High-strength wear-resistant copper alloy material and preparation method thereof

Abstract

The invention belongs to the technical field of alloys, and particularly relates to a high-strength wear-resistant copper alloy material and a preparation method thereof, the high-strength wear-resistant copper alloy material comprises the following raw materials by weight: 85-90 parts of copper powder, 2.5-4 parts of a composite additive, 0.02-0.05 part of a dispersing aid, 0.1-0.3 part of a sintering aid, 0.5-1 part of a process control agent, and 3.5-7 parts of an auxiliary strengthening raw material; the preparation method of the composite additive comprises the following steps: firstly coating SiC on the surfaces of particles to form a core-shell structure, then treating by a titanate coupling agent to improve the dispersity, then introducing a Ni-Co alloy layer to construct a gradient interface, and finally plating copper on the outer layer to realize homogeneous connection with a matrix. The copper alloy material with excellent comprehensive properties such as strength, hardness and wear resistance is prepared by ball-milling mixing, segmented heating sintering and multi-stage heat treatment of the raw materials, and has a good industrial application prospect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of alloy, in particular to a high-strength wear-resistant copper alloy material and a preparation method thereof. BACKGROUND

[0002] As an important engineering material, copper alloy is widely used in electronic, mechanical, transportation, energy and other fields due to its good electrical conductivity, thermal conductivity and corrosion resistance. However, with the increasing demand for material performance in modern industry, the shortcomings of traditional copper alloy in high strength and wear resistance are gradually exposed, especially in extreme working conditions such as high temperature and heavy load, copper alloy is prone to wear, fatigue, corrosion and other problems. Therefore, how to improve the strength, wear resistance and high temperature stability of copper alloy has become an important research direction in the field of material science and engineering technology. In order to improve the mechanical properties of copper alloy, in recent years, many researchers have developed new copper alloys through the optimization design of alloying elements and advanced preparation process. For example, by adding aluminum, zinc, tin, nickel and other elements, not only the strength of copper alloy can be improved, but also the wear resistance and corrosion resistance can be improved. However, there is a certain trade-off between high strength and wear resistance of traditional copper alloy materials, especially in extreme environments, the performance of traditional alloy still cannot meet the application requirements of high load and high wear resistance.

[0003] A high-strength wear-resistant copper alloy is provided in Chinese Patent No. CN202410574305.7, and its preparation method comprises the following steps: Step 1, synthesis of iron-manganese boride powder: after weighing and thoroughly mixing nine hydrated iron nitrate, four hydrated manganese nitrate, sodium borohydride and ammonium carbonate, placing them in a ceramic crucible, and performing powdering and sieving after microwave treatment, iron-manganese boride powder is obtained; Step 2, wet grinding treatment; Step 3, forming treatment; Step 4, high-temperature sintering; Step 5, post-processing: the obtained alloy green compact is subjected to annealing and cooling treatment, and finally a high-strength wear-resistant copper alloy is obtained. The present invention is based on the existing Cu-Ni-based white copper alloy containing aluminum, and the raw materials and preparation process are optimized and improved, thereby successfully preparing a white copper alloy with higher strength and better wear resistance, and the high-temperature thermal cracking resistance is also improved. However, boron iron manganese is used as a strengthening phase, which has poor high-temperature chemical stability. During high-temperature sintering and subsequent annealing, Fe and Mn are prone to diffusion reaction with the copper matrix, forming brittle intermetallic compounds, resulting in interface weakening and strength reduction. In addition, the boron iron manganese powder is added by mechanical mixing, and microcracks and cavities are easily generated at the interface after sintering, resulting in low interface bonding strength, and the elongation and fatigue life of the alloy are significantly reduced. Chinese Patent No. CN202111573459.7 provides a copper alloy material and a preparation method thereof, and the chemical composition comprises, by mass percentage: Ni 8-21%, Sn 5-10%, Al 0.5-2.0%, trace elements 0.05-1.6%, and the balance of Cu; the trace elements are at least one of P, Fe, Co and Si, the invention optimizes the composition by adding Al and at least one of P, Fe, Co and Si in copper-nickel-tin alloy, effectively inhibits the precipitation of grain boundary discontinuous precipitates, thereby improving the strength, corrosion resistance and wear resistance of the alloy. However, due to multiple cold drawing and aging treatment, the ductility and toughness may be affected, especially after secondary cold drawing, the grain size of the alloy is further refined, the strength of the material is improved, but the toughness is reduced, especially in low temperature or high load environment, the brittleness of the material may cause fracture.

[0004] Therefore, it is still a technical problem to be solved to develop a copper alloy material that can provide high strength and excellent wear resistance. SUMMARY

[0005] In order to solve the above problems, the present application provides a high-strength wear-resistant copper alloy material and a preparation method thereof, which comprises the following steps: a four-step gradient coating is used to construct a composite additive, a copper powder is used as a raw material, and is mixed with a dispersing aid, a sintering aid, a process control agent, and an auxiliary strengthening raw material, etc. through ball milling, dispersion, step-by-step sintering and multi-stage heat treatment, a high-strength, wear-resistant and corrosion-resistant copper alloy is finally obtained.

[0006] The technical scheme for solving the above problems is as follows:

[0007] A high-strength wear-resistant copper alloy material comprises the following raw materials in parts by weight: copper powder 85-90 parts, composite additive 2.5-4 parts, dispersion aid 0.02-0.05 parts, sintering aid 0.1-0.3 parts, process control agent 0.5-1 parts, and auxiliary strengthening raw material 3.5-7 parts.

[0008] The preparation method of the composite additive is as follows:

[0009] Step S1, disperse titanium diboride and sodium hexametaphosphate in a mixed solvent, ultrasonic for 40-50 min, then add tetraethyl orthosilicate, adjust pH to 9.3-9.7, stir at 80-90 DEG C for 2.5-3 h, then mix with sucrose, and obtain core-shell protected titanium diboride by keeping at 1245-1255 DEG C in an inert atmosphere for 3.5-4 h.

[0010] Step S2, dissolve titanium acid ester coupling agent HY-109, magnesium nitrate and core-shell protected titanium diboride in isopropyl alcohol, ultrasonic for 50-60 min, and obtain high-temperature compatibility additive after post-treatment.

[0011] Step S3, dissolve nickel nitrate, cobalt nitrate, citric acid and magnesium nitrate in deionized water, stir at 55-65 DEG C for 30-40 min, then add high-temperature compatibility additive, ultrasonic for 20-30 min, keep at 590-610 DEG C for 2-2.5 h, and keep at 340-360 DEG C in hydrogen atmosphere for 1-1.5 h to obtain stable coated additive.

[0012] Step S4, dissolve copper sulfate and disodium ethylenediaminetetraacetate in deionized water, stir uniformly, then add formaldehyde, stir for 10-15 min, adjust pH to 12.4-12.6, then add stable coated additive, and react at 55-65 DEG C for 2-2.5 h to obtain composite additive after post-treatment.

[0013] Further, the solid-liquid ratio of titanium diboride and anhydrous ethanol in step S1 is 1g:5.5-6.5mL, and the mass ratio of titanium diboride, sodium hexametaphosphate, tetraethyl orthosilicate and sucrose is 1:0.0005-0.001:0.2-0.3:0.5-0.8, and the mixed solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 3.5-4.5:1.

[0014] Further, the mass ratio of core-shell protected titanium diboride, titanium acid ester coupling agent HY-109, magnesium nitrate and isopropyl alcohol in step S2 is 10:0.1-0.15:0.003-0.004:80-100.

[0015] Further, the mass ratio of the high-temperature compatible additive, nickel nitrate, cobalt nitrate, citric acid, magnesium nitrate, deionized water in step S3 is 10:1-1.4:0.2-0.6:1.5-2:0.001-0.002:75-85.

[0016] Further, the mass ratio of the stable coating additive, copper sulfate, disodium ethylenediaminetetraacetate, formaldehyde, deionized water in step S4 is 1:0.1-0.15:0.14-0.18:0.06-0.1:7-8.

[0017] Further, the dispersing aid is sodium hexametaphosphate; the sintering aid is yttrium oxide; and the process control agent is zinc stearate.

[0018] Further, the auxiliary strengthening raw material is composed of tin powder, nickel powder, chromium powder, and aluminum powder with a mass ratio of 2-3.5:1-2:0.3-0.8:0.2-0.7.

[0019] The application further provides a preparation method of the high-strength wear-resistant copper alloy material.

[0020] (1) mixing copper powder and auxiliary strengthening raw material, stirring for 2-2.5 hours, then adding composite additive, dispersing aid, sintering aid, and process control agent, ball milling for 2-2.5 hours, and drying to obtain a pretreated mixture;

[0021] (2) loading the pretreated mixture into a mold, pre-pressing to a relative density of ≥60%, then performing segmented temperature rising sintering, cooling, and demolding to obtain a sintered blank;

[0022] (3) heat treating the sintered blank in an inert atmosphere at 890-910℃ for 2-2.5 hours, then oil quenching, then heat treating at 190-210℃ for 2-2.5 hours, then increasing the temperature to 410-430℃ for 4-4.5 hours, and then cooling to room temperature, and then grinding the obtained blank to a surface roughness Ra≤0.8μm.

[0023] Further, the segmented temperature rising sintering process in step (2) first increases the temperature from room temperature to 590-610℃, and then maintains the temperature for 10-15 minutes, then increases the temperature to 790-810℃, and then maintains the temperature for 15-20 minutes, and then increases the temperature to 890-910℃, and then maintains the temperature for 20-25 minutes.

[0024] The application has the following beneficial effects:

[0025] The application realizes the significant improvement of the comprehensive performance of the high-strength wear-resistant copper alloy through the synergistic effect of the multi-step modified composite additive and the multiple raw material components. A SiC shell is coated on the surface of the hard core, forming a stable core-shell structure. This SiC layer acts as a highly efficient diffusion barrier, effectively suppressing harmful interfacial reactions between the reinforcing phase and the copper matrix during subsequent high-temperature sintering and service, thus ensuring the long-term stability of the reinforcing phase under extreme conditions. Subsequently, the particle dispersion is improved by treatment with a titanate coupling agent, laying the foundation for uniform coating. Then, by introducing a Ni-Co alloy transition layer, its good compatibility with the copper matrix is ​​utilized to construct an interface layer with a performance gradient between the hard ceramic phase and the tough copper matrix. This greatly alleviates the interfacial stress caused by the difference in physical properties between the two, significantly improves the interfacial bonding strength, and enables the load to be efficiently transferred from the matrix to the reinforcing phase. The outermost copper shell achieves homogeneous bonding between the additive and the copper matrix powder, forming a metallurgical bond through atomic diffusion during sintering, further optimizing the interfacial strength and toughness. The auxiliary strengthening raw materials, such as tin, nickel, chromium, and aluminum, are dissolved into the copper matrix to produce solid solution strengthening. Dispersing agents ensure the uniform distribution of the reinforcing phase, sintering aids promote the densification process of the material, and process control agents ensure the stability of the preparation process. These auxiliary components, together with the main raw materials, constitute a complete and synergistic copper alloy material system.

[0026] Through a precisely controlled multi-step preparation process, followed by segmented heating sintering and multi-stage heat treatment, the raw materials collectively ensure the uniform and dispersed precipitation of the reinforcing phase and the precise control of the microstructure, thereby improving the overall strength, hardness, corrosion resistance, and wear resistance of the material. The high-strength, high-toughness, high-wear-resistance, high-corrosion-resistance, and high-hardness copper alloy material prepared by this invention provides a new solution for the development of high-performance copper alloys, meeting the demands of modern industry for high-performance materials. Attached Figure Description

[0027] Fig. 1 The diagram shows the wear resistance of the high-strength wear-resistant copper alloy materials prepared in Examples 1-4 and Comparative Examples 1-4 of this invention.

[0028] Fig. 2 The diagram shows the corrosion resistance of the high-strength wear-resistant copper alloy materials prepared in Examples 1-4 and Comparative Examples 1-4 of this invention. Detailed Implementation

[0029] The technical solutions of 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. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0030] All raw materials used in the following examples are commercially available products. Copper powder with a copper content ≥99.9% and a particle size of 500 mesh was purchased from Nangong Jiuxin New Material Technology Co., Ltd.; sucrose with an effective ingredient content of 99% was purchased from Shaanxi Yangyuanshen Biotechnology Co., Ltd.; titanate coupling agent HY-109 with an effective ingredient content of 99% was purchased from Jinan Rongzheng Chemical Co., Ltd.; ammonia water with a density of 25-28% was used. Purchased from Jinan Yingshun Chemical Co., Ltd.; Copper sulfate (copper sulfate pentahydrate) with an effective ingredient content of 98% was purchased from Jinan Jiayang Chemical Co., Ltd.; Yttrium oxide with an effective ingredient content of 99%, a particle size of 50 nm, and a density of... The following materials were purchased from Ganzhou Tejing New Material Technology Co., Ltd.: tin powder (tin content ≥ 99.9%, particle size 200 mesh), nickel powder (nickel content 99.7%, C content ≤ 0.05%, S content ≤ 0.1%, particle size 5-10μm), chromium powder (chromium content ≥ 99.9%, Fe content < 0.3%, particle size 150 mesh), all purchased from Qinghe County Tebo Metal Materials Co., Ltd.; aluminum powder (6061 aluminum alloy powder, aluminum content ≥ 97%, particle size 300 mesh), purchased from Hebei Yinghe Metal Materials Co., Ltd.

[0031] Example 1

[0032] A high-strength, wear-resistant copper alloy material comprises the following raw materials in parts by weight: 85 parts copper powder, 2.5 parts composite additives, 0.02 parts dispersant, 0.1 parts sintering aid, 0.5 parts process control agent, and 3.5 parts auxiliary strengthening raw materials;

[0033] The preparation method of the composite additive is as follows:

[0034] Step S1: Titanium diboride and sodium hexametaphosphate are dispersed in a mixed solvent and sonicated at 300W and 40kHz for 45min. Then, tetraethyl orthosilicate is added, and the pH is adjusted to 9.3-9.7 with ammonia. The mixture is stirred at 85℃ for 2.7h at 600rpm. Then, it is mixed with sucrose and kept at 1250℃ for 3.8h under a nitrogen atmosphere at a rate of 6℃ / min to obtain core-shell protected titanium diboride. The solid-liquid ratio of titanium diboride and anhydrous ethanol is 1g:6mL, and the mass ratio of titanium diboride, sodium hexametaphosphate, tetraethyl orthosilicate, and sucrose is 1:0.0008:0.25:0.6. The mixed solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 4:1.

[0035] Step S2: Dissolve titanate coupling agent HY-109, magnesium nitrate, and core-shell protected titanium diboride in isopropanol, sonicate at 400W and 25kHz for 55 min, and vacuum dry at 85℃ for 2.5 h to obtain a high-temperature compatible additive. The mass ratio of core-shell protected titanium diboride, titanate coupling agent HY-109, magnesium nitrate, and isopropanol is 10:0.12:0.0035:90.

[0036] Step S3: Dissolve nickel nitrate, cobalt nitrate, citric acid, and magnesium nitrate in deionized water, stir at 60°C for 35 min, then add a high-temperature compatibility additive, sonicate at 200W power and 30kHz frequency for 25 min, then heat to 600°C at a rate of 5°C / min and hold for 2.2 h, and finally hold at 350°C for 1.3 h in a hydrogen atmosphere with a flow rate of 1.5 L / min to obtain a stable coating additive. The mass ratio of the high-temperature compatibility additive, nickel nitrate, cobalt nitrate, citric acid, magnesium nitrate, and deionized water is 10:1.2:0.4:1.7:0.0015:80.

[0037] Step S4: Dissolve copper sulfate and disodium ethylenediaminetetraacetate in deionized water, stir until homogeneous, then add formaldehyde and stir for 13 min. Adjust the pH to 12.4-12.6 with 10% NaOH solution, then add the stabilizing coating additive. React at 60℃ for 2.3 h, cool naturally to room temperature, and then filter under vacuum using a 0.45µm filter membrane. Wash three times with deionized water and once with anhydrous ethanol, and then vacuum dry at 80℃ for 2 h to obtain the composite additive. The mass ratio of the stabilizing coating additive, copper sulfate, disodium ethylenediaminetetraacetate, formaldehyde, and deionized water is 1:0.13:0.16:0.08:7.5.

[0038] The dispersing agent is sodium hexametaphosphate; the sintering aid is yttrium oxide; and the process control agent is zinc stearate.

[0039] The auxiliary strengthening raw materials are composed of tin powder, nickel powder, chromium powder and aluminum powder in a mass ratio of 2:1:0.3:0.2.

[0040] The preparation method of the above-mentioned high-strength and wear-resistant copper alloy material includes the following steps:

[0041] (1) Mix copper powder and auxiliary strengthening raw materials, stir at 150 rpm for 2 hours, then add composite additives, dispersant, sintering aid and process control agent, and ball mill for 2 hours under argon protection. Agate balls are used for ball milling. The diameters of large, medium and small balls are 10 mm, 6 mm and 3 mm respectively. The mass ratio is large: medium: small = 4:3:3, the ball-to-material ratio is 10:1, the rotation speed is 200 rpm, and then vacuum dry at 80℃ for 4 hours to obtain the pretreated mixture.

[0042] (2) The pretreated mixture is loaded into a graphite mold. The inner wall of the mold is coated with a boron nitride coating with a thickness of 5-8 μm. The mixture is manually pre-pressed to a relative density of ≥60%, and then sintered by heating in stages. The process is as follows: first, the temperature is raised from room temperature to 590℃ at a heating rate of 10℃ / min and held for 10 min; then, the temperature is raised to 790℃ at a heating rate of 5℃ / min and held for 15 min; finally, the temperature is raised to 890℃ at a heating rate of 3℃ / min, a pressure of 50 MPa is applied, and the temperature is held for 20 min. Then, the temperature is cooled to room temperature at a cooling rate of 8℃ / min and the sintered preform is demolded.

[0043] (3) The sintered blank is kept at 890℃ for 2 hours in an argon atmosphere, then oil quenched at 80℃, then kept at 190℃ for 2 hours, then heated to 410℃ and kept for 4 hours. After air cooling to room temperature, the blank is ground until the surface roughness Ra≤0.8μm.

[0044] Example 2

[0045] A high-strength and wear-resistant copper alloy material comprises the following raw materials in parts by weight: 90 parts copper powder, 4 parts composite additives, 0.05 parts dispersant, 0.3 parts sintering aid, 1 part process control agent, and 7 parts auxiliary strengthening raw materials;

[0046] The preparation method of the composite additive is the same as in Example 1;

[0047] The dispersing agent, sintering aid, and process control agent are the same as in Example 1;

[0048] The auxiliary strengthening raw materials consist of tin powder, nickel powder, chromium powder, and aluminum powder in a mass ratio of 3.5:2:0.8:0.7.

[0049] The preparation method of the above-mentioned high-strength and wear-resistant copper alloy material includes the following steps:

[0050] (1) Mix copper powder and auxiliary strengthening raw materials, stir at 150 rpm for 2.5 h, then add composite additives, dispersant, sintering aid and process control agent, and ball mill under argon protection for 2.5 h. Agate balls are used for ball milling. The diameters of large, medium and small balls are 10 mm, 6 mm and 3 mm respectively. The mass ratio is large: medium: small = 4:3:3, the ball-to-material ratio is 10:1, the rotation speed is 200 rpm, and then vacuum dry at 80℃ for 4 h to obtain the pretreated mixture.

[0051] (2) The pretreated mixture is loaded into a graphite mold. The inner wall of the mold is coated with a boron nitride coating with a thickness of 5-8 μm. The mold is manually pre-pressed to a relative density of ≥60%, and then sintered by heating in stages. The process is to first heat the mixture from room temperature to 610℃ at a heating rate of 10℃ / min and hold it for 15 min, then heat it to 810℃ at a heating rate of 5℃ / min and hold it for 20 min, and finally heat it to 910℃ at a heating rate of 3℃ / min, apply a pressure of 50 MPa and hold it for 25 min, and then cool it to room temperature at a cooling rate of 8℃ / min before demolding to obtain the sintered preform.

[0052] (3) The sintered blank is kept at 910℃ for 2.5h in an argon atmosphere, then oil quenched at 80℃, then kept at 210℃ for 2.5h, then heated to 430℃ and kept for 4.5h, then air cooled to room temperature and the resulting blank is ground until the surface roughness Ra≤0.8μm.

[0053] Example 3

[0054] A high-strength, wear-resistant copper alloy material comprises the following raw materials in parts by weight: 87 parts copper powder, 3 parts composite additives, 0.03 parts dispersant, 0.2 parts sintering aid, 0.8 parts process control agent, and 5.5 parts auxiliary strengthening raw materials;

[0055] The preparation method of the composite additive is the same as in Example 1;

[0056] The dispersing agent, sintering aid, and process control agent are the same as in Example 1;

[0057] The auxiliary strengthening raw materials consist of tin powder, nickel powder, chromium powder, and aluminum powder in a mass ratio of 3:1.5:0.5:0.5.

[0058] The preparation method of the above-mentioned high-strength and wear-resistant copper alloy material includes the following steps:

[0059] (1) Mix copper powder and auxiliary strengthening raw materials, stir at 150 rpm for 2.2 h, then add composite additives, dispersant, sintering aid and process control agent, and ball mill under argon protection for 2.3 h. Agate balls are used for ball milling. The diameters of large, medium and small balls are 10 mm, 6 mm and 3 mm respectively. The mass ratio is large: medium: small = 4:3:3, the ball-to-material ratio is 10:1, the rotation speed is 200 rpm, and then vacuum dry at 80℃ for 4 h to obtain the pretreated mixture.

[0060] (2) The pretreated mixture is loaded into a graphite mold. The inner wall of the mold is coated with a boron nitride coating with a thickness of 5-8 μm. The mixture is manually pre-pressed to a relative density of ≥60%, and then sintered by heating in stages. The process is to first heat the mixture from room temperature to 600℃ at a heating rate of 10℃ / min and hold it for 10-15 min, then heat it to 800℃ at a heating rate of 5℃ / min and hold it for 18 min, and finally heat it to 900℃ at a heating rate of 3℃ / min, apply a pressure of 50 MPa and hold it for 23 min, and then cool it to room temperature at a cooling rate of 8℃ / min before demolding to obtain the sintered preform.

[0061] (3) The sintered blank is kept at 900℃ for 2.3h in an argon atmosphere, then oil quenched at 80℃, then kept at 200℃ for 2.3h, then heated to 420℃ and kept for 4.4h, and then air-cooled to room temperature. The resulting blank is then ground until the surface roughness Ra≤0.8μm.

[0062] Example 4

[0063] A high-strength, wear-resistant copper alloy material comprises the following raw materials in parts by weight: 85 parts copper powder, 2.5 parts composite additives, 0.02 parts dispersant, 0.1 parts sintering aid, 0.5 parts process control agent, and 3.5 parts auxiliary strengthening raw materials;

[0064] The preparation method of the composite additive is as follows:

[0065] Step S1: Titanium diboride and sodium hexametaphosphate are dispersed in a mixed solvent and sonicated at 300W and 40kHz for 50min. Then, tetraethyl orthosilicate is added, and the pH is adjusted to 9.3-9.7 with ammonia. The mixture is stirred at 90℃ for 3h at 600rpm. Then, it is mixed with sucrose and kept at 1255℃ for 4h under a nitrogen atmosphere at a rate of 6℃ / min to obtain core-shell protected titanium diboride. The solid-liquid ratio of titanium diboride and anhydrous ethanol is 1g:6.5mL, and the mass ratio of titanium diboride, sodium hexametaphosphate, tetraethyl orthosilicate, and sucrose is 1:0.001:0.3:0.8. The mixed solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 4.5:1.

[0066] Step S2: Dissolve titanate coupling agent HY-109, magnesium nitrate, and core-shell protected titanium diboride in isopropanol, sonicate at 400W and 25kHz for 60min, and vacuum dry at 85℃ for 2.5h to obtain a high-temperature compatible additive. The mass ratio of core-shell protected titanium diboride, titanate coupling agent HY-109, magnesium nitrate, and isopropanol is 10:0.15:0.004:100.

[0067] Step S3: Dissolve nickel nitrate, cobalt nitrate, citric acid, and magnesium nitrate in deionized water, stir at 65°C for 40 min, then add a high-temperature compatibility additive, sonicate at 200W power and 30kHz frequency for 30 min, then heat to 610°C at a rate of 5°C / min and hold for 2.5 h, and finally hold at 360°C for 1.5 h in a hydrogen atmosphere with a flow rate of 1.5 L / min to obtain a stable coating additive. The mass ratio of high-temperature compatibility additive, nickel nitrate, cobalt nitrate, citric acid, magnesium nitrate, and deionized water is 10:1.4:0.6:2:0.002:85.

[0068] Step S4: Dissolve copper sulfate and disodium ethylenediaminetetraacetate in deionized water, stir until homogeneous, add formaldehyde, stir for 15 min, adjust the pH to 12.4-12.6 with 10% NaOH solution, add the stabilizing coating additive, react at 65℃ for 2.5 h, cool naturally to room temperature, vacuum filter with a 0.45µm filter membrane, wash three times with deionized water, wash once with anhydrous ethanol, and vacuum dry at 80℃ for 2 h to obtain the composite additive. The mass ratio of the stabilizing coating additive, copper sulfate, disodium ethylenediaminetetraacetate, formaldehyde, and deionized water is 1:0.15:0.18:0.1:8.

[0069] The dispersing agent is sodium hexametaphosphate; the sintering aid is yttrium oxide; and the process control agent is zinc stearate.

[0070] The auxiliary strengthening raw materials are composed of tin powder, nickel powder, chromium powder and aluminum powder in a mass ratio of 2:1:0.3:0.2.

[0071] The preparation method of the above-mentioned high-strength and wear-resistant copper alloy material includes the following steps:

[0072] (1) Mix copper powder and auxiliary strengthening raw materials, stir at 150 rpm for 2 hours, then add composite additives, dispersant, sintering aid and process control agent, and ball mill for 2 hours under argon protection. Agate balls are used for ball milling. The diameters of large, medium and small balls are 10 mm, 6 mm and 3 mm respectively. The mass ratio is large: medium: small = 4:3:3, the ball-to-material ratio is 10:1, the rotation speed is 200 rpm, and then vacuum dry at 80℃ for 4 hours to obtain the pretreated mixture.

[0073] (2) The pretreated mixture is loaded into a graphite mold. The inner wall of the mold is coated with a boron nitride coating with a thickness of 5-8 μm. The mixture is manually pre-pressed to a relative density of ≥60%, and then sintered by heating in stages. The process is as follows: first, the temperature is raised from room temperature to 590℃ at a heating rate of 10℃ / min and held for 10 min; then, the temperature is raised to 790℃ at a heating rate of 5℃ / min and held for 15 min; finally, the temperature is raised to 890℃ at a heating rate of 3℃ / min, a pressure of 50 MPa is applied, and the temperature is held for 20 min. Then, the temperature is cooled to room temperature at a cooling rate of 8℃ / min and the sintered preform is demolded.

[0074] (3) The sintered blank is kept at 890℃ for 2 hours in an argon atmosphere, then oil quenched at 80℃, then kept at 190℃ for 2 hours, then heated to 410℃ and kept for 4 hours. After air cooling to room temperature, the blank is ground until the surface roughness Ra≤0.8μm.

[0075] Comparative Example 1

[0076] A high-strength, wear-resistant copper alloy material comprises the following raw materials in parts by weight: 80 parts copper powder, 1 part composite additive, 0.03 parts dispersant, 0.2 parts sintering aid, 0.8 parts process control agent, and 5.5 parts auxiliary strengthening raw materials;

[0077] The preparation method of the composite additive is as follows:

[0078] Step S1: Titanium diboride and sodium hexametaphosphate are dispersed in a mixed solvent and sonicated for 10 min at a power of 300 W and a frequency of 40 kHz. Then, tetraethyl orthosilicate is added, and the pH is adjusted to 9.3-9.7 with ammonia. The mixture is stirred at 85 °C for 2.7 h at a speed of 600 rpm. Then, it is mixed with sucrose and kept at 600 °C for 3.8 h under a nitrogen atmosphere at a rate of 6 °C / min to obtain core-shell protected titanium diboride. The solid-liquid ratio of titanium diboride and anhydrous ethanol is 1 g: 6 mL, and the mass ratio of titanium diboride, sodium hexametaphosphate, tetraethyl orthosilicate, and sucrose is 1:0.0008:0.25:1. The mixed solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 4:1.

[0079] Step S2: Dissolve titanate coupling agent HY-109, magnesium nitrate, and core-shell protected titanium diboride in isopropanol, sonicate at 400W and 25kHz for 55 min, and vacuum dry at 85℃ for 2.5 h to obtain a high-temperature compatible additive. The mass ratio of core-shell protected titanium diboride, titanate coupling agent HY-109, magnesium nitrate, and isopropanol is 10:0.12:0.001:90.

[0080] Step S3: Dissolve nickel nitrate, cobalt nitrate, citric acid, and magnesium nitrate in deionized water, stir at 40°C for 35 min, then add a high-temperature compatibility additive, sonicate at 200W power and 30kHz frequency for 25 min, then heat to 600°C at a rate of 5°C / min and hold for 1 h, and finally hold at 350°C for 1.3 h in a hydrogen atmosphere with a flow rate of 1.5 L / min to obtain a stable coating additive. The mass ratio of the high-temperature compatibility additive, nickel nitrate, cobalt nitrate, citric acid, magnesium nitrate, and deionized water is 10:2:0.4:1.7:0.0015:80.

[0081] Step S4: Dissolve copper sulfate and disodium ethylenediaminetetraacetate in deionized water, stir until homogeneous, add formaldehyde, stir for 13 min, add stabilizing coating additive, react at 60℃ for 2.3 h, cool naturally to room temperature, vacuum filter with a 0.45 µm filter membrane, wash three times with deionized water, wash once with anhydrous ethanol, and vacuum dry at 80℃ for 2 h to obtain composite additive. The mass ratio of stabilizing coating additive, copper sulfate, disodium ethylenediaminetetraacetate, formaldehyde, and deionized water is 1:0.13:0.16:0.08:7.5.

[0082] The dispersing agent is sodium hexametaphosphate; the sintering aid is yttrium oxide; and the process control agent is zinc stearate.

[0083] The auxiliary strengthening raw materials are composed of tin powder, nickel powder, chromium powder and aluminum powder in a mass ratio of 2:1:0.3:0.2.

[0084] The preparation method of the above-mentioned high-strength and wear-resistant copper alloy material includes the following steps:

[0085] (1) Mix copper powder and auxiliary strengthening raw materials, stir at 150 rpm for 2.2 h, then add composite additives, dispersant, sintering aid and process control agent, stir under argon protection for 2.3 h, and then vacuum dry at 80℃ for 4 h to obtain pretreated mixture;

[0086] (2) The pretreated mixture is loaded into a graphite mold. The inner wall of the mold is coated with a boron nitride coating with a thickness of 5-8 μm. The mixture is manually pre-pressed to a relative density of ≥60%, and then sintered by heating in stages. The process is to first heat the mixture from room temperature to 600℃ at a heating rate of 10℃ / min and hold it for 10-15 min, then heat it to 800℃ at a heating rate of 5℃ / min and hold it for 18 min, and finally heat it to 900℃ at a heating rate of 3℃ / min, apply a pressure of 50 MPa and hold it for 23 min, and then cool it to room temperature at a cooling rate of 8℃ / min before demolding to obtain the sintered preform.

[0087] (3) The sintered blank is kept at 900℃ for 2.3h in an argon atmosphere, then oil quenched at 80℃, then kept at 200℃ for 2.3h, then heated to 420℃ and kept for 4.4h, and finally air cooled to room temperature to obtain the blank.

[0088] Comparative Example 2

[0089] The only difference between this comparative example and Example 1 is the composite additive; everything else is the same as Example 1.

[0090] The preparation method of the composite additive is as follows:

[0091] Step S1: Titanium diboride and sodium hexametaphosphate are dispersed in a mixed solvent and sonicated at 300W and 40kHz for 45min. Then, tetraethyl orthosilicate is added, and the pH is adjusted to 9.3-9.7 with ammonia. The mixture is stirred at 85℃ for 2.7h at 600rpm. Then, it is mixed with sucrose and kept at 1250℃ for 3.8h under a nitrogen atmosphere at a rate of 6℃ / min to obtain core-shell protected titanium diboride. The solid-liquid ratio of titanium diboride and anhydrous ethanol is 1g:6mL, and the mass ratio of titanium diboride, sodium hexametaphosphate, tetraethyl orthosilicate, and sucrose is 1:0.0008:0.25:0.6. The mixed solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 4:1.

[0092] Step S2: Dissolve titanate coupling agent HY-109, magnesium nitrate, and core-shell protected titanium diboride in isopropanol, sonicate at 400W and 25kHz for 55 min, and vacuum dry at 85℃ for 2.5 h to obtain a high-temperature compatible additive. The mass ratio of core-shell protected titanium diboride, titanate coupling agent HY-109, magnesium nitrate, and isopropanol is 10:0.12:0.0035:90.

[0093] Step S3: Dissolve nickel nitrate, cobalt nitrate, citric acid, and magnesium nitrate in deionized water, stir at 60°C for 35 min, then add a high-temperature compatibility additive, sonicate at 200W power and 30kHz frequency for 25 min, then heat to 600°C at a rate of 5°C / min and hold for 2.2 h, and finally hold at 350°C for 1.3 h in a hydrogen atmosphere with a flow rate of 1.5 L / min to obtain a composite additive. The mass ratio of the high-temperature compatibility additive, nickel nitrate, cobalt nitrate, citric acid, magnesium nitrate, and deionized water is 10:1.2:0.4:1.7:0.0015:80.

[0094] Comparative Example 3

[0095] The only difference between this comparative example and Example 1 is the composite additive; everything else is the same as Example 1.

[0096] The preparation method of the composite additive is as follows:

[0097] Step S1: Titanium diboride and sodium hexametaphosphate are dispersed in a mixed solvent and sonicated at 300W and 40kHz for 45min. Then, tetraethyl orthosilicate is added, and the pH is adjusted to 9.3-9.7 with ammonia. The mixture is stirred at 85℃ for 2.7h at 600rpm. Then, it is mixed with sucrose and kept at 1250℃ for 3.8h under a nitrogen atmosphere at a rate of 6℃ / min to obtain core-shell protected titanium diboride. The solid-liquid ratio of titanium diboride and anhydrous ethanol is 1g:6mL, and the mass ratio of titanium diboride, sodium hexametaphosphate, tetraethyl orthosilicate, and sucrose is 1:0.0008:0.25:0.6. The mixed solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 4:1.

[0098] Step S2: Dissolve titanate coupling agent HY-109, magnesium nitrate, and core-shell protected titanium diboride in isopropanol, sonicate at 400W and 25kHz for 55 minutes, and vacuum dry at 85℃ for 2.5 hours to obtain a composite additive. The mass ratio of core-shell protected titanium diboride, titanate coupling agent HY-109, magnesium nitrate, and isopropanol is 10:0.12:0.0035:90.

[0099] Comparative Example 4

[0100] In this comparative example, commercially available titanium diboride was used instead of the composite additive, and everything else was the same as in Example 1.

[0101] The following performance tests were performed on the four embodiments and four comparative examples, and the results are recorded in Table 1. Figs. 1-2 .

[0102] Mechanical property testing: Tensile strength, yield strength and elongation were tested on an electronic universal mechanical property testing machine in accordance with GB / T 228.1-2010 "Metallic materials - Tensile testing - Part 1: Test method at room temperature", with a specimen width of 20 mm and a tensile speed of 5 mm / min.

[0103] Hardness performance test: Tested according to GB / T 4340.1-2024 "Metallic materials Vickers hardness test - Part 1: Test method".

[0104] Wear resistance test: Wear resistance is expressed by the amount of wear, and is tested on a wear tester using the method of GB / T 12444-2006 "Metallic materials wear test method test ring-block sliding wear test".

[0105] Corrosion performance test: The corrosion rate is taken as the average of three times and tested in accordance with the method of GB / T 19746-2005 "Corrosion of metals and alloys by immersion in salt solution".

[0106] Table 1 Performance Tests of High-Strength Wear-Resistant Copper Alloy Materials

[0107]

[0108] From Table 1 and Figs. 1-2 It can be seen that the mechanical, hardness, wear resistance, and corrosion resistance properties of the high-strength wear-resistant copper alloy materials prepared in Examples 1-4 are all better than those of Comparative Example 1. This indicates that the proportions and experimental parameters proposed in this invention for preparing copper alloys are optimal.

[0109] From Table 1 and Figs. 1-2 It can be seen that the mechanical, hardness, wear resistance, and corrosion resistance properties of the copper alloy material prepared in Comparative Example 2 are worse than those in the Example. This is because step S4 is missing. Step S4 is the final coating process in the preparation of the composite additive. Its core function is to uniformly deposit a dense metal Cu shell on the surface of the stable coating additive. The composition of the Cu shell is consistent with that of the base copper powder, which can eliminate the interfacial compatibility problem between the composite additive and the base, so that the composite additive and the base form a strong whole and reduce the risk of interface peeling during service. It can also avoid the coating layer prepared in step S3 from being oxidized or reacting adversely with other additives during subsequent ball milling and sintering, thus improving the corrosion resistance of the copper alloy. In addition, the Cu shell surface is more compatible with the copper powder, which can reduce the agglomeration of the composite additive in the mixed powder, ensure that the composite additive is uniformly dispersed in the base, give full play to the dispersion strengthening effect, and effectively improve the tensile strength and other mechanical properties and hardness of the copper alloy. In addition, the uniformly dispersed hard phase can effectively resist abrasive cutting during the friction process, while the dense interface structure avoids the abrasive particles embedded in the interface, which leads to accelerated wear and significantly reduces the wear rate of the alloy.

[0110] From Table 1 and Figs. 1-2It can be seen that the properties of the copper alloy material prepared in Comparative Example 3 are worse than those in the Example. This is because steps S3 and S4 are missing. The core function of steps S3 and S4 is to first coat the high-temperature compatible additive particles with a Ni-Co alloy binder layer, and then introduce a pure copper shell to form a quaternary gradient structure. This allows the composite additive and the matrix copper powder to achieve a homogeneous and seamless bond, while retaining the high wear resistance of the ceramic core. Step S3 solves the defect of weak interfacial bonding between the ceramic reinforcing phase of the core and the metallic copper matrix due to the huge differences in physical properties such as thermal expansion coefficient and lattice constant. By forming a Ni-Co alloy layer, it establishes a gradient interface with continuously changing composition and properties between the hard ceramic and the soft copper. This can significantly improve the interfacial wettability, effectively transfer the load from the matrix to the reinforcing phase, and thus greatly improve the strength, hardness and wear resistance of the alloy. At the same time, the Ni-Co layer has good high-temperature stability, which can ensure that the interface will not fail prematurely due to element diffusion when the alloy is used at high temperatures. If steps S3 and S4 are missing at the same time, the poor compatibility between the ceramic phase and the copper matrix and the lack of a homogeneous interface will lead to stress concentration at the interface, resulting in pore cracks and extremely weak bonding force, making it easy to peel off. At the same time, particle agglomeration will severely reduce the alloy's tensile strength, elongation, yield strength, hardness, and wear rate.

[0111] From Table 1 and Figs. 1-2 It can be seen that the copper alloy material prepared in Comparative Example 4 has the worst performance in all aspects. This is because commercially available titanium diboride was used instead of the composite additive. The composite additive has a quaternary core-shell structure, and its core function is to improve the comprehensive properties of the copper alloy, such as strength and wear resistance, through multi-phase synergistic strengthening. The core of this structure is titanium diboride, which provides high hardness and wear resistance. A SiC shell is coated onto the surface of the hard core, forming a stable core-shell protection for titanium diboride, effectively preventing harmful diffusion of the reinforcing phase to the copper matrix at high temperatures. Subsequently, surface grafting is performed using a titanate coupling agent to improve particle dispersion, laying the foundation for uniform coating. The third step introduces a Ni-Co alloy transition layer, utilizing its excellent lattice matching with the copper matrix to significantly alleviate interfacial stress between ceramic and metal, and significantly enhance interfacial bonding strength. Finally, a copper layer is introduced on the outer layer to achieve homogeneous bonding between the additive and the copper matrix, forming a perfect metallurgical bond through atomic diffusion, further optimizing interfacial strength and toughness. This multi-scale, multi-level synergistic design allows the material to simultaneously exert its full potential. The dispersion strengthening of SiC, the interface stabilization of the Ni-Co layer, and the homogeneous bonding effect of the Cu shell work together to achieve high strength, high hardness, excellent wear resistance, and corrosion resistance.

[0112] Although embodiments of this application have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-strength, wear-resistant copper alloy material, characterized in that, The raw materials include the following parts by weight: 85-90 parts copper powder, 2.5-4 parts composite additives, 0.02-0.05 parts dispersant, 0.1-0.3 parts sintering aid, 0.5-1 part process control agent, and 3.5-7 parts auxiliary strengthening raw materials; The preparation method of the composite additive is as follows: Step S1: Disperse titanium diboride and sodium hexametaphosphate in a mixed solvent, sonicate for 40-50 min, then add tetraethyl orthosilicate, adjust the pH to 9.3-9.7, stir at 80-90℃ for 2.5-3 h, then mix with sucrose, and keep warm at 1245-1255℃ for 3.5-4 h under an inert atmosphere to obtain core-shell protected titanium diboride; Step S2: Dissolve titanate coupling agent HY-109, magnesium nitrate, and core-shell protected titanium diboride in isopropanol, sonicate for 50-60 minutes, and obtain a high-temperature compatibility additive after post-treatment. Step S3: Dissolve nickel nitrate, cobalt nitrate, citric acid, and magnesium nitrate in deionized water, stir at 55-65℃ for 30-40 min, then add high-temperature compatibility additive, sonicate for 20-30 min, and then keep warm at 590-610℃ for 2-2.5 h, and keep warm at 340-360℃ for 1-1.5 h in a hydrogen atmosphere to obtain a stable coating additive. Step S4: Dissolve copper sulfate and disodium ethylenediaminetetraacetate in deionized water, stir until homogeneous, add formaldehyde, stir for 10-15 minutes, adjust the pH to 12.4-12.6, add stabilizing coating additive, and react at 55-65℃ for 2-2.5 hours. After post-treatment, the composite additive is obtained.

2. The high-strength, wear-resistant copper alloy material according to claim 1, characterized in that, In step S1, the solid-liquid ratio of titanium diboride and anhydrous ethanol is 1g:5.5-6.5mL, the mass ratio of titanium diboride, sodium hexametaphosphate, tetraethyl orthosilicate, and sucrose is 1:0.0005-0.001:0.2-0.3:0.5-0.8, and the mixed solvent is composed of anhydrous ethanol and deionized water in a volume ratio of 3.5-4.5:

1.

3. The high-strength, wear-resistant copper alloy material according to claim 1, characterized in that, In step S2, the mass ratio of the core-shell protected titanium diboride, titanate coupling agent HY-109, magnesium nitrate, and isopropanol is 10:0.1-0.15:0.003-0.004:80-100.

4. The high-strength, wear-resistant copper alloy material according to claim 1, characterized in that, The mass ratio of the high-temperature compatibility additive, nickel nitrate, cobalt nitrate, citric acid, magnesium nitrate, and deionized water in step S3 is 10:1-1.4:0.2-0.6:1.5-2:0.001-0.002:75-85.

5. The high-strength, wear-resistant copper alloy material according to claim 1, characterized in that, The mass ratio of the stabilizing coating additive, copper sulfate, disodium ethylenediaminetetraacetate, formaldehyde, and deionized water in step S4 is 1:0.1-0.15:0.14-0.18:0.06-0.1:7-8.

6. The high-strength, wear-resistant copper alloy material according to claim 1, characterized in that, The dispersing agent is sodium hexametaphosphate; the sintering aid is yttrium oxide; and the process control agent is zinc stearate.

7. The high-strength, wear-resistant copper alloy material according to claim 1, characterized in that, The auxiliary strengthening raw material is composed of tin powder, nickel powder, chromium powder and aluminum powder in a mass ratio of 2-3.5:1-2:0.3-0.8:0.2-0.

7.

8. The method for preparing the high-strength, wear-resistant copper alloy material according to any one of claims 1-7, characterized in that, Includes the following steps: (1) Mix copper powder and auxiliary strengthening raw materials, stir for 2-2.5h, then add composite additives, dispersant, sintering aid and process control agent, ball mill for 2-2.5h, and dry to obtain pretreated mixture; (2) The pretreated mixture is loaded into a mold, pre-pressed to a relative density ≥60%, and then sintered in stages by heating, cooling, and demolding to obtain a sintered green body; (3) The sintered blank is kept at 890-910℃ for 2-2.5h in an inert atmosphere, then oil quenched, then kept at 190-210℃ for 2-2.5h, then heated to 410-430℃ and kept for 4-4.5h. After cooling to room temperature, the heat-treated blank is ground until the surface roughness Ra≤0.8μm, and the blank is obtained.

9. The method for preparing the high-strength, wear-resistant copper alloy material according to claim 8, characterized in that, The segmented heating sintering process described in step (2) first raises the temperature from room temperature to 590-610℃ and holds it for 10-15 minutes, then raises it to 790-810℃ and holds it for 15-20 minutes, and finally raises it to 890-910℃ and holds it for 20-25 minutes.

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