阅读说明：本技术 一种提高铁镍合金有序转变温度的方法 (Method for increasing ordered transformation temperature of iron-nickel alloy ) 是由 王鑫铭 文涛 娄嘉 陈夏琪 陈永志 于 2020-06-11 设计创作，主要内容包括：本项目提出了一种提高铁镍合金有序转变温度的方法,该方法是在Fe-Ni粉末中加入Cu粉,从而提高其有序转变温度。一般来说,在Fe-Ni体系中发生有序相转变的温度条件非常严苛,只能在320℃以下才能发生转变。本专利采用Fe:Ni:Cu＝50:50-X:X(X＝0～1.5)的比例由平均粒度为7～9微米Fe、Ni细粉和平均粒度为20～25微米的Cu粗粉混合而成。经过烧结完成后再在特定温度回火,在合金中观察到L1<Sub>0</Sub>相。实验表明有序转变温度提高了15℃,合金饱和磁感应强度最大可达1.60T。本方法工艺简单,无需添加昂贵的稀土元素,为高性能磁性材料的研究和应用提供了新的方向。(The project provides a method for improving the ordered transition temperature of iron-nickel alloy, which is to add Cu powder into Fe-Ni powder so as to improve the ordered transition temperature. Generally, the temperature conditions for ordered phase transformation in the Fe-Ni system are very severe, and transformation can only occur below 320 ℃. The alloy is prepared by mixing Fe, Ni and Cu with the ratio of 50:50-X: X (X is 0-1.5) and fine Ni powder with the average particle size of 7-9 microns and Cu coarse powder with the average particle size of 20-25 microns. After sintering, tempering at a specific temperature was carried out, and L1 was observed in the alloy 0 And (4) phase(s). Experiments show that the ordered transformation temperature is increased by 15 ℃, and the alloy saturation magnetic induction intensity can reach 1.60T at most. The method has simple process and no need of addingAdding expensive rare earth elements provides a new direction for the research and application of high-performance magnetic materials.)

1. The method for improving the order transition temperature of the iron-nickel alloy is characterized in that the iron-nickel alloy is prepared by taking Fe, Ni and Cu powder as raw materials, and the mass ratio of the raw materials of the powder Fe to Ni to Cu is 50:50-X to X (X is 0-1.5).

2. The method of claim 1, wherein the alloy powder is formed by mixing fine Fe and Ni powders having an average particle size of 7 to 9 μm and coarse Cu powder having an average particle size of 20 to 25 μm.

3. The method for increasing the order transition temperature of the iron-nickel alloy according to claim 1 or 2, wherein the Fe-Ni-Cu powder is subjected to tempering treatment after sintering, the temperature is 320-340 ℃, and the holding time is 30-90 days.

4. The Fe-Ni alloy obtained according to claim 1, 2 or 3, wherein the Fe-Ni alloy obtained by the method is excellent in magnetic property by VSM test, and the saturation induction can reach 1.60T at most.

5. Iron-nickel alloy according to claim 1 or 2 or 3 or 4, characterized in that it is obtained by means of a slow sweep by X-ray diffractometer (XRD) at 5 degrees per minute, with L1 being clearly observed at 34.5 degrees₀Diffraction peak of phase (100), while L1 was observed by Transmission Electron Microscope (TEM)₀A superlattice pattern of the (101) crystal plane.

Technical Field

The invention belongs to the field of magnetic materials, relates to an iron-nickel material, and particularly relates to a method for preparing L1 with excellent magnetic property in iron-nickel-based alloy with nearly equal atomic ratio₀In addition, the present invention raises the temperature of ordered transition by replacing nickel atoms with copper atoms.

Background

The iron-nickel alloy is a soft magnetic material widely applied at present and is in the near-isogenic fieldIn the case of the sub-ratio, a disordered Al phase and ordered L1 can be formed₀And (4) phase(s). Wherein L1₀The phases have superior magnetic properties, but their formation is subject to severe thermodynamic and exceptionally slow kinetic conditions. At present, the atom migration can only be initiated by using methods such as electrons, neutron irradiation, nanoparticle technology, mechanical alloying, large plastic deformation and the like, so that the small-volume L1 is obtained₀And (4) phase(s). However, these methods are to promote L1 from the viewpoint of dynamics₀The formation of a phase does not thermodynamically increase its order transition temperature. For Fe-Ni alloys, L1₀The phase ordering temperature is 320 ℃ and only below this temperature L1 is formed₀And (4) phase(s). Near this temperature, diffusion of Fe and Ni is very difficult, making large volumes of L1 unproductive under laboratory preparation₀And (4) phase(s).

Disclosure of Invention

The technical problem to be solved by the invention is as follows: l1 in bulk iron-nickel based material₀The formation of the phase is limited by its severe thermodynamics, at preparation temperatures below 320 ℃, where the atomic diffusion rate is extremely slow and it is almost impossible to form large volumes of L1₀And (4) phase(s).

In order to solve the technical problem, the technical scheme of the invention is to increase the order transition temperature of the iron-nickel alloy, wherein the iron-nickel alloy is prepared from powders of Fe, Ni, Cu and the like serving as raw materials in a mass ratio of Fe to Ni to Cu of 50 to 50-X to X (X of 0-1.5). The alloy powder is formed by mixing fine Fe and Ni powder with the average particle size of 7-9 micrometers and coarse Cu powder with the average particle size of 20-25 micrometers. Increasing the order transition temperature of the Fe-Ni alloy by adding Cu so that L1 is formed₀The temperature range of the phase is wider, and the diffusion rate between Fe atoms and Ni atoms is improved, so that the transition temperature is increased. The method can prepare the Fe-Ni-based alloy with larger ordered transition temperature range and excellent magnetic property.

The invention provides an iron-nickel alloy which is prepared by a powder metallurgy method. The powder is composed of Fe, Ni and Cu in a mass ratio of 50:50-X: X (X is 0-1.5), wherein the alloy powder is formed by mixing Fe and Ni fine powder with an average particle size of 8.5 microns and Cu coarse powder with an average particle size of 25 microns, and a sintered blank with a density of more than 97% is obtained through pressing and vacuum sintering. And then putting the alloy into a vacuum quartz tube and tempering the alloy in a box furnace for a long time at the tempering temperature of 320-340 ℃ for 7-90 days.

According to the invention, Cu is added into the Fe-Ni alloy to replace Ni, so that an austenite phase region can be expanded to a certain extent, and formation of L1 at a higher temperature is facilitated₀Phase, and increased atomic diffusion rate at higher temperatures, can result in more voluminous and larger L1₀And (4) phase(s). The saturation induction density of the prepared alloy is obviously improved and exceeds the range of disordered A1 phase alloy (not more than 1.52T), and the maximum saturation induction intensity is 1.60T. The method does not need to add expensive rare earth elements, has low cost and simple process, and most importantly provides a new direction for the application range of the novel high-performance magnetic material.

L1 was observed at 34.5 degrees in the iron-nickel alloy by X-ray diffractometer (XRD)₀The diffraction peak of phase (100) is shown in FIG. 1. Meanwhile, the high power electron microscope can obviously observe that L1 exists in the alloy₀Phase, and this L1 can be confirmed by transmission electron microscopy₀The morphology and diffraction pattern of the phase ordered structure are shown in FIGS. 2 and 3.

Drawings

FIG. 1 is L1 of an alloy obtained in example 2 of the present invention₀XRD pattern of the phases.

FIG. 2 shows the observation of L1 under a transmission electron microscope₀Topography of phase particles.

FIG. 3 is L1 of an alloy obtained in example 2 of the present invention₀Diffraction pattern of the phases.

Detailed Description