为了改善Fe-Ga合金的磁致伸缩性能, 采用真空非自耗电弧炉制备了Fe₈₃Ga₁₇Ce_x (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0)合金,用X射线衍射仪(XRD)和扫描电镜及能谱仪(SEM/EDS)分析了合金的微结构,用电阻应变法测量了合金的磁致伸缩性能. 结果表明: Fe₈₃Ga₁₇合金由单一的bcc结构A2相组成. 而添加稀土Ce后, 除x=0.2合金外,Fe₈₃Ga₁₇Ce_x合金主要由bcc结构的A2相和CeFe₂第二相组成.此外, Fe₈₃Ga₁₇合金的微观组织是晶粒粗大的等轴晶,而Fe₈₃Ga₁₇Ce_0.8合金的微观组织是晶粒细小的柱状晶.与Fe₈₃Ga₁₇对照合金相比, 除x=0.2合金的磁致伸缩系数略小于对照合金外,其他添加稀土Ce后的合金样品磁致伸缩系数均明显增加. 添加稀土Ce后,Fe₈₃Ga₁₇Ce_x合金的磁致伸缩系数随稀土Ce含量的增加呈现出先增加后减小的变化趋势, x=0.8合金的磁致伸缩系数最大,在557 kA/m外加磁场下, 磁致伸缩系数达到356×10^-6.

Fe-Ga alloy, which was a new type of magnetostrictive material with high magnetostriction, low hysteresis, high tensile strength and good machinability, has been widely studied. However, the magnetostrictive properties of the practically prepared Fe-Ga alloys were quite small at present. In order to improve magnetostrictive properties of the Fe-Ga alloy, the Fe₈₃Ga₁₇Ce_x (x=0.0, 0.2, 0.4, 0.6, 0.8, 1.0) alloys were prepared by non--consumable vacuum arc melting furnace using high purity elements under a protective argon atmosphere. The crystal structures and surface morphologies of the alloys were intensively studied by X--ray diffraction (XRD) and scanning electron microscopy (SEM) combined with energy—dispersive spectroscopy (EDS), respectively. The magnetostriction coefficients of the alloys were measured by means of the resistance strain method. The results showed that Fe₈₃Ga₁₇ alloy is composed only of a single phase of A2 with bcc structure. However, the Fe₈₃Ga₁₇Ce_x alloys are composed of the A2 phase and a small amount of CeFe₂ secondary phase with MgCu₂ structure except the alloy with x=0.2, which is composed only of a single phase of A2. Furthermore, the microstructure of the Fe₈₃Ga₁₇ alloy presents the equiaxial morphology with coarse grains. However, the microstructure of the Fe₈₃Ga₁₇Ce_0.8 alloy is a columnar structure with fine grains. Compared with the Fe₈₃Ga₁₇ alloy, the magnetostriction coefficients of the Fe₈₃Ga₁₇Ce_x alloys are increased significantly except the alloy with x=0.2. The magnetostriction coefficient of the Fe₈₃Ga₁₇Ce_0.2 alloy (81×10^-6) is slightly smaller than that of the Fe₈₃Ga₁₇ alloy (84×10^-6). With the increase of the rare earth Ce content, the magnetostriction coefficients of the Fe₈₃Ga₁₇Ce_x alloys increase firstly and then decrease. When x=0.8, the maximum magnetostriction coefficient of 356×10^-6 is obtained at the magnetic field of 557 kA/m.For the Fe₈₃Ga₁₇Ce_x alloys except the alloy with x=0.2, the noticeable increase of the magnetostriction coefficients derives from the following reasons: (1) the secondary phase of CeFe₂ with MgCu₂ structure appears and increases with the increase of the rare earth Ce content in the alloys. (2) the preferred orientation along <100>of A2 phase of the Fe₈₃Ga₁₇Ce_x alloy is more favorable to the increase of magnetostriction coefficient of Fe-Ga alloy. As for the Fe₈₃Ga₁₇Ce_0.2 alloy, the decrease of magnetostriction coefficient is attributed to the fact that the rare earth Ce dissolves in the Fe-Ga alloy and forms the solid solution alloy.