Geometrical effects on residual stress in selective laser melting

Parry, L.A.; Ashcroft, I.A.; Wildman, R.D.

Abstract

Selective laser melting is an increasingly attractive technology for the manufacture of complex and low volume / high value metal parts. However, the inevitable residual stresses that are generated can lead to defects or build failure. Due to the complexity of this process, efficient and accurate prediction of residual stress in large components remains challenging. For the development of predictive models of residual stress, knowledge on their generation is needed. This study investigates the geometrical effect of scan strategy on residual stress development. It was found that the arrangement of scan vectors due to geometry, heavily influenced the thermal history within a part, which in turn significantly affected the transverse residual stresses generated. However, irrespective of the choice of scanned geometry and the thermal history, the higher magnitude longitudinal stresses had consistent behaviour based on the scan vector length. It was shown that the laser scan strategy becomes less important for scan vector length beyond 3 mm. Together, these findings, provide a route towards optimising scan strategies at the meso-scale, and additionally, developing a model abstraction for predicting residual stress based on scan vectors alone.

Citation

Parry, L., Ashcroft, I., & Wildman, R. (2019). Geometrical effects on residual stress in selective laser melting. Additive Manufacturing, 25, 166-175. https://doi.org/10.1016/j.addma.2018.09.026

• Journal Article Type: Article
• Acceptance Date: Sep 23, 2018
• Online Publication Date: Sep 25, 2018
• Publication Date: 2019-01
• Deposit Date: Oct 16, 2018
• Publicly Available Date: Dec 17, 2018
• Journal: Additive Manufacturing
• Print ISSN: 2214-7810
• Electronic ISSN: 2214-8604
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 25
• Pages: 166-175
• DOI: https://doi.org/10.1016/j.addma.2018.09.026
• Keywords: Selective laser melting; Residual stress; simulation; laser scan strategy
• Public URL: https://nottingham-repository.worktribe.com/output/1169443
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S2214860418304202
• Contract Date: Oct 16, 2018