Giant segregation transition as origin of liquid metal embrittlement in the Fe-Zn system

التفاصيل البيبلوغرافية
العنوان: Giant segregation transition as origin of liquid metal embrittlement in the Fe-Zn system
المؤلفون: Kamachali, Reza Darvishi, Wallis, Theophilus, Ikeda, Yuki, Saikia, Ujjal, Ahmadian, Ali, Liebscher, Christian H., Hickel, Tilmann, Maaß, Robert
المصدر: Scripta Materialia 238 (2024) 115758
سنة النشر: 2023
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Materials Science
الوصف: A giant Zn segregation transition is revealed using CALPHAD-integrated density-based modelling of segregation into Fe grain boundaries (GBs). The results show that above a threshold of only a few atomic percent Zn in the alloy, a substantial amount of up to 60 at.\% Zn can segregate to the GB. We found that the amount of segregation abruptly increases with decreasing temperature, while the Zn content in the alloy required for triggering the segregation transition decreases. Direct evidence of the Zn segregation transition is obtained using high-resolution scanning transmission electron microscopy. Base on the model, we trace the origin of the segregation transition back to the low cohesive energy of Zn and a miscibility gap in Fe-Zn GB, arising from the magnetic ordering effect, which is confirmed by ab-initio calculations. We also show that the massive Zn segregation resulting from the segregation transition greatly assists with liquid wetting and reduces the work of separation along the GB. The current predictions suggest that control over Zn segregation, by both alloy design and optimizing the galvanization and welding processes, may offer preventive strategies against liquid metal embrittlement.
Comment: Original work, Letter, 14 pages including supplementary material (SM), 8 figures (3 in SM), 2 tables in SM
نوع الوثيقة: Working Paper
DOI: 10.1016/j.scriptamat.2023.115758
URL الوصول: http://arxiv.org/abs/2304.13336
رقم الأكسشن: edsarx.2304.13336
قاعدة البيانات: arXiv
الوصف
DOI:10.1016/j.scriptamat.2023.115758