Y2O3 reinforced graphene / titanium alloy composite material, preparation method and application thereof

Abstract

The application relates to a Y2O3 reinforced graphene / TC4 composite material and a preparation method and application thereof, and belongs to the technical field of graphene / titanium-based composite materials. In order to solve the problem that graphene and a titanium matrix are prone to interface reaction, the structure of graphene is degraded, and the intrinsic strengthening effect cannot be fully exerted, the application provides a Y2O3 reinforced graphene / TC4 composite material component which comprises graphene, Y2O3 and TC4 titanium alloy. The application adopts 0.2-0.4% low graphene addition, combines Y2O3 to construct a multi-level synergistic strengthening network, inhibits excessive interface reaction, protects the intrinsic structure of graphene, realizes efficient load transmission and improvement of strengthening utilization rate. The prepared composite material has excellent strength and plasticity matching, the ultimate tensile strength reaches 1420 MPa, the yield strength reaches 1250 MPa, and the elongation at break is 8.3%. The application has simple and green process, is suitable for batch production, and has important engineering and industrialization value.

Description

Technical Field

[0001] This invention pertains to graphene / titanium-based composite materials, and particularly relates to a Y2O3-reinforced graphene / TC4 composite material, its preparation method, and its applications. Background Technology

[0002] TC4 alloy (Ti-6Al-4V), as a typical α+β type titanium alloy, is widely used in key components such as fuselage structures, engine parts, and load-bearing fasteners in aerospace, shipbuilding, and high-end equipment due to its advantages of low density, high specific strength, and good corrosion resistance. However, as service environments evolve towards higher loads, longer lifespans, and more complex operating conditions, the contradiction between increasing the strength of traditional TC4 alloys and decreasing plasticity and damage tolerance is becoming increasingly prominent. Traditional microstructure control methods are no longer sufficient to break through the existing strength-plasticity balance and cannot meet the needs of equipment upgrades.

[0003] Graphene, with its ultra-high strength, excellent elastic modulus, and good thermal conductivity, has become an ideal reinforcing phase for optimizing the properties of TC4 alloys. In practical applications, graphene is uniformly dispersed in the TC4 alloy matrix in a two-dimensional sheet-like form. Its microscopic strengthening mechanism is mainly reflected in two aspects: first, as a rigid support, it effectively hinders dislocation movement, suppresses plastic deformation, and significantly improves the strength and stiffness of the alloy; second, by utilizing its excellent thermal conductivity, it accelerates stress transfer and heat diffusion within the alloy, alleviates stress concentration, and overcomes the limitations of traditional strengthening methods that cannot simultaneously achieve both strength and plasticity.

[0004] However, graphene and titanium are prone to interfacial reactions during high-temperature preparation and hot deformation, resulting in the in-situ formation of a brittle TiC phase. This leads to graphene structural degradation and loss of intrinsic reinforcing properties, making it difficult to achieve the expected reinforcing effect. Although the invention patent application with application number 202410143343.7 increases the graphene content to 0.80~1.00wt%, it fails to effectively suppress the interfacial reaction. During high-temperature preparation, graphene reacts violently with the titanium matrix, resulting in severe structural degradation and the inability to retain its two-dimensional sheet characteristics and intrinsic reinforcing function. The improvement in the composite material's performance mainly relies on the microalloying effect of Ta, Mo, and Sn, and graphene does not truly play the role of a highly efficient reinforcing agent.

[0005] The aforementioned interfacial reaction problem has become a core bottleneck restricting the engineering application of graphene-reinforced TC4 composite materials. There is an urgent need to develop a systematic technical solution that takes into account composition design, process control and strengthening effect in order to overcome the limitations of existing technologies. Summary of the Invention

[0006] To address the problem that graphene and titanium matrix are prone to interfacial reactions, leading to graphene structural degradation and failing to fully realize its intrinsic strengthening effect, this invention provides a Y2O3-reinforced graphene / TC4 composite material, its preparation method, and its application.

[0007] The technical solution of the present invention:

[0008] A Y2O3-reinforced graphene / TC4 composite material comprises the following components in mass percentage: 0.20-0.40% graphene, 0.15-0.20% Y2O3, and the balance being TC4 titanium alloy.

[0009] A method for preparing a Y2O3-reinforced graphene / TC4 composite material includes the following steps:

[0010] Step 1, ball milling: Place graphene, Y2O3 powder, TC4 titanium alloy powder and grinding balls into a ball mill jar, and ball mill to obtain composite powder;

[0011] Step 2, Plasma sintering: The obtained composite powder is loaded into a mold, and axial pressure is applied to the mold under vacuum conditions. This pressure is kept constant during the heating and holding stages. The temperature is raised to 1000℃ in stages and held for a certain time to complete the densification and microstructure stabilization treatment. Then it is cooled to room temperature to obtain the composite material preform.

[0012] Step 3, hot rolling: After the obtained composite material billet is heated evenly, it is rolled in multiple passes with a total reduction of 75%, and then air-cooled to room temperature to obtain the Y2O3 reinforced graphene / TC4 composite material.

[0013] Furthermore, the graphene mentioned in step one is reduced graphene oxide, which is added to the ball mill jar in batches; the particle size of the Y2O3 powder is 30~50nm, and the particle size of the TC4 titanium alloy powder is 15~53μm.

[0014] Furthermore, in step one, the ball-to-material ratio for ball milling is 5:1, the ball milling speed is 200 rpm, and the ball milling time is 6 hours.

[0015] Furthermore, the vacuum condition described in step two is a vacuum degree of less than 1.0 × 10⁻⁶. -3 Pa, the axial pressure is 30~50MPa.

[0016] Furthermore, in step two, the phased heating is first carried out at a heating rate of 50°C / min from room temperature to 700°C, and then the heating is continued at a heating rate of 100°C / min to 1000°C, with a holding time of 5 minutes at 1000°C.

[0017] Furthermore, in step two, the temperature is first reduced to 600°C at a cooling rate of 50°C / min, and then cooled to room temperature along with the furnace.

[0018] Furthermore, in step three, the composite material preform is heated to 900℃ and held for 20 minutes. During the multi-pass rolling process, each pass is tempered at 900℃ for 1 to 1.5 minutes after rolling.

[0019] Furthermore, in step three, the rolling speed of the multi-pass rolling is 10 m / min. During the multi-pass rolling process, the reduction is 1 mm per pass before reaching 37.5%, and 0.5 mm per pass after reaching 37.5%.

[0020] Application of a Y2O3-reinforced graphene / TC4 composite material in aerospace, shipbuilding, or high-end equipment fields.

[0021] The beneficial effects of this invention are:

[0022] This invention constructs a Y2O3 dispersion-reinforced graphene / TC4 composite material system, using only 0.2-0.4% graphene. By optimizing the composition ratio and ball milling, sintering, and rolling process parameters, a multi-level synergistic reinforcement network of "TiC-Y2O3-graphene" is formed. The dispersed Y2O3 phase preferentially occupies interfacial active sites, stabilizing the interface and significantly inhibiting excessive interfacial reactions between graphene and the titanium matrix at high temperatures. This avoids excessive formation of the brittle TiC phase, which could lead to graphene structural degradation, thus effectively protecting and preserving the intrinsic structure of graphene. This fully leverages the two-dimensional nano-reinforcement effect and intrinsic strengthening function, achieving efficient load transfer and higher strengthening efficiency with a lower addition amount, truly improving the effective utilization rate and practical contribution of graphene.

[0023] The Y2O3-reinforced graphene / TC4 composite material prepared by this invention exhibits excellent mechanical properties, with a balanced strength and plasticity. Its ultimate tensile strength reaches 1420 MPa, yield strength reaches 1250 MPa, and elongation at break is 8.3%. Compared with pure TC4 alloy, the yield strength is increased by 29% and the ultimate tensile strength is increased by 20%. Compared with graphene / TC4 composite material without Y2O3, both yield strength and ultimate tensile strength are increased by 16%, while the elongation is only reduced by 3.9%. This significantly improves the strength level and service reliability of titanium alloy without significantly sacrificing plasticity.

[0024] The preparation method provided by this invention achieves uniform dispersion and stable interfacial bonding of graphene and Y2O3 in a TC4 matrix by optimizing key process parameters such as powder mixing, densification, and thermal deformation. The process is simple and controllable, energy-efficient, and environmentally friendly, generating no toxic or harmful substances, and is suitable for engineering scale-up and mass production. This invention provides a replicable and scalable composition design concept and preparation process route for the engineering application of next-generation high-specific-strength, high-damage-tolerance titanium-based structural materials, and has significant engineering application value and long-term industrialization significance. Attached Figure Description

[0025] Figure 1 EBSD backscattered image of the Y2O3 dispersion-reinforced graphene / TC4 composite material prepared in Example 1;

[0026] Figure 2 The image shows the secondary electronic morphology of the Y2O3 dispersion-reinforced graphene / TC4 composite material prepared in Example 1. Detailed Implementation

[0027] The technical solution of the present invention will be further described below with reference to embodiments, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention. In the following embodiments, the process equipment or apparatus not specifically specified are all conventional equipment or apparatus in the art. Unless otherwise specified, the raw materials used in the embodiments of the present invention are all commercially available; unless otherwise specified, the technical means used in the embodiments of the present invention are all conventional means well known to those skilled in the art.

[0028] Example 1

[0029] This embodiment provides a Y2O3 dispersion-reinforced graphene / TC4 composite material and its preparation method.

[0030] The Y2O3-reinforced graphene / TC4 composite material in this embodiment includes the following components by mass percentage: 0.30% graphene, 0.19% Y2O3, and the balance being TC4 titanium alloy.

[0031] In this embodiment, the graphene is reduced graphene oxide; the particle size of the Y2O3 powder is 30~50nm. The TC4 titanium alloy is produced by Sinochem Materials Technology Co., Ltd., with a particle size range of 15~53μm. The chemical composition of the purchased TC4 titanium alloy was analyzed by X-ray diffraction, and the results are shown in Table 1.

[0032] Table 1

[0033]

[0034] The preparation method of the Y2O3-reinforced graphene / TC4 composite material of the present invention includes the following steps:

[0035] Step 1, ball milling:

[0036] The grinding jar and steel grinding balls, made of hardened chromium steel, were cleaned with water and a brush, dried, and then rinsed three times with anhydrous ethanol and dried again. Using an analytical balance, the raw materials were weighed at a ball-to-material ratio of 5:1: 600g of steel grinding balls, 119.07g of commercial TC4 powder, 0.36g of graphene, and 0.229g of Y2O3 powder. The graphene was divided into four batches, each weighing 0.1g, 0.1g, 0.1g, and 0.06g. The TC4 powder, Y2O3 powder, and the first batch of graphene were poured into the grinding jar. The grinding jar was placed on a ball mill, and the main disc speed was set to 200 rpm. The next batch of graphene was added after every 1 hour of grinding. The total grinding time was 6 hours, yielding a composite powder.

[0037] Step 2, Plasma Sintering:

[0038] The obtained composite powder was loaded into a mold and subjected to a vacuum degree of less than 1.0 × 10⁻⁶. -3 Under vacuum conditions of 40 MPa, a mold filled with composite powder is placed in a sintering furnace, and an axial pressure of 40 MPa is applied to the mold and maintained at this pressure during the heating and holding stages.

[0039] First, the temperature was increased from room temperature to 700℃ at a heating rate of 50℃ / min, then increased to 1000℃ at a heating rate of 100℃ / min, and held at 1000℃ for 5 minutes to complete the densification and microstructure stabilization treatment. After the holding period, the temperature was reduced to 600℃ at a cooling rate of 50℃ / min, the heating power was turned off, and the sample was cooled to room temperature using a furnace cooling method to obtain the composite material preform.

[0040] Step 3: Hot rolling:

[0041] Using a wire EDM machine, an 8mm thick round billet is taken from the sintered composite material billet and used as the initial sample for hot rolling. The billet is polished with 80#-2000# sandpaper until the wire cutting marks are eliminated and the surface is smooth. Then, it is placed in a muffle furnace, heated to 900℃ and held for 20 minutes before being rolled in multiple passes.

[0042] During the multi-pass rolling process, the rolling speed was 10 m / min, and the reduction was 1 mm per pass. After each pass, the sample was placed in a muffle furnace and tempered at 900℃ for 1.5 min. After the thickness of the billet was reduced to 5 mm, the reduction was 0.5 mm per pass. After each pass, the sample was tempered at 900℃ for 1 min until the total reduction was 75%. Then, the sample was air-cooled to room temperature to obtain the Y2O3-reinforced graphene / TC4 composite material.

[0043] Example 2

[0044] This embodiment provides a Y2O3 dispersion-reinforced graphene / TC4 composite material and its preparation method.

[0045] The Y2O3-reinforced graphene / TC4 composite material in this embodiment includes the following components by mass percentage: 0.20% graphene, 0.15% Y2O3, and the balance being TC4 titanium alloy.

[0046] The graphene, Y2O3 powder, and TC4 titanium alloy used in this embodiment are the same as those in Example 1.

[0047] The preparation method of the Y2O3-reinforced graphene / TC4 composite material of the present invention includes the following steps:

[0048] Step 1, ball milling:

[0049] The grinding jar and steel grinding balls, made of hardened chromium steel, were cleaned with water and a brush, dried, and then rinsed three times with anhydrous ethanol and dried again. Using an analytical balance, the raw materials were weighed at a ball-to-material ratio of 5:1: 600g of steel grinding balls, 119.24g of commercial TC4 powder, 0.24g of graphene, and 0.18g of Y2O3 powder. The graphene was divided into four batches, each weighing 0.06g, 0.06g, 0.06g, and 0.06g respectively. The TC4 powder, Y2O3 powder, and the first batch of graphene were first poured into the grinding jar. The grinding jar was placed on a ball mill, and the main disc speed was set to 200 rpm. The next batch of graphene was added after each 1-hour grinding session. The total grinding time was 6 hours, yielding a composite powder.

[0050] Step 2, Plasma Sintering:

[0051] The obtained composite powder was loaded into a mold and subjected to a vacuum degree of less than 1.0 × 10⁻⁶. -3 Under vacuum conditions of 30 MPa, a mold filled with composite powder is placed in a sintering furnace, and an axial pressure of 30 MPa is applied to the mold and maintained at this pressure during the heating and holding stages.

[0052] First, the temperature was increased from room temperature to 700℃ at a heating rate of 50℃ / min, then increased to 1000℃ at a heating rate of 100℃ / min, and held at 1000℃ for 5 minutes to complete the densification and microstructure stabilization treatment. After the holding period, the temperature was reduced to 600℃ at a cooling rate of 50℃ / min, the heating power was turned off, and the sample was cooled to room temperature using a furnace cooling method to obtain the composite material preform.

[0053] Step 3: Hot rolling:

[0054] Using a wire EDM machine, an 8mm thick round billet is taken from the sintered composite material billet and used as the initial sample for hot rolling. The billet is polished with 80#-2000# sandpaper until the wire cutting marks are eliminated and the surface is smooth. Then, it is placed in a muffle furnace, heated to 900℃ and held for 20 minutes before being rolled in multiple passes.

[0055] During the multi-pass rolling process, the rolling speed was 10 m / min, and the reduction was 1 mm per pass. After each pass, the sample was placed in a muffle furnace and tempered at 900℃ for 1.5 min. After the thickness of the billet was reduced to 5 mm, the reduction was 0.5 mm per pass. After each pass, the sample was tempered at 900℃ for 1 min until the total reduction was 75%. Then, the sample was air-cooled to room temperature to obtain the Y2O3-reinforced graphene / TC4 composite material.

[0056] Example 3

[0057] This embodiment provides a Y2O3 dispersion-reinforced graphene / TC4 composite material and its preparation method.

[0058] The Y2O3-reinforced graphene / TC4 composite material in this embodiment includes the following components by mass percentage: 0.40% graphene, 0.20% Y2O3, and the balance being TC4 titanium alloy.

[0059] The graphene, Y2O3 powder, and TC4 titanium alloy used in this embodiment are the same as those in Example 1.

[0060] The preparation method of the Y2O3-reinforced graphene / TC4 composite material of the present invention includes the following steps:

[0061] Step 1, ball milling:

[0062] The grinding jar and steel grinding balls, made of hardened chromium steel, were cleaned with water and a brush, dried, and then rinsed three times with anhydrous ethanol and dried again. Using an analytical balance, the raw materials were weighed at a ball-to-material ratio of 5:1: 600g of steel grinding balls, 118.94g of commercial TC4 powder, 0.48g of graphene, and 0.24g of Y2O3 powder. The graphene was divided into five batches, each with a mass of 0.1g, 0.1g, 0.1g, 0.1g, and 0.08g. The TC4 powder, Y2O3 powder, and the first batch of graphene were poured into the grinding jar. The grinding jar was placed on a ball mill, and the main disc speed was set to 200 rpm. The next batch of graphene was added after each 1-hour grinding session. The total grinding time was 6 hours, yielding a composite powder.

[0063] Step 2, Plasma Sintering:

[0064] The obtained composite powder was loaded into a mold and subjected to a vacuum degree of less than 1.0 × 10⁻⁶. -3 Under vacuum conditions of 50 MPa, a mold filled with composite powder is placed in a sintering furnace, and an axial pressure of 50 MPa is applied to the mold and maintained at this pressure during the heating and holding stages.

[0065] First, the temperature was increased from room temperature to 700℃ at a heating rate of 50℃ / min, then increased to 1000℃ at a heating rate of 100℃ / min, and held at 1000℃ for 5 minutes to complete the densification and microstructure stabilization treatment. After the holding period, the temperature was reduced to 600℃ at a cooling rate of 50℃ / min, the heating power was turned off, and the sample was cooled to room temperature using a furnace cooling method to obtain the composite material preform.

[0066] Step 3: Hot rolling:

[0067] Using a wire EDM machine, an 8mm thick round billet is taken from the sintered composite material billet and used as the initial sample for hot rolling. The billet is polished with 80#-2000# sandpaper until the wire cutting marks are eliminated and the surface is smooth. Then, it is placed in a muffle furnace, heated to 900℃ and held for 20 minutes before being rolled in multiple passes.

[0068] During the multi-pass rolling process, the rolling speed was 10 m / min, and the reduction was 1 mm per pass. After each pass, the sample was placed in a muffle furnace and tempered at 900℃ for 1.5 min. After the thickness of the billet was reduced to 5 mm, the reduction was 0.5 mm per pass. After each pass, the sample was tempered at 900℃ for 1 min until the total reduction was 75%. Then, the sample was air-cooled to room temperature to obtain the Y2O3-reinforced graphene / TC4 composite material.

[0069] Comparative Example 1

[0070] This comparative example provides a pure TC4 alloy material and its preparation method.

[0071] The TC4 titanium alloy used in this comparative example is the same as that in Example 1, and the preparation method includes the following steps:

[0072] Step 1, ball milling:

[0073] Clean the ball mill jar and steel grinding balls made of hardened chromium steel with water and a brush, let them dry, then clean them three times with anhydrous ethanol and blow them dry. Weigh the raw materials according to the ball-to-material ratio of 5:1 using an analytical balance. Weigh 600g of steel grinding balls and 120g of commercial TC4 powder into the ball mill jar. Place the ball mill jar on the ball mill, set the main disc speed to 200rpm, and the total ball milling time to 6h to obtain TC4 ball mill powder.

[0074] Step 2, Plasma Sintering:

[0075] The obtained TC4 ball-milled powder was loaded into a mold and subjected to a vacuum degree of less than 1.0 × 10⁻⁶. -3 Under vacuum conditions of 40 MPa, a grinding mold filled with TC4 ball mill powder is placed in a sintering furnace, and an axial pressure of 40 MPa is applied to the mold and maintained at this pressure during the heating and holding stages.

[0076] First, the temperature was increased from room temperature to 700℃ at a heating rate of 50℃ / min, then increased to 1000℃ at a heating rate of 100℃ / min, and held at 1000℃ for 5 minutes to complete the densification and microstructure stabilization treatment. After the holding period, the temperature was reduced to 600℃ at a cooling rate of 50℃ / min, the heating power was turned off, and the sample was cooled to room temperature using a furnace cooling method to obtain the TC4 green body.

[0077] Step 3: Hot rolling:

[0078] Using a wire EDM machine, an 8mm thick round billet is taken from the sintered TC4 billet and used as the initial sample for hot rolling. The billet is polished with 80#-2000# sandpaper until the wire cutting marks are eliminated and the surface is smooth. Then, it is placed in a muffle furnace, heated to 900℃ and held for 20 minutes before being rolled in multiple passes.

[0079] During the multi-pass rolling process, the rolling speed is 10m / min, and the reduction is 1mm per pass. After each pass, the sample is placed in a muffle furnace and tempered at 900℃ for 1.5min. After the thickness of the billet is reduced to 5mm, the reduction is 0.5mm per pass. After each pass, the sample is tempered at 900℃ for 1min until the total reduction is 75%. Then, the sample is air-cooled to room temperature to obtain pure TC4 alloy material.

[0080] Comparative Example 2

[0081] This comparative example provides a graphene / TC4 composite material and its preparation method.

[0082] This comparative graphene / TC4 composite material comprises the following components by mass percentage: 0.30% graphene, with the balance being TC4 titanium alloy.

[0083] The graphene and TC4 titanium alloy used in this comparative example are the same as those in Example 1, and the preparation method includes the following steps:

[0084] Step 1, ball milling:

[0085] The grinding jar and steel grinding balls, made of hardened chromium steel, were cleaned with water and a brush, then dried. They were then rinsed three times with anhydrous ethanol and dried again. Using an analytical balance, the raw materials were weighed at a ball-to-material ratio of 5:1: 600g of steel grinding balls, 119.64g of commercial TC4 powder, and 0.36g of graphene. The graphene was divided into four batches, each weighing 0.1g, 0.1g, 0.1g, and 0.06g. The TC4 powder and the first batch of graphene were first poured into the grinding jar. The grinding jar was placed on a ball mill, and the main disc speed was set to 200 rpm. The next batch of graphene was added after every 1 hour of grinding. The total grinding time was 6 hours, yielding a composite powder.

[0086] Step 2, Plasma Sintering:

[0087] The obtained composite powder was loaded into a mold and subjected to a vacuum degree of less than 1.0 × 10⁻⁶. -3 Under vacuum conditions of 40 MPa, a mold filled with composite powder is placed in a sintering furnace, and an axial pressure of 40 MPa is applied to the mold and maintained at this pressure during the heating and holding stages.

[0088] First, the temperature was increased from room temperature to 700℃ at a heating rate of 50℃ / min, then increased to 1000℃ at a heating rate of 100℃ / min, and held at 1000℃ for 5 minutes to complete the densification and microstructure stabilization treatment. After the holding period, the temperature was reduced to 600℃ at a cooling rate of 50℃ / min, the heating power was turned off, and the sample was cooled to room temperature using a furnace cooling method to obtain the composite material preform.

[0089] Step 3: Hot rolling:

[0090] Using a wire EDM machine, an 8mm thick round billet is taken from the sintered composite material billet and used as the initial sample for hot rolling. The billet is polished with 80#-2000# sandpaper until the wire cutting marks are eliminated and the surface is smooth. Then, it is placed in a muffle furnace, heated to 900℃ and held for 20 minutes before being rolled in multiple passes.

[0091] During the multi-pass rolling process, the rolling speed is 10 m / min, and the reduction is 1 mm per pass. After each pass, the sample is placed in a muffle furnace and tempered at 900℃ for 1.5 min. After the thickness of the billet is reduced to 5 mm, the reduction is 0.5 mm per pass. After each pass, the sample is tempered at 900℃ for 1 min until the total reduction is 75%. Then, the sample is air-cooled to room temperature to obtain the graphene / TC4 composite material.

[0092] Experimental Example 1

[0093] The microstructure of the Y2O3-reinforced graphene / TC4 composite material prepared in Example 1 was observed using the following methods:

[0094] A. The Y2O3-reinforced graphene / TC4 composite material obtained in Example 1 was wire-cut using wire cutting technology to obtain a sample block with a size of 5mm×5mm×5mm. The surface of the sample block was then ground with 120#~2000# sandpaper until there were no obvious scratches on the surface. Then, it was polished carefully on a polishing machine. Water was continuously injected while the polishing machine was rotating until the surface of the sample block reached a scratch-free and bright state.

[0095] B. Immerse the sample block for 3 seconds using an etching solution composed of 7 mL H₂O + 1 mL HF + 2 mL HNO₃. Then observe the sample block using a scanning electron microscope. The EBSD backscattered image of the Y₂O₃-reinforced graphene / TC₄ composite material is shown below. Figure 1As shown, the SEM secondary electron morphology image is as follows. Figure 2 As shown.

[0096] As can be seen from the EBSD backscattered image, after thermal deformation, the matrix grains are significantly refined and exhibit an elongated deformed morphology. The grain boundaries are clear and there are no coarse brittle phases. At the same time, Y2O3 and a small amount of TiC second phase are uniformly dispersed in the grains and grain boundaries in the form of fine particles. This proves that Y2O3 can preferentially occupy the interfacial active sites, stabilize the interface, and significantly inhibit the excessive interfacial reaction between graphene and titanium matrix at high temperature, thus avoiding the excessive formation of brittle TiC phase that would lead to graphene structural degradation. The absence of obvious coarse TiC or reaction layer in the image indicates that Y2O3 inhibits the excessive interfacial reaction between graphene and titanium matrix, avoids graphene structural degradation, and protects its intrinsic structure.

[0097] As seen in the SEM secondary electron morphology images, the material surface exhibits uniform deformation flow lines without obvious cracks or coarse brittle phases, demonstrating that the material maintains good plasticity and interfacial bonding after hot deformation, resulting in high load transfer efficiency. Numerous nanoscale reinforcing phases are visible dispersed within the matrix, indicating that the low-dosage graphene, under Y₂O₃ protection, did not agglomerate or undergo structural damage, preserving its intrinsic structure and achieving higher strengthening efficiency with a lower dosage.

[0098] Experimental Example 2

[0099] Tensile tests were performed on the Y2O3-reinforced graphene / TC4 composite material prepared in Example 1, the pure TC4 alloy material prepared in Comparative Example 1, and the graphene / TC4 composite material prepared in Comparative Example 2 using an electronic universal testing machine (MTS810 electronic universal testing machine). In order to eliminate wire cutting and improve the accuracy and stability of tensile properties, sandpaper with different grit sizes was used to grind the samples from 240# to 2000# sandpaper to ensure that the surface roughness of each sample was basically the same.

[0100] The test temperature was room temperature, the maximum load on the equipment was 100 kN, the tensile rate was 1 mm / min, and an extensometer was used throughout the room temperature tensile process. To maintain the accuracy of the tensile properties, three sets of parallel specimens were tested, and the average value was taken as the final strength and elongation values ​​as the final results. The test results are shown in Table 2.

[0101] Table 2

[0102]

[0103] As shown in Table 2, the Y2O3-reinforced graphene / TC4 composite material prepared in this invention exhibits a yield strength of 1250 MPa, an ultimate tensile strength of 1420 MPa, and an elongation at break of 8.3%. Compared to pure TC4 alloy, the composite material of this invention shows a 29% increase in yield strength and a 20% increase in ultimate tensile strength; compared to the graphene / TC4 composite material without Y2O3, the yield strength and ultimate tensile strength are both increased by 16%, while the elongation at break decreases by only 3.9%.

[0104] This result confirms that by constructing a multi-level synergistic strengthening network of "TiC-Y2O3-graphene", the dispersed Y2O3 phase effectively occupies the active sites at the interface and inhibits the excessive interfacial reaction at high temperature. This not only avoids the excessive generation of brittle TiC and the degradation of the graphene structure, thus achieving an intrinsic strengthening effect, but also promotes a fine-grained, uniform, defect-free, and dense deformable structure at the microstructure level, ultimately achieving a balance between strength and plasticity.

[0105] This invention optimizes ball milling, sintering, and rolling processes to achieve uniform component dispersion and stable interfacial bonding. The process flow is simple, controllable, and suitable for engineering scale-up. This achievement provides a replicable composition design and process route for the engineering application of next-generation high-specific-strength, high-damage-tolerance titanium-based structural materials, possessing significant engineering application value and industrialization significance.

Claims

1. A Y2O3-reinforced graphene / TC4 composite material, characterized in that, It includes the following components by mass percentage: graphene 0.20~0.40%, Y2O3 0.15~0.20%, and the balance is TC4 titanium alloy.

2. A method for preparing the Y2O3-reinforced graphene / TC4 composite material as described in claim 1, characterized in that, Includes the following steps: Step 1, ball milling: Place graphene, Y2O3 powder, TC4 titanium alloy powder and grinding balls into a ball mill jar, and ball mill to obtain composite powder; Step 2, Plasma sintering: The obtained composite powder is loaded into a mold, and axial pressure is applied to the mold under vacuum conditions. This pressure is kept constant during the heating and holding stages. The temperature is raised to 1000℃ in stages and held for a certain time to complete the densification and microstructure stabilization treatment. Then it is cooled to room temperature to obtain the composite material preform. Step 3, hot rolling: After the obtained composite material billet is heated evenly, it is rolled in multiple passes with a total reduction of 75%, and then air-cooled to room temperature to obtain the Y2O3 reinforced graphene / TC4 composite material.

3. The preparation method of the Y2O3-reinforced graphene / TC4 composite material according to claim 2, characterized in that, The graphene mentioned in step one is reduced graphene oxide, which is added to the ball mill jar in batches; the particle size of the Y2O3 powder is 30~50nm, and the particle size of the TC4 titanium alloy powder is 15~53μm.

4. The preparation method of the Y2O3-reinforced graphene / TC4 composite material according to claim 2, characterized in that, The ball-to-material ratio for ball milling in step one is 5:1, the ball milling speed is 200 rpm, and the ball milling time is 6 hours.

5. The preparation method of the Y2O3-reinforced graphene / TC4 composite material according to claim 2, characterized in that, The vacuum condition described in step two is a vacuum degree less than 1.0 × 10⁻⁶. -3 Pa, the axial pressure is 30~50MPa.

6. The preparation method of the Y2O3-reinforced graphene / TC4 composite material according to claim 2, characterized in that, In step two, the temperature is first increased from room temperature to 700°C at a rate of 50°C / min, and then increased to 1000°C at a rate of 100°C / min. The temperature is then held at 1000°C for 5 minutes.

7. The preparation method of the Y2O3-reinforced graphene / TC4 composite material according to claim 2, characterized in that, The cooling process described in step two involves first cooling the temperature to 600°C at a rate of 50°C / min, and then cooling it to room temperature along with the furnace.

8. The preparation method of the Y2O3-reinforced graphene / TC4 composite material according to claim 2, characterized in that, In step three, the composite material preform is heated to 900℃ and held for 20 minutes. During the multi-pass rolling process, each pass is tempered at 900℃ for 1 to 1.5 minutes after rolling.

9. The preparation method of the Y2O3-reinforced graphene / TC4 composite material according to claim 2, characterized in that, The rolling speed of the multi-pass rolling in step three is 10 m / min. During the multi-pass rolling process, the reduction is 1 mm per pass before the reduction reaches 37.5%, and 0.5 mm per pass after the reduction reaches 37.5%.

10. The application of the Y2O3-reinforced graphene / TC4 composite material as described in claim 1 in the fields of aerospace, shipbuilding, or high-end equipment.

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