论文部分内容阅读
详细研究了Ni50Mn38-xIn12Fex(x=0,3,4,5,6)合金体系中Fe取代Mn对合金马氏体相变行为及磁学性能的影响。发现当x≤4时,合金表现出由B2结构的奥氏体向正交结构的马氏体转变的相变行为,而当x≥5时该相变被完全抑制。当Fe对Mn的取代超过3%时,合金的显微结构中出现γ相,并发现其数量随Fe含量的增加而增加。γ相的形成改变了合金基体相成分,进而带来了基体相e/a(每原子的电子浓度)值的变化,研究结果证明合金的一系列性能改变均与基体相e/a值的变化相关。第一,基体相e/a(每原子的电子浓度)值随着Fe含量的增加而迅速减小,导致了合金马氏体相变温度、相变潜热及相变熵变的降低。第二,Fe的引入有效地增强了合金基体相的铁磁性能,提高了合金的居里转变温度和合金的磁化强度。详细阐述了Fe的引入是合金马氏体相变及磁学性能变化的本质原因。
The effects of Fe substitution for Mn on the martensitic transformation behavior and magnetic properties of the alloy in Ni50Mn38-xIn12Fex (x = 0,3,4,5,6) alloy were investigated in detail. It is found that when x≤4, the alloy exhibits the transformation behavior of martensitic transformation from the B2 structure to the orthorhombic structure, whereas the transformation is completely suppressed when x ≧ 5. When the Fe substitution of Mn exceeds 3%, the γ phase appears in the microstructure of the alloy, and the amount of γ phase increases with the increase of Fe content. The formation of γ phase changes the phase composition of the alloy matrix, which in turn leads to the change of e / a (electron concentration per atom) of the matrix phase. The results show that the series of properties of the alloy change with the change of the e / a value Related. First, the value of e / a (the electron concentration per atom) decreases rapidly with the increase of Fe content, which leads to the decrease of the martensitic transformation temperature, the latent heat of transformation and the entropy change of the phase transformation. Second, the introduction of Fe effectively enhanced the ferromagnetic properties of the alloy matrix phase and improved the Curie temperature and the magnetization of the alloy. It is elaborated that the introduction of Fe is the essential reason for martensitic transformation and the change of magnetic properties.