阅读说明：本技术 一种多晶FeNiCoAlNbV超弹性合金及其制备方法 (Polycrystalline FeNiCoAlNbV hyperelastic alloy and preparation method thereof ) 是由 张洋 杜康 张中武 黄涛 马亚玺 郁永政 黄楷岚 于 2021-07-19 设计创作，主要内容包括：本发明公开一种多晶FeNiCoAlNbV超弹性合金及其制备方法,该超弹性合金的表达式为Fe-(a)Ni-(b)Co-(c)Al-(d)Nb-(e)V-(f),合金表达式中a,b,c,d,e,f分别表示对应各组元的原子百分比含量,且满足以下条件：a为35～60,b为25～50,c为8～35,d为1～20,e为1～5,f为1～5,a+b+c+d+e+f＝100。本发明的超弹性合金在热处理方面进行了优化,均匀化之后直接进行冷轧,然后时效,工艺更加简化,过程更加可控。该超弹性合金通过调整每个组元的含量来调控纳米沉淀相的析出体积分数,以获得薄片状马氏体,促进热弹性马氏体转变,从而获得高塑性、高强度和大的可回复应变。(The invention discloses a polycrystalline FeNiCoAlNbV hyperelastic alloy and a preparation method thereof, wherein the expression of the hyperelastic alloy is Fe a Ni b Co c Al d Nb e V f In the formula of the alloy, a, b, c, d, e and f are respectively shown in the tableThe atom percentage content of each corresponding component is shown, and the following conditions are met: a is 35 to 60, b is 25 to 50, c is 8 to 35, d is 1 to 20, e is 1 to 5, f is 1 to 5, and a + b + c + d + e + f is 100. The super-elastic alloy is optimized in the aspect of heat treatment, is directly cold-rolled after being homogenized, and is aged, so that the process is simplified, and the process is controllable. The super-elastic alloy regulates and controls the precipitation volume fraction of a nano precipitated phase by adjusting the content of each component to obtain sheet martensite and promote the transformation of the thermo-elastic martensite, thereby obtaining high plasticity, high strength and large recoverable strain.)

1. A polycrystalline FeNiCoAlNbV hyperelastic alloy is characterized in that,the expression of the super-elastic alloy is Fe_aNi_bCo_cAl_dNb_eV_fIn the alloy expression, a, b, c, d, e and f respectively represent the atom percentage content of each corresponding component, and the following conditions are met: a is 35 to 60, b is 25 to 50, c is 8 to 35, d is 1 to 20, e is 1 to 5, f is 1 to 5, and a + b + c + d + e + f is 100. The super-elastic alloy and the preparation method thereof comprise the following steps: mainly comprises the treatment processes of smelting, casting, homogenizing, cold rolling, aging and the like.

2. The method of producing a superelastic alloy according to claim 1, comprising the steps of: the super-elastic alloy is prepared according to the atomic percentage of each element in the super-elastic alloy, and is put into a smelting furnace to be smelted and cast into an alloy casting.

3. The method of claim 1 wherein the melting and casting process is performed under a gas blanket, and wherein the melting process utilizes a related stirring technique to mix the molten metal uniformly.

4. The method for preparing a superelastic alloy according to claim 1, wherein the homogenizing and cold rolling processes comprise: heating the casting to 1050-1250 ℃, preserving heat for 1-12 h, then performing water quenching, and performing cold rolling with large deformation of more than or equal to 90% at room temperature.

5. A method of making a superelastic alloy according to claim 1, wherein said aging is by the process of: aging at 550-700 ℃ for 1-90 h.

Technical Field

The invention relates to a polycrystalline FeNCoAlNbV hyperelastic alloy and a preparation method thereof, belonging to the technical field of hyperelastic alloys.

Background

Generally, a metal material deforms under the action of external force, and when the deformation is in an elastic stage, the material can recover the original state after being unloaded; when the deformation is larger than the elastic stage, the material is subjected to permanent plastic deformation, after the external force is removed, the material cannot be restored to the state before deformation, and the elastic strain of the metal material is generally limited to about 0.2%. However, there is a special class of metallic materials that, although deformed by a significantly greater amount than their elastic phase, pass through at A_fWhen the alloy is loaded above the point, the alloy will generate a certain strain due to stress-induced martensitic transformation, and when the load is removed, the strain will recover. Such metallic materials are known as superelastic alloys.

As one of the novel functional materials, the superelastic alloy has many specific functions such as good biocompatibility, better corrosion resistance, wear resistance, etc., as compared to other materials. Because of its many advantages, the super-elastic alloy is widely used in the fields of electronics, machinery, aerospace, ship damping and noise reduction, medical treatment, daily life and the like, and has a wide research prospect.

According to the composition of the material, the super-elastic alloy can be divided into three categories, namely Ti-Ni-based super-elastic alloy, Cu-based super-elastic alloy and Fe-based super-elastic alloyAn elastic alloy. The maximum recoverable strain energy of the Ti-Ni-based super-elastic alloy reaches about 8 percent, and the Ti-Ni-based super-elastic alloy has relatively mature application in industry, but has poor processing performance, complex smelting process, high preparation cost and high price, so that the practical application of the Ti-Ni-based super-elastic alloy is greatly limited. The maximum recoverable strain energy of the Cu-based superelasticity alloy reaches about 5%, and although the Cu-based superelasticity alloy has the advantages of excellent electric and heat conducting performance, adjustable temperature change in a wide range and the like, the Cu-based superelasticity alloy is unstable in performance, poor in corrosion resistance, low in strength and easy to break at grain boundaries, and development and application of the Cu-based superelasticity alloy are limited. Compared with Ti-Ni-based and Cu-based super-elastic alloys, the Fe-based super-elastic alloy has the advantages of excellent machining performance, rich raw material resources, low price, excellent mechanical property and the like, so that the Fe-based super-elastic alloy has great research value. However, most polycrystalline Fe-based superelastic alloys generally do not have superelasticity, as measured by metastable Ni₃Ti-γ'(L1₂) The Fe-Ni-Co-Ti alloy strengthened by coherent educts can obtain super elasticity only at minus 30 ℃, and the recoverable strain is only 0.7 percent, which is far from the requirement of practical production and application.

The Fe-Ni-Co-Al-Nb-V super-elastic alloy is developed by taking FeNiCoAl as a matrix, and the precipitation of a nano phase is regulated and controlled by adding Nb element to form a coherent stress field with a parent phase, so that the austenite matrix is strengthened to a certain extent, and the strength and the hardness of the alloy are improved; the thermal hysteresis is reduced by adding V elements with different proportions, the order degree and the strength of a parent phase are increased, and the tetragonal degree of martensite is improved, so that the super-elastic alloy has high strength and excellent plasticity, the defect of poor plasticity of the super-elastic alloy under the condition of high strength is overcome, and the recoverable strain is up to 5.7%.

The invention patent application of publication No. CN 103509988A discloses a polycrystalline Fe-Ni-Co-Al-Nb-B shape memory alloy with superelasticity and a preparation method thereof, wherein the shape memory alloy comprises the following components (at.%), Fe_aNi_bCo_cAl_dNb_eB_fIn the alloy expression, a, b, c, d, e and f respectively represent the atom percentage content of each corresponding component, and the following conditions are met: a is 30 to 50, b is 28 to 40, c is10 to 30, d is 8 to 15, e is 1 to 4, f is 0.1 to 3, and a + b + c + d + e + f is 100. The alloy of the patent shows good superelasticity, and is completely different from the heat treatment process of the invention in that the alloy is subjected to solid solution after hot rolling, then water quenching, then cold rolling, then secondary solid solution and finally aging. The heat treatment process of the alloy is homogenization, cold rolling and aging, so that the super-elastic alloy material is obtained, solution treatment is not needed, the process conditions are simplified, and the method is more suitable for industrial production practice.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the problem that the existing super-elastic alloy cannot simultaneously have high plasticity and high strength, the invention provides the super-elastic alloy with high plasticity and high strength, so that the super-elastic alloy has larger application potential, and provides a preparation method of the super-elastic alloy.

The technical scheme is as follows: the invention relates to a high-plasticity high-strength super-elastic alloy and a preparation method thereof, wherein the expression of the super-elastic alloy is Fe_aNi_bCo_cAl_dNb_eV_fIn the alloy expression, a, b, c, d, e and f respectively represent the atom percentage content of each corresponding principal component, and the following conditions are satisfied: a is 35 to 60, b is 25 to 50, c is 8 to 35, d is 1 to 20, e is 1 to 5, f is 1 to 5, and a + b + c + d + e + f is 100.

The invention principle and the component design of the high-strength high-plasticity super-elastic alloy are as follows:

the invention principle is as follows: compared with the super-elastic alloy of other inventions, the super-elastic alloy of the invention is more simplified in heat treatment process and can be better applied to industrial production, the metal ingot obtained by smelting is heated to 1050-1250 ℃ to homogenize the casting, the temperature is kept for 1-12 h at the temperature, then water quenching is carried out, and then cold rolling with large deformation of more than or equal to 90% is carried out at room temperature. And regulating the content of Nb and V elements to raise the volume fraction of precipitated nanophase, reduce heat stagnation and promote the transformation of thermoelastic martensite so as to obtain high-plasticity and high-strength alloy.

The basis of component design is as follows: the high-plasticity high-strength super-elastic alloy selects Fe, Ni, Co and Al as matrix phasesThe four elements, Fe is the main element of Fe-based super-elastic alloy, Ni is the important element influencing martensite phase transformation, and the increase of Ni content can effectively reduce the martensite phase transformation temperature, thereby strengthening Ni₃Al precipitates, and Al is favorable for forming Ni₃The important alloy elements of the Al precipitated phase can effectively reduce the martensite phase transformation volume by adding Co, thereby reducing the stress concentration of the alloy and improving the plasticity of the alloy. The addition of Nb not only promotes Ni₃The precipitation of Al phase can also refine grains, and effectively improve the plasticity and hardness of the alloy. The V element can effectively reduce the temperature of martensite phase transformation, so that the shape of the V element is changed from a lens shape to a sheet shape, which is beneficial to the super-elasticity obtaining and the mechanical property improvement of the alloy.

The invention relates to a high-plasticity high-strength super-elastic alloy and a preparation method thereof, which comprises the following steps:

(1) proportioning according to the atomic percentage of each element in the super-elastic alloy, putting the super-elastic alloy into a vacuum smelting furnace, smelting and casting to form an alloy ingot;

(2) homogenizing and cold rolling;

(3) and (5) aging treatment.

And (1) carrying out smelting and casting processes in gas protection, and uniformly mixing the metal solution by using a related stirring technology in the smelting process.

And (2) heating the casting to 1050-1250 ℃, preserving heat for 1-12 h, then performing water quenching, and performing cold rolling with large deformation of more than or equal to 90% at room temperature.

And (3) aging the rolled alloy at 550-700 ℃ for 1-90 h.

Has the advantages that: compared with the prior art, the invention has the advantages that: (1) the precipitation of the nano phase is strengthened by adding the Nb element, and the Nb element and the matrix are kept coherent to generate an elastic stress field, thereby being beneficial to the occurrence of thermoelastic martensite phase transformation; the thermal hysteresis is reduced by adding V element which is used as a stabilizer in the Ni-based high-temperature alloy, so that the gamma 'phase can be stabilized and the precipitation of the gamma' phase is promoted. (2) Compared with the preparation of other super-elastic alloys, the preparation method of the invention optimizes the heat treatment aspect, carries out water cooling after homogenization, keeps the mother phase in a high-temperature single-phase region, then carries out large-deformation cold rolling with the deformation of more than or equal to 90 percent at room temperature, promotes the generation of small-angle grain boundaries, improves the strength of the recrystallized texture, inhibits the segregation of elements and the formation of beta-NiAl phase, and then carries out aging, thereby avoiding the reduction of the strength of the recrystallized texture due to solid solution treatment. The invention has the advantages of simpler process, more controllable process, greatly reduced aging time and easy realization of industrial production.

Drawings

FIG. 1 is a microstructure of the Fe-Ni-Co-Al-Nb-V alloy of example 1 after aging at 600 ℃ for 21 hours in accordance with the invention;

FIG. 2 is a stress-strain curve of the Fe-Ni-Co-Al-Nb-V alloy of example 1 of the present invention aged at 600 ℃ for 21 hours at room temperature for loading-unloading;

FIG. 3 is a stress-strain curve of the Fe-Ni-Co-Al-Nb-V alloy of example 2 of the present invention after aging at 600 ℃ for 36 hours at room temperature for loading-unloading;

FIG. 4 example 2 the microstructure of the Fe-Ni-Co-Al-Nb-V alloy of the present invention after aging at 600 ℃ for 36 h.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Obvious changes and modifications to these elements without departing from the spirit of the invention are within the scope of the invention. The scope of the invention is limited only by the claims.

Example 1

Selecting metal iron, metal nickel, metal cobalt, metal aluminum, metal niobium and metal vanadium, wherein the alloy comprises the following components (atom percentage): fe-40.0, Ni-30.0, Co-16.0, Al-10.0, Nb-2.0, V-2.0.

The preparation method comprises the following steps: smelting by electric arc, and casting into alloy cast ingots; smelting is carried out in the protection of argon, and a magnetic stirring technology is utilized to uniformly mix the metal solution in the smelting process; casting the bar material into a bar material with the diameter of 20mm by protective casting under the protection of argon;

heating the cast ingot to 1100 ℃, preserving heat for 1.5h, and then performing water quenching;

cold rolling the sheet to a thickness of 2mm at room temperature;

aging the cold-rolled material at 600 ℃ for 21h, and then air-cooling to room temperature.

Example 2

Selecting metal iron, metal nickel, metal cobalt, metal aluminum, metal niobium and metal vanadium, wherein the alloy comprises the following components (atom percentage): fe-40.0, Ni-30.0, Co-16.0, Al-10.0, Nb-2.0, V-2.0.

The preparation method comprises the following steps: smelting by electric arc, and casting into alloy cast ingots; smelting is carried out in the protection of argon, and a magnetic stirring technology is utilized to uniformly mix the metal solution in the smelting process; and (5) casting the mixture into a bar with the diameter of 20mm by protective casting under the protection of argon.

Heating the cast ingot to 1100 ℃, preserving heat for 1.5h, and then performing water quenching;

cold rolling the sheet to a thickness of 2mm at room temperature;

aging the cold-rolled material at 600 ℃ for 36h, and then air-cooling to room temperature.

The invention discloses a polycrystalline FeNiCoAlNbV hyperelastic alloy and a preparation method thereof, wherein the expression of the hyperelastic alloy is Fe_aNi_bCo_cAl_dNb_eV_fIn the alloy expression, a, b, c, d, e and f respectively represent the atom percentage content of each corresponding component, and the following conditions are met: a is 35 to 60, b is 25 to 50, c is 8 to 35, d is 1 to 20, e is 1 to 5, f is 1 to 5, and a + b + c + d + e + f is 100. The super-elastic alloy is optimized in the aspect of heat treatment, is directly cold-rolled after being homogenized, and is aged, so that the process is simplified, and the process is controllable. The super-elastic alloy regulates and controls the precipitation volume fraction of a nano precipitated phase by adjusting the content of each component to obtain sheet martensite and promote the transformation of the thermo-elastic martensite, thereby obtaining high plasticity, high strength and large recoverable strain and having wide application prospect.