Phase Equilibria and Phase Transition of the Ni–Fe–Ga Ferromagnetic Shape Memory Alloy System
Phase Equilibria and Phase Transition of the Ni–Fe–Ga Ferromagnetic Shape Memory Alloy System
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DOI：
10.1007/s11661-007-9095-8
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发表时间：
2007-04
期刊：
影响因子：
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通讯作者：
K. Oikawa;T. Omori;Y. Sutou;H. Morito;R. Kainuma;K. Ishida
中科院分区：
文献类型：
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作者：
K. Oikawa;T. Omori;Y. Sutou;H. Morito;R. Kainuma;K. Ishida
研究了Ni-Fe-Ga系β（B2和L21）相的相平衡、马氏体相变和磁相变。发现B相与γ（A1结构）或γ '（L12结构）相处于平衡状态。β单相合金的居里温度Tc、平衡温度To 5（Ms + Af）/2、马氏体相变开始温度Ms和逆相变结束温度Af对Fe和Ga的含量敏感。Fe替代Ni使T0和Tc分别降低和升高。Ga替代Ni或Fe使T0和Tc均降低。伴随着逆马氏体相变的熵变表现出成分依赖性，由于磁的贡献。Ni-Fe-Ga系统的饱和磁化强度Is与磁价ZM有很强的依赖关系。Ni-Fe-Ga合金在1023 K退火后的Is值与其它铁磁形状记忆合金（FSMA）一样，具有Zm依赖性。
Phase equilibria and martensitic and magnetic transitions of the β (B2 and L21) phase in the Ni–Fe–Ga system were investigated. The b phase was found to be in equilibrium with the γ (A1 structure) or γ′ (L12structure) phase. The Curie temperature, Tc, equilibrium temperature, To5 (Ms + Af)/2, martensitic transition starting temperature,Ms, and reverse transition finishing temperature, Af , of the β single–phase alloys were sensitive to the Fe and Ga compositions. The Fe substitution for Ni decreased and increased theToandTc, respectively. The Ga substitution for Ni or Fe decreased both theToandTc. The entropy change accompanying the reverse martensitic transition showed compositional dependence due to the magnetic contribution. The saturation magnetizationIsof the Ni–Fe–Ga system showed a strong dependence on the magnetic valenceZM. The Is values of the Ni–Fe–Ga alloys annealed at 1023 K showed the sameZmdependence as other ferromagnetic shape memory alloy (FSMA) systems.