Microscopic phase-field method was used to simulate the site occupation of a series of alloys with a stoichiometric composition of Ni75Al25?xFex (x=0, 5?10) aged at 1273 K. With the change of Fe content, quantitative ...Microscopic phase-field method was used to simulate the site occupation of a series of alloys with a stoichiometric composition of Ni75Al25?xFex (x=0, 5?10) aged at 1273 K. With the change of Fe content, quantitative calculations were made on each atomic site occupation probability (SOP) in L12-Ni3 (Al1?xFex), so as to find out the dynamic response law. The result of the study shows that, with the increase of Fe content, the Fe atom preferentially occupies the B sites (corner sites of FCC) with its SOP value being increased gradually, and the SOP of the Al atom on the B sites is greatly decreased. Meanwhile, AlNi and FeNi anti-sites form in the precipitation of L12 phase. Moreover, with the increase of Fe content, the formation of AlNi and FeNi anti-sites becomes much easier. In addition, it has been found that the instantaneous dynamic evolution of the atomic SOP is completed at the early stage of the growth of L12 phases.展开更多
The microstructure and phase relationship of (Dy0.65Tb0.25Pr0.1)Fex alloys in the composition range of 1.6≤x≤2.1 were investigated using optical microscopy, X-ray diffraction , DTA and EPMA techniques. The variatio...The microstructure and phase relationship of (Dy0.65Tb0.25Pr0.1)Fex alloys in the composition range of 1.6≤x≤2.1 were investigated using optical microscopy, X-ray diffraction , DTA and EPMA techniques. The variations of microstructure and lattice parameter with the iron content,the effect of heat treatment on the microstructure and the phase relationship have been studied.The phase relationship in the vicinity of the Laves phase is proposed展开更多
The structure and magnetostriction of R_0.5Pr_0.5Fex (R = Dy_0.7Tb_0.3,1.10 ≤x≤1.85) alloys were investigated. It was found that the matrix of arc-melting R_0.5Pr_0.5Fe_x alloys is the (Dy, Tb, Pr) Fe_2 phase with t...The structure and magnetostriction of R_0.5Pr_0.5Fex (R = Dy_0.7Tb_0.3,1.10 ≤x≤1.85) alloys were investigated. It was found that the matrix of arc-melting R_0.5Pr_0.5Fe_x alloys is the (Dy, Tb, Pr) Fe_2 phase with the MgCu_2-type cubic structure and the second phase is rare earth-rich phase when x<1.25. In the range of 1.40≤x<1.55, the second phase is (Dy, Tb, Pr)Fe_3 and it becomes the main phase when x >1.55. The crystalline structure of mechanically grinding R_0.5Pr_0.5Fe_x alloys is similar to that of the arc-melted alloys. The magnetostriction of the alloys increases with increasing Fe content when x ≤1.25 and decreases when x >1.25.展开更多
基金Project(2013011014-1)supported by the Natural Science Funds of Shanxi Province,ChinaProject(2009021028)supported by Science and Technique Foundation for Young Scholars of Shanxi Province,China
文摘Microscopic phase-field method was used to simulate the site occupation of a series of alloys with a stoichiometric composition of Ni75Al25?xFex (x=0, 5?10) aged at 1273 K. With the change of Fe content, quantitative calculations were made on each atomic site occupation probability (SOP) in L12-Ni3 (Al1?xFex), so as to find out the dynamic response law. The result of the study shows that, with the increase of Fe content, the Fe atom preferentially occupies the B sites (corner sites of FCC) with its SOP value being increased gradually, and the SOP of the Al atom on the B sites is greatly decreased. Meanwhile, AlNi and FeNi anti-sites form in the precipitation of L12 phase. Moreover, with the increase of Fe content, the formation of AlNi and FeNi anti-sites becomes much easier. In addition, it has been found that the instantaneous dynamic evolution of the atomic SOP is completed at the early stage of the growth of L12 phases.
文摘The microstructure and phase relationship of (Dy0.65Tb0.25Pr0.1)Fex alloys in the composition range of 1.6≤x≤2.1 were investigated using optical microscopy, X-ray diffraction , DTA and EPMA techniques. The variations of microstructure and lattice parameter with the iron content,the effect of heat treatment on the microstructure and the phase relationship have been studied.The phase relationship in the vicinity of the Laves phase is proposed
基金National Natural Science Foundation of China!(No. 59871030) National Natural Science Foundation of Liaoning Province
文摘The structure and magnetostriction of R_0.5Pr_0.5Fex (R = Dy_0.7Tb_0.3,1.10 ≤x≤1.85) alloys were investigated. It was found that the matrix of arc-melting R_0.5Pr_0.5Fe_x alloys is the (Dy, Tb, Pr) Fe_2 phase with the MgCu_2-type cubic structure and the second phase is rare earth-rich phase when x<1.25. In the range of 1.40≤x<1.55, the second phase is (Dy, Tb, Pr)Fe_3 and it becomes the main phase when x >1.55. The crystalline structure of mechanically grinding R_0.5Pr_0.5Fe_x alloys is similar to that of the arc-melted alloys. The magnetostriction of the alloys increases with increasing Fe content when x ≤1.25 and decreases when x >1.25.
