阅读说明：本技术 一种高强度高塑性的铝铁铬镍高熵合金的制备方法 (Preparation method of high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy ) 是由 赵宇宏 徐晓桃 张小波 程鹏 潘玥 王帅 侯华 于 2021-08-07 设计创作，主要内容包括：本发明涉及一种高强度高塑性的铝铁铬镍高熵合金的制备方法,大幅度提高铝铁铬镍高熵合金的综合力学性能。一种高强度高塑性的铝铁铬镍高熵合金的制备方法,该方法是采用如下步骤实现的：S1：原材料准备；S2：熔炼：熔炼电流为260A-280A,并在合金呈液态后停留2.5min-3min,熔炼次数为五次；S3：热处理试样的切割；S4：热处理：热处理温度设定为900℃,热处理时间设定为15h；S5：拉伸样品的切割、表面处理；S6：用拉伸样品进行室温拉伸性能测试。本发明制备的Al-(0.5)FeCrNi高熵合金成品,在时效热处理之后,材料的抗拉强度从465MPa提高到了1297MPa,延伸率提升到了12%,具有广泛的工业应用前景。(The invention relates to a preparation method of a high-strength and high-plasticity aluminum-iron-chromium-nickel high-entropy alloy, which can greatly improve the comprehensive mechanical property of the aluminum-iron-chromium-nickel high-entropy alloy. A preparation method of a high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy is realized by adopting the following steps: s1: preparing raw materials; s2: smelting: the smelting current is 260A-280A, the alloy stays for 2.5min-3min after being in a liquid state, and the smelting frequency is five times; s3: cutting the heat treatment sample; s4: and (3) heat treatment: setting the heat treatment temperature to 900 ℃ and the heat treatment time to 15 h; s5: cutting and surface treating a tensile sample; s6: room temperature tensile property testing was performed with the tensile specimens. Al prepared by the invention 0.5 The FeCrNi high-entropy alloy finished product has the advantages that after aging heat treatment, the tensile strength of the material is improved from 465MPa to 1297MPa, the elongation is improved to 12 percent, and the FeCrNi high-entropy alloy finished product has wide industrial application prospects.)

1. A preparation method of a high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy is characterized by comprising the following steps: the method is realized by adopting the following steps:

s1: preparing raw materials: respectively taking analytically pure aluminum, iron, chromium and nickel particles, polishing surface oxides, then cleaning the surface oxides by using absolute ethyl alcohol in ultrasonic equipment, drying the cleaned surface oxides, and then respectively weighing the particles by using an electronic balance, wherein the molar ratio of the aluminum to the iron to the chromium to the nickel is 0.5: 1: 1: 1;

s2: smelting:

s2.1: cleaning a water-cooled copper mold and a furnace chamber wall in a vacuum arc melting furnace by using absolute ethyl alcohol;

s2.2: putting the weighed aluminum, iron, chromium and nickel particles into a water-cooled copper mold main melting pool, and putting a titanium ingot into a water-cooled copper mold auxiliary melting pool;

s2.3: closing a furnace door of the vacuum arc melting furnace, opening a water cooling system, then sequentially opening a mechanical pump and a molecular pump for vacuumizing until the pressure in the furnace reaches below 0.005Pa, and closing a vacuum valve;

s2.4: opening an argon valve, filling high-purity argon into the vacuum arc melting furnace until the pressure in the furnace reaches 0.5Pa, and closing the argon valve;

s2.5: smelting a titanium ingot after arc striking, and adsorbing residual oxygen in the furnace;

s2.6: starting to smelt the alloy, and gradually increasing smelting current after arc striking until the smelting current reaches 260-280A; keeping the smelting current at 260A-280A, continuing to smelt until the alloy is in a liquid state, staying for 2.5-3 min after the alloy is in the liquid state, and then closing the electric arc to obtain an alloy ingot;

s2.7: after the alloy ingot is cooled on the water-cooling copper mold, the alloy ingot is turned over by using the mechanical arm;

s2.8: smelting the alloy ingot again according to the method of the step S2.6-the step S2.7, and repeating the method for four times to obtain the as-cast aluminum-iron-chromium-nickel high-entropy alloy;

s3: cutting of the heat-treated sample: cutting the as-cast aluminum-iron-chromium-nickel high-entropy alloy into heat treatment samples with the length of 25mm, the width of 20mm and the thickness of 10mm by using a wire cutting machine;

s4: and (3) heat treatment: setting the heat treatment temperature to 900 ℃ and the heat treatment time to 15h, and obtaining the finished product of the aluminum-iron-chromium-nickel high-entropy alloy after heat treatment;

s5: cutting and surface treatment of the tensile sample: cutting the finished product of the aluminum-iron-chromium-nickel high-entropy alloy into a bone-shaped tensile sample with the gauge length of 10mm by using a wire cutting machine, and grinding and polishing the front side, the back side and the two side surfaces of the tensile sample;

s6: room temperature tensile property testing was performed with the tensile specimens.

2. The preparation method of the high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy according to claim 1, characterized by comprising the following steps: in the step S2.2, four high-entropy alloy raw materials are sequentially placed into a water-cooling copper mold main molten pool according to the sequence of melting points from low to high.

3. The preparation method of the high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy according to claim 1, characterized by comprising the following steps: the heat treatment process described in step S4 is implemented by the following steps: a) heating the box type resistance furnace to 900 ℃; b) when the temperature is increased to 900 ℃, putting the heat treatment sample into a box type resistance furnace, and preserving the heat of the heat treatment sample along with the box type resistance furnace; c) and after the heat preservation time reaches 15h, taking out the heat treatment sample from the box-type resistance furnace and performing water quenching.

Technical Field

The invention relates to a preparation method of a high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy, belonging to the technical field of heat treatment of metal materials.

Background

The high-entropy alloy proposed by scholars such as the sambucus chinensis et al in 2004 attracts extensive attention of researchers all over the world. Due to its excellent properties, such as high mechanical strength and ductility, good high-temperature oxidation resistance and various physical properties, the high-entropy alloy has a wide application prospect in the metal field. The existing research shows that the FCC structure high-entropy alloy usually has higher plasticity and lower strength, the BCC structure high-entropy alloy is just the opposite, and the dual-phase structure high-entropy alloy has better strong plasticity matching. The cast-state high-entropy alloy structure is a typical dendritic crystal structure and has the defects of element segregation, porosity and the like, so that the industrial application of the alloy structure is limited. The heat treatment process can refine grains, eliminate segregation and reduce internal stress, so that the structure and the performance of the alloy are more uniform.

Disclosure of Invention

Object of the Invention

The invention aims to provide a preparation method of a high-strength and high-plasticity aluminum-iron-chromium-nickel high-entropy alloy, which can greatly improve the comprehensive mechanical property of the aluminum-iron-chromium-nickel high-entropy alloy.

Technical scheme

A preparation method of a high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy is realized by adopting the following steps:

s1: preparing raw materials: respectively taking analytically pure aluminum, iron, chromium and nickel particles, polishing surface oxides, then cleaning the surface oxides by using absolute ethyl alcohol in ultrasonic equipment, drying the cleaned surface oxides, and then respectively weighing the particles by using an electronic balance, wherein the molar ratio of the aluminum to the iron to the chromium to the nickel is 0.5: 1: 1: 1;

s2: smelting:

s2.1: cleaning a water-cooled copper mold and a furnace chamber wall in a vacuum arc melting furnace by using absolute ethyl alcohol;

s2.2: putting the weighed aluminum, iron, chromium and nickel particles into a water-cooled copper mold main melting pool, and putting a titanium ingot into a water-cooled copper mold auxiliary melting pool;

s2.3: closing a furnace door of the vacuum arc melting furnace, opening a water cooling system, then sequentially opening a mechanical pump and a molecular pump for vacuumizing until the pressure in the furnace reaches below 0.005Pa, and closing a vacuum valve;

s2.4: opening an argon valve, filling high-purity argon into the vacuum arc melting furnace until the pressure in the furnace reaches 0.5Pa, and closing the argon valve;

s2.5: smelting a titanium ingot after arc striking, and adsorbing residual oxygen in the furnace;

s2.6: starting to smelt the alloy, and gradually increasing smelting current after arc striking until the smelting current reaches 260-280A; keeping the smelting current at 260A-280A, continuing to smelt until the alloy is in a liquid state, staying for 2.5-3 min after the alloy is in the liquid state, and then closing the electric arc to obtain an alloy ingot;

s2.7: after the alloy ingot is cooled on the water-cooling copper mold, the alloy ingot is turned over by using the mechanical arm;

s2.8: smelting the alloy ingot again according to the method of the step S2.6-the step S2.7, and repeating the method for four times to obtain the as-cast aluminum-iron-chromium-nickel high-entropy alloy;

s3: cutting of the heat-treated sample: cutting the as-cast aluminum-iron-chromium-nickel high-entropy alloy into heat treatment samples with the length of 25mm, the width of 20mm and the thickness of 10mm by using a wire cutting machine;

s4: and (3) heat treatment: setting the heat treatment temperature to 900 ℃ and the heat treatment time to 15h, and obtaining the finished product of the aluminum-iron-chromium-nickel high-entropy alloy after heat treatment;

s5: cutting and surface treatment of the tensile sample: cutting the finished product of the aluminum-iron-chromium-nickel high-entropy alloy into a bone-shaped tensile sample with the gauge length of 10mm by using a wire cutting machine, and grinding and polishing the front side, the back side and the two side surfaces of the tensile sample;

s6: room temperature tensile property testing was performed with the tensile specimens.

Further, in step S2.2, the four high-entropy alloy raw materials are sequentially placed into the main molten pool of the water-cooled copper mold from low melting point to high melting point.

Further, the heat treatment process described in step S4 is implemented by the following steps: a) heating the box type resistance furnace to 900 ℃; b) when the temperature is increased to 900 ℃, putting the heat treatment sample into a box type resistance furnace, and preserving the heat of the heat treatment sample along with the box type resistance furnace; c) and after the heat preservation time reaches 15h, taking out the heat treatment sample from the box-type resistance furnace and performing water quenching.

Advantageous effects

The Al-Fe-Cr-Ni high-entropy alloy finished product (Al) prepared by the invention_0.5FeCrNi high-entropy alloy finished product), after aging heat treatment, the tensile strength of the material is improved from 465MPa to 1297MPa, the elongation is improved to 12 percent, and the material has wide industrial application prospect.

Drawings

FIG. 1 is an X-ray diffraction pattern of an as-cast aluminum-iron-chromium-nickel high-entropy alloy of the present invention;

FIG. 2 is a gold phase diagram of an as-cast Al-Fe-Cr-Ni high-entropy alloy of the present invention;

FIG. 3 is a gold phase diagram of the finished Al-Fe-Cr-Ni high-entropy alloy product in the invention;

FIG. 4 is a schematic structural view of a stretched sample in the present invention;

FIG. 5 is a stress-strain curve of the finished products of the as-cast Al-Fe-Cr-Ni high-entropy alloy and the Al-Fe-Cr-Ni high-entropy alloy.

Detailed Description

Example 1

A preparation method of a high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy is realized by adopting the following steps:

s1: preparing raw materials: respectively taking analytically pure aluminum, iron, chromium and nickel particles with the purity higher than 99.9%, polishing surface oxides, cleaning the particles in an ultrasonic device by using absolute ethyl alcohol, drying the particles after cleaning, and then respectively weighing the particles by using an electronic balance, wherein the molar ratio of the aluminum to the iron to the chromium to the nickel is 0.5: 1: 1: 1, and the difference value between the weighing value and the calculated value is controlled within 0.001 g;

s2: smelting:

s2.1: cleaning a water-cooled copper mold and a furnace chamber wall in a vacuum arc melting furnace by using absolute ethyl alcohol;

s2.2: sequentially putting the weighed aluminum, iron, chromium and nickel particles into a water-cooled copper mold main melting pool according to the sequence of melting points from low to high, and putting a titanium ingot into a water-cooled copper mold auxiliary melting pool;

s2.3: closing a furnace door of the vacuum arc melting furnace, opening a water cooling system, then sequentially opening a mechanical pump and a molecular pump for vacuumizing until the pressure in the furnace reaches below 0.005Pa, and closing a vacuum valve;

s2.4: opening an argon valve, filling high-purity argon with the purity of 99.999% into the vacuum arc melting furnace until the pressure in the furnace reaches 0.5Pa, and closing the argon valve;

s2.5: smelting a titanium ingot after arc striking, and adsorbing residual oxygen in the furnace;

s2.6: starting to smelt the alloy, and gradually increasing smelting current after arc striking until the smelting current reaches 280A; keeping the smelting current at 280A, continuing to smelt until the alloy is in a liquid state, staying for 3min after the alloy is in the liquid state, and then closing the electric arc to obtain an alloy ingot;

s2.7: after the alloy ingot is cooled on the water-cooling copper mold, the alloy ingot is turned over by using the mechanical arm;

s2.8: smelting the alloy ingot again according to the method of the step S2.6-the step S2.7, and repeating the method for four times to obtain the as-cast aluminum-iron-chromium-nickel high-entropy alloy with uniform structure;

s3: characterization of the as-cast aluminum-iron-chromium-nickel high-entropy alloy: a) performing phase analysis on the as-cast aluminum-iron-chromium-nickel high-entropy alloy obtained in the step S2.8 by using an X-ray diffractometer of Japan science company, wherein the working voltage is 40KV, the working current is 100mA, and the X-ray source is Cu Ka rays (lambda =0.1542 nm); the detection results are shown in figure 1; b) performing microstructure characterization on the as-cast aluminum-iron-chromium-nickel high-entropy alloy obtained in the step S2.8 by using a metallographic microscope with a Leica DMi8 model, wherein the result is shown in the attached drawing 2;

s4: cutting of the heat-treated sample: the cast aluminum-iron-chromium-nickel high-entropy alloy has more defects such as internal shrinkage cavities and shrinkage porosity, and the internal defects are eliminated and the alloy is strengthened by using heat treatment; before heat treatment, cutting the as-cast aluminum-iron-chromium-nickel high-entropy alloy into heat treatment samples with the length of 25mm, the width of 20mm and the thickness of 10mm by using a wire cutting machine;

s5: and (3) heat treatment: the heat treatment equipment is a box type resistance furnace with the model number of SRJX29, the heat treatment temperature is set to 900 ℃, the heat treatment time is set to 15h, and the heat treatment process is realized by adopting the following steps: a) heating the box type resistance furnace to 900 ℃; b) when the temperature is increased to 900 ℃, putting the heat treatment sample into a box type resistance furnace, and preserving the heat of the heat treatment sample along with the box type resistance furnace; c) after the heat preservation time reaches 15h, taking out the heat treatment sample from the box-type resistance furnace and performing water quenching to obtain an aluminum-iron-chromium-nickel high-entropy alloy finished product; then, performing microstructure characterization on the finished product of the aluminum-iron-chromium-nickel high-entropy alloy by using a metallographic microscope with the model of Leica DMi8, wherein the result is shown in the attached figure 3;

s6: cutting and surface treatment of the tensile sample: firstly, fixing the as-cast aluminum-iron-chromium-nickel high-entropy alloy prepared in the step S2.8 and the aluminum-iron-chromium-nickel high-entropy alloy finished product prepared in the step S5 on a processing table respectively, cutting the two into bone-shaped tensile samples with the gauge length of 10mm by using a wire cutting machine, and grinding and polishing the front and back surfaces and the two side surfaces of the two tensile samples as shown in the attached figure 4;

s7: carrying out room-temperature tensile property test on two tensile samples; the tensile property test was carried out using an AG-X PLUS electronic universal tester, and the strain rate was set to 10^-3s^-1The stress-strain curves of the two tensile samples are shown in FIG. 5.

Finished Al-Fe-Cr-Ni high-entropy alloy (Al) prepared by the embodiment_0.5FeCrNi high-entropy alloy finished product), after aging heat treatment, the tensile strength of the material is improved from 465MPa to 1297MPa, the elongation is improved to 12 percent, and the material has wide industrial application prospect.

Example 2

A preparation method of a high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy is realized by adopting the following steps:

s1: preparing raw materials: respectively taking analytically pure aluminum, iron, chromium and nickel particles with the purity higher than 99.9%, polishing surface oxides, cleaning the particles in an ultrasonic device by using absolute ethyl alcohol, drying the particles after cleaning, and then respectively weighing the particles by using an electronic balance, wherein the molar ratio of the aluminum to the iron to the chromium to the nickel is 0.5: 1: 1: 1, and the difference value between the weighing value and the calculated value is controlled within 0.001 g;

s2: smelting:

s2.1: cleaning a water-cooled copper mold and a furnace chamber wall in a vacuum arc melting furnace by using absolute ethyl alcohol;

s2.2: sequentially putting the weighed aluminum, iron, chromium and nickel particles into a water-cooled copper mold main melting pool according to the sequence of melting points from low to high, and putting a titanium ingot into a water-cooled copper mold auxiliary melting pool;

s2.3: closing a furnace door of the vacuum arc melting furnace, opening a water cooling system, then sequentially opening a mechanical pump and a molecular pump for vacuumizing until the pressure in the furnace reaches below 0.005Pa, and closing a vacuum valve;

s2.4: opening an argon valve, filling high-purity argon with the purity of 99.999% into the vacuum arc melting furnace until the pressure in the furnace reaches 0.5Pa, and closing the argon valve;

s2.5: smelting a titanium ingot after arc striking, and adsorbing residual oxygen in the furnace;

s2.6: starting to smelt the alloy, and gradually increasing smelting current after arc striking until the smelting current reaches 260A; keeping the smelting current at 260A, continuously smelting until the alloy is in a liquid state, staying for 2.5min after the alloy is in the liquid state, and then closing the electric arc to obtain an alloy ingot;

s2.7: after the alloy ingot is cooled on the water-cooling copper mold, the alloy ingot is turned over by using the mechanical arm;

s2.8: smelting the alloy ingot again according to the method of the step S2.6-the step S2.7, and repeating the method for four times to obtain the as-cast aluminum-iron-chromium-nickel high-entropy alloy with uniform structure;

s3: cutting of the heat-treated sample: the cast aluminum-iron-chromium-nickel high-entropy alloy has more defects such as internal shrinkage cavities and shrinkage porosity, and the internal defects are eliminated and the alloy is strengthened by using heat treatment; before heat treatment, cutting the as-cast aluminum-iron-chromium-nickel high-entropy alloy into heat treatment samples with the length of 25mm, the width of 20mm and the thickness of 10mm by using a wire cutting machine;

s4: and (3) heat treatment: the heat treatment equipment is a box type resistance furnace with the model number of SRJX29, the heat treatment temperature is set to 900 ℃, the heat treatment time is set to 15h, and the heat treatment process is realized by adopting the following steps: a) heating the box type resistance furnace to 900 ℃; b) when the temperature is increased to 900 ℃, putting the heat treatment sample into a box type resistance furnace, and preserving the heat of the heat treatment sample along with the box type resistance furnace; c) after the heat preservation time reaches 15h, taking out the heat treatment sample from the box-type resistance furnace and performing water quenching to obtain an aluminum-iron-chromium-nickel high-entropy alloy finished product;

s5: cutting and surface treatment of the tensile sample: firstly, fixing the as-cast aluminum-iron-chromium-nickel high-entropy alloy prepared in the step S2.8 and the aluminum-iron-chromium-nickel high-entropy alloy finished product prepared in the step S4 on a processing table respectively, cutting the two into bone-shaped tensile samples with the gauge length of 10mm by using a wire cutting machine, and grinding and polishing the front and back surfaces and the two side surfaces of the two tensile samples as shown in the attached figure 4;

s6: room temperature tensile property testing was performed with two tensile samples.

Example 3

A preparation method of a high-strength high-plasticity aluminum-iron-chromium-nickel high-entropy alloy is realized by adopting the following steps:

s1: preparing raw materials: respectively taking analytically pure aluminum, iron, chromium and nickel particles with the purity higher than 99.9%, polishing surface oxides, cleaning the particles in an ultrasonic device by using absolute ethyl alcohol, drying the particles after cleaning, and then respectively weighing the particles by using an electronic balance, wherein the molar ratio of the aluminum to the iron to the chromium to the nickel is 0.5: 1: 1: 1, and the difference value between the weighing value and the calculated value is controlled within 0.001 g;

s2: smelting:

s2.1: cleaning a water-cooled copper mold and a furnace chamber wall in a vacuum arc melting furnace by using absolute ethyl alcohol;

s2.2: sequentially putting the weighed aluminum, iron, chromium and nickel particles into a water-cooled copper mold main melting pool according to the sequence of melting points from low to high, and putting a titanium ingot into a water-cooled copper mold auxiliary melting pool;

s2.3: closing a furnace door of the vacuum arc melting furnace, opening a water cooling system, then sequentially opening a mechanical pump and a molecular pump for vacuumizing until the pressure in the furnace reaches below 0.005Pa, and closing a vacuum valve;

s2.4: opening an argon valve, filling high-purity argon with the purity of 99.999% into the vacuum arc melting furnace until the pressure in the furnace reaches 0.5Pa, and closing the argon valve;

s2.5: smelting a titanium ingot after arc striking, and adsorbing residual oxygen in the furnace;

s2.6: starting to smelt the alloy, and gradually increasing smelting current after arc striking until the smelting current reaches 270A; keeping the smelting current at 270A, continuing to smelt until the alloy is in a liquid state, staying for 2.8min after the alloy is in the liquid state, and then closing the electric arc to obtain an alloy ingot;

s2.7: after the alloy ingot is cooled on the water-cooling copper mold, the alloy ingot is turned over by using the mechanical arm;

s2.8: smelting the alloy ingot again according to the method of the step S2.6-the step S2.7, and repeating the method for four times to obtain the as-cast aluminum-iron-chromium-nickel high-entropy alloy with uniform structure;

s3: cutting of the heat-treated sample: the cast aluminum-iron-chromium-nickel high-entropy alloy has more defects such as internal shrinkage cavities and shrinkage porosity, and the internal defects are eliminated and the alloy is strengthened by using heat treatment; before heat treatment, cutting the as-cast aluminum-iron-chromium-nickel high-entropy alloy into heat treatment samples with the length of 25mm, the width of 20mm and the thickness of 10mm by using a wire cutting machine;

s4: and (3) heat treatment: the heat treatment equipment is a box type resistance furnace with the model number of SRJX29, the heat treatment temperature is set to 900 ℃, the heat treatment time is set to 15h, and the heat treatment process is realized by adopting the following steps: a) heating the box type resistance furnace to 900 ℃; b) when the temperature is increased to 900 ℃, putting the heat treatment sample into a box type resistance furnace, and preserving the heat of the heat treatment sample along with the box type resistance furnace; c) after the heat preservation time reaches 15h, taking out the heat treatment sample from the box-type resistance furnace and performing water quenching to obtain an aluminum-iron-chromium-nickel high-entropy alloy finished product;

s5: cutting and surface treatment of the tensile sample: firstly, fixing the as-cast aluminum-iron-chromium-nickel high-entropy alloy prepared in the step S2.8 and the aluminum-iron-chromium-nickel high-entropy alloy finished product prepared in the step S4 on a processing table respectively, cutting the two into bone-shaped tensile samples with the gauge length of 10mm by using a wire cutting machine, and grinding and polishing the front and back surfaces and the two side surfaces of the two tensile samples as shown in the attached figure 4;

s6: room temperature tensile property testing was performed with two tensile samples.