PBO fiber fabric reinforced aluminum-based composite material and preparation method thereof

Abstract

The invention belongs to the technical field of metal-based composite materials, and discloses a PBO fiber fabric reinforced aluminum-based composite material and a preparation method thereof.The preparation method comprises the steps of aluminum sheet cold press molding, PBO fiber fabric surface nickel plating treatment, multi-layer laminated preform preparation, spark plasma sintering and subsequent high-temperature annealing treatment. The prepared PBO fiber fabric reinforced aluminum-based composite material has an obvious layered alternating structure. The surface density of the PBO fibers is 100-600g / m < 2 >, the average particle size of the superfine aluminum powder or aluminum alloy powder is 1-15 microns, and the volume fraction of the fibers is 30-75%. The compactness of the prepared aluminum-based composite material reaches 98.5% or above, the interface bonding strength can reach 100 MPa, the tensile strength can reach 500 MPa, the bending strength can reach 550 MPa, the percentage elongation after fracture can reach 12.0%, and the aluminum-based composite material has good strength and plasticity matching. Meanwhile, the preparation process is simple, and subsequent engineering application and popularization are facilitated.

Description

Technical Field

[0001] This invention belongs to the field of metal matrix composite technology, and specifically provides a PBO fiber fabric reinforced aluminum matrix composite material and its preparation method. Background Technology

[0002] Aluminum-based composite materials are composite materials with metallic aluminum or aluminum alloys as the matrix and fibers, whiskers, and particles as reinforcing phases. They possess excellent comprehensive properties such as high specific strength, corrosion resistance, and low coefficient of thermal expansion, and have broad application prospects in aerospace, automotive, and armor protection fields. The research and application of aluminum-based composite materials began in the 1950s, and commonly used reinforcing materials mainly include metal and ceramic particles, as well as short-cut or continuous silicon carbide fibers and carbon fibers.

[0003] Compared to silicon carbide fibers and carbon fibers, PBO fibers (poly(p-phenylenebenzodioxazole) fibers) possess higher strength, modulus, and plasticity, with a tensile strength reaching 5.8 GPa and an elongation after fracture of 3.5%, making them a more ideal fiber reinforcement material. Patents CN202411560048.8 and CN202411560046.9 disclose PBO chopped fiber and nickel-plated PBO chopped fiber reinforced aluminum matrix composites and their preparation methods, respectively. The introduction of PBO fibers significantly improves the overall mechanical properties of the aluminum matrix material. However, the fiber content in current PBO fiber reinforced aluminum matrix composites is relatively low, with a mass fraction of only 2-10%, limiting further improvement in the composite's mechanical properties. In contrast, fiber fabrics, woven from continuous long fibers with a specific texture, can effectively increase the fiber content in the composite, improve the load transfer efficiency between the fiber and matrix, and enhance the fatigue performance and damage tolerance of the composite. Furthermore, fiber fabric reinforced composites exhibit significant anisotropy in their mechanical properties, offering greater design flexibility.

[0004] However, research on using continuous PBO fibers and their fabrics as reinforcements for aluminum matrix composites has not yet been conducted. Whether continuous PBO fiber fabrics can more effectively improve the overall mechanical properties of aluminum matrix composites, and how to prepare PBO fiber fabric-reinforced aluminum matrix composites, are all unknown to those skilled in the art. Summary of the Invention

[0005] This invention addresses the problems existing in the above-mentioned technologies by providing a PBO fiber-reinforced aluminum matrix composite material and its preparation method. Through cold pressing of aluminum sheets, nickel plating of the PBO fiber fabric surface, preparation of multilayer laminated preforms, spark plasma sintering, and subsequent high-temperature annealing, the prepared PBO fiber-reinforced aluminum matrix composite material exhibits a distinct layered alternating structure. The areal density of the PBO fibers is 100-600 g / m³. 2The average particle size of the ultrafine aluminum powder or aluminum alloy powder is 1-15 μm, and the fiber volume fraction is 30-75%. The prepared aluminum-based composite material has a density of over 98.5%, an interfacial bonding strength of 80-100 MPa, a tensile strength of 440-500 MPa, a flexural strength of 500-550 MPa, and an elongation after fracture of 12.0%, exhibiting good strength-plasticity matching. Furthermore, the preparation process is simple, which is beneficial for the subsequent engineering application and promotion of PBO fiber-reinforced aluminum-based composite materials.

[0006] The main technical solutions of this invention are as follows: Compared to chopped fibers, the complete fiber skeleton formed by continuous fiber fabrics can significantly improve the load-bearing efficiency of composite materials, giving them superior specific strength, specific modulus, impact resistance, and fatigue resistance. Simultaneously, the unique structural anisotropy of continuous fiber fabrics makes precise design of material properties possible, thus meeting the requirements for lightweight and high-performance design of load-bearing components. The technical solution of this application involves first pre-pressing aluminum powder into aluminum sheets using a cold press, then surface-modifying PBO fiber fabric. The aluminum sheets and surface-modified PBO fiber fabric are then alternately laid to obtain a laminated preform, which is placed in a cemented carbide mold and then sintered in a spark plasma sintering furnace (SPS) under high temperature and high pressure to obtain a composite material preform. Finally, the composite material preform is placed in a vacuum atmosphere sintering furnace for high-temperature annealing to obtain a PBO fiber fabric-reinforced aluminum matrix composite material with excellent comprehensive mechanical properties.

[0007] The more specific technical solution of this application is as follows: The inventors first provided a method for preparing PBO fiber fabric reinforced aluminum matrix composites, the specific steps of which are as follows: (1) Preparation of aluminum sheet: Ultrafine aluminum powder is mixed evenly with trace organic binder and cold-pressed under pressure of 50-200 MPa to prepare a dense aluminum sheet with a thickness of 0.01-0.2 mm; (2) Pretreatment of PBO fiber fabric: The PBO fiber fabric is cleaned and dried, and then a layer of metallic nickel is uniformly coated on its surface by chemical nickel plating process. The metallic nickel plating layer is 1-10 μm. The PBO fiber fabric mentioned above is a flat fabric woven from continuous PBO fiber filaments according to a certain texture. Specifically, it can be one of the following: unidirectional woven fabric, plain woven fabric, twill woven fabric, satin woven fabric, or cross-woven fabric. (3) Preparation of the laminated preform: The aluminum sheet prepared in step (1) and the PBO fiber fabric treated in step (2) are alternately laminated according to the designed number of layers to form a multi-layered laminated preform of “-PBO fiber fabric-aluminum sheet-PBO fiber fabric-aluminum sheet-PBO fiber fabric-”, and the fiber volume fraction in the preform is 30-75%; (4) Mold assembly and SPS sintering densification: The laminated preform is placed in an SPS sintering hard alloy mold; the mold is placed in an SPS sintering furnace, and the system vacuum is evacuated to a level below 10 Pa. Then, axial pressure is applied and sintering begins. The sintering process parameters are as follows: heating rate of 100-500℃ / min, sintering temperature of 500-600℃, sintering pressure of 100-300MPa, holding time of 15-60min, and maintaining vacuum degree below 10Pa during sintering.

[0008] Compared with existing technologies, especially those using chopped fibers as reinforcing composite materials, the inventors have increased the minimum sintering temperature and extended the heat preservation and pressure holding time because the PBO fiber fabric reinforced composite material used in this application has a higher PBO fiber content.

[0009] (5) Cooling and demolding, high-temperature annealing: After sintering, the furnace is cooled to below room temperature, the pressure is removed, and the sintered body is taken out from the mold to obtain a dense PBO fiber fabric reinforced aluminum matrix composite blank. The blank is placed in a vacuum atmosphere sintering furnace for high-temperature annealing. The annealing temperature is 300-500℃ and the annealing time is 1-4h. After annealing, the furnace is cooled to room temperature to obtain PBO fiber fabric reinforced aluminum matrix composite.

[0010] Preferably, in step (1), the ultrafine aluminum powder is selected from pure aluminum powder or aluminum-silicon, aluminum-zinc, or aluminum-magnesium alloy powders, with an average particle size of 1-15 μm; the organic binder is selected from polyvinyl alcohol (PVA), paraffin wax, or polyethylene glycol (PEG), with an addition amount of 0.5-2.5% of the mass of the ultrafine aluminum powder, and the organic binder can be completely decomposed and volatilized in the temperature range of 200-400℃.

[0011] More preferably, the cold pressing pressure is 80-150 MPa, the amount of organic binder added is 1-2% of the mass of aluminum powder, and the thickness of the dense aluminum sheet is 0.01-0.15 mm.

[0012] In step (2), the areal density of the PBO fiber fabric is 100-600 g / m³. 2 The thickness of the nickel plating is 3-8 μm.

[0013] The cleaning and drying process in step (2) involves ultrasonically cleaning the PBO fiber fabric for 15 minutes, followed by drying in an oven for 1-2 hours at a temperature of 80-100°C.

[0014] Preferably, in step (3), the fiber volume fraction in the multilayer preform is 50-70%, which is determined by the thickness of the PBO fiber fabric, the thickness of the aluminum thin layer, and the number of layers of both. The thickness of the PBO fiber fabric is determined by its areal density. The volume fraction can be controlled by adjusting the relationship between the number of layers of the thickness gauge.

[0015] Preferably, in step (4), the SPS sintering heating rate is 150-400℃ / min, the sintering temperature is 520-560℃, the sintering pressure is 150-250MPa, and the holding time is 20-40 min.

[0016] In step (4), the high-temperature annealing temperature is 350-450℃, and the annealing holding time is 2-3h.

[0017] The inventors further claim protection for the PBO fiber fabric reinforced aluminum matrix composite material obtained by the above preparation method. The composite material has an obvious layered alternating structure with a density greater than 98.5%. The PBO fibers maintain a complete circular cross-sectional morphology in the composite material, and the fiber properties are effectively preserved. The PBO fibers react with the aluminum matrix at the interface to form NiAl intermetallic compounds with good plasticity and toughness. The interface bonding is good, and the interface bonding strength can reach 80-100 MPa.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) The composite material of the present invention is obtained by alternating layers of nickel-plated PBO fiber fabric and pre-pressed aluminum sheets, using spark plasma sintering and subsequent high-temperature annealing. The pre-pressing process forms dense sheets of aluminum powder, avoiding problems such as uneven powder distribution and low filling rate caused by direct filling of loose powder, and achieving a highly uniform and controllable distribution of the aluminum matrix in the composite material. In addition, the trace amount of organic binder used in the cold pressing process helps to improve the strength and toughness of the dense aluminum sheets, making them easy to handle and lay up. It can be completely decomposed and discharged by the vacuum system in the low-temperature stage (<400℃) of the early stage of SPS sintering, without introducing any impurities into the composite material.

[0019] (2) The areal density of the PBO fiber fabric used in the composite material of the present invention is 100-600 g / m³. 2 If the areal density of PBO fiber fabric is too low (below 100g / m²), 2On the one hand, this can easily lead to a lower PBO fiber content in the composite material, which is not conducive to improving the performance of the composite material. On the other hand, using too many layers of fiber fabric during the layup operation results in low preparation efficiency. Furthermore, if the areal density of the PBO fiber fabric is too high (above 600 g / m³), it will result in a lower PBO fiber content in the composite material. 2 During the sintering process, aluminum particles cannot completely wet and fill the gaps between the fiber fabrics, resulting in a low density of the composite material, which has an adverse effect on its mechanical properties.

[0020] (3) The SPS process in the preparation method has the characteristics of ultra-fast heating and ultra-short sintering time. Combined with a sintering temperature that is much lower than the melting point of aluminum (660℃) and the performance damage temperature of PBO fibers (600℃), the exposure time of PBO fibers at high temperature is greatly shortened, avoiding performance damage of PBO fibers at high temperature, and improving preparation efficiency. At the same time, a nickel plating layer is coated on the surface of PBO fiber fabric by chemical nickel plating. During the high-temperature sintering process, atomic diffusion and chemical reaction occur at the interface between the fiber and the matrix to generate NiAl intermetallic compounds with good plasticity and toughness, which improves the interfacial bonding between the fiber and the matrix and is conducive to further improving the comprehensive mechanical properties of the composite material. The thickness of the nickel plating layer has an important influence on the preparation and performance of the composite material. When the thickness of the nickel plating layer is less than 3μm, there are fewer NiAl intermetallic compounds generated at the interface between PBO fibers and aluminum matrix, resulting in poor interfacial bonding performance at the fiber / matrix interface. When the thickness of the nickel plating layer exceeds 8μm, although the interfacial bonding between the fiber and matrix is ​​further improved, the preparation efficiency of the composite material is reduced due to the excessive thickness of the nickel plating layer and the long nickel plating time.

[0021] (4) In the PBO fiber-reinforced aluminum matrix composite material, the volume fraction of PBO fibers is comprehensively controlled by the thickness of the aluminum sheet, the areal density of the PBO fibers, and the number of layers. The PBO fiber content has a significant impact on the mechanical properties of the composite material. If its volume fraction is less than 30%, the fiber reinforcement cannot be fully utilized due to the low fiber content, resulting in poor overall mechanical properties of the composite material. If the PBO fiber volume fraction is higher than 75%, the aluminum matrix cannot fully impregnate and fill the gaps between the PBO fiber fabrics due to the excessive fiber content, leading to low density and poor mechanical properties of the composite material. Therefore, the inventors determined that when the volume fraction of PBO fibers in the composite material is 30-75%, it is more conducive to exerting the reinforcing effect of PBO fibers, thereby improving the mechanical properties of the composite material.

[0022] (5) The SPS sintering temperature is 500-600℃ and the sintering pressure is 100-300MPa. Under high temperature and high pressure, the aluminum powder in the aluminum sheet undergoes plastic flow and gradually fills the internal voids of the PBO fiber fabric, ultimately obtaining a dense PBO fiber fabric reinforced aluminum matrix composite material. Compared with the nickel-plated chopped PBO fiber reinforced aluminum matrix composite material, the composite material in this invention has a higher minimum sintering temperature and a longer holding time. This is because a higher sintering temperature and a longer holding time are beneficial to improving the fluidity of the aluminum powder, which can more effectively fill the internal voids of the fiber fabric, thereby improving the density of the composite material and improving the comprehensive mechanical properties of the composite material. However, when the sintering temperature is higher than 600℃, under high temperature and high pressure, on the one hand, the PBO fiber is easily damaged, leading to a decrease in performance; on the other hand, high temperature easily causes the aluminum powder to partially melt and flow into the mold voids, resulting in difficulty in demolding. Therefore, the above-mentioned SPS sintering temperature was finally determined.

[0023] (6) The heating and cooling rates of the SPS sintering process are relatively fast, which leads to excessive internal stress in the sintered composite material, which can have an adverse effect on its mechanical properties. Therefore, a subsequent high-temperature annealing treatment is adopted to eliminate the internal stress in the material and improve the overall mechanical properties of the composite material.

[0024] (7) The composite material prepared by the present invention has high fiber content, high density and good fiber properties. It can give full play to the advantages of high strength and high modulus of PBO fiber and obtain comprehensive mechanical properties far exceeding those of matrix alloy. The density of the aluminum-based composite material is above 98.5%, the tensile strength is 440-500MPa and the flexural strength can reach 500-550MPa. Compared with the surface nickel-plated short PBO fiber reinforced aluminum-based composite material with tensile strength <320MPa and flexural strength <435MPa, the performance is significantly improved. At the same time, the PBO fiber fabric reinforced aluminum-based composite material has good plastic deformation ability and its maximum elongation after fracture can reach 12.0%, which has good comprehensive mechanical properties. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the multilayer laminated preform of PBO fiber fabric reinforced aluminum matrix composite material according to the present invention. In the figure, 1 is an aluminum sheet and 2 is a PBO fiber fabric. Detailed Implementation

[0026] The present invention will be further described below with reference to specific embodiments, which will enable those skilled in the art to have a more comprehensive understanding of the invention, but will not limit the invention in any way. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. In this application, a chemical nickel plating process is used to uniformly coat a layer of metallic nickel on the surface of PBO fiber fabric. For details, please refer to the chemical nickel plating process disclosed in the applicant's earlier application CN202411560046.9, which will not be elaborated upon further by the inventor.

[0027] In the following embodiments: (1) Density testing equipment: JA2003 electronic balance.

[0028] (2) Tensile testing equipment: The INSTRON5985 electronic universal testing machine (Instrand, USA) was used.

[0029] (3) Tensile strength and elongation were measured by tensile stress-strain curves obtained from tensile tests in accordance with GB / T 228.1-2021.

[0030] (4) The bending strength was measured using an INSTRON5985 electronic universal testing machine (Instron, USA) in accordance with GB / T232-2024 "Metallic Materials Bending Test Method".

[0031] Example 1: A PBO fiber fabric reinforced aluminum matrix composite material and its preparation method, the specific steps of which are as follows: (1) Preparation of aluminum sheet: Ultrafine aluminum powder is mixed evenly with trace organic binder and cold-pressed under 50MPa pressure to prepare a dense aluminum sheet with a thickness of 0.15mm. The ultrafine aluminum powder has a particle size of 1μm and the organic binder is polyvinyl alcohol (PVA), which is added at 0.5% of the mass of aluminum powder.

[0032] (2) Pretreatment of PBO fiber cloth: The PBO fiber woven cloth was ultrasonically cleaned for 15 minutes, then placed in an oven for drying at 100℃ for 1 hour to remove surface contaminants and moisture. A layer of metallic nickel was then uniformly coated onto its surface using a chemical nickel plating process, with a nickel plating thickness of 1 μm. The PBO fiber cloth is a unidirectional woven cloth with an areal density of 100 g / m². 2 .

[0033] (3) Preparation of the laminated prefabricated body: Cut aluminum sheets into circular pieces with a diameter of 50 mm, and cut PBO fiber cloth into the same size. Repeat the stacking of the PBO fiber cloth in the order of "-PBO fiber cloth-aluminum sheet-PBO fiber cloth-aluminum sheet-PBO fiber cloth-" for 30 layers to form a multi-layer laminated prefabricated body (see reference). Figure 1As shown, the fiber volume fraction in the preform is approximately 30%.

[0034] (4) Mold installation: Place the laminated preform into a cemented carbide mold specifically for SPS sintering.

[0035] (5) SPS sintering densification: The mold is placed in an SPS sintering furnace, and the system vacuum is evacuated to a level below 10 Pa. Then, axial pressure is applied and sintering begins. The sintering process parameters are: heating rate of 100℃ / min, sintering temperature of 500℃, sintering pressure of 100MPa, holding time of 15min, and maintaining a vacuum level below 10 Pa during the sintering process.

[0036] (6) Cooling and demolding: After sintering, the furnace is cooled to below room temperature, the pressure is removed, and the sintered body is taken out from the mold to obtain a dense PBO fiber fabric reinforced aluminum matrix composite preform.

[0037] (7) Subsequent high-temperature annealing: The PBO fiber fabric reinforced aluminum matrix composite material blank obtained in step (6) is placed in a vacuum atmosphere sintering furnace for high-temperature annealing. The annealing temperature is 300℃ and the annealing time is 1h. After annealing, it is cooled to room temperature with the furnace to obtain PBO fiber fabric reinforced aluminum matrix composite material. Testing revealed that the PBO fiber-reinforced aluminum matrix composite material prepared in this embodiment has a density of 98.7%, an interfacial bonding strength of 90 MPa, a tensile strength of 440 MPa, a flexural strength of 500 MPa, and an elongation after fracture of 11.5%, exhibiting excellent comprehensive mechanical properties.

[0038] Example 2: A PBO fiber fabric reinforced aluminum matrix composite material and its preparation method, the specific steps of which are as follows: (1) Preparation of aluminum sheet: Ultrafine aluminum powder and trace organic binder are mixed evenly and cold-pressed under 200 MPa pressure to prepare a dense aluminum sheet with a thickness of 0.13 mm. The ultrafine aluminum powder has a particle size of 15 μm and the organic binder is paraffin wax, which is added at 2.5% of the mass of aluminum powder.

[0039] (2) Pretreatment of PBO fiber cloth: The PBO fiber woven cloth was ultrasonically cleaned for 15 minutes, then placed in an oven for drying for 2 hours at a temperature of 80°C to remove surface contaminants and moisture. A layer of metallic nickel was then uniformly coated onto its surface using a chemical nickel plating process, with a nickel plating thickness of 10 μm. The PBO fiber cloth was an orthogonal woven cloth with a surface density of 600 g / m². 2 .

[0040] (3) Preparation of the laminated preform: Cut aluminum sheets into circular pieces with a diameter of 50 mm, and cut PBO fiber cloth into the same size. Repeat the stacking of 15 layers in the order of "-PBO fiber cloth-aluminum sheet-PBO fiber cloth-aluminum sheet-PBO fiber cloth-" to form a multi-layer laminated preform, in which the fiber volume fraction is about 75%.

[0041] (4) Mold installation: Place the laminated preform into a cemented carbide mold specifically for SPS sintering.

[0042] (5) SPS sintering densification: The mold is placed in an SPS sintering furnace, and the system vacuum is evacuated to below 10 Pa. Then, axial pressure is applied and sintering begins. The sintering process parameters are: heating rate of 500℃ / min, sintering temperature of 600℃, sintering pressure of 300MPa, holding time of 40min, and maintaining the vacuum level below 10 Pa during the sintering process.

[0043] (6) Cooling and demolding: After sintering, the furnace is cooled to below room temperature, the pressure is removed, and the sintered body is taken out from the mold to obtain a dense PBO fiber fabric reinforced aluminum matrix composite preform.

[0044] (7) Subsequent high-temperature annealing: The PBO fiber fabric reinforced aluminum matrix composite material blank obtained in step (6) is placed in a vacuum atmosphere sintering furnace for high-temperature annealing. The annealing temperature is 500℃ and the annealing time is 4h. After annealing, it is cooled to room temperature with the furnace to obtain PBO fiber fabric reinforced aluminum matrix composite material. Testing revealed that the PBO fiber-reinforced aluminum matrix composite material prepared in this embodiment has a density of 98.5%, an interfacial bonding strength of 100 MPa, a tensile strength of 465 MPa, a flexural strength of 535 MPa, and an elongation after fracture of 10.0%, exhibiting excellent comprehensive mechanical properties.

[0045] Example 3: A PBO fiber fabric reinforced aluminum matrix composite material and its preparation method, the specific steps of which are as follows: (1) Preparation of aluminum sheet: Ultrafine aluminum-magnesium alloy powder was mixed evenly with a trace amount of organic binder and cold-pressed under 80 MPa pressure to prepare a dense aluminum sheet with a thickness of 0.2 mm. The ultrafine aluminum-magnesium alloy powder had a particle size of 10 μm, and the organic binder was polyethylene glycol (PEG), which was added at 1% of the mass of the ultrafine aluminum-magnesium alloy powder.

[0046] (2) Pretreatment of PBO fiber cloth: The PBO fiber woven cloth was ultrasonically cleaned for 15 minutes, then placed in an oven for drying at 90℃ for 1 hour to remove surface contaminants and moisture. A layer of metallic nickel was then uniformly coated onto its surface using a chemical nickel plating process, with a nickel plating thickness of 3 μm. The PBO fiber cloth was a twill woven cloth with an areal density of 440 g / m². 2 .

[0047] (3) Preparation of the laminated preform: Cut aluminum sheets into circular pieces with a diameter of 50 mm, and cut PBO fiber cloth into the same size. Repeat the stacking 20 times in the order of "-PBO fiber cloth-aluminum sheet-PBO fiber cloth-aluminum sheet-PBO fiber cloth-" to form a multi-layer laminated preform, in which the fiber volume fraction is about 50%.

[0048] (4) Mold installation: Place the laminated preform into a cemented carbide mold specifically for SPS sintering.

[0049] (5) SPS sintering densification: The mold is placed in an SPS sintering furnace, and the system vacuum is evacuated to a level below 10 Pa. Then, axial pressure is applied and sintering begins. The sintering process parameters are: heating rate of 150℃ / min, sintering temperature of 520℃, sintering pressure of 150MPa, holding time of 60min, and maintaining a vacuum level below 10 Pa during the sintering process.

[0050] (6) Cooling and demolding: After sintering, the furnace is cooled to below room temperature, the pressure is removed, and the sintered body is taken out from the mold to obtain a dense PBO fiber fabric reinforced aluminum matrix composite preform.

[0051] (7) Subsequent high-temperature annealing: The PBO fiber fabric reinforced aluminum matrix composite material blank obtained in step (6) is placed in a vacuum atmosphere sintering furnace for high-temperature annealing. The annealing temperature is 350℃ and the annealing time is 2h. After annealing, it is cooled to room temperature with the furnace to obtain PBO fiber fabric reinforced aluminum matrix composite material. Testing revealed that the PBO fiber-reinforced aluminum matrix composite material prepared in this embodiment has a density of 99.0%, an interfacial bonding strength of 80 MPa, a tensile strength of 490 MPa, a flexural strength of 540 MPa, and an elongation after fracture of 12.0%, exhibiting excellent comprehensive mechanical properties.

[0052] Example 4: A PBO fiber fabric reinforced aluminum matrix composite material and its preparation method, the specific steps of which are as follows: (1) Preparation of aluminum sheet: Ultrafine aluminum-silicon alloy powder was mixed evenly with a trace amount of organic binder and cold-pressed under a pressure of 150 MPa to prepare a dense aluminum sheet with a thickness of 0.01 mm. The ultrafine aluminum-silicon alloy powder had a particle size of 10 μm, and the organic binder was paraffin wax, which was added at 2% of the mass of the ultrafine aluminum-silicon alloy powder.

[0053] (2) Pretreatment of PBO fiber cloth: The PBO fiber woven cloth was ultrasonically cleaned for 15 minutes, then dried in an oven at 100℃ for 1 hour to remove surface contaminants and moisture. A layer of metallic nickel was then uniformly coated onto its surface using a chemical nickel plating process, with a thickness of 8 μm. The PBO fiber cloth was a satin woven cloth with a surface density of 230 g / m². 2 .

[0054] (3) Preparation of the multilayer preform: Cut aluminum sheets into circular pieces with a diameter of 50 mm, and cut PBO fiber cloth into the same size. Repeat the stacking of 40 layers in the order of "-PBO fiber cloth-aluminum sheet-PBO fiber cloth-aluminum sheet-PBO fiber cloth-" to form a multilayer multilayer preform. The fiber volume fraction in the multilayer multilayer preform is about 70%.

[0055] (4) Mold installation: Place the laminated preform into a cemented carbide mold specifically for SPS sintering.

[0056] (5) SPS sintering densification: The mold is placed in an SPS sintering furnace, and the system vacuum is evacuated to a level below 10 Pa. Then, axial pressure is applied and sintering begins. The sintering process parameters are: heating rate of 400℃ / min, sintering temperature of 560℃, sintering pressure of 250MPa, holding time of 20min, and maintaining a vacuum level below 10 Pa during the sintering process.

[0057] (6) Cooling and demolding: After sintering, the furnace is cooled to below room temperature, the pressure is removed, and the sintered body is taken out from the mold to obtain a dense PBO fiber fabric reinforced aluminum matrix composite preform.

[0058] (7) Subsequent high-temperature annealing: The PBO fiber fabric reinforced aluminum matrix composite material blank obtained in step (6) is placed in a vacuum atmosphere sintering furnace for high-temperature annealing. The annealing temperature is 450℃ and the annealing time is 3h. After annealing, it is cooled to room temperature with the furnace to obtain PBO fiber fabric reinforced aluminum matrix composite material. Testing revealed that the PBO fiber-reinforced aluminum matrix composite material prepared in this embodiment has a density of 98.5%, an interfacial bonding strength of 85 MPa, a tensile strength of 500 MPa, a flexural strength of 550 MPa, and an elongation after fracture of 11.0%, exhibiting excellent comprehensive mechanical properties.

[0059] The difference between Comparative Example 1 and Example 2 is that: (5) SPS sintering densification: The mold is placed in an SPS sintering furnace, and the system vacuum is evacuated to a level below 10 Pa. Then, axial pressure is applied and sintering begins. The sintering process parameters are: heating rate of 500℃ / min, sintering temperature of 350℃, sintering pressure of 200MPa, holding time of 40 min, and maintaining a vacuum level below 10 Pa during the sintering process.

[0060] The PBO fiber fabric reinforced aluminum matrix composite material prepared in this comparative example has a density of 85.7%, an interfacial bonding strength of 30 MPa, a tensile strength of 80 MPa, a flexural strength of 100 MPa, and an elongation after fracture of 3.0%.

[0061] As can be seen from the comparison between Example 2 and this comparative example, under the premise of the same aluminum sheet thickness, PBO fiber areal density, heating rate, sintering pressure and annealing process, due to the lower sintering temperature, the aluminum powder has poorer fluidity and the composite material has lower density, resulting in a significant reduction in its tensile strength, flexural strength and elongation after fracture, and thus failing to achieve good comprehensive mechanical properties.

[0062] The difference between Comparative Example 2 and Example 3 is as follows: (1) Preparation of aluminum sheet: Ultrafine aluminum-magnesium alloy powder was mixed evenly with a trace amount of organic binder and cold-pressed under a pressure of 200 MPa to prepare a dense aluminum sheet with a thickness of 0.1 mm. The ultrafine aluminum powder had a particle size of 10 μm, and the organic binder was polyethylene glycol (PEG), which was added at 1% of the mass of the ultrafine aluminum-magnesium alloy powder.

[0063] (2) Pretreatment of PBO fiber cloth: The PBO fiber woven cloth is cleaned and dried, and a layer of metallic nickel is uniformly coated on its surface using a chemical nickel plating process. The thickness of the metallic nickel plating layer is 3μm. The PBO fiber cloth is a unidirectional woven cloth or an orthogonal fabric with an areal density of 900g / m². 2 .

[0064] (3) Preparation of the laminated preform: Cut aluminum sheets into circular pieces with a diameter of 50 mm, and cut PBO fiber cloth into the same size. Repeat the stacking of 50 layers in the order of "-PBO fiber cloth-aluminum sheet-PBO fiber cloth-aluminum sheet-PBO fiber cloth-" to form a multi-layer laminated preform with a fiber volume fraction of approximately 85%.

[0065] The PBO fiber fabric reinforced aluminum matrix composite material prepared in this comparative example has a density of 83.5%, an interfacial bonding strength of 40 MPa, a tensile strength of 105 MPa, a flexural strength of 85 MPa, and an elongation after fracture of 4.5%.

[0066] As can be seen from the comparison between Example 3 and this comparative example, under the premise of the same discharge plasma sintering pressure, heat preservation and pressure holding time and annealing process, when the volume fraction of PBO fiber fabric in the composite material is too high, the wettability of the aluminum matrix to the fiber becomes worse, the interfacial bonding performance between the two weakens, and the overall mechanical properties of the composite material are reduced.

[0067] Comparative Example 3: A method for preparing a nickel-plated PBO chopped fiber reinforced aluminum matrix composite material, comprising the following steps: (1) Place the PBO short-cut fibers in an ultrasonic dispersion device, add anhydrous ethanol, and perform ultrasonic dispersion treatment. (2) The PBO fibers after dispersion treatment are subjected to surface nickel plating treatment, and the nickel plating layer thickness is 1μm to obtain nickel-plated PBO short chopped fibers. (3) Mix the nickel-plated PBO short chopped fibers and aluminum powder and put them into a ball mill jar. The aluminum powder has a particle size of 200 μm and the nickel-plated PBO short chopped fibers account for 10% of the mass of the mixture. Add alumina ball milling balls to the mixture. The ball-to-material ratio is 8:1. (4) The ball mill jar was fixed in a three-dimensional planetary vibrating ball mill for ball milling and mixing. The ball milling speed was 500 r / min and the ball milling time was 6 h to obtain a uniformly mixed material of nickel-plated PBO short-cut fibers / aluminum powder. (5) The mixture is placed in a hard alloy mold and sintered in a spark plasma sintering furnace (SPS) at a temperature of 500°C and a pressure of 100 MPa. The holding time is 15 min. After sintering, the mold is removed to obtain a nickel-plated PBO short fiber reinforced aluminum matrix composite blank. (6) The nickel-plated PBO short fiber reinforced aluminum matrix composite material blank is placed in a vacuum atmosphere sintering furnace for high-temperature annealing treatment. The annealing temperature is 300℃ and the annealing holding time is 1h. After annealing, it is cooled to room temperature with the furnace to obtain the nickel-plated PBO short fiber reinforced aluminum matrix composite material. The obtained PBO chopped fiber reinforced aluminum matrix composite material has a density of 99.1%, a tensile strength of 310 MPa, a flexural strength of 400 MPa, and an elongation after fracture of 13.5%.

[0068] A comparison of Example 1 and Comparative Example 3 shows that, with the same PBO fiber nickel plating thickness, SPS sintering temperature, sintering pressure, holding time, and annealing temperature and time, the tensile and flexural strength of the nickel-plated chopped PBO fiber reinforced aluminum matrix composite material is significantly lower than that of the PBO fiber fabric reinforced aluminum matrix composite material due to the lower PBO fiber content (mass fraction of only 10%, corresponding to a volume fraction of 16.3%). Furthermore, the preparation of the nickel-plated PBO chopped fibers requires ball milling and mixing, which takes several hours, making the composite material preparation process more complex and severely impacting the preparation efficiency.

[0069] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for producing a PBO fiber fabric-reinforced aluminum matrix composite material, characterized by, The specific steps are as follows: (1) Preparation of aluminum sheet: mix ultra-fine aluminum powder with a small amount of organic binder uniformly, cold-press into shape under a pressure of 50-200 MPa to obtain dense aluminum sheet with a thickness of 0.01-0.2 mm; (2) Pretreatment of PBO fiber fabric: clean and dry the PBO fiber fabric, and then coat a layer of metal nickel on the surface of the fabric, the metal nickel plating layer being 1-10 μm; (3) Preparation of laminated preform: alternately stack the aluminum sheet prepared in step (1) and the PBO fiber fabric treated in step (2) according to the designed number of layers to form a multi-layer laminated preform of "-PBO fiber fabric-aluminum sheet-PBO fiber fabric-aluminum sheet-PBO fiber fabric-". (4) Molding and SPS sintering densification: place the laminated preform into a SPS sintering hard alloy mold, place the mold in a SPS sintering furnace, vacuumize the system to a vacuum degree lower than 10 Pa, then apply axial pressure and start sintering; The sintering process parameters are as follows: the heating rate is 100-500 ℃ / min, the sintering temperature is 500-600 ℃, the sintering pressure is 100-300 MPa, the holding time is 15-60 min, and the vacuum degree is kept lower than 10 Pa during sintering; (5) Cooling, demolding and high-temperature annealing treatment: after sintering, cool down to room temperature, remove the pressure, take out the sintered body from the mold to obtain a dense PBO fiber fabric reinforced aluminum matrix composite blank, and then place the blank in a vacuum atmosphere sintering furnace for high-temperature annealing treatment, the annealing temperature being 300-500 ℃ and the annealing time being 1-4 h, and then cool down to room temperature to obtain a PBO fiber fabric reinforced aluminum matrix composite material.

2. The method of claim 1, wherein the PBO fabric reinforced aluminum matrix composite is prepared by the steps of: (a) preparing a PBO fabric; (b) preparing an aluminum matrix material; (c) mixing the PBO fabric and the aluminum matrix material; and (d) heating the mixture to a temperature of 300°C or higher. In step (1), the ultra-fine aluminum powder is selected from one of pure aluminum powder or aluminum-silicon, aluminum-zinc, aluminum-magnesium aluminum alloy powder, and the average particle size is 1-15 μm; the organic binder is one of polyvinyl alcohol, paraffin or polyethylene glycol, and the addition amount is 0.5-2.5% of the mass of the ultra-fine aluminum powder.

3. The method of producing a PBO fiber fabric-reinforced aluminum matrix composite material according to claim 1 or 2, characterized by, In step (1), the cold-pressing forming pressure is 80-150 MPa, the addition amount of the organic binder is 1-2% of the mass of the aluminum powder, and the thickness of the dense aluminum sheet is 0.01-0.15 mm.

4. The method of claim 1, wherein the PBO fabric reinforced aluminum matrix composite is prepared by the steps of: (a) preparing a PBO fabric; (b) preparing an aluminum matrix material; (c) mixing the PBO fabric and the aluminum matrix material; and (d) heating the mixture to a temperature of 300°C or higher. The PBO fiber fabric in step (2) is a planar fabric woven by continuous PBO fiber filaments according to certain texture; the area density of the PBO fiber fabric is 100-600 g / m 2 The thickness of the metal nickel plating layer is 3-8 μm.

5. The method of claim 1 or 4, wherein the PBO fabric reinforced aluminum matrix composite is prepared by the steps of: (a) mixing PBO fabric and an aluminum matrix material; (b) heating the mixture to a temperature of 400 to 600°C; (c) applying pressure to the mixture; and (d) cooling the mixture. In step (2), the PBO fiber fabric is one of unidirectional woven cloth, plain woven cloth, twill woven cloth, satin woven cloth or orthogonal woven cloth.

6. The method of claim 1 or 4, wherein the PBO fabric reinforced aluminum matrix composite is prepared by the steps of: (a) mixing PBO fabric and an aluminum matrix material; (b) heating the mixture to a temperature of 400 to 600°C; (c) applying pressure to the mixture; and (d) cooling the mixture. In step (2), the cleaning and drying treatment step is ultrasonic cleaning treatment of the PBO fiber fabric for 15 min, and then drying in an oven for 1-2 h at a temperature of 80-100 ℃.

7. The method of claim 1, wherein the PBO fabric reinforced aluminum matrix composite is prepared by the steps of: (a) mixing PBO fabric and an aluminum matrix material; (b) heating the mixture to a temperature of 400 to 600°C; (c) applying pressure to the mixture; and (d) cooling the mixture. In step (3), the fiber volume fraction in the multi-layer laminated preform is 50-70%.

8. The method for preparing the PBO fiber fabric reinforced aluminum matrix composite material according to claim 1, characterized in that, In step (4), the SPS sintering heating rate is 150-400 ℃ / min, the sintering temperature is 520-560 ℃, the sintering pressure is 150-250 MPa, and the holding time is 20-40 min.

9. The method for preparing the PBO fiber fabric reinforced aluminum matrix composite material according to claim 1, characterized in that, In the step (4), the high-temperature annealing temperature is 350-450 DEG C, and the annealing holding time is 2-3h.

10. The PBO fabric reinforced aluminum matrix composite material obtained by the preparation method according to any one of claims 1-9.

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