The three-prong method: a novel assessment of residual stress in laser powder bed fusion
Residual stress is a major problem for most metal-based laser powder bed fusion (L-PBF) components. Residual stress can be reduced by appropriate build planning and post-process heat treatments; however, it is not always avoidable and can lead to build failures due to distortion and cracking. Accura...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Taylor & Francis Group
2018-01-01
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| Series: | Virtual and Physical Prototyping |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/17452759.2017.1392682 |
| _version_ | 1797678663950401536 |
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| author | S. A. Sillars C. J. Sutcliffe A. M. Philo S. G. R. Brown J. Sienz N. P. Lavery |
| author_facet | S. A. Sillars C. J. Sutcliffe A. M. Philo S. G. R. Brown J. Sienz N. P. Lavery |
| author_sort | S. A. Sillars |
| collection | DOAJ |
| description | Residual stress is a major problem for most metal-based laser powder bed fusion (L-PBF) components. Residual stress can be reduced by appropriate build planning and post-process heat treatments; however, it is not always avoidable and can lead to build failures due to distortion and cracking. Accurate measurement of residual stress levels can be difficult due to high equipment set-up costs and long processing times. This paper introduces a simple but novel method of measuring residual stresses via a three-pronged cantilever component, the three-prong method (TPM). The method allows for a quick and easy characterisation of residual stress for a wide range of machine parameters, build strategies and materials. Many different cantilever designs have been used to indicate residual stress within additive manufacturing techniques. All of which share the same shortcoming that they indicate stress in one direction. If the principal component of stress is not aligned with the beam geometry, it will underestimate peak stress values. A novel three-prong design is proposed which covers two dimensions by utilising three adjoined cantilever beams, a configuration which echoes that of hole-drilling where three measurements are used to calculate the stress field around a drilled hole. Each arm of the component resembles a curved bridge-like structure; one end of each bridge is cut away from the base plate leaving the centre intact. Deformation of the beams is then measured using a co-ordinate measurement machine. Stress profiles are then estimated using finite element analysis by meshing the deflected structure and forcing it back to its original shape. In this paper, the new TPM is used to compare the residual stress levels of components built in Ti–6Al–4V with different hatch patterns, powers and exposure times. |
| first_indexed | 2024-03-11T23:03:12Z |
| format | Article |
| id | doaj.art-0555c775067a427b9ae8a1720544ae94 |
| institution | Directory Open Access Journal |
| issn | 1745-2759 1745-2767 |
| language | English |
| last_indexed | 2024-03-11T23:03:12Z |
| publishDate | 2018-01-01 |
| publisher | Taylor & Francis Group |
| record_format | Article |
| series | Virtual and Physical Prototyping |
| spelling | doaj.art-0555c775067a427b9ae8a1720544ae942023-09-21T13:56:59ZengTaylor & Francis GroupVirtual and Physical Prototyping1745-27591745-27672018-01-01131202510.1080/17452759.2017.13926821392682The three-prong method: a novel assessment of residual stress in laser powder bed fusionS. A. Sillars0C. J. Sutcliffe1A. M. Philo2S. G. R. Brown3J. Sienz4N. P. Lavery5Swansea UniversityRenishaw Plc, Additive Manufacturing Products DivisionSwansea UniversitySwansea UniversitySwansea UniversitySwansea UniversityResidual stress is a major problem for most metal-based laser powder bed fusion (L-PBF) components. Residual stress can be reduced by appropriate build planning and post-process heat treatments; however, it is not always avoidable and can lead to build failures due to distortion and cracking. Accurate measurement of residual stress levels can be difficult due to high equipment set-up costs and long processing times. This paper introduces a simple but novel method of measuring residual stresses via a three-pronged cantilever component, the three-prong method (TPM). The method allows for a quick and easy characterisation of residual stress for a wide range of machine parameters, build strategies and materials. Many different cantilever designs have been used to indicate residual stress within additive manufacturing techniques. All of which share the same shortcoming that they indicate stress in one direction. If the principal component of stress is not aligned with the beam geometry, it will underestimate peak stress values. A novel three-prong design is proposed which covers two dimensions by utilising three adjoined cantilever beams, a configuration which echoes that of hole-drilling where three measurements are used to calculate the stress field around a drilled hole. Each arm of the component resembles a curved bridge-like structure; one end of each bridge is cut away from the base plate leaving the centre intact. Deformation of the beams is then measured using a co-ordinate measurement machine. Stress profiles are then estimated using finite element analysis by meshing the deflected structure and forcing it back to its original shape. In this paper, the new TPM is used to compare the residual stress levels of components built in Ti–6Al–4V with different hatch patterns, powers and exposure times.http://dx.doi.org/10.1080/17452759.2017.1392682laser powder bed fusionresidual stressadditive manufacturing3d printingselective laser melting |
| spellingShingle | S. A. Sillars C. J. Sutcliffe A. M. Philo S. G. R. Brown J. Sienz N. P. Lavery The three-prong method: a novel assessment of residual stress in laser powder bed fusion Virtual and Physical Prototyping laser powder bed fusion residual stress additive manufacturing 3d printing selective laser melting |
| title | The three-prong method: a novel assessment of residual stress in laser powder bed fusion |
| title_full | The three-prong method: a novel assessment of residual stress in laser powder bed fusion |
| title_fullStr | The three-prong method: a novel assessment of residual stress in laser powder bed fusion |
| title_full_unstemmed | The three-prong method: a novel assessment of residual stress in laser powder bed fusion |
| title_short | The three-prong method: a novel assessment of residual stress in laser powder bed fusion |
| title_sort | three prong method a novel assessment of residual stress in laser powder bed fusion |
| topic | laser powder bed fusion residual stress additive manufacturing 3d printing selective laser melting |
| url | http://dx.doi.org/10.1080/17452759.2017.1392682 |
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