A graphene-reinforced Ti / Al3Ti composite material with a brick structure and a preparation method thereof

Abstract

The present invention discloses a graphene-enhanced Ti / Al3Ti composite material with a brick-like structure and a preparation method thereof, belonging to the technical field of metal-based composite materials. The present invention comprises the following steps: (1) configuring and spraying graphene slurry, (2) sequentially stacking different metal foils, (3) preforming and pressing, (4) rolling after high-temperature insulation, and (5) subsequent rolling treatment. The graphene-enhanced Ti / Al3Ti composite material prepared in the present invention exhibits a brick-like microstructure formed by a residual Ti layer and a discontinuous graphene-enhanced Al3Ti layer. The hard phase brick-like graphene-enhanced Al3Ti has a significant strengthening effect on the Ti matrix, which is beneficial to improving the overall strength of the composite material. The discontinuous brick-like structure can effectively transmit loads, release stress concentration under tensile and impact loads, increase crack propagation resistance, and extend the crack propagation path, thereby significantly improving the plasticity and toughness of the material, so that the composite material has a good match between strong plasticity and strong toughness.

Description

Technical Field

[0001] The present invention belongs to the technical field of metal matrix composite materials, and in particular relates to a graphene-reinforced Ti / Al3Ti composite material with a brick structure and a preparation method thereof. Background Art

[0002] Ti / Al3Ti micro-laminated composites have great application potential in aerospace, marine equipment, automobiles, national defense and other fields due to their good comprehensive mechanical properties, including high compressive strength, specific modulus, fracture toughness and low density. However, the intermetallic compound Al3Ti is obviously brittle at room temperature, resulting in poor plasticity and toughness of Ti / Al3Ti micro-laminated composites, with an elongation of less than 4% and a fracture toughness of less than 40MPa·m 1 / 2 , which limits its wider application. To this end, researchers have explored adding a certain amount of fiber or graphene inside the composite material to improve its plasticity and toughness. Chinese patent CN202311692057.8 discloses a graphene-reinforced Ti / Al3Ti micro-laminated composite material and its preparation method. By introducing a certain amount of graphene into the Ti / Al3Ti micro-laminated composite material, the tensile strength, elongation after fracture and fracture toughness of the material are increased to about 750MPa, 8% and 60MPa·m respectively. 1 / 2 , with improved overall performance. However, its elongation and fracture toughness remain low, failing to meet the evolving needs of engineering. Furthermore, the service environment of Ti / Al3Ti composites requires good impact toughness, but limited research on this topic has limited their further engineering application and promotion.

[0003] Compared to conventional continuous micro-laminated structures, brick masonry structures can more effectively relieve stress concentration under tensile and impact loads, increase crack propagation resistance, and extend the crack propagation path, thereby significantly improving the material's plasticity and toughness. Currently, there are no reports on graphene-reinforced Ti / Al3Ti composites with a brick masonry microstructure. Whether brick masonry structures can improve the plasticity and toughness matching of Ti / Al3Ti composites, and how to prepare such graphene-reinforced Ti / Al3Ti composites with a brick masonry structure through a process with promising industrial applications, remains uncertain. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a graphene-reinforced Ti / Al3Ti composite material with a brick structure and a preparation method thereof.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows: first, graphene is evenly coated on an Al foil, and then stacked with pure Ti or Ti alloy foil in sequence. A press is used to press and pre-form the stacked foils to obtain a composite foil blank, which is placed in a vacuum high-temperature furnace and kept warm for a certain period of time. The resulting composite foil blank consists of a micro-laminated structure with a soft phase Ti layer matrix and a hard phase graphene-reinforced Al3Ti layer arranged alternately; then, it is subjected to multiple high-temperature rolling processes to obtain a graphene-reinforced Ti / Al3Ti composite material layer. Thereafter, multiple composite material layers are stacked and subsequently subjected to high-temperature rolling processes. After rolling is completed, the layers are cooled to room temperature. Finally, a graphene-reinforced Ti / Al3Ti composite material with good strong plasticity and matched toughness is obtained, thereby achieving the purpose of the present invention.

[0006] The present invention relates to a graphene-reinforced Ti / Al3Ti composite material with a brick structure and a preparation method thereof, the method comprising the following steps:

[0007] (1) Dispersing graphene powder in a volatile solvent to prepare a graphene slurry;

[0008] (2) uniformly coating the graphene slurry on Al foil to obtain graphene-loaded Al foil, and stacking the Al foil with Ti or Ti alloy foil, so that the graphene layer in the Al foil contacts the Ti or Ti alloy foil, to form a single-layer composite foil; stacking a desired number of single-layer composite foils to form a composite foil;

[0009] (3) Using a press to preform the stacked composite foil sheets to obtain a composite foil blank;

[0010] (4) The preformed composite foil blank is heated to 500-650°C in a sealed vacuum environment and kept warm for 2-4 hours. The prepared composite foil blank is composed of a micro-laminated structure in which soft phase Ti layers and hard phase graphene-reinforced Al3Ti layers are alternately arranged.

[0011] (5) The composite foil blank after insulation is placed in a rolling mill for rolling, and the rolling deformation is 40%~80%. The temperature is kept in an environment of 500~650℃ between any two rolling passes to obtain a graphene-enhanced Ti / Al3Ti composite material layer, which is composed of a soft phase Ti layer matrix and a hard phase "brick-like" graphene-enhanced Al3Ti structure with gaps between adjacent layers. Among them, the hard phase "brick-like" graphene-enhanced Al3Ti structure is embedded in the soft phase Ti layer matrix, and the thickness of the soft phase Ti layer matrix is ​​10~70μm;

[0012] (6) Repeat steps (2) to (5) according to the thickness of the prepared composite material and the composite foil to roll the required number of graphene-reinforced Ti / Al3Ti composite material layers;

[0013] (7) The graphene-enhanced Ti / Al3Ti composite material layers prepared in step (6) are stacked. When stacked, the hard phase "brick-like" graphene-enhanced Al3Ti structures of adjacent graphene-enhanced Ti / Al3Ti composite material layers are staggered; after being kept warm in an environment of 500-650°C, the graphene-enhanced Ti / Al3Ti composite material is placed in a rolling mill for rolling to obtain a graphene-enhanced Ti / Al3Ti composite material with a brick structure.

[0014] Preferably, in step (5), the deformation amount of each rolling pass is 5%, and the holding time between any two rolling passes is 5 to 10 minutes.

[0015] Preferably, in step (5), the thickness of the soft phase Ti layer in the composite material is 20-50 μm.

[0016] Preferably, the sum of the rolling deformation in step (7) is 5% to 10%, and the holding time is 0.5 to 1 hour.

[0017] Preferably, the concentration of the graphene slurry prepared in step (1) is 1 mg / mL to 4 mg / mL.

[0018] Preferably, the Ti foil in step (2) is pure Ti foil or Ti alloy foil with a thickness of 100 to 180 μm.

[0019] Preferably, the thickness of the Al foil in step (2) is 40 to 80 μm.

[0020] Preferably, the pre-forming pressure in step (3) is 50-200 MPa, and the pressing time is 10-30 min.

[0021] The present invention also relates to a graphene-enhanced Ti / Al3Ti composite material with a brick structure, which is composed of a soft-phase Ti layer matrix and a hard-phase "brick-like" graphene-enhanced Al3Ti structure. The "brick-like" graphene-enhanced Al3Ti structure is embedded in the soft-phase Ti layer matrix, and the hard-phase "brick-like" graphene-enhanced Al3Ti structures of adjacent layers are staggered.

[0022] Beneficial effects of the present invention:

[0023] (1) The present invention relates to a graphene-enhanced Ti / Al3Ti composite material with a brick-structure and a preparation method thereof. The composite material is formed by pressing and preforming pure Ti or Ti alloy foil, Al foil and graphene and then rolling them at high temperature. During the heat preservation process before rolling, the Al layer softens and graphene gradually moves into the Al layer. At the same time, the Ti or Ti alloy foil reacts with the Al foil, gradually obtaining a micro-laminated structure with alternating arrangement of "soft and hard phases" formed by the soft phase Ti layer and the graphene-enhanced Al3Ti layer; thereafter, during the subsequent high-temperature rolling process, the Ti or Ti alloy foil and the Al foil further react. At the same time, the graphene-enhanced Al3Ti layer, due to its relatively poor plasticity, breaks as the rolling deformation increases, forming a hard phase "brick-like structure" and gradually "embedded" in the soft phase Ti layer, thereby obtaining a brick-structured microstructure formed by the soft phase Ti layer and the hard phase discontinuous graphene-enhanced Al3Ti.

[0024] (2) In the method of the present invention, the holding temperature before rolling is 500~650℃, and the holding time is 2~4h. If the holding temperature is lower than 500℃, the Al layer is softened to a limited extent due to the low temperature, and the graphene cannot move into the Al layer. The brick structure formed by the graphene-enhanced Al3Ti and Ti layer cannot be obtained through the subsequent rolling process. When the holding temperature is higher than 650℃, the Al foil is excessively softened or even melted to a fluid state due to the high temperature. During the holding and subsequent rolling process, the Al liquid gradually flows out, resulting in the failure of the composite material preparation. When the holding time is lower than 2h, the Ti or Ti alloy foil does not react sufficiently with the Al foil, resulting in less hard phase graphene-enhanced Al3Ti layer. After the subsequent rolling process, the brick structure formed by the alternating arrangement of Ti or Ti alloy layer and graphene-enhanced Al3Ti layer cannot be formed. When the holding time exceeds 4h, the holding time is too long, which will lead to a significant reduction in the preparation efficiency of the composite material, which is not conducive to its engineering application.

[0025] (3) In the method of the present invention, the rolling deformation of the composite foil blank after heat preservation is 40% to 80%. After rolling treatment within this deformation range, the hard phase graphene-enhanced Al3Ti layer in the composite material gradually breaks and forms an ideal brick structure with the remaining Ti or Ti alloy layer. When the rolling deformation is less than 40%, due to the small rolling deformation, the graphene-enhanced Al3Ti layer does not break significantly and cannot effectively form a brick structure, resulting in limited performance improvement of the composite material; and when the rolling deformation is higher than 80%, due to the large rolling deformation, the graphene-enhanced Al3Ti layer in the composite material is too fragmented. Under the action of tensile or impact loads, it cannot fully play the role of inhibiting crack propagation, which is not conducive to improving the plasticity and toughness of the material, resulting in poor matching of strength and plasticity and strength and toughness of the composite material.

[0026] (4) The present invention provides a graphene-enhanced Ti / Al3Ti micro-laminated composite material with a brickwork structure and a preparation method thereof. By comprehensively controlling and optimizing the holding temperature and time before rolling, the rolling temperature, and the deformation amount, a graphene-enhanced Ti / Al3Ti composite material with a brickwork structure as described in the present invention is finally obtained. The adjacent rows of hard-phase "brick-like" graphene-enhanced Al3Ti structures are staggered, which has a significant strengthening effect on the Ti matrix, can effectively increase the strength of the composite material, hinder crack propagation, and thus improve the overall mechanical properties of the composite material.

[0027] (5) The density of the graphene-reinforced Ti / Al3Ti composite material with a brick structure of the present invention is above 99.0%, the tensile strength is about 820 MPa, the tensile fracture strain is about 13.0%, and the fracture toughness is about 80.0 MPa·m 1 / 2 The room-temperature impact energy absorption is approximately 140 J, demonstrating a good balance between strength and toughness. Compared to existing micro-laminated graphene-reinforced Ti / Al3Ti composites, its performance is significantly improved, offering broad application prospects in both civilian industry and military fields. Furthermore, the material's simple preparation process and strong practicality hold broad promise for engineering applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the graphene-reinforced Ti / Al3Ti composite material with a brick structure according to the present invention.

[0029] Description of reference numerals:

[0030] 1-soft phase Ti matrix; 2-hard phase graphene reinforced Al3Ti brick structure. DETAILED DESCRIPTION

[0031] The technical solutions of the present invention are further described in detail below in conjunction with the embodiments. Obviously, the embodiments described here are only used to explain the present invention, but the present invention is not limited to these embodiments.

[0032] In the following embodiments:

[0033] (1) The graphene purity is greater than 90%, and the number of Al foils and pure Ti or Ti alloy foils stacked is 400.

[0034] (2) Density testing equipment: JA2003 electronic balance.

[0035] (3) Tensile test equipment: An electronic universal material testing machine model INSTRON5985 (Instron, USA) was used.

[0036] (4) The tensile strength, yield strength and elongation are measured according to GB / T228-2002 based on the tensile stress-strain curve obtained from the tensile test.

[0037] (5) Fracture toughness was measured using an Instron 5500R electronic universal testing machine in accordance with ASTM E399-06 fracture toughness test standard.

[0038] (6) Impact test equipment: The impact test machine model is JB-300B.

[0039] (7) The room temperature impact absorption energy is measured using a standard Charpy V-notch impact specimen using an impact testing machine in accordance with GB / T 229-2007.

[0040] Example 1

[0041] In this embodiment, a graphene-reinforced Ti / Al3Ti composite material with a brick structure is prepared by the following method:

[0042] (1) Graphene powder was dispersed in anhydrous ethanol solvent to prepare a graphene slurry with a concentration of 1 mg / mL.

[0043] (2) The graphene slurry was evenly coated on an Al foil with a thickness of 60 μm by spraying to obtain a graphene-loaded Al foil. The Al foil was then stacked with a pure Ti foil with a thickness of 120 μm, so that the graphene layer in the Al foil was in contact with the pure Ti foil, forming a single-layer composite foil. 50 sets of single-layer composite foils were stacked to form a composite foil.

[0044] (3) Use a press to preform the stacked composite foil to obtain a flat composite foil blank. The preforming pressure is 50 MPa and the pressing time is 10 min.

[0045] (4) The formed composite foil blank is placed in a metal sheath, welded and sealed, and vacuumed. The sheathed composite foil blank is then placed in a high-temperature heat treatment furnace for insulation at 500°C for 2 hours. During the insulation process, the Al layer softens and graphene gradually moves into the Al layer. At the same time, the pure Ti foil reacts with the Al foil, resulting in a micro-laminated structure with alternating "soft and hard phases" formed in the thickness direction by the unreacted soft phase Ti layer matrix and the reacted hard phase graphene reinforced Al3Ti layer.

[0046] (5) The composite foil blank with a micro-laminated structure of alternating "soft and hard phases" after heat preservation is placed in a rolling mill for eight rolling passes, with a rolling deformation of 40% and a rolling deformation of 5% per pass. The heat preservation temperature between each pass is the same as the heat preservation temperature set in step (4), and the heat preservation time is 5 minutes. After the rolling is completed, it is cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material layer. During the high-temperature rolling process, the pure Ti foil and the Al foil further react, and the soft phase Ti layer matrix becomes thinner; at the same time, the hard phase graphene-enhanced Al3Ti layer, due to its relatively poor plasticity, breaks as the rolling deformation increases, forming a rectangular hard phase "brick-like structure" with gaps between adjacent layers, and gradually "embedded" in the soft phase Ti layer matrix, thereby obtaining a graphene-enhanced Ti / Al3Ti composite material layer, which is composed of a brick-like microstructure formed by a soft phase Ti layer matrix 1 and a hard phase discontinuous graphene-enhanced Al3Ti structure 2. The schematic diagram of its microstructure is shown in the attached figure. Figure 1 As shown, the thickness of the soft phase Ti layer matrix 1 is 50 μm.

[0047] (6) Repeat steps (2) to (5) to roll four graphene-reinforced Ti / Al3Ti composite material layers.

[0048] (7) The four graphene-enhanced Ti / Al3Ti composite material layers prepared in step (6) are stacked and placed; when placed, the hard phase "brick-like" graphene-enhanced Al3Ti structures 2 of adjacent graphene-enhanced Ti / Al3Ti composite material layers are staggered. After being kept at 500°C for 1 hour, subsequent rolling treatment is performed with a rolling deformation of 10% to ensure that different graphene-enhanced Ti / Al3Ti composite material layers are tightly bonded. After rolling, the composite material is cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material with a brick structure, which is composed of a soft phase Ti layer matrix 1 and a hard phase "brick-like" graphene-enhanced Al3Ti structure 2. The "brick-like" graphene-enhanced Al3Ti structure 2 is embedded in the soft phase Ti layer 1, and the hard phase "brick-like" graphene-enhanced Al3Ti structures 2 of adjacent layers are staggered.

[0049] The graphene-reinforced Ti / Al3Ti composite material with a brick structure prepared in this embodiment has a density of 99.1%, a tensile strength of 810 MPa, an elongation after fracture of 12.9%, and a fracture toughness of 77.8 MPa·m 1 / 2 , and the room temperature impact absorption energy is 140 J. Compared with ordinary micro-laminated graphene reinforced Ti / Al3Ti composite materials, its tensile strength is increased by 8%, elongation after fracture is increased by 62%, and fracture toughness is increased by 30%.

[0050] Example 2

[0051] In this embodiment, a graphene-reinforced Ti / Al3Ti composite material with a brick structure is prepared by the following method:

[0052] (1) Graphene powder was dispersed in anhydrous ethanol solvent to prepare a graphene slurry with a concentration of 4 mg / mL.

[0053] (2) The graphene slurry was evenly coated on an 80 μm thick Al foil by spraying to obtain a graphene-loaded Al foil. The Al foil was then stacked with a 180 μm thick Ti alloy foil so that the graphene layer in the Al foil was in contact with the Ti alloy foil, thereby forming a single-layer composite foil. 50 sets of single-layer composite foils were stacked to form a composite foil.

[0054] (3) Use a press to preform the stacked foils to obtain a composite foil blank. The preforming pressure is 200 MPa and the pressing time is 30 min.

[0055] (4) The formed composite foil blank is placed in a metal sheath, welded and sealed, and vacuumed. The sheathed composite foil blank is then placed in a high-temperature heat treatment furnace for insulation at 650°C for 4 hours. During the insulation process, the Al layer softens and graphene gradually moves into the Al layer. At the same time, the Ti alloy foil reacts with the Al foil, resulting in a micro-laminated structure with alternating "soft and hard phases" formed in the thickness direction by the unreacted soft phase Ti alloy layer matrix and the reacted hard phase graphene reinforced Al3Ti layer.

[0056] (5) The composite foil blank having a micro-laminated structure with alternating "soft and hard phases" after heat preservation is placed in a rolling mill for sixteen rolling passes, with a rolling deformation of 80% and a rolling deformation of 5% per pass. The heat preservation temperature between each pass is the same as the heat preservation temperature set in step (4), and the heat preservation time is 10 minutes. After rolling is completed, it is cooled to room temperature in air to obtain a graphene-reinforced Ti / Al3Ti composite material layer. During the high-temperature rolling process, the Ti alloy foil and the Al foil further reacted, and the soft-phase Ti alloy layer matrix became thinner; at the same time, the hard-phase graphene-reinforced Al3Ti layer had relatively poor plasticity and broke as the rolling deformation increased, forming a rectangular hard-phase "brick-like structure" with gaps between adjacent layers, and gradually "embedded" in the soft-phase Ti layer matrix of the soft-phase Ti alloy layer, thereby obtaining a graphene-reinforced Ti / Al3Ti composite material layer, which was composed of a brick-like microstructure formed by the soft-phase Ti alloy layer matrix 1 and the hard-phase discontinuous graphene-reinforced Al3Ti layer 2, wherein the soft-phase Ti alloy layer matrix 1 had a thickness of 10 μm.

[0057] (6) Repeat steps (2) to (5) to roll three graphene-reinforced Ti / Al3Ti composite material layers.

[0058] (7) The three graphene-enhanced Ti / Al3Ti composite material layers prepared in step (6) are stacked and placed; when placed, the hard phase "brick-like" graphene-enhanced Al3Ti structures of adjacent graphene-enhanced Ti / Al3Ti composite material layers are staggered. After being kept at 650°C for 0.5h, subsequent rolling treatment is performed with a rolling deformation of 5% to ensure close bonding between different material layers. After rolling, the composite material is cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material with a brick structure, which is composed of a Ti alloy layer matrix 1 and a hard phase "brick-like" graphene-enhanced Al3Ti structure 2, the "brick-like" graphene-enhanced Al3Ti structure 2 being embedded in the soft phase Ti alloy layer 1, and the hard phase "brick-like" graphene-enhanced Al3Ti structures 2 of adjacent layers are staggered.

[0059] The graphene-reinforced Ti / Al3Ti composite material with a brick structure prepared in this embodiment has a density of 99.2%, a tensile strength of 830 MPa, an elongation after fracture of 12.5%, and a fracture toughness of 80.2 MPa·m 1 / 2 , and the room temperature impact absorption energy is 120 J. Compared with ordinary micro-laminated graphene reinforced Ti / Al3Ti composite materials, its tensile strength is increased by 10.6%, elongation after fracture is increased by 56.2%, and fracture toughness is increased by 33.6%.

[0060] Example 3

[0061] In this embodiment, a graphene-reinforced Ti / Al3Ti composite material with a brick structure is prepared by the following method:

[0062] (1) Graphene powder was dispersed in anhydrous ethanol solvent to prepare a graphene slurry with a concentration of 2 mg / mL.

[0063] (2) The graphene slurry was evenly coated on an Al foil with a thickness of 40 μm by spraying to obtain a graphene-loaded Al foil. The Al foil was then stacked with a pure Ti foil with a thickness of 100 μm, so that the graphene layer in the Al foil was in contact with the pure Ti foil, forming a single-layer composite foil. 50 sets of single-layer composite foils were stacked to form a composite foil.

[0064] (3) Use a press to preform the stacked foils to obtain a composite foil blank. The preforming pressure is 100 MPa and the pressing time is 30 min.

[0065] (4) Place the formed composite foil blank into a metal sheath, weld and seal it, and evacuate it. Then, place the sheathed composite foil blank into a high-temperature heat treatment furnace for insulation at a temperature of 600°C for 3 hours.

[0066] (5) The composite foil blank with a micro-laminated structure of alternating "soft and hard phases" after insulation is placed in a rolling mill for twelve rolling passes, with a rolling deformation of 60% and a rolling deformation of 5% per pass. The heat preservation temperature between each pass is the same as the heat preservation temperature set in step (4), and the heat preservation time is 8 minutes. After rolling is completed, it is cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material layer, which consists of a soft phase Ti layer matrix 1 and a hard phase "brick-shaped" graphene-enhanced Al3Ti structure 2, wherein the thickness of the soft phase Ti layer matrix 1 is 20 μm.

[0067] (6) Repeat steps (2) to (5) to roll 5 graphene-reinforced Ti / Al3Ti composite material layers.

[0068] (7) The five graphene-enhanced Ti / Al3Ti composite material layers prepared in step (6) are placed alternately; when placed, the hard phase "brick-like" graphene-enhanced Al3Ti structures of adjacent graphene-enhanced Ti / Al3Ti composite material layers are staggered. After being kept at 650°C for 1 hour, subsequent rolling treatment is performed with a rolling deformation of 10% to ensure close bonding between different material layers. After rolling, the composite material is cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material with a brick structure, which consists of a soft phase Ti layer matrix 1 and a hard phase "brick-like" graphene-enhanced Al3Ti structure 2. The "brick-like" graphene-enhanced Al3Ti structure 2 is embedded in the soft phase Ti layer 1, and the hard phase "brick-like" graphene-enhanced Al3Ti structures 2 of adjacent layers are staggered.

[0069] The graphene-reinforced Ti / Al3Ti composite material with a brick structure prepared in this embodiment has a density of 99.2%, a tensile strength of 820 MPa, an elongation after fracture of 13.0%, and a fracture toughness of 73.1 MPa·m 1 / 2 , and the room temperature impact absorption energy is 135 J. Compared with ordinary micro-laminated graphene reinforced Ti / Al3Ti composite materials, its tensile strength is increased by 9.3%, its elongation after fracture is increased by 62.5%, and its fracture toughness is increased by 21.8%.

[0070] Example 4

[0071] In this embodiment, a graphene-reinforced Ti / Al3Ti composite material with a brick structure is prepared by the following method:

[0072] (1) Graphene powder was dispersed in anhydrous ethanol solvent to prepare a graphene slurry with a concentration of 3 mg / mL.

[0073] (2) The graphene slurry was evenly coated on an Al foil with a thickness of 60 μm by spraying to obtain a graphene-loaded Al foil. The Al foil was then stacked with a Ti alloy foil with a thickness of 180 μm, so that the graphene layer in the Al foil was in contact with the Ti alloy foil, thereby forming a single-layer composite foil. 50 sets of single-layer composite foils were stacked to form a composite foil.

[0074] (3) Use a press to preform the stacked foils to obtain a composite foil blank. The preforming pressure is 150 MPa and the pressing time is 20 min.

[0075] (4) Place the formed composite foil blank into a metal sheath, weld and seal it, and evacuate it. Then, place the sheathed composite foil blank into a high-temperature heat treatment furnace for insulation at a temperature of 625°C for 2 hours.

[0076] (5) The composite foil blank having a micro-laminated structure with alternating arrangement of "soft and hard phases" after insulation is placed in a rolling mill for ten rolling passes, with a rolling deformation of 50% and a rolling deformation of 5% per pass. The heat preservation temperature between each pass is the same as the heat preservation temperature set in step (4), and the heat preservation time is 10 minutes. After rolling is completed, it is cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material, which consists of a soft phase Ti layer matrix 1 and a hard phase "brick-shaped" graphene-enhanced Al3Ti structure 2, wherein the thickness of the soft phase Ti layer matrix 1 is 70 μm.

[0077] (6) Repeat steps (2) to (5) to roll three graphene-reinforced Ti / Al3Ti composite material layers.

[0078] (7) The three graphene-enhanced Ti / Al3Ti composite material layers prepared in step (6) are stacked and placed; when placed, the hard phase "brick-like" graphene-enhanced Al3Ti structures of adjacent graphene-enhanced Ti / Al3Ti composite material layers are staggered. After being kept at 625°C for 1 hour, subsequent rolling treatment is performed with a rolling deformation of 5% to ensure close bonding between different material layers. After rolling, the composite material is cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material with a brick structure, which consists of a soft phase Ti layer matrix 1 and a hard phase "brick-like" graphene-enhanced Al3Ti structure 2. The "brick-like" graphene-enhanced Al3Ti structure 2 is embedded in the soft phase Ti layer 1, and the hard phase "brick-like" graphene-enhanced Al3Ti structures 2 of adjacent layers are staggered.

[0079] The graphene-reinforced Ti / Al3Ti composite material with a brick structure prepared in this embodiment has a density of 99.0%, a tensile strength of 795 MPa, an elongation after fracture of 11.8%, and a fracture toughness of 76.5 MPa·m 1 / 2, and the room temperature impact absorption energy is 125 J. Compared with ordinary micro-laminated graphene reinforced Ti / Al3Ti composite materials, its tensile strength is increased by 6%, elongation after fracture is increased by 47.5%, and fracture toughness is increased by 27.5%.

[0080] Example 5

[0081] In this embodiment, a graphene-reinforced Ti / Al3Ti composite material with a brick structure is prepared by the following method:

[0082] (1) Graphene powder was dispersed in anhydrous ethanol solvent to prepare a graphene slurry with a concentration of 2 mg / mL.

[0083] (2) The graphene slurry was evenly coated on an Al foil with a thickness of 50 μm by spraying to obtain a graphene-loaded Al foil. The Al foil was then stacked with a Ti foil with a thickness of 130 μm, so that the graphene layer in the Al foil was in contact with the Ti foil, thereby forming a single-layer composite foil. 50 sets of single-layer composite foils were stacked to form a composite foil.

[0084] (3) Use a press to preform the stacked foils to obtain a composite foil blank. The preforming pressure is 180 MPa and the pressing time is 20 min.

[0085] (4) Place the formed composite foil blank into a metal sheath, weld and seal it, and evacuate it. Then, place the sheathed composite foil blank into a high-temperature heat treatment furnace for insulation at a temperature of 575°C for 3 hours.

[0086] (5) The composite foil blank with a micro-laminated structure of alternating "soft and hard phases" after insulation is placed in a rolling mill for twelve rolling passes, with a rolling deformation of 60% and a rolling deformation of 5% per pass. The heat preservation temperature between each pass is the same as the heat preservation temperature set in step (4), and the heat preservation time is 10 minutes. After rolling is completed, it is cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material layer, which consists of a soft phase Ti layer matrix 1 and a hard phase "brick-shaped" graphene-enhanced Al3Ti structure 2, wherein the thickness of the soft phase Ti layer matrix 1 is 30 μm.

[0087] (6) Repeat steps (2) to (5) to roll out five graphene-reinforced Ti / Al3Ti composite material layers with a brick structure.

[0088] (7) The five graphene-enhanced Ti / Al3Ti composite materials prepared in step (6) are stacked and placed; when placed, the hard phase "brick-like" graphene-enhanced Al3Ti structures of adjacent graphene-enhanced Ti / Al3Ti composite materials are staggered. After being kept at 575°C for 0.5h, subsequent rolling treatment is performed with a rolling deformation of 10% to ensure close bonding between different material layers. After rolling, the composite materials are cooled to room temperature in air to obtain a graphene-enhanced Ti / Al3Ti composite material with a brick-like structure, which is composed of a soft phase Ti layer matrix 1 and a hard phase "brick-like" graphene-enhanced Al3Ti structure 2. The "brick-like" graphene-enhanced Al3Ti structure 2 is embedded in the soft phase Ti layer 1, and the hard phase "brick-like" graphene-enhanced Al3Ti structures 2 of adjacent layers are staggered.

[0089] The graphene-reinforced Ti / Al3Ti composite material with a brick structure prepared in this embodiment has a density of 99.5%, a tensile strength of 815 MPa, an elongation after fracture of 12.7%, and a fracture toughness of 73.2 MPa·m 1 / 2 , and the room temperature impact absorption energy is 130 J. Compared with ordinary micro-laminated graphene reinforced Ti / Al3Ti composite materials, its tensile strength is increased by 8.6%, its elongation after fracture is increased by 58.8%, and its fracture toughness is increased by 22%.

[0090] Comparative Example 1

[0091] The difference from Example 1 is that:

[0092] (5) The composite foil blank after insulation is placed in a rolling mill for three rolling passes, with a rolling deformation of 15% and a rolling deformation of 5% per pass. The insulation temperature between each pass is the same as the insulation temperature set in step (4), and the insulation time is 5 minutes. After rolling is completed, it is cooled to room temperature in air to obtain a graphene-reinforced Ti / Al3Ti composite material layer.

[0093] The graphene reinforced Ti / Al3Ti composite material prepared in this comparative example has a density of 98.7%, a tensile strength of 695 MPa, an elongation after fracture of 7.9%, and a fracture toughness of 50.2 MPa·m 1 / 2 , the impact absorption energy at room temperature is 80J.

[0094] By comparing Example 1 with this comparative example, it can be seen that, under the premise of the same foil thickness, graphene content, preforming conditions and rolling temperature, due to the small rolling deformation, the graphene-enhanced Ti / Al3Ti layer cannot be fully broken, resulting in no effective brick structure being formed in the composite material, and its strength, elongation after fracture, fracture toughness and room temperature impact absorption energy are all significantly reduced, and a good match between strength and plasticity and strength and toughness cannot be achieved.

[0095] Comparative Example 2

[0096] The difference from Example 1 is that:

[0097] (5) The composite foil blank after insulation is placed in a rolling mill for eighteen rolling passes, with a rolling deformation of 90% and a rolling deformation of 5% per pass. The insulation temperature between each pass is the same as the insulation temperature set in step (4), and the insulation time is 5 minutes. After rolling is completed, it is cooled to room temperature in air to obtain a graphene-reinforced Ti / Al3Ti composite material layer.

[0098] The graphene-reinforced Ti / Al3Ti composite material prepared in this comparative example has a density of 99.5%, a tensile strength of 800 MPa, an elongation after fracture of 9.1%, and a fracture toughness of 49.1 MPa·m 1 / 2 , the impact absorption energy at room temperature is 70J.

[0099] By comparing Example 1 with this comparative example, it can be seen that, under the premise of the same foil thickness, graphene content, preforming conditions and rolling temperature, due to the excessive rolling deformation, the degree of rupture of the graphene-enhanced Ti / Al3Ti layer is too large, the size of the hard phase "brick-like structure" and the adjacent spacing are too small, and the comprehensive mechanical properties of the composite material cannot be effectively improved. The elongation after fracture, fracture toughness and room temperature impact absorption energy of the graphene-enhanced Ti / Al3Ti composite material are significantly reduced, and a good match between strength and plasticity and strength and toughness cannot be achieved.

[0100] Comparative Example 3

[0101] The difference from Example 3 is that:

[0102] (4) Place the formed composite foil blank into a metal sheath, weld and seal it, and evacuate it. Then, place the sheathed composite foil blank into a high-temperature heat treatment furnace for insulation at a temperature of 200°C for 3 hours.

[0103] The graphene reinforced Ti / Al3Ti composite material prepared in this comparative example has a density of 98.5%, a tensile strength of 720 MPa, an elongation after fracture of 5.7%, and a fracture toughness of 40.3 MPa·m 1 / 2 , the impact absorption energy at room temperature is 50J.

[0104] By comparing Example 3 with this comparative example, it can be seen that, under the premise of the same foil thickness, graphene content, preforming conditions and rolling deformation, when the holding temperature before rolling is too low, the Ti foil and the Al foil cannot fully react to obtain the graphene-enhanced Al3Ti layer. After the subsequent rolling treatment, the brick structure with alternating soft and hard phases cannot be effectively formed inside. The strength, elongation after fracture, fracture toughness and room temperature impact absorption energy of the graphene-enhanced Ti / Al3Ti composite material are significantly reduced, and a good match between strength and plasticity and strength and toughness cannot be achieved.

[0105] Comparative Example 4

[0106] The difference from Example 2 is that:

[0107] (4) Place the formed composite foil blank into a metal sheath, weld and seal it, and evacuate it. Then, place the sheathed composite foil blank into a high-temperature heat treatment furnace for insulation at a temperature of 650°C for 0.5 h.

[0108] The graphene-reinforced Ti / Al3Ti composite material prepared in this embodiment has a density of 98.5%, a tensile strength of 695 MPa, an elongation after fracture of 8.5%, and a fracture toughness of 43.5 MPa·m 1 / 2 , the impact absorption energy at room temperature is 45J.

[0109] By comparing Example 2 with this comparative example, it can be seen that, under the premise of the same foil thickness, graphene content, pre-forming conditions and rolling deformation, when the holding time before rolling is too short, the Ti alloy foil and the Al foil cannot fully react to obtain the graphene-enhanced Al3Ti layer. After the subsequent rolling treatment, the brick structure with alternating soft and hard phases cannot be effectively formed inside. The strength, elongation after fracture, fracture toughness and room temperature impact absorption energy of the graphene-enhanced Ti / Al3Ti composite material are significantly reduced, and a good match between strength and plasticity and strength and toughness cannot be achieved.

[0110] In summary, the invention includes but is not limited to the above embodiments. Any equivalent replacement or partial improvement made under the spirit and principle of the present invention shall be deemed to be within the scope of protection of the present invention.

Claims

1. A method for preparing a graphene-reinforced Ti / Al3Ti composite material with a brick structure, characterized in that: The method steps include: (1) Dispersing graphene powder in a volatile solvent to prepare a graphene slurry; (2) uniformly coating the graphene slurry on the Al foil to obtain the graphene-loaded Al foil, and stacking the Al foil with the Ti foil so that the graphene layer in the Al foil contacts the Ti foil to form a single-layer composite foil; stacking the required number of single-layer composite foils to form a composite foil; (3) Using a press to preform the stacked composite foil sheets to obtain a composite foil blank; (4) The preformed composite foil blank is heated to 500-650°C in a sealed vacuum environment and kept warm for 2-4 hours. The prepared composite foil blank is composed of a micro-laminated structure with a soft phase Ti layer matrix and a hard phase graphene reinforced Al3Ti layer alternately arranged; (5) placing a composite foil blank having a micro-laminated structure with alternating "soft and hard phases" into a rolling mill for rolling, with a rolling deformation of 40% to 80%, and keeping the temperature in an environment of 500 to 650°C between any two rolling passes, to obtain a graphene-enhanced Ti / Al3Ti composite material layer, which is composed of a soft phase Ti layer matrix (1) and a hard phase "brick-like" graphene-enhanced Al3Ti structure (2) with gaps between adjacent layers, wherein the hard phase "brick-like" graphene-enhanced Al3Ti structure (2) is embedded in the soft phase Ti layer matrix (1), and the thickness of the soft phase Ti layer matrix (1) is 10 to 70 μm; (6) Repeat steps (2) to (5) according to the thickness of the prepared composite material and the composite foil to roll the required number of graphene-reinforced Ti / Al3Ti composite material layers; (7) stacking the graphene-enhanced Ti / Al3Ti composite material layers prepared in step (6); when stacking, the hard phase "brick-like" graphene-enhanced Al3Ti structures (2) of adjacent graphene-enhanced Ti / Al3Ti composite material layers are staggered; after being kept warm in an environment of 500-650°C, the layers are placed in a rolling mill for rolling to obtain a graphene-enhanced Ti / Al3Ti composite material with a brick structure.

2. The method for preparing a graphene-reinforced Ti / Al3Ti composite material having a brick structure according to claim 1, wherein: In the step (5), the deformation of each rolling pass is 5%, and the holding time between any two rolling passes is 5 to 10 minutes.

3. The method for preparing a graphene-reinforced Ti / Al3Ti composite material with a brick structure according to claim 1, characterized in that: In the step (5), the thickness of the remaining Ti layer substrate (1) is 20-50 μm.

4. The method for preparing a graphene-reinforced Ti / Al3Ti composite material having a brick structure according to claim 1, wherein: The sum of the rolling deformation in step (7) is 5% to 10%, and the holding time is 0.5 to 1 hour.

5. The method for preparing a graphene-reinforced Ti / Al3Ti composite material having a brick structure according to claim 1, wherein: The concentration of the graphene slurry prepared in step (1) is 1 mg / mL to 4 mg / mL.

6. The method for preparing a graphene-reinforced Ti / Al3Ti composite material with a brick structure according to claim 1, wherein: In the step (2), the Ti foil is pure Ti foil or Ti alloy foil with a thickness of 100 to 180 μm.

7. The method for preparing a graphene-reinforced Ti / Al3Ti composite material with a brick structure according to claim 1, wherein: The thickness of the Al foil in step (2) is 40 to 80 μm.

8. The method for preparing a graphene-reinforced Ti / Al3Ti composite material with a brick structure according to claim 1, wherein: In the step (3), the pre-forming pressure is 50-200 MPa, and the pressing time is 10-30 min.

9. A graphene-reinforced Ti / Al3Ti composite material having a brick structure prepared by the method of claim 1, characterized in that: It is composed of a soft phase Ti layer matrix (1) and a hard phase "brick-shaped" graphene-enhanced Al3Ti structure (2). The "brick-shaped" graphene-enhanced Al3Ti structure (2) is embedded in the soft phase Ti layer matrix (1), and the hard phase "brick-shaped" graphene-enhanced Al3Ti structure (2) of adjacent layers is staggered.

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