High-entropy alloy reinforced high-strength and high-toughness vermicular graphite cast iron material and preparation method thereof

Abstract

The invention particularly relates to a high-entropy alloy reinforced high-strength and high-toughness vermicular graphite cast iron material and a preparation method thereof. The material is composed of 2.8 to 4.2% of C, 0.8 to 2.5% of Si, 0.3 to 0.5% of Mn, and Plt. 0.05%, Slt; the high-entropy alloy comprises, by weight, 0.05% of Fe, 0.6%-1.5% of Cu, 0.8%-1.2% of Ni, 1%-3% of high-entropy alloy precast blocks and the balance Fe and inevitable impurities. In preparation, according to alloy components, raw materials are added into a medium-frequency induction furnace to be melted, and high-entropy alloy precast blocks are high-purity equal-proportion Hf, Nb, Ta, Ti and Zr; the bottom layer of the vermicularizing inoculation process comprises a vermicularizing agent and a high-entropy alloy precast block, and the upper layer of the vermicularizing inoculation process comprises an inoculant; and when the molten iron is discharged from the furnace, vermicular inoculation treatment is performed, and material preparation is completed through pouring. The problem of strength-toughness inversion is effectively solved, a vermicular graphite / matrix composite structure with more uniform size distribution and improved interface bonding strength is obtained, the prepared material can be used for manufacturing key components of a combustion chamber, the performance and reliability of a diesel engine are effectively improved, and the harsh service condition requirement of the diesel engine is met.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal materials, and in particular relates to a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material and a preparation method thereof. Technical Background

[0002] Compacted graphite iron (CGI), combining the performance advantages of both ductile iron and flake graphite gray cast iron, is a promising new material for manufacturing key combustion chamber components in modern diesel engines. However, cast iron's strength and toughness are significantly inverted, making conventional CGI difficult to meet the rigorous operating conditions of high-power-density diesel engines. The diesel engine industry, particularly high-power-density diesel engines, urgently demands CGI with both higher strength and toughness to meet the performance requirements of key combustion chamber components.

[0003] Existing technologies, such as the "Silicon Carbide Reinforced Synthetic Compacted Graphite Cast Iron Material and Its Preparation Method" disclosed in the document with authorization publication number "CN114318118B", use silicon carbide reinforcement. Due to the difference in physical properties between silicon carbide particles and the matrix material, the two deform to different degrees during stress. However, high silicon carbide will split the matrix, and stress concentration will occur around the silicon carbide particles. As the load increases, the cracks will extend along the interface between the silicon carbide particles and the matrix, further exacerbating the damage to the matrix and increasing the embrittlement tendency of the material. The "Yttrium-Based Heavy Rare Earth Magnesium Alloy Core Wire and Its Application in the Preparation of Thick Compacted Graphite Castings" disclosed in the document with authorization publication number "CN114318118B" improves strength through rare earth microalloying. However, during the rare earth microalloying process, due to the active chemical properties of rare earth elements, they easily react with oxygen, moisture, etc. in the surrounding environment, resulting in the loss of rare earth elements. In addition, during the smelting and processing processes, a certain amount of rare earth elements will remain in the equipment and waste slag, which cannot be completely recycled, further increasing production costs.

[0004] In the field of metal materials, high-entropy alloys (HEAs) have become a research hotspot due to their unique performance advantages. HEAs are used to prepare various composite materials, including in-situ preparation and preparation using HEAs as master alloys.

[0005] In-situ preparation methods, such as the one disclosed in patent publication number CN117187661A, "An In-situ TiC-Reinforced FeCoNiCrAl-Based High-Entropy Alloy Composite Material with Weakened Interface Structure, Coating, and Preparation Method." This material formulation comprises 10-35wt% high-purity Fe powder, 10-35wt% Co powder, 10-35wt% Ni powder, 10-35wt% Cr powder, 5-35wt% Al powder, 10-35wt% Ti powder, and 0.2-5wt% graphite powder. The Ti and graphite powders in this composite material are milled using high-energy ball milling to obtain a pre-in-situ powder. This powder is then mixed with the other components using low-energy ball milling, and a high-entropy alloy coating is produced using a laser cladding process. Patent authorization publication number CN106995898B discloses "A High-Performance Compacted Graphite High-Entropy Alloy and Its Preparation Method," describing a high-entropy alloy with the composition formula Al[NiaFeb]2Mc-Cd, where M is one or more of Co, Cr, Cu, Ga, Hf, Mn, Mo, Ta, Ti, V, W, Zn, Zr, and rare earth elements, with a+b=2, 0<c≤1, and 0.1≤d≤0.25. This method combines the excellent properties of both compacted graphite iron and high-entropy alloys. However, the in-situ preparation method suffers from the following problems: the rate and extent of elemental reaction are difficult to precisely control during the reaction process, which can easily lead to uneven size and discrete distribution of the reinforcing phase, causing a strength-toughness inversion problem: increased strength accompanied by a significant decrease in toughness, preventing a good match between the two. Furthermore, the preparation process often involves multiple high-energy ball milling steps, complex heat treatments, or specialized molding techniques. This not only results in a cumbersome and time-consuming process, but also places high demands on equipment, increasing preparation costs and energy consumption, limiting its large-scale industrial application. A method for preparing a high-entropy alloy by adding it to a matrix material as an intermediate alloy, such as the "A High-Entropy Alloy Reinforced High-Speed ​​Steel Wear-Resistant Material" disclosed in the document with patent authorization announcement number "CN114875288B", is composed of a composite of a high-entropy alloy and a high-speed steel matrix. The high-entropy alloy is FeCrCoNiHf0.2+xB0.8x, and the atomic ratio of Fe, Cr, Co, Ni, Hf, and B in the high-entropy alloy is 1:1:1:1:(0.2+x):(0.8x). The matrix is ​​made of high-speed steel. The composite ratio of the high-entropy alloy to the high-speed steel matrix is ​​310:9790 by mass fraction. The high-entropy alloy powder is added to the molten high-speed steel liquid, and the composite material is prepared using a vacuum microwave energy stirring melting furnace or a vacuum medium- and high-frequency induction melting furnace.For example, the document with patent authorization announcement number "CN113000858B" discloses "a graphene-high entropy alloy composite material and a method for preparing the same by selective laser melting". Al, Co, Cr, Fe, Ni and B powders are weighed and ball-milled to mechanically alloy the metal powders to obtain a high-entropy alloy; then, a graphene anhydrous ethanol solution is added to the high-entropy alloy, and ball milling is continued. After the ball milling is completed, the composite material powder is dried to obtain a composite material powder, which is then synthesized using the SLM molding process using RP Build software. The above-mentioned preparation methods have the following problems: whether it is vacuum melting or laser forming process, it is extremely sensitive to process parameters, and slight parameter fluctuations may cause defects such as microstructure inhomogeneity and residual stress concentration. At the same time, in the above-mentioned preparation methods, the high entropy alloy used as the intermediate alloy is a CoCrFeNi system high entropy alloy. The purpose in the system is that the high entropy alloy used as the intermediate alloy is a CoCrFeNi system high entropy alloy. The purpose in the system is mainly to improve a specific property of the composite material (such as wear resistance and high-temperature stability). However, due to the lack of coordinated control of the alloy composition and the preparation process, it is difficult to balance the strength and toughness, and thus it is impossible to simultaneously improve the overall performance of the composite material. However, in cast iron systems, especially complex solidification systems involving graphite / matrix multiphase coevolution, its atomic-scale hysteresis diffusion mechanism and mesoscopic-scale stress field distortion effect have a great influence on the properties of the material. The existing method of adding high entropy alloys as intermediate alloys to matrix materials for preparation is difficult to apply to complex cast iron systems and suffers from the problem of strength-toughness inversion. Summary of the Invention

[0006] The object of the present invention is to provide a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material and a preparation method thereof, so as to overcome the strength-toughness inversion problem existing in the prior art.

[0007] To achieve the above object, the technical solution adopted by the present invention is: a method for preparing a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material, comprising the following steps:

[0008] Step 1: Prefabrication of high entropy alloy blocks:

[0009] First, high-purity Hf, Nb, Ta, Ti, and Zr metal raw materials of equal weight ratio are used to prepare alloy ingots through a vacuum arc melting process. The alloy ingots are then crushed into powder and agglomerates are eliminated. Finally, the powder is assembled into a cemented carbide mold and pressed under a uniaxial pressure of 600 MPa for 150 seconds to form a high-entropy alloy prefabricated block, which is then crushed into particles of 3-5 mm in size for later use.

[0010] Step 2: Ingredients:

[0011] Target composition: C: 2.8-4.2%, Si: 0.8-2.5%, Mn: 0.3-0.5%, P < 0.05%, S < 0.05%, Cu: 0.6-1.5%, Ni: 0.8-1.2%, high entropy alloy preform 1-3%, the balance is Fe and unavoidable impurities;

[0012] Weigh the raw materials according to the target composition, including pig iron, 45# steel, Mn-Fe, Cu, and Ni, and record the mass of the raw materials; weigh 4 / 5 of the designed addition amount of high-entropy alloy particles;

[0013] Step 3: Melting:

[0014] Pig iron and 45# steel are placed in an induction furnace in sequence. After the pig iron and 45# steel are completely melted, Mn-Fe, Cu, and Ni are added until they are completely melted. The temperature of the molten iron is recorded using an infrared thermometer. High-entropy alloy particles are added and allowed to stand to ensure that the high-entropy alloy particles are melted. The molten iron is then taken out of the furnace for creep inoculation.

[0015] Step 4: Vermicular inoculation treatment:

[0016] Weigh 1 / 5 of the designed addition amount of high entropy alloy particles; weigh MgRE5 creeping agent and 75SiFe inoculant;

[0017] In the creep inoculation process: the bottom layer is creep inoculation agent and high entropy alloy prefabricated block particles accounting for 1 / 5 of the raw material mass, and the upper layer is inoculant;

[0018] Step 5: Pouring:

[0019] Vermicular inoculation treatment: pouring molten iron into a pre-prepared sand mold to complete the preparation of high-entropy alloy-reinforced high-strength and toughness vermicular graphite cast iron material.

[0020] Furthermore, in the above step 2, the target composition is C: 3.8%, Si: 1.9%, Mn: 0.5%, P: 0.02%, S: 0.04%, Cu: 0.9%, Ni: 1.0%, high entropy alloy prefabricated block: 3%, and the balance is Fe and unavoidable impurities.

[0021] Furthermore, in the above step 1, the alloy ingot is crushed into powder by plasma rotating electrode atomization method.

[0022] Furthermore, in the above step 1, airflow screening and vacuum drying are used to eliminate agglomeration, the particle size of the airflow screening is controlled to be 50-150 μm, and the temperature of the vacuum drying is 80-120° C. and the time is 2-4 hours.

[0023] Furthermore, in the above step 1, when pressing the high entropy alloy prefabricated block, the powder is assembled into a cemented carbide mold, the uniaxial pressure is 200-800 MPa, and the pressure is maintained for 30-180 seconds.

[0024] Furthermore, in the above step 3, high entropy alloy particles are added at 1300-1400°C, left to stand at this temperature for 300-500s, and taken out of the furnace at 1450-1550°C.

[0025] Furthermore, the particle size of the MgRE5 vermicular agent is 5-15 mm, accounting for 0.5-0.6% of the total mass of the designed raw materials; the particle size of the 75SiFe inoculant is 5-15 mm, accounting for 0.9-1.1% of the total mass of the designed raw materials.

[0026] Furthermore, the high-entropy alloy-reinforced high-strength and toughness compacted graphite cast iron material prepared by the above preparation method has the following beneficial effects compared with the prior art:

[0027] 1. The present invention innovatively introduces refractory high entropy alloy (Hf-Nb-Ta-Ti-Zr) powder into the compacted graphite cast iron system, achieving a breakthrough improvement in the material's strength and toughness through a multi-scale synergistic strengthening mechanism. Its core mechanism is reflected in two aspects: First, the high entropy alloy provided by the present invention is a refractory system, and the high entropy alloy contains multiple principal element elements with large atomic radius (atomic radius range 1.46- Significantly greater than Fe ) forms a gradient solid solution structure in the iron matrix, and the resulting lattice distortion can significantly improve the strengthening effect compared to traditional single elements. Lattice distortion not only hinders dislocation movement through the pinning effect, but also changes the graphite / matrix interface energy through the stress field induced by the distortion, causing the vermicular graphite to present a better morphological distribution. Secondly, the ultra-high mixing entropy of the quinary system forms a stable BCC solid solution phase during solidification, and the synergistic effect of each main element produces a unique "hysteresis diffusion effect". In the cast iron eutectic reaction stage, Zr and Hf preferentially form metastable carbides with C, delaying the precipitation kinetics of Fe3C, while Ta and Nb regulate the graphite growth interface through adsorption. Therefore, the high entropy alloy provided by the present invention is applied to the vermicular graphite cast iron system, that is, the refractory high entropy alloy is introduced into the vermicular graphite cast iron eutectic reaction process. By constructing a gradient solid solution and multi-scale interface engineering, the dilemma of strength-toughness inversion is effectively solved, and finally a vermicular graphite / matrix composite structure with a more uniform size distribution and improved interface bonding strength is obtained.

[0028] 2. The high-entropy alloy powder composite-reinforced compacted graphite cast iron prepared by this invention has broad application prospects and enormous market value. In the diesel engine industry, particularly high-power density diesel engines, this material can be used to manufacture key combustion chamber components such as cylinder liners and cylinder heads, effectively improving the performance and reliability of diesel engines and meeting their rigorous service requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1The stress-strain curve of the compacted graphite cast iron prepared in Example 1;

[0030] Figure 2 This is an optical microstructure photograph of the compacted graphite cast iron prepared in Example 1;

[0031] Figure 3 The stress-strain curve of the high entropy alloy prepared in Example 2;

[0032] Figure 4 This is an optical microstructure photograph of the high entropy alloy prepared in Example 2;

[0033] Figure 5 The stress-strain curve of the high entropy alloy prepared in Example 3;

[0034] Figure 6 This is an optical microstructure photograph of the high entropy alloy prepared in Example 3. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Example 1, a method for preparing a high-entropy alloy reinforced high-strength and high-toughness compacted graphite cast iron material, comprising the following steps:

[0037] Step 1: Prefabrication of high entropy alloy blocks:

[0038] First, an alloy ingot is prepared using high-purity raw materials of Hf, Nb, Ta, Ti, and Zr weighed in equal proportions by mass through a vacuum arc melting process. The ingot is then crushed into powder using a plasma rotating electrode atomization method. Agglomerates are then removed using airflow screening (100 μm) and vacuum drying (100°C / 3 h). Finally, the powder is assembled into a cemented carbide mold and pressed into a high-entropy alloy preform using a uniaxial pressure of 600 MPa for 150 seconds, crushing it into particles of 3-5 mm in size.

[0039] Step 2: Prepare ingredients according to target quality:

[0040] Target composition: C: 3.8%, Si: 1.9%, Mn: 0.5%, P: 0.02%, S: 0.04%, Cu: 0.9%, Ni: 1.0%, high entropy alloy particles 3%, and the balance Fe and unavoidable impurities.

[0041] The raw materials, including pig iron, 45# steel, Mn-Fe, Cu, and Ni, were weighed according to the target composition, and the mass of the raw materials was recorded; high-entropy alloy particles, 4 / 5 of the designed addition amount, were weighed.

[0042] Step 3: Melting:

[0043] Put pig iron and 45# steel into the induction furnace in sequence. After the pig iron and 45# steel are completely melted, add Mn-Fe, Cu, and Ni until they are completely melted. Use an infrared thermometer to record the temperature of the molten iron. Add high-entropy alloy particles at 1300-1400℃ and let it stand for 400s at this temperature to ensure that the high-entropy alloy particles are melted. Wait until the temperature reaches 1450-1550℃ and take it out of the furnace for creep inoculation.

[0044] Step 4: Vermicular inoculation treatment:

[0045] Weigh 1 / 5 of the designed addition amount of high entropy alloy particles; weigh 0.5% of the designed total mass of the raw materials, MgRE5 vermicular agent (particle size of 5-15mm) and 1.0% of the 75SiFe inoculant (5-15mm);

[0046] In the creep inoculation process: the bottom layer is the creep agent and high entropy alloy prefabricated block particles, and the upper layer is the inoculant.

[0047] Step 5: Pouring:

[0048] Vermicular inoculation treatment: pouring molten iron into a pre-prepared sand mold to complete the preparation of high-entropy alloy-reinforced high-strength and toughness vermicular graphite cast iron material.

[0049] After testing, see Figure 1 The high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material prepared in Example 1 has a tensile strength of 563 MPa and an elongation of 3.7%. Compared with JV / 450 / S in the ISO 16112:2017 international standard, the strength is increased by 25% and the elongation is more than doubled.

[0050] Example 2, a method for preparing a high-entropy alloy reinforced high-strength and high-toughness compacted graphite cast iron material, comprising the following steps:

[0051] Step 1: Prefabrication of high entropy alloy blocks:

[0052] First, an alloy ingot is prepared using high-purity raw materials of Hf, Nb, Ta, Ti, and Zr in equal weight proportions via vacuum arc melting. The ingot is then crushed into powder using a plasma rotating electrode atomization method. Agglomerates are then removed using airflow screening (120 μm) and vacuum drying (110°C / 2.5 hours). The powder is then assembled into a cemented carbide mold and pressed into a high-entropy alloy preform using a uniaxial pressure of 500 MPa for 100 seconds, crushing it into particles of 3-5 mm in size.

[0053] Step 2: Prepare ingredients according to target quality:

[0054] Target composition: C: 3.6%, Si: 2.4%, Mn: 0.3%, P: 0.03%, S: 0.024%, Cu: 1.2%, Ni: 0.9%, high entropy alloy particles 2%, and the balance is Fe and unavoidable impurities.

[0055] The raw materials, including pig iron, 45# steel, Mn-Fe, Cu, and Ni, were weighed according to the target composition, and the mass of the raw materials was recorded; high-entropy alloy particles, 4 / 5 of the designed addition amount, were weighed.

[0056] Step 3: Melting:

[0057] Put pig iron and 45# steel into the induction furnace in sequence. After the pig iron and 45# steel are completely melted, add Mn-Fe, Cu, and Ni until they are completely melted. Use an infrared thermometer to record the temperature of the molten iron. Add high-entropy alloy particles when the temperature is 1300-1400℃. Let it stand at this temperature for 500s to ensure that the high-entropy alloy particles are melted. Wait until the temperature reaches 1450-1550℃ and take it out of the furnace for creep inoculation.

[0058] Step 4: Vermicular inoculation treatment:

[0059] Weigh 1 / 5 of the designed addition amount of high entropy alloy particles; weigh 0.6% of the designed total mass of the raw materials, MgRE5 vermicular agent (particle size of 5-15mm) and 1.1% of the 75SiFe inoculant (5-15mm);

[0060] In the creep inoculation process: the bottom layer is the creep agent and high entropy alloy prefabricated block particles, and the upper layer is the inoculant.

[0061] Step 5: Pouring:

[0062] Vermicular inoculation treatment: pouring molten iron into a pre-prepared sand mold to complete the preparation of high-entropy alloy-reinforced high-strength and toughness vermicular graphite cast iron material.

[0063] After testing, see Figure 3, the high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material prepared in Example 2 has a tensile strength of 553 MPa and an elongation of 3.1%. Compared with JV / 450 / S in the ISO 16112:2017 international standard, the strength is increased by 22% and the elongation is more than doubled.

[0064] Example 3, a method for preparing a high-entropy alloy reinforced high-strength and high-toughness compacted graphite cast iron material, comprising the following steps:

[0065] Step 1: Prefabrication of high entropy alloy blocks:

[0066] First, an alloy ingot was prepared using high-purity raw materials of Hf, Nb, Ta, Ti, and Zr in equal weight proportions via vacuum arc melting. The ingot was then crushed into powder using a plasma rotating electrode atomization method. Agglomerates were removed using airflow screening (130 μm) and vacuum drying (90°C / 2.5 hours). The powder was then assembled into a cemented carbide mold and pressed into a high-entropy alloy preform using a uniaxial pressure of 700 MPa for 160 seconds, crushing it into particles of 3-5 mm in size.

[0067] Step 2: Prepare ingredients according to target quality:

[0068] Target composition: C: 4.0%, Si: 1.6%, Mn: 0.3%, P: 0.02%, S: 0.03%, Cu: 1.3%, Ni: 0.9%, high entropy alloy preform: 2.8%, and the balance is Fe and unavoidable impurities.

[0069] The raw materials, including pig iron, 45# steel, Mn-Fe, Cu, and Ni, were weighed according to the target composition, and the mass of the raw materials was recorded; high-entropy alloy particles, 4 / 5 of the designed addition amount, were weighed.

[0070] Step 3: Melting:

[0071] Put pig iron and 45# steel into the induction furnace in sequence. After the pig iron and 45# steel are completely melted, add Mn-Fe, Cu and Ni until they are completely melted. Use an infrared thermometer to record the temperature of the molten iron. Add high entropy alloy particles at 1300-1400℃ and let it stand for 300℃ at this temperature to ensure that the high entropy alloy particles are melted. Wait until the temperature reaches 1450-1550℃ and take it out of the furnace for creep inoculation.

[0072] Step 4: Vermicular inoculation treatment:

[0073] Weigh 1 / 5 of the designed addition amount of high entropy alloy particles; weigh 0.55% of the designed total mass of the raw materials, MgRE5 vermicular agent (particle size of 5-15 mm) and 0.9% of the 75SiFe inoculant (5-15 mm);

[0074] In the creep inoculation process: the bottom layer is the creep agent and high entropy alloy prefabricated block particles, and the upper layer is the inoculant.

[0075] Step 4: Pouring:

[0076] Vermicular inoculation treatment: pouring molten iron into a pre-prepared sand mold to complete the preparation of high-entropy alloy-reinforced high-strength and toughness vermicular graphite cast iron material.

[0077] After testing, see Figure 5The high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material prepared in Example 3 has a tensile strength of 563 MPa and an elongation of 3.9%. Compared with JV / 450 / S in the ISO 16112:2017 international standard, the strength is increased by 25% and the elongation is more than doubled.

[0078] See also Figure 2 、 Figure 4 and Figure 6 The optical microstructure photos of the vermicular cast iron show that Example 1 presents a better vermiform morphology distribution. Figure 1 、 Figure 3 and Figure 5 The stress-strain curve of the present invention is shown in FIG1 , and Example 1 is the best embodiment.

[0079] The above description is an explanation of the specific implementation of the present invention, rather than a limitation of the present invention. Those skilled in the relevant technical field can also make various equivalent technical solutions without departing from the scope of the present invention, so all equivalent technical solutions should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a high-entropy alloy reinforced high-strength and high-toughness compacted graphite cast iron material, characterized by: The following steps are involved: Step 1: Prefabrication of high entropy alloy blocks: First, high-purity Hf, Nb, Ta, Ti, and Zr metal raw materials of equal weight ratio are used to prepare alloy ingots through a vacuum arc melting process. The alloy ingots are then crushed into powder and agglomerates are eliminated. Finally, the powder is assembled into a cemented carbide mold and pressed under a uniaxial pressure of 600 MPa for 150 seconds to form a high-entropy alloy prefabricated block, which is then crushed into particles of 3-5 mm in size for later use. Step 2: Ingredients according to quality: Target composition: C: 2.8-4.2%, Si: 0.8-2.5%, Mn: 0.3-0.5%, P < 0.05%, S < 0.05%, Cu: 0.6-1.5%, Ni: 0.8-1.2%, high entropy alloy preform 1-3%, the balance is Fe and unavoidable impurities; Weigh the raw materials according to the target composition, including pig iron, 45# steel, Mn-Fe, Cu, and Ni, and record the mass of the raw materials; weigh 4 / 5 of the designed addition amount of high-entropy alloy particles; Step 3: Melting: Pig iron and 45# steel are placed in an induction furnace in sequence. After the pig iron and 45# steel are completely melted, Mn-Fe, Cu, and Ni are added until they are completely melted. The temperature of the molten iron is recorded using an infrared thermometer. High-entropy alloy particles are added and allowed to stand to ensure that the high-entropy alloy particles are melted. The molten iron is then taken out of the furnace for creep inoculation. Step 4: Vermicular inoculation treatment: Weigh 1 / 5 of the designed addition amount of high entropy alloy particles; weigh MgRE5 creeping agent and 75SiFe inoculant; In the creep inoculation process: the bottom layer is creep inoculation agent and high entropy alloy prefabricated block particles, and the upper layer is inoculant; Step 5: Pouring: Vermicular inoculation treatment: pouring molten iron into a pre-prepared sand mold to complete the preparation of high-entropy alloy-reinforced high-strength and toughness vermicular graphite cast iron material.

2. The method for preparing a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material according to claim 1, characterized in that: In the step 2, the target composition is C: 3.8%, Si: 1.9%, Mn: 0.5%, P: 0.02%, S: 0.04%, Cu: 0.9%, Ni: 1.0%, high entropy alloy prefabricated block: 3%, and the balance is Fe and unavoidable impurities.

3. The method for preparing a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material according to claim 1, characterized in that: In the step 1, the alloy ingot is crushed into powder by a plasma rotating electrode atomization method.

4. The method for preparing a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material according to claim 1, characterized in that: In the step 1, airflow screening and vacuum drying are used to eliminate agglomeration, the particle size of the airflow screening is controlled to be 50-150 μm, and the temperature of the vacuum drying is 80-120° C. and the time is 2-4 hours.

5. The method for preparing a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material according to claim 1, characterized in that: In the step 1, when pressing the high entropy alloy prefabricated block, the powder is assembled into a cemented carbide mold, the uniaxial pressure is 200-800 MPa, and the pressure is maintained for 30-180 seconds.

6. The method for preparing a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material according to claim 1, characterized in that: In the step 3, high entropy alloy particles are added at 1300-1400°C, allowed to stand at this temperature for 300-500s, and taken out of the furnace at 1450-1550°C.

7. The method for preparing a high-entropy alloy reinforced high-strength and toughness compacted graphite cast iron material according to claim 1, characterized in that: The particle size of the MgRE5 vermicular agent is 5-15 mm, accounting for 0.5-0.6% of the total mass of the designed raw materials; the particle size of the 75SiFe inoculant is 5-15 mm, accounting for 0.9-1.1% of the total mass of the designed raw materials.

8. A high-entropy alloy reinforced high-strength and high-toughness compacted graphite cast iron material prepared by the preparation method according to claim 1.

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