CN114855097A - Method for improving strength and low-temperature wear resistance of FeMnCoCr high-entropy alloy - Google Patents
Method for improving strength and low-temperature wear resistance of FeMnCoCr high-entropy alloy Download PDFInfo
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
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Abstract
The invention discloses a method for improving the strength and low-temperature wear resistance of FeMnCoCr high-entropy alloy, which comprises the following steps of determining the mass of each element and an additionally added B element according to the molar ratio of each element of the alloy, uniformly mixing, and then smelting and casting to obtain an alloy ingot; carrying out hot rolling on the alloy ingot, and obtaining an alloy plate after air cooling; removing the surface oxide skin of the alloy plate, cold rolling to obtain an alloy crude product, and carrying out heat treatment on the alloy crude product to obtain the high-entropy alloy with the target component. According to the invention, a proper amount of B atoms are added into the alloy, so that the yield strength and the low-temperature wear resistance of the high-entropy alloy are improved to different degrees compared with the FeMnCoCr high-entropy alloy without adding the strengthening elements, and the crystal grains of the alloy are further refined by matching with a proper machining and manufacturing process, so that the strength of the alloy is further improved. In addition, the preparation method of the alloy is simple, the strengthening elements are cheap, and the application of the high-entropy alloy in actual production is promoted.
Description
Technical Field
The invention belongs to the technical field of high-strength wear-resistant alloy materials, and particularly relates to a method for improving the strength and low-temperature wear resistance of FeMnCoCr high-entropy alloy.
Background
High entropy alloys, also known as multi-principal element alloys, which are composed of components of various elements in equal or near equal atomic ratios, exhibit a number of unique advantages over conventional alloys due to the fact that several properties of the high entropy alloys are initially attributed to entropy-driven phase stability, resulting in entropy maximization as a prevailing design rule, as compared to conventional metal alloys based on one or two main elements.
The face-centered cubic high-entropy alloy is generally considered to have excellent plasticity, but the strength, the hardness and the like of the alloy are not satisfactory, the yield strength is only 200-300 MPa generally, and the application of the high-entropy alloy is seriously influenced. Strengthening and toughening of face-centered cubic alloys has become an important issue. The addition of a small amount of interstitial atoms to the alloy system is considered to be an effective alloy strengthening and toughening means.
The metastable state high-entropy alloy is a novel alloy which is emerging at present, and is different from the traditional single-phase alloy in that a series of phase changes can occur after the alloy system is subjected to the action of external force and the like due to the addition of phase-unstable elements in the alloy system, so that the mechanical property of the alloy is influenced. Such as Fe 50 Mn 30 Co 10 Cr 10 The metastable high-entropy alloy matrix phase is metastable FCThe C-gamma phase can generate FCC → HCP phase transformation after being applied with external force, and the HCP-epsilon phase is considered to improve the plasticity of the alloy, thereby improving the mechanical property of the alloy.
The material not only works in normal temperature environment, but also is often used in extreme environments such as low temperature, high temperature and the like. At present, national important projects related to low-temperature service of materials, such as polar scientific research, extraterrestrial planet detection and the like, are proposed successively, and the demand for high-performance low-temperature materials is more and more urgent.
At present, the friction and wear performance research on high entropy alloys is mainly focused on room temperature and high temperature environments, and the friction and wear performance and mechanism thereof at low temperature are only studied a few times. The FeMnCoCr series high-entropy alloy is considered by extensive researchers to have good low-temperature mechanical properties, but the friction of the material under the low-temperature working condition still remains a problem to be solved urgently.
Based on the method, the method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy is provided.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy aiming at the defects of the prior art, wherein the alloy can generate martensite phase transformation from FCC-gamma phase to HCP-epsilon phase when being stretched at room temperature, so that the plasticity of the alloy is improved; the addition of a small amount of interstitial B atoms can improve the strength of the alloy due to the interstitial solid solution strengthening effect; proper alloy processing and manufacturing process can further refine alloy grains and improve alloy strength；The original HCP phase in the alloy ensures that the alloy has higher hardness and reduces the abrasion of the alloy. The alloy is rubbed at low temperature, the martensite phase transformation from FCC-gamma phase to HCP-epsilon phase is generated on the surface of the alloy under the action of friction stress, the HCP phase with higher hardness prevents the further abrasion of the alloy, and the problems in the background art are solved.
In order to solve the technical problems, the invention adopts the technical scheme that: a method for improving the strength and the low-temperature wear resistance of FeMnCoCr high-entropy alloy comprises the following steps:
determining the mass of each element and the additionally added B element according to the molar ratio of each element of the alloy, uniformly mixing, and then smelting and casting to obtain an alloy ingot;
carrying out hot rolling on the alloy ingot, and carrying out air cooling to obtain an alloy plate;
removing the oxide skin on the surface of the alloy plate, then cold-rolling to obtain an alloy crude product, and performing heat treatment on the alloy crude product to obtain the high-entropy alloy with the target component.
Further, the FeMnCoCr high-entropy alloy comprises the following components in molar ratio: fe: 45% -55%, Mn: 25% -35%, Co: 5% -15%, Cr: 5 to 15 percent, and the weight of the additionally added B element is 10 to 250 ppm.
Further, smelting is carried out in a vacuum induction smelting furnace, specifically, elements of the alloy and the element B which are uniformly mixed are smelted in an inert gas atmosphere, then the obtained alloy mother ingot is cast by a copper mold, and after casting, the temperature is kept at 1100-1300 ℃ for 1-3 h to obtain the alloy ingot.
Further, the hot rolling of the alloy ingot is specifically to immediately hot-roll the alloy ingot after heat preservation with a hot rolling reduction of 97%, hot-roll the alloy ingot to a thickness of 3mm, and air-cool the alloy ingot to room temperature to obtain a hot-rolled and cooled alloy sheet.
Further, after removing the oxide skin on the surface of the alloy sheet by pickling, the alloy sheet is cold-rolled to a thickness of 1.5mm at a reduction ratio of 50% to obtain an alloy crude product.
Further, the heat treatment of the alloy crude product is to place the alloy crude product in a heat treatment furnace at 650-900 ℃, preserve heat for 1 hour, and then cool the alloy crude product by water to obtain the high-entropy alloy with the target component.
Furthermore, the obtained high-entropy alloy structure of the target component presents a dual-phase structure with coexisting FCC phase and HCP phase, B atoms in the high-entropy alloy exist in the alloy in a form of interstitial solid solution, and the high-entropy alloy can generate martensite phase transformation from the FCC phase to the HCP phase under the action of external force.
Furthermore, through component design, the high-entropy alloy is in a metastable state, and the alloy undergoes the martensite phase transformation from an FCC phase to an HCP phase in the process of low-temperature friction, so that the wear resistance of the alloy is improved.
Furthermore, the yield strength of the obtained high-entropy alloy with target components reaches 449MPa, and the wear rate of the wear resistance of the alloy at minus 120 ℃ reaches 7.35 multiplied by 10 -5 mm 3 /(m·N)。
Compared with the prior art, the invention has the following advantages:
1. in the alloy composition design, Fe and Mn elements regulate the stacking fault energy and the phase stability of the FCC-gamma phase, so that the FCC-gamma phase is easier to generate phase change under the action of thermal activation or external force to generate an HCP-epsilon phase, and Co and Cr elements can stabilize the HCP phase generated by phase change. Thus, at the molar ratios of the alloying elements of the present invention, the alloy ultimately exhibits FCC-HCP dual phase characteristics.
2. According to the invention, by means of Thermo-Calc software, the change of the existence form of B atoms with the alloy components after the B atoms with different contents are added is calculated, and theoretical guidance is provided for the performance improvement of the alloy.
3. The invention provides a method for effectively improving the alloy performance, which avoids the segregation of alloy components and eliminates the casting defects such as holes and the like caused by casting by heat preservation and hot rolling after obtaining an alloy ingot; the acid washing after the hot rolling removes an oxide layer formed in the hot rolling process, and avoids alloy cracking in the subsequent cold rolling process; the cold rolling process further refines alloy grains, is beneficial to obtaining a fine alloy structure and improves the comprehensive performance of the alloy; the heat treatment at different temperatures determines the optimal heat treatment parameters of the alloy, and partial martensite transformation in the quenching process after the heat treatment is the only method which can cause the alloy to form the dual-phase high-entropy alloy.
4. The high-strength low-temperature wear-resistant high-entropy alloy provided by the invention is added with B atoms, and the proper amount of B atoms can improve the bearing capacity of each interface by improving the cohesion of the alloy grain boundary and lead to grain refinement in the heat treatment process. Compared with FeMnCoCr high-entropy alloy without adding strengthening elements, the yield strength and the low-temperature wear resistance of the high-entropy alloy are improved to different degrees, and the crystal grains of the alloy are further refined by matching with a proper machining and manufacturing process, so that the strength of the alloy is further improved.
5. The high-strength low-temperature wear-resistant high-entropy alloy provided by the invention has excellent mechanical properties at room temperature. The high-entropy alloy provided by the invention is a metastable state high-entropy alloy, and can generate martensite phase transformation from an FCC-gamma phase to an HCP-epsilon phase after being subjected to the action of external force, so that the plasticity of the alloy is improved.
6. The high-strength low-temperature wear-resistant high-entropy alloy provided by the invention has excellent wear resistance at low temperature. Under the condition of low temperature, the stacking fault energy of the alloy is reduced along with the reduction of the temperature, so that the phase transformation of the alloy at the low temperature is promoted, and the generation of HCP (hydrogen phosphate) phase is facilitated. HCP phases, on the other hand, may make the alloy more wear resistant at low temperatures due to their high hardness properties. So that the alloy has the characteristics of lower temperature and higher wear resistance in a certain temperature range.
Drawings
FIG. 1 is a phase diagram of the existing state and the adding amount of a target high-strength low-temperature wear-resistant high-entropy alloy B element calculated by means of Thermo-Calc software;
FIG. 2 is an X-ray diffraction pattern (XRD) and a back-scattered electron diffraction pattern (EBSD) of a microstructure of a target high-strength low-temperature wear-resistant high-entropy alloy provided by the invention; wherein the content of the first and second substances,
(a) is an XRD and EBSD phase composition diagram of the high-entropy alloy microstructure prepared in example 1;
(b) the XRD and EBSD phase composition diagrams of the high-entropy alloy microstructure prepared in example 2;
(c) is an XRD and EBSD phase composition diagram of the high-entropy alloy microstructure prepared in example 3;
FIG. 3 is a tensile stress-strain curve of the target high-strength, low-temperature, wear-resistant and high-entropy alloy prepared in examples 1, 2 and 3 provided by the invention;
FIG. 4 is a bar graph of hardness of the target high-strength, low-temperature, wear-resistant and high-entropy alloy obtained in examples 1, 2 and 3 provided by the invention;
FIG. 5 is a low-temperature friction result chart of the target high-strength, low-temperature, wear-resistant and high-entropy alloy obtained in example 2 provided by the invention, wherein,
(a) the friction coefficient curves of the high entropy alloy prepared in example 2 at 0 ℃, -40 ℃, -80 ℃, -120 ℃;
(b) wear rate graphs of the high entropy alloy prepared in example 2 at 0 ℃, -40 ℃, -80 ℃, and-120 ℃;
(c) the wear three-dimensional profile morphology graph of the high entropy alloy prepared by the embodiment 2 at 0 ℃, 40 ℃, 80 ℃ and 120 ℃.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Embodiment 1, the present invention provides a technical solution: a method for improving the strength and the low-temperature wear resistance of FeMnCoCr high-entropy alloy comprises the following steps of: fe: 45% -55%, Mn: 25% -35%, Co: 5% -15%, Cr: 5 to 15 percent. In addition, 10ppm to 250ppm of B element is added into the alloy by mass; comprises the following steps of (a) carrying out,
s1, preparing and weighing raw materials. Firstly, the raw materials are cleaned in an ultrasonic cleaning machine by taking absolute ethyl alcohol as a cleaning agent and dried in the air so as to remove impurities on the surfaces of the raw materials. And then 50kg of elementary substance raw materials of Fe, Mn, Co and Cr are calculated and weighed according to the target component proportion for later use. Weighing 0.0015-0.0375 kg of the B simple substance for later use. Wherein the manganese simple substance is washed by concentrated hydrochloric acid before being cleaned and weighed so as to remove inevitable oxides on the surface of the manganese simple substance. In order to avoid the influence of volatilization on alloy components during manganese smelting, a proper amount of manganese simple substance needs to be weighed more when weighing, and the manganese simple substance can be weighed to be 2-3% more according to molar ratio.
And S2, smelting and casting. Repeatedly melting the above raw materials in inert gas atmosphere for 3-5 times by using a vacuum induction melting furnace. And carrying out copper mold casting on the obtained alloy mother ingot, and carrying out heat preservation for 1-3 h at the temperature of 1100-1300 ℃ to obtain an alloy ingot with the thickness of 100 mm.
And S3, rolling. And immediately hot rolling the alloy ingot with the temperature of 1100-1300 ℃ after heat preservation, wherein the diameter of a roller of a hot rolling mill is 450 mm. And (3) performing ten-pass rolling on the alloy cast ingot, rolling the final alloy thickness from 100mm to 3mm, and then performing air cooling to room temperature to obtain a hot-rolled and cooled alloy plate. And then, immersing the alloy plate into a 20% hydrochloric acid solution for acid washing, removing an oxide layer on the surface of the alloy caused by hot rolling, then, cold rolling after removing the oxide layer, and rolling the thickness of the alloy plate from 3mm to 1.5mm through multi-pass rolling to obtain an alloy crude product.
And S4, heat treatment. And (3) preserving the heat of the crude alloy product in a heat treatment furnace at 650 ℃ for 1h, and then cooling with water to obtain the high-entropy alloy 1 with the target component.
Testing the mechanical property of the obtained high-entropy alloy; and cutting the alloy plate into tensile samples by using a wire cut electric discharge machine, and testing the tensile mechanical properties of the alloy by using a universal mechanical testing machine.
Carrying out friction performance test on the obtained high-entropy alloy; and placing the alloy sample with the polished surface at the ambient temperature of 0 ℃, 40 ℃, 80 ℃ and 120 ℃ respectively in a rotary friction tester refrigerated by liquid nitrogen. The opposite grinding pair is a GCr15 steel ball with the diameter of 6.35 mm. The load during rubbing was 10N, the radius of rotation was 1mm, the rotational speed was 60rpm, and the single experiment time was 20 min.
Embodiment 2, the present invention provides a technical solution: a method for improving the strength and low-temperature wear resistance of FeMnCoCr high-entropy alloy, wherein the composition of the alloy can be expressed by the molar ratio as follows: fe: 45% -55%, Mn: 25% -35%, Co: 5% -15%, Cr: 5 to 15 percent. In addition, 10 ppm-250 ppm of B element is added into the alloy by mass, and the method comprises the following steps;
s1, preparing and weighing raw materials. Firstly, the raw materials are cleaned in an ultrasonic cleaning machine by taking absolute ethyl alcohol as a cleaning agent and dried in the air so as to remove impurities on the surfaces of the raw materials. And then 50kg of elementary substance raw materials of Fe, Mn, Co and Cr are calculated and weighed according to the target component proportion for later use. Weighing 0.0015-0.0375 kg of the B simple substance for later use. Wherein the manganese simple substance is washed by concentrated hydrochloric acid before being cleaned and weighed so as to remove inevitable oxides on the surface of the manganese simple substance. In order to avoid the influence of volatilization on alloy components during manganese smelting, a proper amount of manganese simple substance needs to be weighed more when weighing, and the manganese simple substance can be weighed to be 2-3% more according to molar ratio.
And S2, smelting and casting. Repeatedly melting the above raw materials in inert gas atmosphere for 3-5 times by using a vacuum induction melting furnace. And carrying out copper mold casting on the obtained alloy mother ingot, and carrying out heat preservation for 1-3 h at the temperature of 1100-1300 ℃ to obtain an alloy ingot with the thickness of 100 mm.
And S3, rolling. And immediately hot rolling the alloy ingot with the temperature of 1100-1300 ℃ after heat preservation, wherein the diameter of a roller of a hot rolling mill is 450 mm. And (3) performing ten-pass rolling on the alloy cast ingot, rolling the final alloy thickness from 100mm to 3mm, and then performing air cooling to room temperature to obtain a hot-rolled and cooled alloy plate. And then, immersing the alloy plate into a 20% hydrochloric acid solution for acid washing, removing an oxide layer on the surface of the alloy caused by hot rolling, then, cold rolling after removing the oxide layer, and rolling the thickness of the alloy plate from 3mm to 1.5mm through multi-pass rolling to obtain an alloy crude product.
And S4, heat treatment. And (3) preserving the heat of the crude alloy product in a heat treatment furnace at 800 ℃ for 1h, and then cooling with water to obtain the high-entropy alloy 2 with the target component.
And (5) carrying out mechanical property test. And cutting the alloy plate into tensile samples by using a wire cut electric discharge machine, and testing the tensile mechanical properties of the alloy by using a universal mechanical testing machine.
And (5) carrying out a friction performance test. And placing the alloy sample with the polished surface at the ambient temperature of 0 ℃, 40 ℃, 80 ℃ and 120 ℃ respectively in a rotary friction tester refrigerated by liquid nitrogen. The opposite grinding pair is a GCr15 steel ball with the diameter of 6.35 mm. The load during rubbing was 10N, the radius of rotation was 1mm, the rotational speed was 60rpm, and the single experiment time was 20 min.
Embodiment 3, the present invention provides a technical solution: a method for improving the strength and the low-temperature wear resistance of FeMnCoCr high-entropy alloy comprises the following steps of: fe: 45% -55%, Mn: 25% -35%, Co: 5% -15%, Cr: 5 to 15 percent. In addition, 10ppm to 250ppm of B element is added into the alloy by mass, and the method comprises the following steps;
s1, preparing and weighing raw materials. Firstly, the raw materials are cleaned in an ultrasonic cleaning machine by taking absolute ethyl alcohol as a cleaning agent and dried in the air so as to remove impurities on the surfaces of the raw materials. And then 50kg of elementary substance raw materials of Fe, Mn, Co and Cr are calculated and weighed according to the target component proportion for later use. Weighing 0.0015-0.0375 kg of the B simple substance for later use. Wherein the manganese simple substance is washed by concentrated hydrochloric acid before being cleaned and weighed so as to remove inevitable oxides on the surface of the manganese simple substance. In order to avoid the influence of volatilization on alloy components during manganese smelting, a proper amount of manganese simple substance needs to be weighed more when weighing, and the manganese simple substance can be weighed to be 2-3% more according to molar ratio.
And S2, smelting and casting. Repeatedly melting the above raw materials in inert gas atmosphere for 3-5 times by using a vacuum induction melting furnace. And carrying out copper mold casting on the obtained alloy mother ingot, and carrying out heat preservation for 1-3 h at the temperature of 1100-1300 ℃ to obtain an alloy ingot with the thickness of 100 mm.
And S3, rolling. And immediately hot rolling the alloy ingot with the temperature of 1100-1300 ℃ after heat preservation, wherein the diameter of a roller of a hot rolling mill is 450 mm. And (3) performing ten-pass rolling on the alloy cast ingot, rolling the final alloy thickness from 100mm to 3mm, and then performing air cooling to room temperature to obtain a hot-rolled and cooled alloy plate. And then, immersing the alloy plate into a 20% hydrochloric acid solution for acid washing, removing an oxide layer on the surface of the alloy caused by hot rolling, then, cold rolling after removing the oxide layer, and rolling the thickness of the alloy plate from 3mm to 1.5mm through multi-pass rolling to obtain an alloy crude product.
And S4, heat treatment. And (3) preserving the heat of the crude alloy product for 1h in a heat treatment furnace at 900 ℃, and then cooling with water to obtain the high-entropy alloy 3 with the target component.
And (5) carrying out mechanical property test. The alloy plate is cut into a standard tensile sample with the gauge length of 25mm, the width of 6mm and the thickness of 1mm by using a spark wire cutting machine, and a universal mechanical testing machine is used for testing the tensile mechanical property of the alloy.
And (5) performing a friction performance test. And placing the alloy sample with the polished surface at the ambient temperature of 0 ℃, 40 ℃, 80 ℃ and 120 ℃ respectively in a rotary friction tester refrigerated by liquid nitrogen. The opposite grinding pair is a GCr15 steel ball with the diameter of 6.35 mm. The load during rubbing was 10N, the radius of rotation was 1mm, the rotational speed was 60rpm, and the single experiment time was 20 min.
Wherein, FIG. 1 is a phase diagram of the existing state and the adding amount of the target high-strength low-temperature wear-resistant high-entropy alloy B element calculated by using Thermo-Calc software. When the amount of B added is less than 0.025%, i.e., 250ppm, B is present in the alloy in a solid solution state and M is not precipitated by analyzing FIG. 1 2 B-type boride precipitates, and the alloy strengthening mechanism is represented by solid solution strengthening.
When the amount of B added is more than 0.025%, M is present in the alloy 2 B-type boride is precipitated, the strengthening mechanism of the alloy is represented by precipitation strengthening, and the content of boride increases as the addition amount of B increases.
FIG. 2 is an X-ray diffraction pattern (XRD) and a back-scattered electron diffraction pattern (EBSD) of a microstructure of a target high-strength, low-temperature, wear-resistant, high-entropy alloy.
The XRD patterns of the alloys prepared in examples 1, 2 and 3 show the characteristics of both FCC phase and HCP phase.
Analysis of the EBSD-phase composition diagram shows that as the annealing temperature increases, the content of HCP phases in the alloy increases, and HCP exhibits a stripe distribution within the grains.
Fig. 3 is a tensile stress-strain curve of the target high-strength, low-temperature, wear-resistant and high-entropy alloy prepared in example 1, example 2 and example 3, and the following table shows detailed tensile mechanical property indexes of the alloy.
TABLE 1 tensile mechanical Properties of the alloys of the invention
As can be seen from the analysis of FIG. 3 and Table 1, the high-entropy alloy prepared in example 1 shows the most excellent comprehensive mechanical properties, the yield strength can reach 449MPa, the tensile strength can reach 848MPa, the yield strength is better than that of the FeMnCoCr high-entropy alloy without any element added by 340MPa, and the plasticity of the alloy is not significantly reduced. In addition, the grain sizes of the alloys obtained by different heat treatment processes are different, so that the alloy strength is obviously different, and the alloy of the example 1 shows the highest yield strength. This shows that the strength of the alloy can be obviously improved by the solid solution of a very small amount of B in the alloy and the combination of proper process under the premise of not obviously improving the plasticity of the alloy.
FIG. 4 is a bar graph of hardness of the target high-strength, low-temperature, wear-resistant and high-entropy alloys obtained in examples 1, 2 and 3. analysis shows that the alloy obtained in example 1 has the highest hardness of about 327HV, the alloy obtained in example 3 has the lowest hardness of about 227HV, and the main reasons for influencing the hardness of the alloys are different grain sizes of the alloys caused by different heat treatment temperatures.
Fig. 5 is a low-temperature friction result graph of the target high-strength low-temperature wear-resistant high-entropy alloy prepared in example 2, and through analysis, the friction of the alloy at four temperatures in the graph (a) is subjected to a running-in period with a small friction coefficient, then the friction pair and the alloy are stably engaged, and a stable friction period is started, and the friction coefficients at the four temperatures are relatively close and are all between 0.2 and 0.3.
The graph (b) shows the wear rate profile showing the excellent friction performance at-120 ℃ of the alloy of example 2 with a wear rate of 7.35X 10 -5 mm 3 /(m·N)。
Graph (c) shows the wear profile of the alloy of example 2 at different temperatures: the wear scar was wide and deep at 0 ℃ of friction, and gradually became narrow and shallow as the friction ambient temperature decreased, further showing excellent wear resistance of the alloy at low temperature.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (9)
1. A method for improving the strength and the low-temperature wear resistance of FeMnCoCr high-entropy alloy is characterized by comprising the following steps:
determining the mass of each element and the additionally added B element according to the molar ratio of each element of the alloy, uniformly mixing, and then smelting and casting to obtain an alloy ingot;
carrying out hot rolling on the alloy ingot, and carrying out air cooling to obtain an alloy plate;
removing the oxide skin on the surface of the alloy plate, then cold-rolling to obtain an alloy crude product, and performing heat treatment on the alloy crude product to obtain the high-entropy alloy with the target component.
2. The method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy according to claim 1, wherein the FeMnCoCr high-entropy alloy comprises the following components in molar ratio: fe: 45% -55%, Mn: 25% -35%, Co: 5% -15%, Cr: 5 to 15 percent, and the weight of the additionally added B element is 10 to 250 ppm.
3. The method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy according to claim 1, wherein the smelting is performed in a vacuum induction smelting furnace, specifically, the elements of the alloy and the element B which are uniformly mixed are smelted in an inert gas atmosphere, the obtained alloy mother ingot is subjected to copper mold casting, and the temperature is maintained at 1100-1300 ℃ for 1-3 hours after the casting to obtain the alloy ingot.
4. The method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy according to claim 1, wherein the hot rolling of the alloy ingot is carried out, specifically, the alloy ingot after heat preservation is hot rolled, the hot rolling reduction rate is 97%, the alloy ingot is hot rolled to be 3mm thick, and the alloy ingot is air cooled to room temperature, so that a hot-rolled and cooled alloy plate is obtained.
5. The method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy according to claim 1, wherein the cold rolling is to cold-roll the alloy sheet to a thickness of 1.5mm at a reduction ratio of 50% after removing the surface scale of the alloy sheet to obtain a crude alloy.
6. The method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy according to claim 1, wherein the heat treatment of the alloy crude product is to place the alloy crude product in a heat treatment furnace at 650-900 ℃, preserve heat for 1h, and then cool the alloy with water to obtain the high-entropy alloy with target components.
7. The method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy according to claim 6, wherein the high-entropy alloy structure of the target component is obtained to have a dual-phase structure with coexistent FCC phase and HCP phase, B atoms in the high-entropy alloy exist in the alloy in the form of interstitial solid solution, and the high-entropy alloy can generate martensite phase transformation from the FCC phase to the HCP phase under the action of external force.
8. The method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy according to claim 7, wherein the high-entropy alloy is in a metastable state through composition design, and the alloy undergoes the martensite phase transformation from the FCC phase to the HCP phase during the friction process at low temperature, so that the wear resistance of the alloy is improved.
9. The method for improving the strength and the low-temperature wear resistance of the FeMnCoCr high-entropy alloy according to claim 7 or 8, wherein the yield strength of the high-entropy alloy with the target components is 449MPa, and the alloy is wear-resistantThe wear rate reaches 7.35 multiplied by 10 at minus 120 DEG C -5 mm 3 /(m·N)。
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN115354241A (en) * | 2022-09-01 | 2022-11-18 | 西北工业大学 | Low-temperature wear-resistant alloy with synergistically improved strong plasticity and preparation method thereof |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110273153A (en) * | 2019-07-26 | 2019-09-24 | 南昌大学 | A kind of boracic high entropy alloy coating and preparation method thereof |
| US20210222274A1 (en) * | 2017-09-08 | 2021-07-22 | Postech Academy-Industry Foundation | High entropy alloy doped with boron and method for manufacturing the same |
| CN113430405A (en) * | 2021-06-28 | 2021-09-24 | 西北工业大学 | High-strength and high-toughness face-centered cubic high-entropy alloy and preparation method thereof |
-
2022
- 2022-05-09 CN CN202210502763.0A patent/CN114855097B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20210222274A1 (en) * | 2017-09-08 | 2021-07-22 | Postech Academy-Industry Foundation | High entropy alloy doped with boron and method for manufacturing the same |
| CN110273153A (en) * | 2019-07-26 | 2019-09-24 | 南昌大学 | A kind of boracic high entropy alloy coating and preparation method thereof |
| CN113430405A (en) * | 2021-06-28 | 2021-09-24 | 西北工业大学 | High-strength and high-toughness face-centered cubic high-entropy alloy and preparation method thereof |
Non-Patent Citations (2)
| Title |
|---|
| JOSE Y.AGUILAR-HURTADO ET AL.: ""The effect of boron content on the microstructure and mechanical properties of Fe50-XMn30Co10Cr10BX (x = 0, 0.3, 0.6 and 1.7 wt%) multi-component alloys prepared by arc-melting"", 《MATERIALS SCIENCE AND ENGINEERING: A》 * |
| YILIU ET AL.: ""Structure characterization of special boundaries in Fe47Mn30Co10Cr10B3 dual-phase high-entropy alloy"", 《JOURNAL OF ALLOYS AND COMPOUNDS》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115323240A (en) * | 2022-08-29 | 2022-11-11 | 沈阳工业大学 | High-toughness metastable-state dual-phase FeMnCrCo high-entropy alloy and preparation method thereof |
| CN115354241A (en) * | 2022-09-01 | 2022-11-18 | 西北工业大学 | Low-temperature wear-resistant alloy with synergistically improved strong plasticity and preparation method thereof |
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