Decoupling early-stage cracking and propagation mechanisms in liquid metal embrittlement of Zn-galvanised TWIP steel
Liquid metal embrittlement (LME) presents a major barrier to the widespread adoption of advanced high-strength steels in automotive applications. Despite extensive research, decoupling its early-stage cracking and propagation micromechanisms remains challenging and is a key research gap. Distinguish...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2025-09-01
|
| Series: | Journal of Materials Research and Technology |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2238785425020083 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849236168616443904 |
|---|---|
| author | Virgínia Bertolo Gautham Mahadevan René de Kloe Roumen H. Petrov Vera Popovich |
| author_facet | Virgínia Bertolo Gautham Mahadevan René de Kloe Roumen H. Petrov Vera Popovich |
| author_sort | Virgínia Bertolo |
| collection | DOAJ |
| description | Liquid metal embrittlement (LME) presents a major barrier to the widespread adoption of advanced high-strength steels in automotive applications. Despite extensive research, decoupling its early-stage cracking and propagation micromechanisms remains challenging and is a key research gap. Distinguishing these stages is crucial to understanding the conditions and factors that are favourable for LME and to developing mitigation strategies. Moreover, it can improve the accuracy of predictive models through detailed knowledge from initiation to propagation. In this study, this challenge is addressed by performing interrupted Gleeble hot tensile tests on a Zn-galvanised twinning-induced plasticity steel, simulating resistance spot welding conditions. This approach enables tracking LME progression under applied stress and identifying fracture micromechanisms at early and advanced stages of cracking. Additionally, existing theories on LME micromechanisms are often contradictory, highlighting the need for fundamental research in this area. The findings reveal that LME begins with the contact between liquid Zn and the substrate, leading to Zn diffusion into the substrate by diffusion-induced grain boundary migration and dissolution of the substrate by erosion-corrosion. This dissolution generates defects on the substrate and facilitates Fe diffusion into liquid Zn. Subsequently, defects are filled with liquid and the Zn-rich defect tips, connected to grain boundaries, enhance Zn grain boundary diffusion and weaken intergranular cohesion. Under tensile stress, these weakened boundaries decohere and lead to crack nucleation. Newly formed crack surfaces allow fresh Fe-rich liquid Zn to penetrate, continuing the process until fracture. Future work will focus on the influence of microstructure on LME crack growth. |
| format | Article |
| id | doaj-art-08aae5237d2f4e42b95c404270653eef |
| institution | Kabale University |
| issn | 2238-7854 |
| language | English |
| publishDate | 2025-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Materials Research and Technology |
| spelling | doaj-art-08aae5237d2f4e42b95c404270653eef2025-08-20T04:02:26ZengElsevierJournal of Materials Research and Technology2238-78542025-09-01381617163210.1016/j.jmrt.2025.08.055Decoupling early-stage cracking and propagation mechanisms in liquid metal embrittlement of Zn-galvanised TWIP steelVirgínia Bertolo0Gautham Mahadevan1René de Kloe2Roumen H. Petrov3Vera Popovich4Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CN, Delft, the Netherlands; Department of Electromechanical, Systems and Metals Engineering, Ghent University, Technologiepark 131, B-9052, Ghent, Belgium; Corresponding author. Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CN, Delft, the Netherlands.Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CN, Delft, the Netherlands; Department of Electromechanical, Systems and Metals Engineering, Ghent University, Technologiepark 131, B-9052, Ghent, BelgiumEDAX-Gatan, AMETEK BV, Ringbaan Noord 103, 5046 AA, Tilburg, the NetherlandsDepartment of Electromechanical, Systems and Metals Engineering, Ghent University, Technologiepark 131, B-9052, Ghent, BelgiumDepartment of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CN, Delft, the NetherlandsLiquid metal embrittlement (LME) presents a major barrier to the widespread adoption of advanced high-strength steels in automotive applications. Despite extensive research, decoupling its early-stage cracking and propagation micromechanisms remains challenging and is a key research gap. Distinguishing these stages is crucial to understanding the conditions and factors that are favourable for LME and to developing mitigation strategies. Moreover, it can improve the accuracy of predictive models through detailed knowledge from initiation to propagation. In this study, this challenge is addressed by performing interrupted Gleeble hot tensile tests on a Zn-galvanised twinning-induced plasticity steel, simulating resistance spot welding conditions. This approach enables tracking LME progression under applied stress and identifying fracture micromechanisms at early and advanced stages of cracking. Additionally, existing theories on LME micromechanisms are often contradictory, highlighting the need for fundamental research in this area. The findings reveal that LME begins with the contact between liquid Zn and the substrate, leading to Zn diffusion into the substrate by diffusion-induced grain boundary migration and dissolution of the substrate by erosion-corrosion. This dissolution generates defects on the substrate and facilitates Fe diffusion into liquid Zn. Subsequently, defects are filled with liquid and the Zn-rich defect tips, connected to grain boundaries, enhance Zn grain boundary diffusion and weaken intergranular cohesion. Under tensile stress, these weakened boundaries decohere and lead to crack nucleation. Newly formed crack surfaces allow fresh Fe-rich liquid Zn to penetrate, continuing the process until fracture. Future work will focus on the influence of microstructure on LME crack growth.http://www.sciencedirect.com/science/article/pii/S2238785425020083Liquid metal embrittlementFracture onsetMicromechanismsZn-galvanisedTWIP steelInterrupted testing |
| spellingShingle | Virgínia Bertolo Gautham Mahadevan René de Kloe Roumen H. Petrov Vera Popovich Decoupling early-stage cracking and propagation mechanisms in liquid metal embrittlement of Zn-galvanised TWIP steel Journal of Materials Research and Technology Liquid metal embrittlement Fracture onset Micromechanisms Zn-galvanised TWIP steel Interrupted testing |
| title | Decoupling early-stage cracking and propagation mechanisms in liquid metal embrittlement of Zn-galvanised TWIP steel |
| title_full | Decoupling early-stage cracking and propagation mechanisms in liquid metal embrittlement of Zn-galvanised TWIP steel |
| title_fullStr | Decoupling early-stage cracking and propagation mechanisms in liquid metal embrittlement of Zn-galvanised TWIP steel |
| title_full_unstemmed | Decoupling early-stage cracking and propagation mechanisms in liquid metal embrittlement of Zn-galvanised TWIP steel |
| title_short | Decoupling early-stage cracking and propagation mechanisms in liquid metal embrittlement of Zn-galvanised TWIP steel |
| title_sort | decoupling early stage cracking and propagation mechanisms in liquid metal embrittlement of zn galvanised twip steel |
| topic | Liquid metal embrittlement Fracture onset Micromechanisms Zn-galvanised TWIP steel Interrupted testing |
| url | http://www.sciencedirect.com/science/article/pii/S2238785425020083 |
| work_keys_str_mv | AT virginiabertolo decouplingearlystagecrackingandpropagationmechanismsinliquidmetalembrittlementofzngalvanisedtwipsteel AT gauthammahadevan decouplingearlystagecrackingandpropagationmechanismsinliquidmetalembrittlementofzngalvanisedtwipsteel AT renedekloe decouplingearlystagecrackingandpropagationmechanismsinliquidmetalembrittlementofzngalvanisedtwipsteel AT roumenhpetrov decouplingearlystagecrackingandpropagationmechanismsinliquidmetalembrittlementofzngalvanisedtwipsteel AT verapopovich decouplingearlystagecrackingandpropagationmechanismsinliquidmetalembrittlementofzngalvanisedtwipsteel |