Wire + arc additive manufacturing (WAAM) is a modern manufacturing process that has opened new possibilities for rapid builds and reductions in material wastage. This paper explores residual stress in WAAM Ti‐6Al‐4V walls built using three different deposition strategies: single bead, parallel path, and oscillation path. The effect of interlayer hammer peening and interlayer temperature was investigated for the single bead walls. We also examined the residual stress in compact‐tension (C(T)) coupons extracted from large builds (walls) with crack orientation either parallel with or perpendicular to the build direction. This type of sample is often used for the measurement of the fatigue crack growth rate. The contour method was used for experimental determinations of residual stress. In addtion, residual stress in the C(T) coupons was estimated by finite element (FE) analysis. A good agreement was achieved between the contour method and FE analysis. The oscillation‐path wall had the lowest residual stress values. For the single bead walls built with various process conditions, residual stress was significantly reduced after removing the substrate. A interlayer temperature of 110 °C resulted in much higher residual stress values in the wall (both tensile and compressive) compared to the continuous build. with much higher interlayer temperature.
Bibliographical noteCopyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/
FunderFunding: This research was funded by UK Engineering and Physical Sciences Research Council through the NEWAM (New Wire Additive Manufacturing) programme grant (EP/R027218/1).
Acknowledgments: M. E. Fitzpatrick is grateful for funding from the Lloyd’s Register Foundation, a charitable foundation helping to protect life and property by supporting engineering‐related education, public engagement and the application of research. We would also like to thank Steve Damms at the Institute for Advanced Manufacturing and Engineering for his help with the Wire EDM.
- Additive manufacturing
- Contour method
- Finite element analysis
- Residual stress
- Titanium alloy
ASJC Scopus subject areas
- Materials Science(all)
- Metals and Alloys