Aluminum-based bionic composite material with titanium alloy as skeleton reinforcement phase and preparation method of aluminum-based bionic composite material

Abstract

The invention provides an aluminum-based bionic composite material with a titanium alloy as a skeleton reinforcement phase and a preparation method of the aluminum-based bionic composite material, and belongs to the field of metal-based composite materials. The aluminum-based bionic composite material with the titanium alloy as the framework reinforcement phase comprises an aluminum matrix and the titanium alloy framework reinforcement phase. The titanium alloy skeleton reinforced phase is of a porous structure with the characteristics of a bionic tooth enamel columnar microstructure, and the porous structure is cylindrical through holes which are densely distributed; the aluminum matrix is filled in the cylindrical through hole; the volume percent of the titanium alloy framework reinforcement phase in the aluminum-based bionic composite material with the titanium alloy as the framework reinforcement phase is 30-80%. The tensile strength of the aluminum-based bionic composite material can reach 811 MPa, the percentage elongation after fracture can reach 10.3%, the bending strength can reach 1491 MPa, the fracture toughness can reach 47 MPa.m < 1 / 2 >, and the aluminum-based bionic composite material shows an excellent toughness synergistic effect.

Description

Technical Field

[0001] The present invention relates to the field of metal matrix composites, and particularly to an aluminum-based bionic composite material with a titanium alloy as a skeleton reinforcing phase and a preparation method thereof. Background Art

[0002] With the continuous development of science and technology, the demand for lightweight materials is increasing day by day, especially in the fields of automobiles, aerospace, and mechanical manufacturing. Although traditional metal materials have excellent mechanical properties, their relatively high density limits their application in the field of lightweight. Therefore, researchers have gradually turned to the research and development of lightweight and high-strength composite materials.

[0003] Titanium alloys have characteristics such as low density, high strength, corrosion resistance, and high temperature resistance, and have become one of the important structural materials required in multiple fields. Aluminum and its alloys have the advantages of low density, easy processing, and good plasticity, and are one of the most widely used structural materials at present. Titanium-aluminum composite materials can give full play to the excellent properties of the two light metals and are expected to become a high specific strength and lightweight structural material. At present, traditional titanium-aluminum composite materials generally use discontinuous titanium particles, titanium fibers, etc. as reinforcing phases. However, their organizational structure is difficult to precisely design and control, lacking an orderly organizational structure and effective strengthening and toughening matching, and it is difficult to effectively improve the mechanical properties of the material. Summary of the Invention

[0004] The purpose of the present invention is to provide an aluminum-based bionic composite material with a titanium alloy as a skeleton reinforcing phase and a preparation method thereof. The aluminum-based bionic composite material provided by the present invention with a titanium alloy as a skeleton reinforcing phase has both high strength and high toughness, and realizes the synergistic strengthening effect between strength and toughness, thereby optimizing the comprehensive mechanical properties of the material.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions:

[0006] The present invention provides an aluminum-based bionic composite material with a titanium alloy as a skeleton reinforcing phase, including an aluminum matrix and a titanium alloy skeleton reinforcing phase; the titanium alloy skeleton reinforcing phase has a porous structure, and the porous structure is a densely arranged cylindrical through-hole; the aluminum matrix is filled in the cylindrical through-hole; the volume percentage of the titanium alloy skeleton reinforcing phase in the aluminum-based bionic composite material with a titanium alloy as a skeleton reinforcing phase is 30-80%.

[0007] Preferably, the aperture of the cylindrical through-hole is 0.5-2.5 mm, and the distance between adjacent holes is 0.5-1 mm.

[0008] Preferably, the material of the titanium alloy skeleton reinforcing phase is Ti-6Al-4V titanium alloy.

[0009] The present invention also provides a method for preparing an aluminum-based bionic composite material with a titanium alloy as a framework reinforcing phase according to the above technical solution, comprising the following steps:

[0010] (1) Three-dimensionally printing the titanium alloy powder to obtain a titanium alloy framework;

[0011] (2) Placing metallic aluminum above the titanium alloy framework obtained in the step (1) such that the cylindrical through holes of the titanium alloy framework are in the vertical direction, and then performing vacuum infiltration heat treatment to obtain an aluminum-based bionic composite material with a titanium alloy as a framework reinforcing phase.

[0012] Preferably, the particle size of the titanium alloy powder in the step (1) is 15 - 53 μm.

[0013] Preferably, the titanium alloy framework reinforcing phase is subjected to vacuum heat treatment before use in the step (2).

[0014] Preferably, the vacuum degree of the vacuum heat treatment is ≤ 10 -3 Pa, the temperature of the vacuum heat treatment is 750 - 850 °C, and the heat preservation time of the vacuum heat treatment is 2 - 4 h.

[0015] Preferably, the vacuum degree of the vacuum infiltration heat treatment in the step (2) is ≤ 10 -3 Pa, the temperature of the vacuum infiltration heat treatment is 680 - 720 °C, and the heat preservation time of the vacuum infiltration heat treatment is 45 - 75 min.

[0016] Preferably, the heating rate to the temperature of the vacuum infiltration heat treatment is 5 - 10 °C / min.

[0017] Preferably, the cooling rate of the vacuum infiltration heat treatment is 5 - 10 °C / min.

[0018] The present invention provides an aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase, comprising an aluminum matrix and a titanium alloy skeleton reinforcing phase; the titanium alloy skeleton reinforcing phase has a porous structure, and the porous structure is a densely arranged cylindrical through-hole; the aluminum matrix is filled in the cylindrical through-hole; the volume percentage of the titanium alloy skeleton reinforcing phase in the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase is 30-80%. Based on the columnar microstructure characteristics of enamel (enamel is composed of 96% hard tissue (hydroxyapatite) material and 4% soft tissue (protein and water) material and presents a columnar structure), a titanium alloy skeleton with a porous structure is used as the reinforcing phase, and the porous structure is defined as a densely arranged cylindrical through-hole, which can optimize the strength and lightweight of the composite material, disperse stress concentration, improve the specific strength and specific stiffness. The columnar hole structure improves the energy absorption capacity and impact resistance of the composite material, effectively avoids local stress concentration, and at the same time enhances the multi-directional load-bearing capacity; by filling the aluminum matrix in the porous structure, excellent toughness is provided for the composite material; by adjusting the content of the titanium alloy skeleton reinforcing phase in the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase, the strength and toughness of the composite material are further optimized. The results of the examples show that the tensile strength of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase provided by the present invention can reach 811 MPa, the elongation after fracture can reach 10.3%, the flexural strength can reach 1491 MPa, and the fracture toughness can reach 47 MPa·m 1 / 2 , having high strength and high toughness, and achieving a high balance between the strength and toughness of the aluminum-based bionic composite material. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the structure of the titanium alloy skeleton reinforcing phase in Example 1 of the present invention;

[0020] Figure 2 It is a microstructural photograph of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase in Example 1 of the present invention;

[0021] Figure 3 It is a microstructural photograph of the titanium-aluminum bonding interface of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase in Example 1 of the present invention;

[0022] Figure 4 It is a room-temperature tensile engineering stress-strain curve diagram of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase in Example 1 of the present invention;

[0023] Figure 5 It is a room-temperature tensile engineering stress-strain curve diagram of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase in Example 2 of the present invention;

[0024] Figure 6This is the room-temperature tensile engineering stress-strain curve of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase in Embodiment 3 of the present invention. Detailed implementation mode

[0025] The present invention provides an aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase, including an aluminum matrix and a titanium alloy skeleton reinforcing phase; the titanium alloy skeleton reinforcing phase has a porous structure, and the porous structure is a closely arranged cylindrical through-hole; the aluminum matrix is filled in the cylindrical through-hole; the volume percentage of the titanium alloy skeleton reinforcing phase in the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase is 30-80%.

[0026] The aluminum-based bionic composite material provided by the present invention with a titanium alloy as the skeleton reinforcing phase includes an aluminum matrix.

[0027] As an implementation mode of the present invention, the aluminum matrix can be pure aluminum or aluminum alloy; the purity of the pure aluminum can be 99.99%; the aluminum alloy can be AlSi7Mg or AlSi 10 Mg. Limiting the type of the aluminum matrix within the above range in the present invention can enable the composite material to achieve better strength and toughness balance.

[0028] The aluminum-based bionic composite material provided by the present invention with a titanium alloy as the skeleton reinforcing phase includes a titanium alloy skeleton reinforcing phase; the titanium alloy skeleton reinforcing phase has a porous structure, and the porous structure is a closely arranged cylindrical through-hole.

[0029] As an implementation mode of the present invention, the aperture of the cylindrical through-hole can be 0.5-2.5 mm, can also be 1.0-2.0 mm, and can also be 1.5 mm; the distance between adjacent holes of the cylindrical through-hole is 0.5-1 mm, can also be 0.5-0.8 mm, and can also be 0.5-0.6 mm. Limiting the aperture of the cylindrical through-hole and the distance between adjacent holes within the above range in the present invention is beneficial to the filling of the aluminum matrix in the titanium alloy skeleton reinforcing phase.

[0030] As an implementation mode of the present invention, the material of the titanium alloy skeleton reinforcing phase can be Ti-6Al-4V titanium alloy. Limiting the material of the titanium alloy skeleton reinforcing phase within the above range in the present invention can ensure that the composite material has good strength, while taking into account the economy and feasibility of the material.

[0031] In the present invention, the aluminum matrix is filled in the cylindrical through-hole.

[0032] In the present invention, the volume percentage of the titanium alloy skeleton reinforcement phase in the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase is 30-80%; as an embodiment of the present invention, the volume percentage of the titanium alloy skeleton reinforcement phase in the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase can also be 50-70%, can also be 55-65%, can also be 58-65%, and can also be 63-65%. Limiting the volume percentage of the titanium alloy skeleton reinforcement phase in the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase within the above range can further ensure the strength of the composite material.

[0033] The present invention uses a titanium alloy skeleton with a porous structure as the reinforcement phase, and defines the porous structure as closely arranged cylindrical through-holes, which can optimize the strength and light weight of the composite material, disperse stress concentration, improve specific strength and specific stiffness. The columnar hole structure enhances the energy absorption capacity and impact resistance of the composite material, effectively avoids local stress concentration, and at the same time enhances the multi-directional load-bearing capacity; by filling the aluminum matrix in the porous structure, excellent toughness is provided for the composite material; by adjusting the content of the titanium alloy skeleton reinforcement phase in the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase, the strength and toughness of the composite material are further optimized.

[0034] The present invention also provides a preparation method for the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase as described in the above technical solution, including the following steps:

[0035] (1) Three-dimensional stereolithography printing of titanium alloy powder to obtain a titanium alloy skeleton;

[0036] (2) Placing metallic aluminum above the titanium alloy skeleton obtained in step (1) such that the cylindrical through-holes of the titanium alloy skeleton are in the vertical direction, and then performing vacuum non-pressure infiltration heat treatment to obtain an aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase.

[0037] The present invention performs three-dimensional stereolithography printing on titanium alloy powder to obtain a titanium alloy skeleton.

[0038] As an embodiment of the present invention, before the three-dimensional stereolithography printing, it further includes establishing a three-dimensional model of the titanium alloy skeleton reinforcement phase to be manufactured and programming a processing path program according to the three-dimensional model.

[0039] As an embodiment of the present invention, the software for establishing the three-dimensional model of the titanium alloy skeleton reinforcement phase to be manufactured can be the three-dimensional visualization software Solidworks.

[0040] As an embodiment of the present invention, the particle size of the titanium alloy powder can be 15-53 μm. Limiting the particle size of the titanium alloy powder within the above range can ensure the smooth progress of three-dimensional stereolithography printing.

[0041] As an embodiment of the present invention, the three-dimensional printing may be selective laser melting (SLM). By adopting the above three-dimensional printing technology, the titanium alloy framework can be obtained more precisely.

[0042] As an embodiment of the present invention, the laser power of the selective laser melting may be 160-180W; the scanning rate of the selective laser melting may be 1000-1200mm / s; the scanning spacing of the selective laser melting may be 0.1-0.3mm; the powder laying thickness of the selective laser melting may be 30μm; the scanning path of the selective laser melting may be 67°; the substrate preheating temperature of the selective laser melting may be 100°C; the protective gas in the forming chamber of the selective laser melting may be argon; the oxygen content in the forming chamber of the selective laser melting may be <1000ppm. Limiting the parameters of the selective laser melting within the above ranges is beneficial to precisely prepare the titanium alloy framework reinforcing phase.

[0043] After obtaining the titanium alloy framework, the present invention places metallic aluminum above the titanium alloy framework, makes the cylindrical through holes of the titanium alloy framework in the vertical direction, and then performs vacuum non-pressure infiltration heat treatment to obtain an aluminum-based bionic composite material with the titanium alloy as the framework reinforcing phase.

[0044] In the present invention, the titanium alloy framework is preferably subjected to vacuum heat treatment before use; as an embodiment of the present invention, the vacuum degree of the vacuum heat treatment may be ≤10 -3 Pa, or may also be 10 -4 ~10 -3 Pa; the temperature of the vacuum heat treatment may be 750-850°C, or may also be 800°C; the heat preservation time of the vacuum heat treatment may be 2-4h, or may also be 3h. Limiting the vacuum degree, temperature and time of the vacuum heat treatment within the above ranges can further improve the strength of the titanium alloy framework reinforcing phase.

[0045] As an embodiment of the present invention, the cooling method of the vacuum heat treatment is furnace cooling.

[0046] As an embodiment of the present invention, the aluminum matrix may be pure aluminum or aluminum alloy; the purity of the pure aluminum may be 99.99%; the aluminum alloy may be AlSi7Mg or AlSi 10 Mg. Limiting the type and purity of the aluminum matrix within the above ranges can enable the composite material to achieve better strength and toughness balance.

[0047] As an embodiment of the present invention, the operation of placing metallic aluminum above the titanium alloy framework can be carried out in a graphite mold.

[0048] As an embodiment of the present invention, the vacuum infiltration heat treatment can be carried out in a vacuum furnace; the degree of vacuum of the vacuum infiltration heat treatment can be ≤ 10 -3 Pa, or can also be 10 -4 ~10 -3 Pa; the temperature of the vacuum infiltration heat treatment can be 650 - 750 °C, or can also be 700 °C; the heat preservation time of the vacuum infiltration heat treatment can be 45 - 75 min, or can also be 60 min. Limiting the degree of vacuum, temperature and time of the vacuum infiltration heat treatment within the above ranges in the present invention can enable the aluminum matrix to infiltrate into the titanium alloy skeleton without pressure after melting, and the "solid (titanium alloy)-liquid (pure aluminum)" reaction occurs. The Ti element and the Al element diffuse into each other at the interface and form a new phase (Al3Ti), which not only promotes the formation of metallurgical bonding, but also significantly improves the bonding strength of the interface, thereby greatly enhancing the overall mechanical properties of the composite material.

[0049] As an embodiment of the present invention, the heating rate to the temperature of the vacuum infiltration heat treatment can be 5 - 10 °C / min, or can also be 5 - 8 °C / min, or can also be 5 - 6 °C / min. Limiting the heating rate to the temperature of the vacuum infiltration heat treatment within the above ranges in the present invention can enable the titanium alloy skeleton reinforcing phase and the aluminum matrix after combination to be heated evenly during the heating process.

[0050] As an embodiment of the present invention, the cooling rate of the vacuum infiltration heat treatment can be 5 - 10 °C / min, or can also be 5 - 8 °C / min, or can also be 5 - 6 °C / min. Limiting the cooling rate of the vacuum infiltration heat treatment within the above ranges in the present invention can avoid problems such as cavities generated by the solidification shrinkage of the aluminum matrix and debonding from the titanium alloy skeleton reinforcing phase during the cooling process, ensure the tight combination of the composite material, and further improve the overall performance (high strength and high toughness) of the composite material.

[0051] Next, the technical solutions in the present invention will be clearly and completely described in conjunction with the embodiments in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without making creative efforts belong to the scope of protection of the present invention.

[0052] Example 1

[0053] An aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase, which is composed of an aluminum matrix and a titanium alloy skeleton reinforcing phase; the titanium alloy skeleton reinforcing phase has a porous structure (bionic enamel columnar microstructure characteristics), and the porous structure is a cylindrically through-hole with a close-packed distribution; the aluminum matrix is filled in the cylindrically through-hole; the volume percentage of the titanium alloy skeleton reinforcing phase in the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase is 50%; the aperture of the cylindrically through-hole is 2 mm, and the distance between adjacent holes is 0.5 mm; the material of the titanium alloy skeleton reinforcing phase is Ti-6Al-4V titanium alloy; the aluminum matrix is pure aluminum; the purity of the pure aluminum is 99.99%;

[0054] The preparation method of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase:

[0055] (1) Use 3D visualization software (Solidworks) to establish a 3D model of the titanium alloy skeleton reinforcing phase to be manufactured, compile a processing path program according to the 3D model, and perform selective laser melting on the titanium alloy powder to obtain the titanium alloy skeleton reinforcing phase; the particle size of the titanium alloy powder is 15 - 53 μm; the laser power of the selective laser melting is 170 W; the scanning rate of the selective laser melting is 1100 mm / s; the scanning spacing of the selective laser melting is 0.1 mm; the powder spreading thickness of the selective laser melting is 30 μm; the scanning path of the selective laser melting is 67°; the substrate preheating temperature of the selective laser melting is 100 °C; the protective gas in the forming chamber of the selective laser melting is argon; the oxygen content in the forming chamber of the selective laser melting is < 1000 ppm;

[0056] (2) Perform vacuum heat treatment on the titanium alloy skeleton reinforcing phase obtained in step (1) (the vacuum degree of the vacuum heat treatment is 10 -3 Pa, the temperature of the vacuum heat treatment is 800 °C, and the holding time of the vacuum heat treatment is 2 h), and cool it to room temperature with the furnace after the vacuum heat treatment holding is completed; place the pure aluminum block above the titanium alloy skeleton in the graphite mold, make the cylindrically through-holes of the titanium alloy skeleton in the vertical direction, and then perform vacuum non-pressure infiltration heat treatment in a vacuum furnace (the vacuum degree of the vacuum non-pressure infiltration heat treatment is 10 -3 Pa, the temperature of the vacuum non-pressure infiltration heat treatment is 700 °C, the holding time of the vacuum non-pressure infiltration heat treatment is 60 min, and the heating rate to the temperature of the vacuum non-pressure infiltration heat treatment is 5 °C / min), and cool it to room temperature at a rate of 5 °C / min after the vacuum non-pressure infiltration heat treatment holding is completed to obtain an aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase.

[0057] The schematic structural diagram of the titanium alloy skeleton reinforcing phase in Example 1 is as Figure 1 shown, fromFigure 1 It can be seen that the structure consists of cylindrically penetrating holes densely arranged in a plane, forming a reticular titanium alloy skeleton. The volume fraction of the skeleton reinforcement phase is 50%, and the distance between adjacent holes is 0.5 mm.

[0058] The cross-section of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase in Example 1 was observed for its microstructure using a scanning electron microscope. The obtained microstructure photograph is as Figure 2 shown, where the light-colored area is the titanium alloy skeleton reinforcement phase, and the dark-colored area is the pure aluminum matrix. From Figure 2 it can be seen that no obvious defects were observed in the comparison area, which proves that vacuum infiltration without pressure can prepare dense aluminum-based bionic composite materials.

[0059] The titanium-aluminum bonding interface of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase in Example 1 was observed for its microstructure using a scanning electron microscope. The obtained microstructure photograph is as Figure 3 shown, where the light-colored area is the titanium alloy skeleton reinforcement phase, and the dark-colored area is the pure aluminum matrix. From Figure 3 it can be seen that the microstructure presents a typical two-phase configuration. There are unmolten Ti-6Al-4V spherical powder particles at the interface, effectively increasing the solid-liquid contact specific surface area during the vacuum infiltration without pressure process, and realizing mechanical interlock strengthening through the capillary seepage of molten aluminum. In addition, the titanium-aluminum interface bonding is dense, the bonding surface is complete without macroscopic defects (such as cracks, pores, etc.), and a continuously distributed Al3Ti intermetallic compound reaction layer (with a thickness of 5 μm) is formed in the local area, confirming that a stable metallurgical bond is formed between the titanium alloy skeleton and the infiltrated aluminum through the interface element diffusion mechanism.

[0060] The aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase obtained in Example 1 was tested for its tensile strength, elongation after fracture, flexural strength, and fracture toughness using an electronic universal testing machine. The obtained room-temperature tensile engineering stress-strain curve is as Figure 4 shown. From Figure 4 it can be obtained that the tensile strength of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase is 631 MPa, and the elongation after fracture is 5.8%.

[0061] The flexural strength of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcement phase in Example 1 is 1032 MPa, and the fracture toughness is 32 MPa·m 1 / 2 .

[0062] Example 2

[0063] Example 2 is different from Example 1 only in that, by volume percentage, the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase is composed of 58% of the titanium alloy skeleton reinforcing phase and the balance of pure aluminum, and the others are the same as in Example 1.

[0064] An electronic universal testing machine was used to test the tensile strength, elongation after fracture, flexural strength, and fracture toughness of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase obtained in Example 2. The obtained room-temperature tensile engineering stress-strain curve is as Figure 5 shown. From Figure 5 it can be obtained that the tensile strength of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase is 671 MPa, and the elongation after fracture is 7.4%.

[0065] The flexural strength of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase in Example 2 is 1140 MPa, and the fracture toughness is 38 MPa·m 1 / 2 .

[0066] Example 3

[0067] Example 3 is different from Example 1 only in that, by volume percentage, the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase is composed of 65% of the titanium alloy skeleton reinforcing phase and the balance of pure aluminum, and the others are the same as in Example 1.

[0068] An electronic universal testing machine was used to test the tensile strength, elongation after fracture, flexural strength, and fracture toughness of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase obtained in Example 3. The obtained room-temperature tensile engineering stress-strain curve is as Figure 6 shown. From Figure 6 it can be obtained that the tensile strength of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase is 811 MPa, and the elongation after fracture is 10.3%.

[0069] The flexural strength of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase in Example 3 is 1491 MPa, and the fracture toughness is 47 MPa·m 1 / 2 .

[0070] Comparative Example 1

[0071] A 7075 aluminum alloy, by mass percentage, is composed of the following elements: 5.5% Zn, 2.5% Mg, 2.0% Cu, ≤0.28% Cr, and the balance of Al;

[0072] An electronic universal testing machine was used to test the tensile strength, elongation after fracture, flexural strength, and fracture toughness of the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase obtained in Comparative Example 1.

[0073] The tensile strength of the 7075 aluminum alloy in Comparative Example 1 was 600 MPa, the elongation after fracture was 10%, the bending strength was 500 MPa, and the fracture toughness was 30 MPa·m 1 / 2 。

[0074] Comparative Example 2

[0075] A preparation method of a titanium alloy lattice structure toughened nanostructured aluminum alloy material (Example 1 in Chinese Patent, Application No. 202210249202.4). The raw materials required for preparing the titanium alloy lattice structure toughened nanostructured aluminum alloy composite material are: Ti-6Al-4V titanium alloy powder with a particle size distribution of 15-53 μm, pure copper, and Al 84 Ni7Gd6Co3 (at.%) amorphous alloy powder, specifically including the following steps:

[0076] (1) Use the three-dimensional modeling software UG to design the honeycomb structure Ti-6Al-4V titanium alloy lattice, establish the three-dimensional model of the lattice, and use the EOSINT M280 metal 3D printer to print the Ti-6Al-4V titanium alloy lattice structure. The size of this framework is Ф14×20 mm, the porosity is 32%, and the wall thickness inside the lattice is 1 mm;

[0077] (2) Put the Ti-6Al-4V titanium alloy framework printed in step (1) into a vacuum heat treatment furnace, keep it at 800 °C for 2 hours, and then cool it with the furnace;

[0078] (3) Carry out abrasive flow machining on the Ti-6Al-4V titanium alloy framework model obtained in step (2). The abrasive used for abrasive flow is silicon carbide, the abrasive flow pressure is 100 Kg, and the abrasive flow time is 10 h to remove the residual powder attached to the surface of the lattice material;

[0079] (4) Place the three-dimensional Ti-6Al-4V titanium alloy framework obtained in step (3) into a pure copper sleeve, inject the Al 84 Ni7Gd6Co3 (at.%) amorphous alloy powder into the titanium alloy lattice structure in the sleeve and then seal the sleeve. Place the sleeve on an ultrasonic plus mechanical vibrator for compaction, and finally carry out cold pressing forming treatment on the Ti-6Al-4V titanium alloy framework / aluminum alloy powder composite material. The pressure is 700 MPa and the pressure holding time is 3 min; the volume fraction of Ti-6Al-4V titanium alloy is 68%, and the volume fraction of amorphous alloy powder is 32%;

[0080] (5) The cold-pressed Ti-6Al-4V titanium alloy lattice structure / Al after step (4) 84The Ni7Gd6Co3 (at.%) amorphous alloy powder composite material is preheated to 500 °C in a resistance furnace and then placed in a hot extrusion equipment for extrusion molding; the mold in the hot extrusion equipment is preheated to 450 °C, the extrusion pressure is about 700 MPa, the extrusion speed is 2.7 mm / s, the extrusion ratio is 4:1, and the lubricant is graphite powder. After hot extrusion is completed, the bar stock is intercepted and shaped to obtain a titanium alloy lattice structure toughened nanostructured aluminum alloy material.

[0081] The tensile strength of the titanium alloy lattice structure toughened nanostructured aluminum alloy material prepared in Comparative Example 2 is 917 MPa, and the elongation after fracture is 5%.

[0082] From the data measured in Examples 1 to 3 and Comparative Examples 1 to 2, it can be seen that the aluminum-based bionic composite material with a titanium alloy as the skeleton reinforcing phase provided by the present invention has excellent comprehensive mechanical properties (high strength and high toughness). Its tensile strength can reach 811 MPa, the elongation after fracture can reach 10.3%, the bending strength can reach 1491 MPa, and the fracture toughness can reach 47 MPa·m 1 / 2 ; while achieving high strength, this aluminum-based bionic composite material also has relatively high toughness, breaking through the limitation that it is difficult to balance strength and toughness in traditional metal materials, thereby realizing the comprehensive optimization of mechanical properties.

[0083] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can still be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. An aluminum-based bionic composite material with a titanium alloy as a skeleton reinforcement phase, comprising an aluminum matrix and a titanium alloy skeleton reinforcement phase; the titanium alloy skeleton reinforcement phase has a porous structure, and the porous structure is a closely packed cylindrical through-hole; the aluminum matrix is ​​filled in the cylindrical through-holes; the volume percentage of the titanium alloy skeleton reinforcement phase in the aluminum-based bionic composite material with a titanium alloy as a skeleton reinforcement phase is 30 to 80%.

2. The aluminum-based bionic composite material with titanium alloy as the skeleton reinforcement phase according to claim 1, characterized in that: The diameter of the cylindrical through hole is 0.5-2.5 mm, and the distance between adjacent holes is 0.5-1 mm.

3. The aluminum-based bionic composite material with titanium alloy as the skeleton reinforcement phase according to claim 1, characterized in that: The material of the titanium alloy skeleton reinforcement phase is Ti-6Al-4V titanium alloy.

4. The method for preparing the aluminum-based bionic composite material with titanium alloy as the skeleton reinforcement phase according to any one of claims 1 to 3 comprises the following steps: (1) performing three-dimensional printing on titanium alloy powder to obtain a titanium alloy skeleton; (2) placing metallic aluminum on top of the titanium alloy skeleton obtained in step (1) so that the cylindrical through holes of the titanium alloy skeleton are in a vertical direction, and then performing vacuum pressureless infiltration heat treatment to obtain an aluminum-based bionic composite material with the titanium alloy as the skeleton reinforcement phase.

5. The preparation method according to claim 4, characterized in that: The particle size of the titanium alloy powder in step (1) is 15 to 53 μm.

6. The preparation method according to claim 4, characterized in that: In the step (2), the titanium alloy skeleton is subjected to vacuum heat treatment before use.

7. The preparation method according to claim 6, characterized in that: The vacuum degree of the vacuum heat treatment is ≤10 -3 Pa, the temperature of vacuum heat treatment is 750-850℃, and the holding time of vacuum heat treatment is 2-4h.

8. The preparation method according to claim 4, characterized in that: The vacuum degree of the vacuum pressureless infiltration heat treatment in step (2) is ≤10 -3 Pa, the temperature of vacuum pressureless infiltration heat treatment is 680-720°C, and the holding time of vacuum pressureless infiltration heat treatment is 45-75min.

9. The preparation method according to claim 4 or 8, characterized in that: The rate of heating to the vacuum pressureless infiltration heat treatment temperature is 5-10°C / min.

10. The preparation method according to claim 4 or 8, characterized in that: The cooling rate of the vacuum pressureless infiltration heat treatment is 5-10°C / min.

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