Fe-Ga合金微结构与磁致伸缩的关系研究
发布时间：2025-05-04 18:12
固溶体型Fe-Ga磁致伸缩材料具有低场大磁致伸缩特性,与具有本征脆性的化合物型REFe2相比,具有更好的延展性和温度稳定性,因此在致动器、传感器和换能器等领域具有更好的应用前景,是近20年来磁致伸缩材料领域的研究热点。由于Fe-Ga合金具有结构多样性,且平衡态与亚稳态的结构差异巨大,因此磁致伸缩性能对热历史非常敏感。然而,这种热历史敏感性的微结构根源富有极大争议,成为该合金大磁致伸缩效应发现20年以来仍未解决的一个基础问题。为此,本文选择具有磁致伸缩峰值的成分Fe81Ga19进行研究,通过改变热处理条件,采用X射线衍射、透射电子显微镜、光学显微镜、磁性测量和力学性能测试等手段,系统研究介于亚稳和平衡态之间中间态的微结构和磁致伸缩性能差异,揭示了热历史敏感性的微结构根源,并在此基础上提出了进一步提高磁致伸缩性能的策略。主要结果如下:首先,揭示了Fe-Ga合金磁致伸缩热历史敏感性的微结构根源。已有的研究表明,慢冷Fe-Ga合金的磁致伸缩性能远低于高温淬火态,将其归因于慢冷过程中形成了对磁致伸缩有害的D03有序相。然而,我们的对比研究表明,Fe81Ga19多晶样品慢冷至A2固溶线附近温度再淬火...
【文章页数】：125 页
【学位级别】：博士
【文章目录】：
Acknowledgement
Dedication
Abstract
摘要
1 Introduction
1.1 Background
1.2 Magnetostriction and the proposed mechanisms for Fe-Ga alloy
1.3 Investigations on the thermal history sensitivity of magnetostriction
1.4 Motivation
2 Experimental Techniques
2.1 Sample Preparation and heat-treatments
2.1.1 Preparation of polycrystalline sample
2.1.2 Heat-Treatments
2.2 Microstructure Characterizations
2.2.1 X-ray diffraction (XRD)
2.2.2 Transmission Electron Microscopy (TEM)
2.3 Magnetic measurements
2.4 Mechanical tests
3 Microstructural origin of the thermal history sensitivity in slowly cooled FesiGai9
3.1 Introduction
3.2 Experimental Procedure
3.3 Results and Discussion
3.3.1 Magnetostrictive Properties
3.3.2 Microstructure
3.3.3 Discussion
3.4 Conclusion
4 Search for maximum magnetostriction in Fe81Ga19 by quenching above and below thedecomposition phase boundary
4.1 Introduction
4.2 Experimental Procedure
4.3 Results and discussion
4.3.1 Magnetostrictive properties
4.3.2 Microstructure
4.3.3 Mechanical Properties
4.3.4 Discussion
4.4 Conclusions
5 Enhanced magnetostriction of Fe81Ga19 hot-rolled sheets by approaching an instablephase boundary
5.1 Introduction
5.2 Experimental Procedure
5.3 Results and Discussion
5.4 Conclusions
6 Conclusions and Perspectives
6.1 Conclusions
6.2 Perspectives
References
Publication list
Curriculum vitae
本文编号：4042698
【文章页数】：125 页
【学位级别】：博士
【文章目录】：
Acknowledgement
Dedication
Abstract
摘要
1 Introduction
1.1 Background
1.2 Magnetostriction and the proposed mechanisms for Fe-Ga alloy
1.3 Investigations on the thermal history sensitivity of magnetostriction
1.4 Motivation
2 Experimental Techniques
2.1 Sample Preparation and heat-treatments
2.1.1 Preparation of polycrystalline sample
2.1.2 Heat-Treatments
2.2 Microstructure Characterizations
2.2.1 X-ray diffraction (XRD)
2.2.2 Transmission Electron Microscopy (TEM)
2.3 Magnetic measurements
2.4 Mechanical tests
3 Microstructural origin of the thermal history sensitivity in slowly cooled FesiGai9
3.1 Introduction
3.2 Experimental Procedure
3.3 Results and Discussion
3.3.1 Magnetostrictive Properties
3.3.2 Microstructure
3.3.3 Discussion
3.4 Conclusion
4 Search for maximum magnetostriction in Fe81Ga19 by quenching above and below thedecomposition phase boundary
4.1 Introduction
4.2 Experimental Procedure
4.3 Results and discussion
4.3.1 Magnetostrictive properties
4.3.2 Microstructure
4.3.3 Mechanical Properties
4.3.4 Discussion
4.4 Conclusions
5 Enhanced magnetostriction of Fe81Ga19 hot-rolled sheets by approaching an instablephase boundary
5.1 Introduction
5.2 Experimental Procedure
5.3 Results and Discussion
5.4 Conclusions
6 Conclusions and Perspectives
6.1 Conclusions
6.2 Perspectives
References
Publication list
Curriculum vitae
本文编号：4042698
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