Influence of thermal treatment conditions on recovery stress formation in an FeMnSi-SMA

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:802

Article

Yang, Yajiao^1,2  Arabi-Hashemi, Ariyan¹  Leinenbach, Christian¹  Shahverdi, Moslem^1,3 

[1] Empa, Swiss Fed Labs Mat Sci & Technol, Dubendorf, Switzerland

[2] ETH, Lab Multifunct Ferro Mat, Zurich, Switzerland

[3] Univ Tehran, Sch Civil Engn, 16th Azar St, Tehran, Iran

关键词: Recovery stress;    FeMnSi;    Precipitate;    Heat treatment;    Shape memory alloy;    Martensite;    Pseudoelasticity;   

DOI  :  10.1016/j.msea.2020.140694

来源: Elsevier

【 摘 要 】

In the current study, a broad experimental program was designed and conducted to investigate the effect of aging conditions (i.e., aging temperature and time) on the thermomechanical properties (0.1% yield stress, pseudoelasticity, and recovery stress) of an FeMnSi-based shape memory alloy (FeMnSi-SMA) with a chemical composition of Fe-17Mn-5Si-10Cr-4Ni-1(V, C) (wt.%). In addition, transmission electron microscopy (TEM) was used to study the specimens' microstructures under several selected aging conditions. It was found that the aging conditions significantly affected the formation and distribution of precipitates and stacking faults in the aged specimens. At lower temperatures (e.g., 600 and 660 degrees C), numerous fine precipitates were randomly dispersed both in the austenite matrix and on/near stacking faults, resulting in higher yield stress and recovery stress. At elevated temperatures (e.g., 774 degrees C), the majority of the precipitates formed on/near stacking faults, leading to a lower yield stress and recovery stress. Besides, as the aging time increased, the pseudoelasticity increased at all aging temperatures.

【 授权许可】

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