High-entropy alloy casting chimeric-semi-solid pressurized composite structural part as well as preparation method and application of high-entropy alloy casting chimeric-semi-solid pressurized composite structural part

Abstract

The invention provides a high-entropy alloy casting chimeric-semi-solid pressurized composite structural part and a preparation method and application thereof. The method comprises the following steps: prefabricating a circular-truncated-cone-shaped embedding hole with a small-end-up hole diameter in a metal substrate; molten high-entropy alloy is poured into the preheated embedding hole; and pressurizing heat treatment is carried out in a protective atmosphere, interface element diffusion is promoted, and internal holes and shrinkage defects are eliminated. According to the preparation method, high-quality combination between a high-entropy alloy strengthening phase and a base body is achieved through strengthening of combination of macroscopic mechanical locking and microscopic metallurgy, and the prepared part has the base body obdurability and the surface ultra-high abrasion resistance at the same time. Furthermore, the embedding holes are designed to be in directional arrangement (such as linear staggering, concentric circular rings and plum blossom-shaped arrays) matched with the main stress direction, the part can be customized to be applied to key wear-resisting parts such as pin shafts, hammer heads and sealing rings, the performance leap is achieved, meanwhile, the use cost of the high-entropy alloy is remarkably reduced, and the application prospect is wide. And the method has high engineering application value.

Description

Technical Field

[0001] This invention belongs to the technical field of wear-resistant and impact-resistant composite parts, specifically relating to a high-entropy alloy melt-casting-embedded semi-solid pressurized composite structural part and its preparation method, as well as the application of the above-mentioned composite structural part. Background Technology

[0002] In industries such as machinery manufacturing, mining equipment, and aerospace, friction and wear are among the main causes of mechanical part failure. Traditional wear-resistant materials, such as high-carbon tool steel, cemented carbide (e.g., WC-Co), and surface-hardened steel, have long dominated the wear-resistant materials field due to their high hardness and resistance to plastic deformation. However, high hardness is often accompanied by insufficient toughness. These materials are prone to brittle fracture under impact loads or alternating stress, a typical example being the chipping failure of mine crusher hammers during long-term use. Furthermore, these materials are expensive. For example, cemented carbide requires high-temperature sintering (1400-1500℃) and a cobalt binder phase, resulting in an overall cost 5-8 times higher than ordinary steel. In addition, although surface coatings can improve the friction resistance of the substrate, there are problems such as insufficient bonding strength between the coating and the substrate and short-lived wear resistance.

[0003] In recent years, high-entropy alloys (HEAs) have become a hot topic in wear-resistant materials research due to their unique "cocktail effect" and hysteretic diffusion characteristics. HEAs, represented by the CoCrFeNiMn and AlCoCrFeNi systems, exhibit excellent wear resistance, high-temperature stability, and fatigue resistance through high lattice distortion formed by multi-principal solid solution structures. CN115627404 B discloses a method for preparing a high-wear-resistant and corrosion-resistant high-entropy alloy with a surface hardness greater than 1000 HV and excellent corrosion resistance. However, it requires multiple melting processes and has a high proportion of precious metals, resulting in high production costs and hindering large-scale application.

[0004] Based on this, under the premise of reducing the manufacturing cost of parts, a composite structure part and its preparation method are provided for different forms and directions of principal stress during the service of parts. This allows the part to maintain the strength and toughness of the matrix and have excellent friction resistance. At the same time, it is necessary to ensure that the high-hardness wear-resistant reinforcing phase does not fall off under stress, is firmly bonded to the strong and tough matrix, and is dense and defect-free. This is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] One of the objectives of this invention is to provide a method for preparing high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural parts, in order to solve the problems of weak interfacial bonding and numerous internal defects in traditional composite materials.

[0006] The second objective of this invention is to provide a composite structural part that combines the overall strength and toughness of a metal matrix with the ultra-high surface wear resistance of a high-entropy alloy reinforcing phase, and has a strong interface bond and a dense, defect-free interior.

[0007] The third objective of this invention is to provide an application of a high-entropy alloy melt-casting-semi-solid pressurized composite structure part, which improves the lifespan and reliability of key components under extreme conditions by matching the macroscopic arrangement design of the reinforcing phase with specific service conditions.

[0008] One of the technical solutions adopted by this invention to achieve its objective is to provide a method for preparing a high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part, comprising the following steps: S1. Provide a metal substrate, wherein the metal substrate has a plurality of frustum-shaped non-through fitting holes, wherein the diameter D1 of the fitting hole on the side closer to the working surface of the part is smaller than the diameter D2 on the side farther from the working surface. S2. Preheat the metal matrix, pour the molten high-entropy alloy into the interlocking hole, air cool to below the solidus temperature of the high-entropy alloy, and then water cool to room temperature to obtain the composite. S3. Under a protective atmosphere, the cooled composite is heated to temperature T and pressure P is applied, and the pressure is maintained for a certain time. Under the combined action of temperature T and pressure P, elements at the interface between the high-entropy alloy strengthening phase and the metal matrix diffuse into each other and form a metallurgical bond. S4. Air-cool to below the solidus temperature of the high-entropy alloy and then water-cool to room temperature to obtain a composite structure part.

[0009] The overall concept and inventive principle of this invention are as follows: This invention addresses the problems of insufficient toughness in traditional wear-resistant materials and high manufacturing costs of high-entropy alloys by proposing a method for fabricating composite structural parts that utilize macroscopic high-entropy alloy reinforcing phases to strengthen the traditional alloy matrix. The main innovation of this method lies in its unique structural design and optimized fabrication process. In terms of structural design, this invention employs a metal matrix with multiple interlocking holes, where the hole diameter (D1) on the side closer to the working surface of the part is smaller than the hole diameter (D2) on the side farther from the working surface, forming a "smaller at the top and larger at the bottom" structure. This structure provides mechanical self-locking for the subsequently filled high-entropy alloy, preventing it from shifting or falling out under frictional stress. Furthermore, the arrangement of the high-entropy alloy reinforcing phases can be optimized by adjusting the opening method of the interlocking holes to adapt to different principal stress forms during the part's service life, thereby producing a composite structural part that combines a high-strength and tough matrix with excellent surface wear resistance to meet practical application requirements.

[0010] In terms of preparation process, this invention abandons traditional powder mixing or melt infiltration methods and, combined with innovations in the interlocking hole structure, adopts an integrated composite process of "melt casting interlocking - semi-solid pressurization". This process first involves casting a high-entropy alloy melt into preheated interlocking holes in the matrix; subsequently, under set temperature T and pressure P conditions, pressure-holding heat treatment is performed. This greatly activates the atomic diffusion ability of the high-entropy alloy reinforcing phase and the metal matrix, causing plastic flow, thereby completely filling the micropores, compensating for solidification shrinkage, and thoroughly eliminating defects within the reinforcing phase and at the bonding interface. Simultaneously, the combined effect of heat and force greatly promotes the active interdiffusion of elements on both sides of the interface, forming a metallurgical bonding layer with a compositional gradient transition and strong adhesion, achieving reinforcement from macroscopic mechanical locking to microscopic metallurgical bonding.

[0011] Based on the improvements mentioned above, this invention uses only a small amount of high-performance high-entropy alloy in the key areas of the working surface to successfully prepare composite parts with controllable cost, high toughness and super wear resistance, thus achieving a balance between material performance and manufacturing cost.

[0012] Furthermore, in step S1, the arrangement of the plurality of frustum-shaped fitting holes is adapted to the principal stress direction during the service of the part, so as to optimize the wear resistance and load-bearing capacity of the part under specific working conditions. Specifically, the arrangement is adapted to the main wear load and is selected from one of the following: multiple rows of straight lines arranged in an alternating pattern, concentric rings distributed, or a plum blossom-shaped close arrangement.

[0013] Furthermore, the metal matrix is ​​prepared by casting or powder metallurgy, and multiple non-penetrating interlocking holes are obtained by molding or additive manufacturing.

[0014] Preferably, for linear sliding wear: the interlocking holes are arranged in multiple rows of straight lines in an interlaced pattern. This directional arrangement can avoid the formation of continuous weak bands in the matrix material in the main stress direction, so that the load is transferred more evenly between the matrix and the reinforcing phase. At the same time, the interlaced reinforcing phase forms triangular structural units with stronger resistance to deformation.

[0015] Preferably, for rotational friction wear: the fitting holes are distributed in multiple concentric rings with the rotation center as the center. This arrangement ensures that the working surface has a uniformly distributed reinforcing phase to provide wear-resistant protection at any rotation angle.

[0016] Preferably, when primarily subjected to impact or high-stress contact loads, the interlocking holes are arranged in a staggered, closely spaced pattern. This arrangement can accommodate the maximum number of reinforcements per unit area, thereby dispersing the extremely high impact force locally borne to a greater number of high-strength, high-entropy alloy pillars. Simultaneously, when an impact occurs at a point, the force can be rapidly transmitted and dispersed along multiple directions to a larger matrix area, preventing excessive stress concentration in a single reinforcement or localized matrix, and preventing brittle cracking or plastic collapse.

[0017] Further, in step S1, the ratio of the aperture D1 to the aperture D2 of the fitting holes is between 0.4 and 0.8, and the minimum wall thickness between adjacent fitting holes is 1 to 3 times the aperture of a single fitting hole. The aperture ratio (D1 / D2) is preferably controlled between 0.4 and 0.8 to balance the locking effect with the smoothness of casting and filling. The minimum wall thickness between adjacent fitting holes is designed to be 1 to 3 times the aperture of a single fitting hole to ensure that the metal matrix retains sufficient overall strength and toughness after composite formation.

[0018] Furthermore, in step S2, the metal matrix includes one of steel, nickel-based alloy, or titanium alloy.

[0019] Furthermore, prior to casting in step S2, the inner surface of the fitting hole is cleaned and activated, followed by preheating the metal substrate to 200-500°C. Cleaning includes sandblasting to remove oxide scale, and activation includes pickling or electroless plating to coat a thin nickel-based diffusion layer. Cleaning and activation improve the wettability of the subsequent high-entropy alloy melt. Subsequently, the entire metal substrate is preheated to a preheating temperature of 200°C to 500°C to reduce thermal shock during casting and facilitate the flow and filling of the high-entropy alloy melt.

[0020] Further, in step S2, the high-entropy alloy includes at least five elements selected from Fe, Co, Ni, Cr, Al, Ti, V, and Mo, with each element having an atomic percentage of 5% to 35%. Specifically, the content of each element is adjusted to form a single face-centered cubic, body-centered cubic, or mixed structure to avoid the formation of continuous intermetallic compounds at grain boundaries. The pre-designed high-entropy alloy raw material is heated to complete melting in a vacuum induction furnace or a protective atmosphere melting furnace, and then poured into the interlocking holes of a preheated metal matrix. Finally, it is air-cooled to below the solidus temperature and then water-cooled to room temperature. Water cooling effectively prevents grain growth, resulting in a fine-grained structure and increasing the wear resistance of the high-entropy alloy. Excessive water cooling temperature can cause rapid metal shrinkage, leading to incomplete fusion, while excessively low water cooling temperature can cause grain growth, reducing the wear resistance of the high-entropy alloy. Preferably, the composite material treated in step S3 is air-cooled to 30-50°C below the solidus temperature of the high-entropy alloy and then water-cooled to room temperature.

[0021] Furthermore, in step S3, the temperature T is higher than the solidus temperature of the high-entropy alloy but lower than its liquidus temperature; the pressure P is 50-100 MPa, applied by hydrostatic or isostatic pressure; and the holding time is 20-30 minutes. The temperature being higher than the solidus temperature and lower than the liquidus temperature places the high-entropy alloy in a semi-solid state, resulting in high viscosity. Sufficient pressure is needed to drive this viscous medium to produce plastic flow, allowing it to squeeze into and fill the micro-shrinkage cavities between dendrites and the micro-gaps between the dendrite walls and the matrix pore walls. Studies have found that pressures below 50 MPa are insufficient to overcome this internal flow resistance and cannot effectively eliminate micro-shrinkage and interfacial voids; while pressures above 100 MPa can easily cause plastic deformation or even crushing of thinner walls, compromising the integrity of the part. Additionally, eliminating voids and shrinkage is not an instantaneous process. Material flow and pore closure require time. For holding time, less than 20 minutes will result in an incomplete process, with internal defects not being completely eliminated, affecting the final density; while holding time exceeding 30 minutes can easily lead to excessive grain growth in high-entropy alloys or matrix materials, or the formation of unfavorable precipitates, thereby damaging their mechanical properties.

[0022] In step S3 of this invention, the heat treatment promotes the active interdiffusion of elements on both sides of the interface between the high-entropy alloy and the metal matrix, forming a metallurgical bonding layer with a compositional gradient transition and strong adhesion at the interface, thus achieving strengthening from mechanical locking to metallurgical bonding. The heat treatment process applies pressure, forcing the semi-solid high-entropy alloy to undergo viscous flow, completely filling every microscopic pit within the interlocking pores, expelling residual gas at the interface, eliminating voids at the bonding interface, and simultaneously compensating for the volume shrinkage of the high-entropy alloy during the final solidification stage, compressing the liquid metal between dendrites to compensate for shrinkage, thereby eliminating internal shrinkage cavities and porosity, and obtaining a dense high-entropy alloy. Finally, according to the material performance requirements, air cooling to below the solidus temperature followed by water cooling to room temperature is employed. Preferably, the initial water cooling temperature is set to 30-50°C below the solidus temperature.

[0023] The second objective of this invention is to provide a high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part, which is prepared by the preparation method described in one objective of this invention, comprising: The metal substrate has multiple frustum-shaped non-through fitting holes; A high-entropy alloy reinforcing phase fills the interlocking holes and forms a metallurgical bonding layer with a compositional gradient transition at the interface with the metal matrix.

[0024] The composite structure part provided by the present invention has multiple high-entropy alloy reinforcing phase units embedded in the fitting holes of the metal matrix by metallurgical bonding, and the shape of the fitting holes is complementary and locked with the shape of the high-entropy alloy reinforcing phase units. The surface of the high-entropy alloy reinforcing phase units and the surface of the metal matrix together constitute the final working surface of the part.

[0025] The third objective of this invention is to provide the application of the high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structure parts as described in the second objective of this invention.

[0026] Preferably, the high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part is used to manufacture the pin of heavy engineering machinery. The interlocking holes are arranged in multiple rows of straight lines along the axial direction on the journal surface area of ​​the pin to accommodate the wear load of its linear reciprocating motion.

[0027] Preferably, the high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part is used to manufacture the hammer of a mining crusher. The interlocking holes are arranged in an interlaced plum blossom pattern at the striking part of the hammer to maximize the dispersion and bearing of high-stress impact loads.

[0028] Preferably, the high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structure part is used to prepare a high-speed rotating sealing ring. The interlocking holes are distributed in multiple concentric rings with the rotation center as the center on the end face of the sealing ring to ensure the uniformity of wear resistance under rotation conditions.

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The preparation method of high entropy alloy melting and casting interlocking-semi-solid pressurized composite structure parts provided by the present invention uses a metal matrix with interlocking holes that are smaller at the top and larger at the bottom. This not only provides reliable mechanical locking for the high entropy alloy reinforcing phase that is subsequently poured, but also optimizes the arrangement of the interlocking holes according to the load direction, avoids stress concentration, optimizes the overall mechanical properties of the composite structure, and extends the service life of the parts under complex working conditions.

[0030] (2) The preparation method of the high-entropy alloy melt-casting-semi-solid pressurized composite structural parts provided by the present invention achieves a strong metallurgical bond between the high-entropy alloy reinforcing phase and the conventional metal matrix through a composite process of "pretreatment activation + pressurized densification + diffusion heat treatment", fundamentally solving the problem of weak interface bonding in traditional secondary casting. By applying pressure in the semi-solid region, the solidification shrinkage defects inside the high-entropy alloy reinforcing phase and the interface bonding voids are effectively eliminated, so that the reinforcing phase itself has high density and its wear resistance potential can be fully utilized.

[0031] (3) The high-entropy alloy fusion-inlay semi-solid pressurized composite structure part prepared by this invention uses only a small amount of high-performance high-entropy alloy in the key areas of the working surface, while the majority of the matrix still uses conventional metals with low cost and good toughness, thus achieving the best balance between part performance and manufacturing cost. More importantly, by precisely matching the macroscopic arrangement design of the reinforcing phase with specific working conditions (such as linear reciprocating wear of the pin shaft, high-stress impact of the hammer head, and uniform rotational wear of the sealing ring), the part can exhibit optimal wear resistance and load-bearing performance in specific directions. This makes this invention not only have material cost advantages, but also have a clear "design-performance" orientation, showing extremely high engineering application value and market potential in high-end manufacturing fields such as heavy machinery, mining equipment, and high-speed sealing. Attached Figure Description

[0032] Figure 1 This is a top view of the sample obtained in Embodiment 1 of the present invention; Figure 2 This is a side sectional view of the sample obtained in Embodiment 1 of the present invention; Figure 3 This is a top view of the sample obtained in Embodiment 2 of the present invention; Figure 4 This is a top view of the sample obtained in Embodiment 3 of the present invention; Figure 5 The microstructure of the high-entropy alloy in the sample obtained in Example 1 of this invention; Figure 6 This is a distribution diagram of the bonding region elements in the sample obtained in Embodiment 1 of the present invention; Wherein, 1-matrix; 2-interlocking hole; 3-high entropy alloy. Detailed Implementation

[0033] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention provides a method for preparing a high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part, characterized by comprising the following steps: Step 1: Provide a metal substrate with multiple frustum-shaped non-through fitting holes. The diameter D1 of the fitting hole on the side closer to the working surface of the part is smaller than the diameter D2 on the side farther from the working surface. The arrangement of the multiple frustum-shaped fitting holes is adapted to the direction of the principal stress during the service of the part, and is selected from one of the following: multiple rows of straight lines arranged in an alternating pattern, concentric rings distributed, or a plum blossom-shaped close arrangement. The ratio of the diameter D1 to the diameter D2 of the fitting holes is between 0.4 and 0.8, and the minimum wall thickness between adjacent fitting holes is 1 to 3 times the diameter of a single fitting hole.

[0035] Step 2: First, clean and activate the inner surface of the interlocking hole. Then, preheat the metal matrix to 200-500°C, pour the molten high-entropy alloy into the interlocking hole, air cool to 30-50°C below the solidus temperature of the high-entropy alloy, and then water cool to room temperature to obtain the composite. The high-entropy alloy includes at least five elements selected from Fe, Co, Ni, Cr, Al, Ti, V, and Mo, with each element having an atomic percentage of 5% to 35%.

[0036] Step 3: Under a protective atmosphere, the cooled composite is heated to temperature T and pressure P is applied, and the pressure is held for a certain time. Under the combined action of temperature T and pressure P, elements diffuse between the high-entropy alloy reinforcing phase and the metal matrix interface and form a metallurgical bond. The temperature T is higher than the solidus temperature of the high-entropy alloy but lower than its liquidus temperature. The pressure P is 50-100 MPa, and the holding time is 20-30 min.

[0037] Step 4: After air cooling to 30-50°C below the solidus temperature of the high-entropy alloy, water cooling to room temperature is performed to obtain the composite structure part.

[0038] The present invention will be further described below with reference to specific embodiments, but these are not intended to limit the scope of the invention.

[0039] Example 1 like Figure 1 and Figure 2 As shown, a 100mm*100mm*30mm Q235 steel substrate containing multiple rows of straight interlocking holes (ABABA type) was first fabricated using casting technology. The diameter D1 of the interlocking hole friction surface was 8mm, the diameter D2 away from the friction surface was 10mm, the interlocking hole depth was 25mm, and the wall thickness between two interlocking holes on the friction surface was 12mm. Subsequently, the oxide layer inside the interlocking holes was removed by sandblasting, and the substrate was preheated to 200℃. Fe, Co, Cr, Ni, and Al were induction heated to a molten state at 20 at.% each, and then poured into the interlocking holes of the Q235 steel substrate. After cooling, the composite part was placed in a 1300℃ heat treatment furnace, argon gas was introduced, and a pressure of 50MPa was applied to each interlocking hole for 30 minutes. It was then air-cooled to 1220℃ and water-cooled to room temperature.

[0040] like Figure 5 As shown, the high-entropy alloy microstructure in the sample prepared in Example 1 is a two-phase structure of FCC and BCC, with a dense structure and no obvious pores (Note: the pores in the 1μm image are characteristic of the microstructure and not actual pores). Figure 6 As shown, the elements in the bonding region of the sample exhibit a gradient distribution, indicating that the composite parts prepared by this process have atomic interdiffusion between the high-entropy alloy and the matrix, forming a metallurgical bond.

[0041] The sample prepared in Example 1 was subjected to a reciprocating sliding friction test for 30 minutes under a load of 1 kg and a friction speed of 50 mm / s. The wear volume was 3687 mm². 3 .

[0042] Comparative Example 1 A 100mm*100mm*30mm Q2335 steel substrate was heat-treated in a 1300℃ heat treatment furnace for 30 minutes, followed by air cooling to 1220℃ and then water cooling to room temperature. A reciprocating sliding friction test was conducted for 30 minutes under a 1kg load and a friction speed of 50mm / s, resulting in a wear volume of 9583mm². 3 .

[0043] Example 2 like Figure 3 As shown, a Φ100mm*20mm 304 stainless steel substrate with concentric interlocking holes was first fabricated using powder metallurgy. The diameter D1 of the interlocking hole friction surface was 5mm, the diameter D2 away from the friction surface was 10mm, the hole depth was 15mm, and the wall thickness between the two interlocking holes on the friction surface was 15mm. After acid pickling to activate the interlocking holes, the substrate was preheated to 350℃. Fe, Co, Cr, Ni, and Mo were induction heated to a molten state at 20 at.% each and then cast into the interlocking holes of the 304 stainless steel substrate. After cooling, the composite part was placed in a 1370℃ heat treatment furnace, argon gas was introduced, and a pressure of 75MPa was applied to each interlocking hole for 25 minutes. It was then air-cooled to 1280℃ and water-cooled to room temperature. A rotational friction test was conducted for 30 minutes under a load of 1kg and a rotational speed of 200 rpm, resulting in a wear volume of 2863mm². 3 .

[0044] Comparative Example 2 A Φ100mm 304 stainless steel substrate was heat-treated in a 1370℃ furnace for 25 minutes, then air-cooled to 1280℃ and water-cooled to room temperature. A rotational friction test was conducted for 30 minutes under a 1kg load and a rotational speed of 200 rpm, resulting in a wear volume of 9636mm². 3 .

[0045] Example 3 like Figure 4As shown, a 100mm*100mm*10mm 316L stainless steel substrate with plum blossom-shaped interlocking holes was first fabricated using casting technology. The diameter D1 of the interlocking hole friction surface was 4mm, the diameter D2 away from the friction surface was 10mm, the interlocking hole depth was 8mm, and the wall thickness between adjacent interlocking holes on the friction surface was 15mm. Subsequently, Ni was chemically plated into the interlocking holes, and the substrate was preheated to 500℃. Fe, Ti, Cr, Ni, and Al were induction heated to a molten state at 20 at.% each and then cast into the interlocking holes of the 316L stainless steel substrate. After cooling, the composite part was placed in a 1260℃ heat treatment furnace, argon gas was introduced, and a pressure of 100MPa was applied to each interlocking hole for 20 minutes. It was then air-cooled to 1190℃ and water-cooled to room temperature. A reciprocating sliding friction test was conducted for 30 minutes under a load of 5kg and a speed of 200mm / s, with a wear volume of 5689mm². 3 .

[0046] Comparative Example 3 A 100mm*100mm*10mm 316L stainless steel substrate was heat-treated in a 1260℃ heat treatment furnace for 20 minutes, then air-cooled to 1190℃ and water-cooled to room temperature. A reciprocating sliding friction test was conducted for 30 minutes under a load of 5kg and a speed of 200mm / s, resulting in a wear volume of 14289mm². 3 .

[0047] In summary, the high-entropy alloy melt-casting embedded-semi-solid pressurized composite structural parts and their preparation method provided by this invention, through the synergistic design of mechanical locking of irregular holes and semi-solid pressurized metallurgy, successfully achieve local strengthening of high-performance high-entropy alloys on a low-cost metal matrix. Test data from Examples 1-3 show that the composite parts prepared by this method have strong interfacial bonding and dense microstructure, and their wear resistance is significantly improved by several times compared to the single matrix materials in Comparative Examples 1-3. This fully demonstrates that this invention, while ensuring material strength and toughness, can specifically and economically significantly improve the wear resistance of key friction surfaces, demonstrating its application prospects and engineering value in the field of high-end equipment manufacturing.

[0048] The above are merely preferred embodiments of the present invention and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should recognize that any equivalent substitutions and obvious changes made based on the content of this specification should be included within the protection scope of the present invention.

Claims

1. A method for preparing a high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part, characterized in that, Includes the following steps: S1. Provide a metal substrate, in which multiple frustum-shaped non-through fitting holes are provided, the diameter D1 of the fitting hole on the side closer to the working surface of the part is smaller than the diameter D2 on the side farther from the working surface. S2. Preheat the metal matrix, pour the molten high-entropy alloy into the interlocking hole, air cool to below the solidus temperature of the high-entropy alloy, and then water cool to room temperature to obtain the composite. S3. Under a protective atmosphere, the cooled composite is heated to temperature T and pressure P is applied, and the pressure is maintained for a certain time. Under the combined action of temperature T and pressure P, elements at the interface between the high-entropy alloy strengthening phase and the metal matrix diffuse into each other and form a metallurgical bond. S4. Air-cool to below the solidus temperature of the high-entropy alloy and then water-cool to room temperature to obtain a composite structure part.

2. The preparation method according to claim 1, characterized in that, In step S1, the arrangement of the multiple frustum-shaped fitting holes is adapted to the direction of the principal stress during the service of the part, and is selected from one of the following: multiple rows of straight lines arranged in an alternating pattern, concentric rings distributed, or plum blossom-shaped tightly arranged.

3. The preparation method according to claim 1, characterized in that, In step S1, the ratio of the aperture D1 to the aperture D2 of the fitting hole is between 0.4 and 0.8, and the minimum wall thickness between adjacent fitting holes is 1 to 3 times the aperture of a single fitting hole.

4. The preparation method according to claim 1, characterized in that, In step S2, the metal substrate includes one of steel, nickel-based alloy or titanium alloy; before casting, the inner surface of the fitting hole is cleaned and activated, and then the metal substrate is preheated to 200-500℃.

5. The preparation method according to claim 1, characterized in that, In step S2, the high-entropy alloy includes at least five elements selected from Fe, Co, Ni, Cr, Al, Ti, V, and Mo, with each element having an atomic percentage of 5% to 35%.

6. The preparation method according to claim 1, characterized in that, In step S3, the temperature T is higher than the solidus temperature of the high-entropy alloy but lower than its liquidus temperature; the pressure P is 50-100 MPa, and the holding time is 20-30 min.

7. A high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part, prepared by the method according to any one of claims 1-6, characterized in that, include: The metal substrate has multiple frustum-shaped non-through fitting holes; A high-entropy alloy reinforcing phase fills the interlocking holes and forms a metallurgical bonding layer with a compositional gradient transition at the interface with the metal matrix.

8. The application of the high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part according to claim 7 in the manufacture of pins for heavy engineering machinery, characterized in that, The fitting holes are arranged in multiple rows of axially interlaced straight lines on the journal surface of the pin to accommodate the wear load of its linear reciprocating motion.

9. The application of the high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structural part according to claim 7 in the manufacture of hammerheads for mining crushers, characterized in that, The fitting holes are arranged in a staggered, quincunx pattern at the striking point of the hammer to maximize the dispersion and absorption of high-stress impact loads.

10. The application of the high-entropy alloy melt-casting interlocking-semi-solid pressurized composite structure part according to claim 7 in the preparation of a high-speed rotating sealing ring, characterized in that, The fitting holes are distributed in multiple concentric rings with the rotation center as the center on the end face of the sealing ring, so as to ensure the uniformity of wear resistance under rotation conditions.

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