Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering
A new approach to modelling the microstructure evolution and yield strength in laser powder bed fusion components is introduced. Restoration mechanisms such as discontinuous dynamic recrystallization, continuous dynamic recrystallization, and dynamic recovery were found to be activated during laser...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2021-12-01
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| Series: | Materials & Design |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0264127521008017 |
| _version_ | 1818369526478143488 |
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| author | Hossein Eskandari Sabzi Everth Hernandez-Nava Xiao-Hui Li Hanwei Fu David San-Martín Pedro E.J. Rivera-Díaz-del-Castillo |
| author_facet | Hossein Eskandari Sabzi Everth Hernandez-Nava Xiao-Hui Li Hanwei Fu David San-Martín Pedro E.J. Rivera-Díaz-del-Castillo |
| author_sort | Hossein Eskandari Sabzi |
| collection | DOAJ |
| description | A new approach to modelling the microstructure evolution and yield strength in laser powder bed fusion components is introduced. Restoration mechanisms such as discontinuous dynamic recrystallization, continuous dynamic recrystallization, and dynamic recovery were found to be activated during laser powder bed fusion of austenitic stainless steels; these are modelled both via classical Zener-Hollomon and thermostatistical approaches. A mechanism is suggested for the formation of dislocation cells from solidification cells and dendrites, and their further transformation to low-angle grain boundaries to form subgrains. This occurs due to dynamic recovery during laser powder bed fusion. The yield strength is successfully modelled via a Hall–Petch-type relationship in terms of the subgrain size, instead of the actual grain size or the dislocation cell size. The validated Hall–Petch-type equation for austenitic stainless steels provides a guideline for the strengthening of laser powder bed fusion alloys with subgrain refinement, via increasing the low-angle grain boundary fraction (grain boundary engineering). To obtain higher strength, dynamic recovery should be promoted as the main mechanism to induce low-angle grain boundaries. The dependency of yield stress on process parameters and alloy composition is quantitatively described. |
| first_indexed | 2024-12-13T23:25:15Z |
| format | Article |
| id | doaj.art-bd39afde743c4667a0b1a6bd94de7c88 |
| institution | Directory Open Access Journal |
| issn | 0264-1275 |
| language | English |
| last_indexed | 2024-12-13T23:25:15Z |
| publishDate | 2021-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Materials & Design |
| spelling | doaj.art-bd39afde743c4667a0b1a6bd94de7c882022-12-21T23:27:33ZengElsevierMaterials & Design0264-12752021-12-01212110246Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineeringHossein Eskandari Sabzi0Everth Hernandez-Nava1Xiao-Hui Li2Hanwei Fu3David San-Martín4Pedro E.J. Rivera-Díaz-del-Castillo5Department of Engineering, Engineering Building, Lancaster University, LA1 4YW, United KingdomDepartment of Material Science & Engineering, The University of Sheffield, Sir Robert Hadfield Building, Mappin St, Sheffield S13 JD, United KingdomSchool of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing 100191, ChinaSchool of Materials Science and Engineering, Beihang University, No. 37 Xueyuan Road, Beijing 100191, China; Corresponding authors.Materalia Research Group, Physical Metallurgy Department, Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Avda. Gregorio del Amo 8, 28040 Madrid, SpainDepartment of Engineering, Engineering Building, Lancaster University, LA1 4YW, United Kingdom; Corresponding authors.A new approach to modelling the microstructure evolution and yield strength in laser powder bed fusion components is introduced. Restoration mechanisms such as discontinuous dynamic recrystallization, continuous dynamic recrystallization, and dynamic recovery were found to be activated during laser powder bed fusion of austenitic stainless steels; these are modelled both via classical Zener-Hollomon and thermostatistical approaches. A mechanism is suggested for the formation of dislocation cells from solidification cells and dendrites, and their further transformation to low-angle grain boundaries to form subgrains. This occurs due to dynamic recovery during laser powder bed fusion. The yield strength is successfully modelled via a Hall–Petch-type relationship in terms of the subgrain size, instead of the actual grain size or the dislocation cell size. The validated Hall–Petch-type equation for austenitic stainless steels provides a guideline for the strengthening of laser powder bed fusion alloys with subgrain refinement, via increasing the low-angle grain boundary fraction (grain boundary engineering). To obtain higher strength, dynamic recovery should be promoted as the main mechanism to induce low-angle grain boundaries. The dependency of yield stress on process parameters and alloy composition is quantitatively described.http://www.sciencedirect.com/science/article/pii/S0264127521008017Laser powder bed fusionMechanical propertiesStainless steelGrain refinementMicrostructure |
| spellingShingle | Hossein Eskandari Sabzi Everth Hernandez-Nava Xiao-Hui Li Hanwei Fu David San-Martín Pedro E.J. Rivera-Díaz-del-Castillo Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering Materials & Design Laser powder bed fusion Mechanical properties Stainless steel Grain refinement Microstructure |
| title | Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering |
| title_full | Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering |
| title_fullStr | Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering |
| title_full_unstemmed | Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering |
| title_short | Strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering |
| title_sort | strengthening control in laser powder bed fusion of austenitic stainless steels via grain boundary engineering |
| topic | Laser powder bed fusion Mechanical properties Stainless steel Grain refinement Microstructure |
| url | http://www.sciencedirect.com/science/article/pii/S0264127521008017 |
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