Ti / B-regulated FeCoCrNi-based wear-resistant high-entropy alloy and preparation method thereof

Abstract

The invention provides a Ti / B regulated and controlled FeCoCrNi-based wear-resistant high-entropy alloy and a preparation method thereof. Ti and B are accurately proportioned in a (FeCoCrNi) 100-3xTixB2x (x is greater than or equal to 1.5 and less than or equal to 2.5 at.%) system, vacuum electric arc melting is adopted, heat treatment is performed at 700-800 DEG C for 0.5-1.5 h, quenching is performed, and a dispersed TiB2 strengthening phase and a Cr-rich Laves phase are formed in situ. The addition proportion of Ti / B is optimized to realize grain refinement and inter-phase synergistic toughening, the room temperature friction coefficient is about 0.62, the minimum wear volume is about 0.326 mm < 3 >, and the wear mechanism is oxidation and abrasive particle synergistic wear. And by regulating and controlling the Ti / B ratio and heat treatment parameters, excessive aggregation and brittle spalling of the Laves phase are inhibited, so that the wear resistance and mechanical stability of the material are remarkably improved, and the method is suitable for design and preparation of engineering component materials in a high-load wear-resistant environment.

Description

Technical Field

[0001] This invention relates to the field of wear-resistant metal materials, and more particularly to a FeCoCrNi-based high-entropy alloy and its preparation method, which achieves in-situ generation of reinforcing phases through Ti / B synergistic regulation. This alloy, by adjusting the amount of Ti and B added, induces in-situ precipitation of TiB2 reinforcing phases and Cr-Laves-rich phases within the alloy system, thereby enhancing the wear resistance of the high-entropy alloy under high-load friction environments. This invention belongs to the technical fields of high-entropy alloy design, surface and interface engineering, and wear-resistant material preparation. Background Technology

[0002] In mechanical equipment, metallurgical rolling, energy and power systems, and high-end friction pair systems, the wear resistance of materials directly determines the stability, reliability, and service life of the equipment. Parts such as pump and valve sealing pairs, gear meshing pairs, bearing sliding surfaces, die forming surfaces, and roller contact areas are subjected to complex friction-load coupling effects over long periods, making them highly susceptible to wear behaviors involving multiple mechanisms such as ploughing, adhesion, fatigue, and oxidation. Under these conditions, the temperature rise at the friction interface is significant, and the surface micro-regions often experience rapid heating, stress alternation, oxide film rupture, and repeated shearing processes, making it difficult for traditional wear-resistant materials to simultaneously achieve hardness, toughness, and stable wear resistance.

[0003] Although traditional wear-resistant materials, represented by high-hardness alloy steel, have been widely used, their performance systems have inherent structural limitations. These materials typically sacrifice inherent toughness and impact resistance in pursuit of high hardness, making it difficult to achieve both strength and toughness simultaneously. Under dynamic or high-impact load conditions, these materials often experience brittle fracture or surface spalling due to their inability to effectively dissipate energy. Furthermore, due to the relatively fixed composition and limited space for microstructure control, improving their overall performance and long-term stability in complex and variable wear environments has reached a bottleneck, making breakthroughs difficult to achieve through conventional alloying or heat treatment methods.

[0004] High-entropy alloys, due to their unique multi-principal-element structure and solid solution strengthening mechanism, have gradually become a research hotspot in the field of wear-resistant materials in recent years. Typical face-centered cubic FeCoCrNi-based high-entropy alloys possess advantages such as good ductility, high deformation compatibility, and strong corrosion resistance, exhibiting high stability in complex service environments. However, these single-FCC phase high-entropy alloys are still prone to adhesive wear and surface plastic flow under dry friction conditions. This is because their matrix hardness is limited, making it difficult to resist stress concentration at the friction interface. With further increases in load, the damage to the material surface can shift from mild abrasive wear to severe delamination failure, limiting their application as engineering wear-resistant components.

[0005] To improve the wear resistance of high-entropy alloys, researchers typically employ a second-phase strengthening strategy, such as introducing high-hardness ceramic phases like TiC, B4C, and TiB2. However, added ceramic particles in high-entropy alloy melts suffer from poor wettability, large density variations, and difficulty in achieving uniform distribution. After cooling, the interfacial bonding between the ceramic phase and the metal matrix is ​​usually mechanical rather than metallurgical, easily leading to interfacial cracking and reinforcing phase detachment. This, in turn, forms hard secondary abrasive grains during wear, exacerbating the wear rate. Furthermore, large ceramic particle sizes can cause stress concentration in the matrix, leading to brittle spalling; conversely, excessively small particles or low content cannot effectively improve the overall hardness and wear resistance of the material. Therefore, relying solely on added reinforcing phases is insufficient to meet the requirements for both strength and toughness under medium-to-high load friction conditions.

[0006] To address the aforementioned issues, an in-situ self-generating strengthening strategy based on alloy design offers a promising approach to resolving the challenges of synergistic strength and toughness at the interface. This strategy introduces appropriate amounts of active elements (such as Ti and B) into the high-entropy alloy system, causing them to react directly during solidification or heat treatment to generate reinforcing phases such as TiB2, Cr-B, or Laves phases. Because the reinforcing phase and the matrix form an in-situ metallurgical bond, the interfacial bonding strength is significantly improved, and the second phase typically exhibits a dispersed and uniform distribution. By controlling the composition and process, the morphology, size, and volume fraction of the reinforcing phase can be actively designed, theoretically opening up new avenues for obtaining wear-resistant materials that combine strength and toughness.

[0007] However, when implementing this strategy in a typical FeCoCrNi-based high-entropy alloy system, the multi-principal-element, high-mixing-entropy environment makes the reaction pathways and precipitation behavior of elements such as Ti / B particularly complex. Specifically, the precipitation of TiB2 is strongly dependent on the Ti / B atomic ratio and heat treatment regime, and its morphology can vary from nanoscale dispersed phases to micron-scale coarse particles. At the same time, the inherent Cr element in the system is prone to segregation, combining with excess B and other elements to form a brittle Cr-rich Laves phase. This multiphase coexistence microstructure makes the wear resistance of the material exhibit a non-monotonic and complex response: insufficient TiB2 content results in limited strengthening effect; if its particles are too coarse, they can become microcrack initiation sites; and excessive Ti / B addition can induce a large amount of Laves phase, severely impairing the toughness and coordinated deformation capacity of the matrix, leading to stress concentration and delamination failure during wear. Therefore, how to precisely control and achieve a "balance" between the TiB2 reinforcing phase and the harmful brittle phase in this complex system of multi-element coupled reactions has become the core scientific and technological key to further breakthroughs in the wear resistance of FeCoCrNi-based high-entropy alloys.

[0008] In summary, existing technologies still face significant challenges in controlling the microstructure of high-entropy alloys to balance wear resistance and toughness. Specifically, a systematic and reliable solution has yet to be developed for effectively controlling the formation, morphology, and distribution of the TiB2 reinforcing phase and Cr-Laves-rich phase in FeCoCrNi-based alloy systems through the synergistic effect of compositional design and heat treatment processes. Therefore, this paper proposes a method to regulate the formation and evolution of reinforcing phases in FeCoCrNi-based high-entropy alloys by precisely controlling the Ti / B element ratio and optimizing the heat treatment path. This design aims to stabilize and control the morphology, size, and distribution of the TiB2 phase while suppressing the excessive formation of harmful brittle phases, thereby exploring feasible ways to achieve a synergistic improvement in hardness, toughness, and interfacial stability. This aims to provide theoretical and experimental references for developing high-performance high-entropy wear-resistant alloy materials suitable for complex friction conditions. Summary of the Invention

[0009] To address the problems of adhesive wear, ploughing damage, and oxidation spalling in existing FeCoCrNi high-entropy alloys under medium-to-high load wear conditions, and the shortcomings of external ceramic particle reinforcement methods such as weak interfacial bonding, easy detachment, and difficulty in controlling particle size and distribution, this invention aims to provide a Ti / B synergistically regulated FeCoCrNi-based wear-resistant high-entropy alloy and its preparation method. This method utilizes the in-situ reaction of Ti and B in the alloy system to generate the reinforcing phase TiB2 and induces Cr segregation to form a Cr-Laves-rich phase. This allows for directional adjustment of the size, morphology, and volume fraction of the reinforcing phase within a controllable process window, enabling the prepared alloy to meet different requirements such as high hardness wear resistance, comprehensive wear resistance, and impact wear resistance.

[0010] S1. Raw material preparation and elemental metrology design:

[0011] According to (FeCoCrNi) 100-3x Ti x B 2x The design system (1.5 ≤ x ≤ 2.5 at.%) uses high-purity Fe, Co, Cr, Ni, and FeB metal raw materials, maintaining a Ti to B molar ratio of approximately 1:2 to ensure the formation of the TiB2 in-situ reinforcing phase during subsequent heat treatment. The raw materials are deoxygenated, dried, and surface-treated to reduce oxide inclusions. The raw materials are then vacuum arc-melted to obtain a uniform high-entropy alloy melt, which is thoroughly mixed and solidified to obtain an ingot with a uniform alloy microstructure.

[0012] S2. Heat treatment induces in-situ phase formation:

[0013] The high-entropy alloy ingot obtained in step S2 was heated to 750℃ and held for 1 hour to allow Ti and B to react in situ within the alloy to form dispersed TiB2 particles, while simultaneously promoting limited agglomeration of Cr to form a Cr-rich Laves phase. Subsequently, rapid water cooling was performed to preserve the morphology and distribution of the TiB2 and Laves phases, resulting in a homogenized microstructure.

[0014] S3. Molding and processing:

[0015] The alloy obtained in step S3 is cut, ground and machined to obtain a sample that meets the requirements of friction and wear testing or engineering applications.

[0016] Based on the control of Ti / B content and heat treatment regime, the (FeCoCrNi) obtained in this invention 100-3x Ti x B 2x The microstructure of the high-entropy alloy (1.5≤x≤2.5at.%) exhibits the following systematic evolution: TiB2 enters the optimal formation range, with a size of approximately 0.5–1.5 μm, appearing as equiaxed or short rods and uniformly distributed; its quantity increases significantly but does not agglomerate. The volume fraction of Cr-rich Laves phase remains at 5–7 wt.%, distributed at grain boundaries or within grains, without continuous precipitation bands. The overall microstructure achieves a balance between hardness and toughness; this group of samples exhibits the smallest wear volume and stable friction coefficient, representing the optimal strengthening ratio of this invention.

[0017] In summary, this invention utilizes Ti / B synergistic regulation and heat treatment parameter selection to enable the TiB2 reinforcing phase and Laves phase to form, grow, and stably distribute in the matrix according to specific rules, thereby obtaining different microstructure combinations. This provides a systematically adjustable technical solution for realizing wear-resistant high-entropy alloys under low to high wear conditions.

[0018] This invention optimizes the Ti / B addition ratio to achieve grain refinement and interphase synergistic toughening, resulting in a room temperature friction coefficient of approximately 0.62 and a minimum wear volume of approximately 0.326 mm. 3 The wear mechanism is a combination of oxidation and abrasive wear. By adjusting the Ti / B ratio and heat treatment parameters, excessive aggregation and brittle spalling of the Laves phase are suppressed, thereby significantly improving the wear resistance and mechanical stability of the material, making it suitable for the design and fabrication of engineering components under high-load and wear-resistant environments.

[0019] The advantages and beneficial effects of this invention are as follows:

[0020] 1. Enhanced phase in situ formation and stable interface bonding: Both TiB2 and Laves phases precipitate in situ inside the alloy, forming a stable metallurgical bonding interface with the matrix. This avoids the problems of easy detachment of traditional external particles, interface weakening, and secondary abrasive generation, significantly improving the structural stability of the material under complex frictional loads.

[0021] 2. Controllable strengthening phase, adaptable to various wear conditions: By adjusting the Ti / B content and heat treatment process, excess brittle phases can be eliminated, and TiB2 and Laves phases can be generated in situ for synergistic bidirectional strengthening, thus achieving adaptation to light to high load wear conditions.

[0022] 3. Synergistic reinforcement to improve load-bearing capacity and wear resistance: Dispersed TiB2 and a small amount of Laves form an effective pinning effect on the grain boundaries, which significantly refines the matrix and improves its resistance to deformation; combined with solid solution reinforcement and particle reinforcement, it can suppress plastic flow and ploughing damage at the wear track and stabilize the friction interface structure.

[0023] 4. Significantly improved overall wear resistance: Within the optimized Ti / B range (1.5≤x≤2.5at.%), the material achieves the best match between hardness and toughness, resulting in a significant reduction in wear volume (minimum approximately 0.326mm). 3 The coefficient of friction is stable at around 0.60, and the wear resistance is significantly improved compared with other components.

[0024] This invention enables stable, controllable, and efficient in-situ strengthening of TiB2 and Laves phases in high-entropy alloys through synergistic regulation of the Ti / B system. This significantly improves the insufficient wear resistance of traditional high-entropy alloys under medium-to-high load wear conditions, and provides a novel alloying technology route that can be widely promoted for the design and engineering application of high-load friction pair materials. Attached Figure Description

[0025] Figure 1 The XRD patterns of the examples and comparative examples 1-3 are used to characterize the precipitation patterns and phase composition evolution of the TiB2-enhanced phase and the Laves phase under varying Ti / B content.

[0026] Figure 2 The SEM microstructure and corresponding EDS elemental distribution diagrams of the examples and comparative examples 1-3 show the in-situ precipitation characteristics and spatial distribution of TiB2 particles and Laves phase in the alloy matrix: (a) Comparative Example 1, (b) Comparative Example 2, (c) Example, (d) Comparative Example 3.

[0027] Figure 3 The EBSD analysis results for Examples and Comparative Examples 1-3 include phase maps, orientation maps (IPF maps), and grain size distribution histograms: (a) Comparative Example 1, (b) Comparative Example 2, (c) Example, (d) Comparative Example 3.

[0028] Figure 4 The TEM, HRTEM, SAED, and EDS characterization results for the examples are used to reveal the crystal structure, interface features, and chemical composition of the TiB2 reinforced phase and the Laves phase.

[0029] Figure 5 Nanoscale hardness and modulus distribution obtained by nanoindentation in Examples and Comparative Examples 1-3: (a) Comparative Example 1, (b) Comparative Example 2, (c) Example, (d) Comparative Example 3.

[0030] Figure 6 The friction coefficient-time curves and wear depth distribution diagrams for Examples 1-3 and Comparative Examples 1-3 are used to characterize the tribological stability and wear degree of each component system.

[0031] Figure 7 The following are three-dimensional morphology images of the embodiments and comparative examples 1-3 after friction and wear, used to compare the effect of changes in TiB2 / Laves phase content on the geometry of wear tracks and wear mechanism: (a) Comparative example 1, (b) Comparative example 2, (c) Embodiment, (d) Comparative example 3.

[0032] Figure 8 The graph shows a comparison of the average friction coefficient and wear volume of the examples and comparative examples 1-3, used to quantitatively display the change law of the overall wear resistance of the material under Ti / B synergistic reinforcement.

[0033] Figure 9 The SEM observation results of Examples and Comparative Examples 1-3 are used to compare the wear groove width and plowing degree of samples with different compositions: (a) Comparative Example 1, (b) Comparative Example 2, (c) Example, (d) Comparative Example 3. Detailed Implementation

[0034] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0035] The high-entropy alloys in the examples and Comparative Examples 1-3 were all obtained by vacuum arc melting. The expression for the high-entropy alloy (FeCoCrNi) is given. 100-3x Ti x B 2x , where x represents the molar content of Ti in the high-entropy alloy at.%, a=1; and the molar ratio of FeCoCrNi is 1:1:1:1.

[0036] Weigh the Fe, Co, Cr, Ni, Ti metal raw materials and FeB alloying element according to the atomic ratio required for the composition of the new high-entropy alloy. The raw materials are then vacuum arc-melted to obtain a uniform high-entropy alloy melt. The melt is then fully mixed and solidified to obtain an alloy ingot with a uniform structure.

[0037] The alloy ingot, after arc melting, was then placed in a tube furnace and held at 750°C for 1 hour. This allowed Ti and B to react in situ in the matrix to form the TiB2 reinforcing phase, while simultaneously inducing limited segregation of Cr to form the Laves phase, eliminating excess brittle phases. Immediately after holding, the ingot was water-cooled to maintain the size and morphology stability of the dispersed second phase. The chemical composition of the as-cast alloys in specific embodiments and comparative examples is shown in Table 1.

[0038] Table 1. Chemical composition of high-entropy alloys (at.%)

[0039] sample variable x Component expression (at.%) Example 2 <![CDATA[(FeCoCrNi) 94 Ti2B4]]> Comparative Example 1 0.3 <![CDATA[(FeCoCrNi) 99.1 You 0.3 B 0.6 ]]> Comparative Example 2 1 <![CDATA[(FeCoCrNi) 97 Ti1B2]]> Comparative Example 3 3 <![CDATA[(FeCoCrNi) 91 Ti3B6]]>

[0040] Comparative Example 4:

[0041] The process and raw material ratios were the same as in Example 1. The difference was that the alloy ingot after arc melting was placed in a tube furnace and held at 600°C for 1 hour. This high-entropy alloy produced almost no TiB2, but the excessive Sigma phase content was detrimental to improving its friction and wear performance.

[0042] Comparative Example 5:

[0043] The process and raw material ratios were the same as in Example 1. The difference was that the alloy ingot after arc melting was placed in a tube furnace and held at 1000°C for 1 hour. This high-entropy alloy exhibited severe surface oxidation and excessively large TiB2 particles inside, which was detrimental to improving its friction and wear performance.

[0044] Comparative Example 6:

[0045] The process and raw material ratios were the same as in Example 1. The difference was that the alloy ingot after arc melting was placed in a tube furnace and held at 750°C for 0.2 hours. This high-entropy alloy exhibited insufficient element diffusion, severe compositional inhomogeneity, and inadequate precipitation of strengthening phases.

[0046] Comparative Example 7:

[0047] The process and raw material ratios were the same as in Example 1. The difference was that the alloy ingot after arc melting was placed in a tube furnace and held at 750°C for 2 hours. TiB2 coarsened, changing from uniform dispersion to larger blocks, which intensified the continuous grid formation of the Laves phase and severely impaired the plasticity and toughness of the material.

[0048] refer to Figure 1 The XRD patterns of the high-entropy alloys in the examples and comparative examples are shown to determine the phase composition. All HEAs showed an FCC crystal structure, confirming that the addition of Ti and B does not change the primary phase. Furthermore, with increasing Ti and B content, the intensity of the FCC diffraction peaks gradually decreased, while their half-widths increased. The formation of TiB2 is also demonstrated in the examples. (Reference) Figure 2As shown in (c), the TiB2 particles in the example are uniformly dispersed equiaxed, and a significant distinction between the Ti / B enrichment region and the Cr enrichment region can be seen in the EDS; Comparative Example 1 ( Figure 2 (a) Almost no TiB2 was generated, and Cr segregation was not obvious; Figure 2 (b) shows the formation of a small amount of fine TiB2 particles in Comparative Example 2. Figure 2 (d) shows that in Comparative Example 3, TiB2 and Cr-rich phases aggregate at grain boundaries, and locally appear as bands or agglomerates. With the increase of Ti / B content, the volume fraction of TiB2 increases by 0.7% from 0.02%, while the Laves phase is significantly observed in high-content samples, verifying the controllability of phase composition by ratio regulation. Figure 4 Transmission electron microscopy (TEM) and high-resolution images, as well as SAED and EDS distributions, are presented for representative example samples. SAED patterns confirm lattice evidence of three-phase coexistence; EDS mapping clearly shows Ti / B enrichment in the TiB2 region, Cr enrichment in the Laves phase region, while Fe / Co / Ni are uniformly present in the matrix. This combined omics experiment confirms that TiB2 and Cr-rich Laves phases are formed in situ, and the interface exhibits good metallurgical bonding characteristics, providing microscopic evidence for a synergistic strengthening mechanism. Furthermore, the increased TiB2 content preferentially forms during solidification and serves as an effective heterogeneous nucleation site, effectively refining the grain size of the HEA (Hemisphere Emergent Acid). Figure 3 ). Figure 3 EBSD phase diagram analysis showed that the proportions of TiB2 and Laves phases increased synchronously with increasing Ti / B content. Grain size statistics further confirmed that the average grain size of the alloy continuously refined with increasing Ti / B content: from approximately 111.79 μm in Comparative Example 1 to 49.03 μm in the Example, and further refined to 36.34 μm in Comparative Example 3. Simultaneously, the high-angle grain boundary density also increased with increasing Ti / B content. This grain refinement is mainly attributed to the heterogeneous nucleation of TiB2 and Laves phases during solidification and their pinning effect on grain boundary migration, promoting grain refinement and further enhancing the strength of the high-entropy alloy.

[0049] The mechanical properties of the alloys in the examples and comparative examples were evaluated using nanoindentation with a Poisson's ratio of 0.3. The indentation procedure was as follows: a load of 20 mN was applied for 15 seconds, held at the peak load for 15 seconds, and the loading rate was 10 nm / s. To ensure statistical reliability, a 10 × 10 grid of indentations (100 indentations in total) was used on the surface of each sample, with a spacing of 15 μm between adjacent indentations to avoid interaction effects. The hardness and elastic modulus values ​​were determined by averaging the data collected from all indentation points. Nanohardness mapping showed that the high-hardness areas in the examples were uniformly distributed, while local high-hardness agglomerations appeared in Comparative Example 3. Reference Figure 5Nanoscale hardness distribution cloud maps of nanoindentation arrays for four groups of samples are presented. The results show that the overall hardness increases monotonically with Ti / B content, with the TiB2 region exhibiting the highest hardness, the Laves phase falling between the two, and the FCC matrix being the softest. This mechanical heterogeneity and the second-phase distribution directly correspond to differences in wear behavior, providing mechanical evidence for the optimal compositional window for wear resistance.

[0050] refer to Figure 6 The friction coefficient versus time curves and wear depth comparisons for each sample are presented. The test procedure for wear resistance is as follows: Samples of the embodiment and Comparative Examples 1-3, each measuring 10mm × 10mm × 10mm, were subjected to sliding friction and wear tests (WTM-2E controlled atmosphere ball-to-ball friction and wear tester). The wear material was GCr 15 bearing steel balls with a diameter of 3mm and a hardness of approximately 850HV. The load was 10N, the operating temperature was room temperature, the wear time was 30 minutes, the wear mode was rotational motion, and the rotation speed was 200 r / min. Comparative Examples 1 and 2 showed large fluctuations in friction coefficient, indicating insufficient surface bearing capacity and friction stability. The embodiment maintained a stable COF of approximately 0.6 with small fluctuations, indicating the formation of a relatively stable friction interface. Comparative Example 3 showed a rebound in COF in the later stages, indicating a decrease in wear resistance stability. The wear depth profile shows that the embodiment had the shallowest groove (example value 0.13mm), while the grooves of Comparative Examples 1 and 2 were deeper and wider. The aforementioned tribological behavior is highly correlated with the microstructure (TiB2 dispersion degree, Laves phase morphology). From Figure 7 To further compare the differences in surface morphology and volume loss of the wear tracks between the embodiments and the comparative examples, 3D morphology images of the wear tracks were obtained. Figure 7 It can be clearly seen that the wear tracks in Comparative Examples 1 and 2 are both wide and deep, while the wear tracks in Example 3 are the shallowest and narrowest. Comparative Example 3 shows localized deep grooves accompanied by spalling pits. The wear volume obtained by combining the three-dimensional morphology with volume integration further quantifies the advantages of Example 3 and clarifies the microstructure to macroscopic wear behavior.

[0051] refer to Figure 8 In the example, COF reached a stable low value range and had the smallest wear volume. In contrast, although the hardness of Comparative Example 3 was high, the wear volume did not continue to decrease. Instead, the performance degraded due to brittle spalling. Figure 9 SEM images were used to compare the groove width and surface cutting morphology of the four groups of samples. The results showed that Comparative Examples 1 and 2, with low TiB2 content, exhibited obvious ploughing grooves and large-area plastic flow. The example sample showed narrow and shallow cutting grooves with a surface layer consisting more of fine abrasive particles. Comparative Example 3, on the other hand, showed irregular fragments and cracks due to excessive Laves phase. The differences in groove width and ploughing degree further confirmed the influence of the reinforcing phase distribution on the interfacial bearing capacity and ploughing resistance.

[0052] This invention achieves controllable regulation of the in-situ formation behavior and size morphology of the TiB2 reinforcing phase and the Cr-rich Laves phase in a high-entropy alloy system by precisely controlling the Ti / B addition amount and heat treatment regime. With the gradual increase of Ti / B content, the evolution of the reinforcing phase within the alloy follows this pattern: from a small amount of nanoscale dispersed TiB2 to submicron-scale equiaxed TiB2 and a stable distribution of a small amount of Laves phase, then to micron-scale equiaxed TiB2 and a suitable amount of Laves phase synergistic reinforcement, and finally to a tendency towards embrittlement due to TiB2 coarsening and Laves phase segregation. By controlling the size, volume fraction, and spatial distribution of the reinforcing phase, the hardness, toughness, and wear resistance of the high-entropy alloy obtained by this invention can be continuously adjusted within a controllable range, thereby adapting to differentiated service requirements such as high hardness and wear resistance, comprehensive wear resistance, and impact wear resistance. The Ti / B synergistic control method proposed in this invention is simple in process and has strong industrial scalability. It is applicable to obtaining FeCoCrNi-based high-entropy wear-resistant alloys with different microstructures and mechanical property combinations, providing a universal and controllable new technology path for the material design and engineering application of high-load wear-resistant components.

Claims

1. A Ti / B-controlled FeCoCrNi-based high-entropy wear-resistant alloy, characterized in that: The formula for high-entropy alloys (FeCoCrNi) 100-(1+2a)x Ti x B2a x Where 1.5≤x≤2.5 represents the molar content of Ti in the high-entropy alloy at.%, a=0.99-1.01 (preferably a=1); and the molar ratio of Fe, Co, Cr and Ni is 1:0.98-1.02 (preferably 0.99-1.01):0.98-1.02 (preferably 0.99-1.01):0.98-1.02 (preferably 0.99-1.01).

2. A method for preparing the Ti / B-regulated FeCoCrNi-based high-entropy wear-resistant alloy as described in claim 1, characterized in that: Includes the following steps: S1, Ti / B content control: Fe, Co, Cr, Ni, Ti metal raw materials and FeB alloying element are weighed according to the atomic ratio required for the new high-entropy alloy composition. The raw materials are vacuum arc melted to obtain a uniform high-entropy alloy melt, which is fully mixed and solidified to obtain an alloy ingot with uniform structure. S2. Heat treatment: Heat the alloy ingot obtained in step S2 to 700-800℃ and hold for 0.5-1.5h, then cool it with water or oil to precipitate dispersed TiB2 reinforcing phase and controlled Cr-rich Laves phase inside the alloy; obtain a Ti / B controlled FeCoCrNi-based high-entropy wear-resistant alloy.

3. The preparation method according to claim 2, characterized in that: Also includes S3. Forming and processing: The alloy obtained in step S2 is cut, polished and machined to obtain a wear-resistant alloy sample that meets the requirements of testing or application.

4. The preparation method according to claim 2, characterized in that: The atomic ratio of Ti / B is maintained at 1:2 (i.e., a = 1) to prepare a high-entropy alloy, and reinforcing phases with different contents and distributions are generated through in-situ reactions.

5. The preparation method according to claim 2, characterized in that: The heat treatment temperature in step S2 is preferably 720℃-780℃ (preferably 740℃-760℃) to eliminate excess impurities and brittle phases, and the heat treatment time is 0.7h-1.3h (preferably 0.8h-1.2h). With the increase of Ti / B content, the internal grains of the high-entropy alloy are refined, and the volume fraction of in-situ self-generated TiB2 is controlled within 0.4%–0.7% wt.%, exhibiting an irregular shape; the Cr-rich phase changes from uniform distribution to complex network distribution with the increase of Ti / B content.

6. The preparation method according to claim 2, characterized in that: The volume fraction of the Cr-rich Laves phase formed in step S2 is controlled in the range of 3–9 wt.% to achieve a synergistic effect of strength and toughness on the microstructure.

7. The preparation method according to claim 6, characterized in that: By adjusting the Ti / B content, the friction coefficient of the alloy was maintained between 0.55 and 0.70, and the wear volume was controlled between 0.30 and 0.60 mm. 3 Within the range.

8. A Ti / B-controlled (FeCoCrNi)-based wear-resistant high-entropy alloy prepared by the method according to any one of claims 2–7, characterized in that: Its microstructure includes an FCC matrix, a dispersed TiB2 reinforcing phase, and a Cr-rich Laves phase, exhibiting synergistically enhanced wear resistance properties.

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