downstream machining processes were found to increase fatigue life, regardless of the cutting speed. However, circumferential fatigue heterogeneity, inherent from the forging stage was still evident even after machining.
Original language | English |
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Article number | 105949 |
Number of pages | 13 |
Journal | International Journal of Fatigue |
Volume | 142 |
Early online date | 18 Sept 2020 |
DOIs | |
Publication status | Published - 31 Jan 2021 |
Funding
We would like to acknowledge EPSRC grant EP/L016273 Centre for Doctoral Training in Advanced Metallic Systems for supporting this research, and Justin Davies (Sandvik) and Phil Bell, Stephen Tyas and Amber Bennett (AMRC) for advice and assistance with the trials.
Keywords
- forging
- low cycle fatigue
- machining
- titanium alloys