Titanium-magnesium composite material, method for preparing the same and use thereof

Abstract

This invention discloses a titanium-magnesium composite material, its preparation method, and its applications, relating to the field of metal composite materials technology. It includes a titanium base layer, a magnesium base layer, and an aluminum connecting layer located between the titanium and magnesium base layers. By setting an aluminum connecting layer between the titanium and magnesium base layers, aluminum exhibits good metallurgical compatibility with both titanium and magnesium, enabling sufficient atomic diffusion and interfacial reactions to occur during hot rolling. This forms a stable metallurgical bonding interface between titanium and magnesium, effectively solving the problem of direct titanium-magnesium composite material composition and obtaining a titanium-magnesium composite material that combines lightweight and high strength.

Description

Technical Field

[0001] This invention relates to the field of metal composite materials technology, and more specifically, to a titanium-magnesium composite material, its preparation method, and its application. Background Technology

[0002] In the relentless pursuit of "lighter and stronger" for 3C consumer electronics components, automotive parts, and aerospace equipment, balancing lightweighting and high strength has become a core design challenge. Since single materials are insufficient to simultaneously meet both requirements, industry trends are shifting towards systems engineering that synergistically optimizes composite materials and structural design. To further push performance boundaries, composite materials prepared by combining low-density magnesium alloys with high-strength titanium alloys hold promise as a key pathway to achieving a balance between lightweighting and mechanical properties.

[0003] However, since titanium and magnesium are thermodynamically incompatible, their solid solubility is extremely low, and they cannot form an effective interfacial bond through conventional thermal composite processes. As a result, the interfacial bond strength of composite materials is generally low, making it difficult to meet the application requirements.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a titanium-magnesium composite material, its preparation method, and its application.

[0006] This invention is implemented as follows: In a first aspect, the present invention provides a titanium-magnesium composite material, comprising a titanium base layer, a magnesium base layer, and an aluminum connecting layer located between the titanium base layer and the magnesium base layer.

[0007] In a second aspect, the present invention provides a method for preparing a titanium-magnesium composite material as described in any of the foregoing embodiments, comprising: roughening the surfaces of a titanium alloy, a magnesium alloy, and an aluminum alloy; sequentially stacking and fixing the titanium alloy, aluminum alloy, and magnesium alloy in that order to obtain an alloy billet; asynchronously hot rolling the alloy billet to obtain an alloy rolled piece; and heat-treating the alloy rolled piece.

[0008] Thirdly, the present invention provides the application of a titanium-magnesium composite material as described in any of the foregoing embodiments or a titanium-magnesium composite material prepared by any of the foregoing embodiments in 3C consumer electronics components, automotive parts or aerospace equipment.

[0009] The present invention has the following beneficial effects: This invention provides a titanium-magnesium composite material, its preparation method, and its application. By setting an aluminum connecting layer between the titanium base layer and the magnesium base layer, aluminum has good metallurgical compatibility with both titanium and magnesium. It can undergo sufficient atomic diffusion and interfacial reaction during hot rolling, thereby forming a stable metallurgical bonding interface between titanium and magnesium. This effectively solves the problem of direct titanium-magnesium composite material and obtains a titanium-magnesium composite material that is both lightweight and high-strength. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the structure of the titanium-magnesium composite material provided in an embodiment of the present invention; Figure 2 for Figure 1 Enlarged cross-sectional view of the middle structure; Figure 3 This is a physical image of the titanium-magnesium composite material provided in Embodiment 1 of the present invention; Figure 4 This is a CCD magnified view of the interlayer connection region of the titanium-magnesium composite material provided in Embodiment 1 of the present invention; Figure 5 A scanning electron microscope image of the interface between the aluminum connecting layer and the magnesium base layer of the titanium-magnesium composite material provided in Embodiment 1 of the present invention; Figure 6 A scanning electron microscope image of the interface between the aluminum connecting layer and the titanium base layer of the titanium-magnesium composite material provided in Embodiment 1 of the present invention; Figure 7 A physical image of the titanium-magnesium composite material provided in Comparative Example 1 of this invention; Figure 8 This is a physical image of the titanium-magnesium composite material provided in Comparative Example 2 of the present invention; Figure 9 This is an enlarged view of the physical structure of the titanium-magnesium composite material provided in Comparative Example 2 of the present invention; Figure 10 This is a physical image of the titanium-magnesium composite material provided in Comparative Example 3 of the present invention; Figure 11 This is an enlarged view of the crack location of the titanium-magnesium composite material provided in Comparative Example 3 of the present invention. Figure 1 ; Figure 12 This is an enlarged view of the crack location of the titanium-magnesium composite material provided in Comparative Example 3 of the present invention. Figure 2 ; Figure 13 This is a CCD magnified image of the titanium-magnesium composite material provided in Comparative Example 4 of the present invention.

[0012] Explanation of key component symbols: 100-Titanium-magnesium composite material; 110-Titanium base layer; 120-Magnesium base layer; 130-Aluminum connecting layer. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0014] Titanium alloys possess high strength, while magnesium alloys have relatively low density. Titanium-magnesium composites, obtained by combining the two, offer the advantages of both high strength and lightweight. However, the maximum solid solubility of titanium in magnesium is only 0.00043 at%, and both have positive enthalpies of formation, meaning that titanium and magnesium are thermodynamically incompatible and do not spontaneously mix to form stable compounds, thus failing to achieve effective metallurgical bonding. Furthermore, when titanium and magnesium are composited using traditional hot rolling processes, the significant differences in their physical properties result in magnesium shrinking much more than titanium during the cooling process after rolling. This uneven shrinkage generates substantial residual thermal stress at the interface, leading to warping of the composite material and even microcracks at the interface. In severe cases, the composite material may even delaminate and crack directly during cooling. Therefore, the inventors propose the following solution.

[0015] In a first aspect, the present invention provides a titanium-magnesium composite material 100, the structure of which is as follows: Figure 1 and Figure 2 As shown, it includes a titanium substrate 110, a magnesium substrate 120, and an aluminum connecting layer 130 located between the titanium substrate 110 and the magnesium substrate 120.

[0016] By setting an aluminum connecting layer 130 between the titanium base layer 110 and the magnesium base layer 120, aluminum has good metallurgical compatibility with both titanium and magnesium, and can undergo sufficient atomic diffusion and interfacial reaction during hot rolling, thereby forming a stable metallurgical bonding interface between titanium and magnesium, effectively solving the problem of direct titanium-magnesium composite.

[0017] In an optional embodiment, the thickness ratio of the titanium base layer 110, the aluminum connecting layer 130, and the magnesium base layer 120 is (200~600):(2~10):(200~600). Since the aluminum connecting layer 130 has a very small thickness, it serves only as a functional transition layer between the titanium base layer 110 and the magnesium base layer 120, and does not function as the main load-bearing structure. At this thickness ratio, the aluminum connecting layer 130 can coordinate the enormous residual stress generated by the deformation of the titanium and magnesium, and effectively connect the titanium base layer 110 and the magnesium base layer 120; if this thickness ratio is exceeded, the aluminum connecting layer 130 loses its coordinating and connecting function.

[0018] The reason is that the plasticity of the aluminum connecting layer 130 is sacrificed: within the thickness ratio range provided by this invention, during rolling, the aluminum connecting layer 130 absorbs and releases the stress generated by the expansion between titanium and magnesium through its own plastic deformation, avoiding the direct accumulation of stress at the titanium-magnesium composite interface. When the thickness of the aluminum connecting layer 130 exceeds the upper limit of this thickness ratio range, the effective stiffness of the aluminum connecting layer 130 increases, and the hardness increases, resulting in the loss of its buffering effect; when the thickness of the aluminum connecting layer 130 exceeds the lower limit of this thickness ratio range, there is not enough volume to absorb the strain difference between titanium and magnesium, and it is quickly pulled apart, failing to achieve plastic coordination.

[0019] Furthermore, by controlling the thickness ratio of the three layers of titanium, magnesium, and aluminum, it is possible to avoid the adverse effects of aluminum on the lightweight and high-strength properties of the titanium-magnesium composite material 100 while ensuring the stable composite of titanium and magnesium, thus obtaining a titanium-magnesium composite material 100 that combines lightweight and high strength.

[0020] In an optional embodiment, the titanium base layer 110 is made of at least one of TA4 titanium alloy and TC4 titanium alloy, providing high strength to the titanium-magnesium composite material 100.

[0021] Preferably, the magnesium base layer 120 is made of wrought magnesium alloy, including at least one of AZ31 magnesium alloy and ZK61 magnesium alloy, providing a material basis for the lightweighting of the titanium-magnesium composite material 100.

[0022] Preferably, the aluminum connecting layer 130 is made of wrought aluminum alloy, including at least one of 1050 aluminum alloy, 1060B aluminum alloy, and 1070 aluminum alloy. By selecting the above-mentioned types of aluminum alloys, which have a certain plastic deformation capacity, it can buffer the thermal residual stress caused by the difference in thermal expansion coefficients between titanium alloy and magnesium alloy to a certain extent, significantly reducing the risk of warping and cracking of composite materials during cooling, and improving interface stability and product yield.

[0023] In an optional embodiment, the titanium base layer 110 is made of TC4 titanium alloy; the aluminum connecting layer 130 is made of 1060 aluminum alloy; and the magnesium base layer 120 is made of AZ31 magnesium alloy. By laminating the above alloys, the strength of the titanium-magnesium composite material 100 can be significantly improved.

[0024] Among them, TC4 titanium alloy, as an α+β dual-phase titanium alloy, has a high specific strength and can achieve a high-strength connection with aluminum; AZ31 magnesium alloy contains 2~4% aluminum, has good metallurgical compatibility with aluminum alloys, and has good deformation capacity; 1060 aluminum alloy is one of the softest alloys among all aluminum alloys, and its hardness and deformation capacity can better play the role of the intermediate connecting layer, thereby ensuring the stable bonding of the titanium base layer 110 and the magnesium base layer 120.

[0025] In an optional embodiment, the thickness of the intermetallic compound layer at the interface between the aluminum connecting layer 130 and the magnesium base layer 120 is ≤2 μm. The transition zone, mainly composed of aluminum-based compounds with good toughness, achieves metallurgical bonding while avoiding the risk of brittle fracture, thereby ensuring that the interfacial bonding strength between the aluminum connecting layer 130 and the magnesium base layer 120 is ≥85MPa.

[0026] In an optional embodiment, the thickness of the intermetallic compound layer at the interface between the aluminum connecting layer 130 and the magnesium base layer 120 is ≤1 μm, which further effectively avoids the adverse effects of brittleness on the interface performance.

[0027] Preferably, the thickness of the intermetallic compound layer at the interface between the titanium base layer 110 and the aluminum connecting layer 130 is ≤2 μm. The transition zone, mainly composed of aluminum-based compounds with good toughness, achieves metallurgical bonding while avoiding the risk of brittle fracture.

[0028] In an optional embodiment, the thickness of the intermetallic compound layer at the interface between the titanium substrate 110 and the aluminum connecting layer 130 is ≤1 μm, which further effectively avoids the adverse effects of brittleness on the interface performance.

[0029] Preferably, the density of the titanium-magnesium composite material 100 is 2.6~3.1 g / cm³. 3 The density of the titanium-magnesium composite material 100 can be adjusted by regulating the thickness of the titanium base layer 110 and the magnesium base layer 120.

[0030] In a second aspect, the present invention provides a method for preparing a titanium-magnesium composite material 100 as described in any of the foregoing embodiments, comprising: roughening the surfaces of a titanium alloy, a magnesium alloy, and an aluminum alloy; sequentially stacking and fixing the titanium alloy, aluminum alloy, and magnesium alloy in that order to obtain an alloy billet; asynchronously hot rolling the alloy billet to obtain an alloy rolled piece; and heat treating the alloy rolled piece.

[0031] This invention, by employing asynchronous hot rolling and introducing shear stress, can more effectively break the oxide film on the alloy surface, promote fresh metal contact, achieve better interfacial bonding at the same temperature, and simultaneously inhibit the continuous growth of brittle intermetallic compounds. Furthermore, asynchronous hot rolling can also be used to control the differences in the physical properties of titanium and magnesium, preventing defects such as cracking and warping in the titanium-magnesium composite material 100.

[0032] In an optional implementation, during asynchronous hot rolling, the roll in contact with the titanium alloy surface is the first roll, and the roll in contact with the magnesium alloy surface is the second roll, with the speed of the first roll being greater than the speed of the second roll.

[0033] Preferably, the speed of the first roll is 3.5~4.5 m / min; the speed of the second roll is 2.5~3.5 m / min.

[0034] By employing asynchronous hot rolling, the speed difference between the first and second rolls introduces shear stress during the rolling process. This effectively breaks down the oxide film on the alloy surface, promotes fresh metal contact and atomic diffusion, and significantly reduces the energy barrier of the metallurgical reaction. Consequently, the rolling temperature can be lowered, enabling metallurgical bonding to be achieved in a shorter time and at a lower temperature. Simultaneously, the low-temperature, short-time process window achieved by asynchronous hot rolling can significantly limit the continuous growth of brittle intermetallic compounds.

[0035] In an optional embodiment, the preheating temperature of asynchronous hot rolling is 300~500℃, and the preheating time is 8~12min; the preheating atmosphere is an inert atmosphere, which includes either argon or helium, or other gases that do not react with the matrix; the gas flow rate of the preheating atmosphere is 5~10m³ / h. 3 / h.

[0036] Preferably, the reduction in asynchronous hot rolling is 45-55%.

[0037] By controlling asynchronous rolling and reducing the rolling temperature and high-temperature time of the alloy rolls, the thickness of the intermetallic compound (IMCs) layer at any interface of the titanium-magnesium composite material 100 can be effectively controlled to ≤2 μm, effectively avoiding the adverse effects of brittleness on the interfacial properties. Furthermore, the aluminum layer is continuous between the titanium and magnesium interfaces, with no missing or broken aluminum layers, and the material is free of cracks or pores.

[0038] In an optional embodiment, the thickness of the aluminum bonding layer 130 is 0.1~0.5 mm before rolling and 0.02~0.06 mm after rolling. Controlling the thickness of the aluminum bonding layer 130 within the above range can effectively limit the total amount of aluminum diffusion in the interfacial reaction, avoid excessive formation of brittle intermetallic compounds, and ensure the quality of interfacial bonding.

[0039] In an optional embodiment, the heat treatment includes annealing at a temperature of 200-250°C for a time of 0.5-1.5 hours.

[0040] In an optional embodiment, the surface roughness Ra of the titanium alloy after roughening treatment satisfies: Ra max Ra is 6.0~6.5. min It is 3.0~3.5.

[0041] Preferably, the surface roughness Ra of the magnesium alloy after roughening treatment satisfies: Ra max Ra is 6.0~6.5. min It is 3.0~3.5.

[0042] Preferably, the surface roughness Ra of the aluminum alloy after roughening treatment is... min It is 3.0~3.5.

[0043] Thirdly, the present invention provides the application of a titanium-magnesium composite material 100 as described in any of the foregoing embodiments or a titanium-magnesium composite material 100 prepared by any of the foregoing embodiments in automotive parts or aerospace equipment.

[0044] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0045] Example 1 This embodiment provides a titanium-magnesium composite material 100, the preparation method of which is as follows: S01. Raw material preparation: TC4 titanium alloy, dimensions 400×7.0×4 mm; 1060 aluminum foil: dimensions are 400×7.5×0.1 mm; AZ31 magnesium alloy: dimensions are 400×7.5×8 mm.

[0046] S02, Surface texturing: TC4 titanium alloy was used to roughen the surface of a composite with 1060 aluminum foil. The roughness Ra after roughening satisfied: Ra max Ra is 6.3. min It is 3.2.

[0047] 1060 aluminum foil was used to roughen the surface of composites with TC4 titanium alloy and AZ31 magnesium alloy. The roughness Ra after roughening was... min It is 3.2.

[0048] AZ31 magnesium alloy was used to roughen the surface of a composite with 1060 aluminum foil. The roughened surface roughness Ra satisfies: Ra max Ra is 6.3. min It is 3.2.

[0049] After the above raw materials are roughened, they are cleaned by ultrasonic cleaning equipment. The surface is dried immediately after cleaning to ensure that the surface is dry and free of contamination.

[0050] S03, Billet Assembly: The TC4 titanium alloy, 1060 aluminum foil, and AZ31 magnesium alloy, which were roughened in step S02, were stacked in a titanium-aluminum-magnesium sandwich structure, and the three layers of materials were fixed with rivets to obtain an alloy billet.

[0051] S04, Asynchronous Hot Rolling: The alloy billet obtained in step S03 was preheated in a tunnel furnace at 400℃ for 10 minutes, with argon as the protective gas at a flow rate of 10 m³ / s. 3 / h.

[0052] Before rolling, start the rolling mill in advance and apply rolling oil evenly to the rolls. Set the speed of the first roll to 4 m / min and the speed of the second roll to 3 m / min.

[0053] After preheating, the alloy billet is taken out of the tunnel furnace and sent to the rolling mill. The titanium alloy side of the alloy billet is close to the first roll, and the magnesium alloy side is close to the second roll. Rolling is carried out with a rolling reduction of 50% to obtain the alloy rolled product.

[0054] Because titanium alloys have high strength and are not easily deformed during hot rolling, the reduction in asynchronous hot rolling has little effect on the thickness of titanium alloys. It is mainly used to reduce the thickness of softer aluminum and magnesium alloys.

[0055] S05, Annealing The alloy rolled piece obtained in step S04 was annealed in a vacuum annealing furnace at a temperature of 220°C for 1 hour.

[0056] S06, CNC: After annealing, the titanium-magnesium composite material 100 is machined using a computer numerical control (CNC) machine tool to remove the material edges, thus obtaining the titanium-magnesium composite material 100. Figure 3 As shown.

[0057] The titanium-magnesium composite material 100 provided in this embodiment is composed of a titanium base layer 110, an aluminum connecting layer 130 and a magnesium base layer 120 stacked sequentially, and the thickness ratio of the titanium base layer 110, the aluminum connecting layer 130 and the magnesium base layer 120 is 400:2:400.

[0058] In the titanium-magnesium composite material 100 provided in this embodiment, the aluminum connecting layer 130 is as follows: Figure 4 The narrow strip area within the middle frame is composed of Figures 4-6It can be observed that the titanium-magnesium composite material 100 provided in this embodiment has good metallurgical bonding between each layer, and there are no defects such as cracking or aluminum leakage.

[0059] Example 2 This embodiment provides a titanium-magnesium composite material 100, the preparation method of which is as follows: S01. Raw material preparation: TC4 titanium alloy, dimensions 400×7.0×2 mm; 1060 aluminum foil: dimensions are 400×7.5×0.2 mm; AZ31 magnesium alloy: dimensions are 400×7.5×8 mm.

[0060] S02, Surface texturing: TC4 titanium alloy was used to roughen the surface of a composite with 1060 aluminum foil. The roughness Ra after roughening satisfied: Ra max Ra is 6.3. min It is 3.2.

[0061] 1060 aluminum foil was used to roughen the surface of composites with TC4 titanium alloy and AZ31 magnesium alloy. The roughness Ra after roughening was... min It is 3.2.

[0062] AZ31 magnesium alloy was used to roughen the surface of a composite with 1060 aluminum foil. The roughened surface roughness Ra satisfies: Ra max Ra is 6.3. min It is 3.2.

[0063] After the above raw materials are roughened, they are cleaned by ultrasonic cleaning equipment. The surface is dried immediately after cleaning to ensure that the surface is dry and free of contamination.

[0064] S03, Billet Assembly: The TC4 titanium alloy, 1060 aluminum foil, and AZ31 magnesium alloy, which were roughened in step S02, were stacked in a titanium-aluminum-magnesium sandwich structure, and the three layers of materials were fixed with rivets to obtain an alloy billet.

[0065] S04, Asynchronous Hot Rolling: The alloy billet obtained in step S03 was preheated in a tunnel furnace at 400℃ for 10 minutes, with argon as the protective gas at a flow rate of 10 m³ / s. 3 / h.

[0066] Before rolling, start the rolling mill in advance and apply rolling oil evenly to the rolls. Set the speed of the first roll to 4.2 m / min and the speed of the second roll to 3 m / min.

[0067] After preheating, the alloy billet is taken out of the tunnel furnace and fed into the rolling mill. The titanium alloy side of the alloy billet is close to the first roll, and the magnesium alloy side is close to the second roll. Rolling is carried out with a rolling reduction of 48% to obtain the alloy rolled product.

[0068] Because titanium alloys have high strength and are not easily deformed during hot rolling, the reduction in asynchronous hot rolling has little effect on the thickness of titanium alloys. It is mainly used to reduce the thickness of softer aluminum and magnesium alloys.

[0069] S05, Annealing The alloy rolled piece obtained in step S04 was annealed in a vacuum annealing furnace at a temperature of 180°C for 0.5 hours.

[0070] S06, CNC: After annealing, the titanium-magnesium composite material 100 is processed by computer numerical control (CNC) machine tool to remove the material edge to obtain titanium-magnesium composite material 100.

[0071] The titanium-magnesium composite material 100 provided in this embodiment is composed of a titanium base layer 110, an aluminum connecting layer 130 and a magnesium base layer 120 stacked sequentially, and the thickness ratio of the titanium base layer 110, the aluminum connecting layer 130 and the magnesium base layer 120 is 200:2:417.

[0072] Comparative Example 1 This comparative example provides a titanium-magnesium composite material 100, which is prepared in the same way as in Example 1, except that in step S01, the size of the 1060 aluminum foil is 400×7.5×1.0 mm.

[0073] In this comparative example, the increased thickness of the 1060 aluminum foil prevented the interfaces between the titanium alloy, aluminum alloy, and magnesium alloy from bonding. After peeling off the individual layers of the titanium alloy, aluminum alloy, and magnesium alloy, the following results were obtained: Figure 7 The structure shown. (By) Figure 7 It can be seen that the aluminum alloy is severely deformed and there are no traces of metallurgical composite on the surface. There are also no traces of metallurgical composite at the interface of the titanium alloy and magnesium alloy. This indicates that increasing the thickness of the aluminum foil will increase the difficulty of interfacial composite between the titanium alloy, aluminum alloy and magnesium alloy.

[0074] Comparative Example 2 This comparative example provides a titanium-magnesium composite material 100, the preparation method of which is similar to that of Example 1, except that in step S01, the aluminum foil grade is changed to 5A06 aluminum alloy and the thickness is 0.2 mm.

[0075] Depend on Figure 8 and Figure 9 It can be seen that, due to the change of alloy grade, the interfaces between titanium alloy, aluminum alloy and magnesium alloy in this comparative example are difficult to bond.

[0076] Comparative Example 3 This comparative example provides a titanium-magnesium composite material 100, the preparation method of which is similar to that of Example 1, except that the synchronous rolling is used in step S04. The synchronous rolling process is as follows: S04, Synchronous Hot Rolling: The alloy billet obtained in step S03 was preheated in a tunnel furnace at 400°C for 10 minutes, with argon as the protective gas at a flow rate of 6 m³ / s. 3 / h.

[0077] Before rolling, start the rolling mill in advance and apply rolling oil evenly to the rolls. Set the speed of the first roll to 3m / min and the speed of the second roll to 3m / min.

[0078] After preheating, the alloy billet is taken out of the tunnel furnace and sent to the rolling mill. The titanium alloy side of the alloy billet is close to the first roll, and the magnesium alloy side is close to the second roll. Rolling is carried out with a rolling reduction of 50% to obtain the alloy rolled product.

[0079] The titanium-magnesium composite material 100 provided in this comparative example was composited using a synchronous hot rolling method. Due to the extremely small deformation of titanium alloys compared to the 50% deformation of magnesium alloys, the flow rates of the titanium and magnesium metals were inconsistent, resulting in poor composite performance and severe cracking of the magnesium matrix. Figures 10-12 As shown.

[0080] Comparative Example 4 This comparative example provides a titanium-magnesium composite material 100, the preparation method of which is similar to that of Example 1, except that the preheating temperature in step S04 is changed to 520℃.

[0081] Depend on Figure 13 It can be seen that in this comparative example, the increased preheating temperature caused the aluminum-magnesium interface to react rapidly, resulting in cracking of the aluminum-magnesium interface after rolling and poor composite effect.

[0082] Experimental Example 1 The performance of the titanium-magnesium composite materials 100 provided in Examples 1-2 and Comparative Examples 1-4 was tested, and the results are shown in Table 1.

[0083] In Table 1, the test methods for each parameter are in accordance with GB / T 6396-2008.

[0084] Table 1. Properties of Titanium-Magnesium Composite Material 100

[0085] Note: " / " in Table 1 indicates that the data cannot be measured. The reason why the bonding strength of the magnesium-aluminum interface, the thickness of the IMCs layer at the titanium-aluminum interface, and the thickness of the IMCs layer at the magnesium-aluminum interface cannot be measured is that the interface is not composite; the reason why the density cannot be measured is that a complete titanium-magnesium composite material 100 has not been formed, and the measured density value is not meaningful for comparison.

[0086] As shown in Table 1, the titanium-magnesium composite material 100 provided in this embodiment of the invention has an interfacial bonding strength ≥85 MPa, preferably 85~110 MPa, while having a low density, achieving the goal of high strength and lightweight titanium-magnesium composite material 100. Furthermore, the surface of this titanium-magnesium composite material 100 has no obvious cracks or microcracks. Red ink penetration testing showed no ink penetration in any of the tested areas, indicating a dense interfacial bond without penetrating defects. Moreover, this titanium-magnesium composite material 100 has good processing adaptability; after subsequent processing (such as bending, CNC machining, wire cutting, etc.), there is no delamination at the interface and no cracks in the matrix.

[0087] In Comparative Example 1, the greater thickness of the aluminum alloy resulted in an increase in the absolute stiffness of the aluminum layer and a decrease in its ability to coordinate deformation, causing the aluminum layer to lose its function and resulting in a poor composite effect.

[0088] In Comparative Example 2, the use of 5-series aluminum alloy increased the absolute stiffness of the aluminum layer, reduced its ability to coordinate deformation, and caused the aluminum layer to lose its function, resulting in a poor composite effect.

[0089] Comparative Example 3 uses a synchronous hot rolling process, but during the composite process, the inconsistent metal deformation leads to a large difference in metal flow rate. Magnesium metal's plasticity does not support excessively fast flow rates, causing magnesium to crack and making effective composite impossible.

[0090] In Comparative Example 4, increasing the preheating temperature during rolling caused excessive reaction at the aluminum-magnesium interface, resulting in excessively thick IMCs. Excessively thick IMCs can lead to brittle composite interfaces that are prone to cracking.

[0091] The titanium-magnesium composite material 100, its preparation method, and its application provided in this invention have at least the following advantages: 1. By asynchronous rolling and selecting a suitable aluminum alloy as the intermediate connecting structure between titanium and magnesium alloys, aluminum and titanium can form limited solid solutions and intermetallic compounds such as TiAl3. However, through asynchronous rolling, the thickness of the reaction layer between aluminum alloy and titanium alloy can be controlled within a thin layer range of ≤2 μm, thus avoiding the formation of continuous brittle phases.

[0092] In addition, aluminum and magnesium can form Mg 17 Al 12 The main intermetallic compound is aluminum alloy, but by controlling the thickness of the aluminum alloy and introducing shear deformation through asynchronous rolling process, the intermetallic compound is dispersed. The thickness of the reaction layer between the aluminum alloy and magnesium alloy is controlled within the range of ≤2 μm, and a continuous coarse brittle layer is not formed.

[0093] The final titanium-magnesium composite material 100 has an optimized interfacial structure consisting of an intermediate transition zone dominated by aluminum-based compounds with good toughness, which achieves metallurgical bonding while avoiding the risk of brittle fracture.

[0094] 2. The coefficients of linear expansion of the three metals, titanium, aluminum, and magnesium, differ significantly (titanium ≈ 8.6 × 10⁻⁶). -6 / K, Aluminum ≈ 23.6 × 10 -6 / K, magnesium ≈ 26.1 × 10 -6 / K). If titanium and magnesium are directly combined, the difference in their coefficients of linear expansion will cause the resulting composite material to have mismatched thermal shrinkage during cooling, resulting in huge residual tensile stress at the joint interface, leading to warping or even cracking.

[0095] This invention introduces an aluminum alloy as an aluminum connecting layer 130, utilizing its coefficient of linear expansion, which is between that of titanium and magnesium, to construct a natural stress buffer gradient layer between titanium and magnesium. During the cooling process after rolling, the aluminum connecting layer 130 can dissipate some of the thermal stress through plastic deformation, significantly reducing the residual stress level at the titanium-magnesium interface, thereby preventing the formation of interfacial microcracks.

[0096] 3. Currently, synchronous hot rolling processes have high requirements for temperature and deformation control, a narrow process window, and large fluctuations in interface quality. This invention adopts an asynchronous rolling process, introducing shear stress through the speed difference between the first and second rolls. On the one hand, this can break the oxide film on the surface of titanium alloys, aluminum alloys, and magnesium alloys, promoting fresh metal contact and atomic diffusion. On the other hand, it can reduce the preheating temperature of the hot rolling process, achieving high-quality bonding between titanium alloys and magnesium alloys at the same or lower preheating temperature. In addition, shear deformation can also promote the uniform diffusion of interface elements, avoiding the aggregation of brittle compounds caused by local enrichment. Finally, by adopting asynchronous hot rolling, the allowable range of rolling temperature, deformation, speed ratio, and other parameters is widened, and the process window of the rolling process is broadened, making the preparation process of high-performance bonded titanium-magnesium composite material 100 more stable and controllable.

[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A titanium-magnesium composite material, characterized in that, It includes a titanium base layer, a magnesium base layer, and an aluminum connecting layer located between the titanium base layer and the magnesium base layer.

2. The titanium-magnesium composite material according to claim 1, characterized in that, The thickness ratio of the titanium base layer, the aluminum connecting layer, and the magnesium base layer is (200~600):(2~10):(200~600); Preferably, the material of the titanium base layer includes at least one of TA4 titanium alloy and TC4 titanium alloy; Preferably, the magnesium base layer is made of wrought magnesium alloy, which includes at least one of AZ31 magnesium alloy and ZK61 magnesium alloy; Preferably, the material of the aluminum connecting layer is a wrought aluminum alloy, which includes at least one of 1050 aluminum alloy, 1060B aluminum alloy and 1070 aluminum alloy.

3. The titanium-magnesium composite material according to claim 1, characterized in that, The thickness of the intermetallic compound layer at the interface between the aluminum connecting layer and the magnesium base layer is ≤2 μm; Preferably, the thickness of the intermetallic compound layer at the interface between the titanium substrate and the aluminum connecting layer is ≤2 μm.

4. The titanium-magnesium composite material according to claim 1, characterized in that, The interfacial bonding strength between the aluminum connecting layer and the magnesium base layer is ≥85MPa; Preferably, the density of the titanium-magnesium composite material is 2.6~3.1 g / cm³. 3 .

5. A method for preparing a titanium-magnesium composite material as described in any one of claims 1 to 4, characterized in that, The process includes roughening the surfaces of titanium alloy, magnesium alloy, and aluminum alloy, then stacking and fixing them sequentially in the order of titanium alloy, aluminum alloy, and magnesium alloy to obtain an alloy billet; asynchronously hot rolling the alloy billet to obtain an alloy rolled piece; and heat treating the alloy rolled piece.

6. The preparation method according to claim 5, characterized in that, During the asynchronous hot rolling process, the roll that contacts the surface of the titanium alloy is the first roll, and the roll that contacts the surface of the magnesium alloy is the second roll. The speed of the first roll is greater than the speed of the second roll. Preferably, the speed of the first roll is 3.5~4.5 m / min; the speed of the second roll is 2.5~3.5 m / min.

7. The preparation method according to claim 5, characterized in that, The preheating temperature for the asynchronous hot rolling is 300~500℃, and the preheating time is 8~12min; the preheating atmosphere is an inert atmosphere, and the gas flow rate of the preheating atmosphere is 5~10m³ / min. 3 / h; Preferably, the reduction of the asynchronous hot rolling is 45-55%.

8. The preparation method according to claim 5, characterized in that, The heat treatment includes annealing, the annealing temperature is 180~250℃, and the time is 0.5~1.5h.

9. The preparation method according to claim 5, characterized in that, The surface roughness Ra of the titanium alloy after roughening treatment satisfies: Ra max Ra is 6.0~6.

5. min The value is 3.0~3.5; Preferably, the surface roughness Ra of the magnesium alloy after roughening treatment satisfies: Ra max Ra is 6.0~6.

5. min The value is 3.0~3.5; Preferably, the surface roughness Ra of the aluminum alloy after roughening treatment is... min It is 3.0~3.

5.

10. The application of a titanium-magnesium composite material as described in any one of claims 1 to 4 or a titanium-magnesium composite material prepared by any one of claims 5 to 9 in 3C consumer electronics components, automotive parts or aerospace equipment.

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