Titanium-aluminum composite structure with joint surface shear strength larger than 50 MPa, 60 MPa, 70 MPa or 80 MPa and high-strength light composite board

Abstract

The utility model relates to a titanium-aluminum composite structure with the joint surface shear strength larger than 50 MPa, 60 MPa, 70 MPa or 80 MPa and a high-strength light composite board. The titanium-aluminum composite structure comprises a first area, a second area and a third area, wherein the first area is made of titanium or titanium alloy; a second region of aluminum or an aluminum alloy; the intermetallic bonding layer is arranged between the first area and the second area, and the intermetallic bonding layer is a high-pressure liquid-phase metal composite layer; wherein the thickness of the intermetallic bonding layer ranges from 5.0 micrometers to 500 micrometers. The titanium-aluminum composite structure has the advantages of being light in weight, low in cost, good in obdurability, good in heat dissipation performance and the like, the high-strength light composite plate made of the titanium-aluminum composite structure can be further processed and manufactured into middle frames of various types of electronic products according to the specific size and layout of electronic product parts, universality is high, and the application range is wide.

Description

Technical Field

[0001] The present application relates to the field of composite materials, and in particular to a method for manufacturing a titanium-aluminum bimetallic composite plate and a titanium-aluminum bimetallic composite plate. Background Art

[0002] Titanium is a lightweight metal material with good corrosion resistance. Titanium has many good advantages. Titanium has a low density, close to aluminum, but has higher strength. It is stronger than many common metals such as steel and copper. It is an excellent lightweight and high-strength material. Titanium also has good corrosion resistance and can resist the erosion of most chemical media. Although titanium has many excellent properties, it also has a high melting point and is difficult to process, and has high requirements for processing equipment and processes. Moreover, titanium is expensive. Compared with general structural metals, the production and processing costs of titanium are higher.

[0003] Aluminum is a common metal material with the advantages of light weight, easy processing and low price. However, aluminum has low hardness, is prone to surface scratches, and has low strength.

[0004] Therefore, how to better combine titanium and aluminum to propose a new material is a technical problem that needs to be solved urgently. Utility Model Content

[0005] In view of the technical problems existing in the prior art, the utility model proposes a titanium-aluminum composite structure and a high-strength and lightweight composite plate with a shear strength of the bonding surface greater than 50MPa, 60MPa, 70MPa or 80MPa, which have the characteristics of light weight and low price, good strength and toughness, good heat dissipation performance, etc., and the high-strength and lightweight composite plate made of the titanium-aluminum composite structure can be further processed into middle frames of various types of electronic products according to the specific size and layout of electronic product parts. It has strong versatility and a wide range of applications.

[0006] The titanium-aluminum composite structure with a shear strength of the bonding surface greater than 50MPa, 60MPa, 70MPa or 80MPa includes: a first region of titanium or titanium alloy; a second region of aluminum or aluminum alloy; and an intermetallic bonding layer between the first region and the second region, and the intermetallic bonding layer is a high-pressure liquid phase metal composite layer; wherein the thickness of the intermetallic bonding layer is between 5.0-500 microns.

[0007] Optionally, according to an embodiment of the present application, the thickness of the intermetallic bonding layer is between 5.0-300 microns; or, the thickness of the intermetallic bonding layer is between 10-200 microns; or, the thickness of the intermetallic bonding layer is between 20-150 microns.

[0008] Optionally, according to an embodiment of the present application, the intermetallic bonding layer is a metallurgical bonding composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy.

[0009] Optionally, according to an embodiment of the present application, the intermetallic bonding layer is a high-pressure liquid metal composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy.

[0010] Optionally, according to an embodiment of the present application, the morphology of the intermetallic bonding layer is a straight morphology without obvious fluctuations.

[0011] Optionally, according to an embodiment of the present application, the microscopic defect portion in the intermetallic bonding layer includes an intermeshing structure formed when the liquid aluminum or aluminum alloy enters the microscopic defect of the solid titanium or the titanium alloy.

[0012] Optionally, according to an embodiment of the present application, the surface of the first region of the titanium or titanium alloy facing the second region of the aluminum or aluminum alloy includes an artificial concave-convex structure.

[0013] The present application also proposes a high-strength and lightweight composite plate, comprising the titanium-aluminum composite structure as described above, wherein the shear strength of the bonding surface is greater than 50 MPa, 60 MPa, 70 MPa or 80 MPa.

[0014] Optionally, according to an embodiment of the present application, comprising a support plate of aluminum or aluminum alloy and a frame of titanium or titanium alloy, the titanium-aluminum composite structure having a shear strength of the bonding surface greater than 50MPa, 60MPa, 70MPa or 80MPa is located between the support plate of aluminum or aluminum alloy and the frame of titanium or titanium alloy.

[0015] Optionally, according to an embodiment of the present application, the aluminum or aluminum alloy support plate includes a first part compounded with the titanium or titanium alloy frame and a second part connected to the first part, and the thickness of the first part is greater than the thickness of the second part.

[0016] Optionally, according to an embodiment of the present application, the second portion of the aluminum or aluminum alloy support plate includes one or more of the following structures: a hole, a slot, and a boss.

[0017] Optionally, according to an embodiment of the present application, the titanium or titanium alloy frame includes an inner surface and an outer surface, and the inner surface is composited with the aluminum or aluminum alloy support plate; the height of the inner surface is the same as or greater than the height of the first part of the aluminum or aluminum alloy support plate.

[0018] Optionally, according to an embodiment of the present application, the outer surface is smooth and the inner surface includes one or more concave and convex parts.

[0019] The shear strength of the bonding surface of the present application is greater than 50MPa, 60MPa, 70MPa or 80MPa. The titanium-aluminum composite structure has the characteristics of light weight, low price, good strength and toughness, good heat dissipation performance, etc., and the high-strength and lightweight composite plate made of the above-mentioned titanium-aluminum composite structure can be further processed into middle frames of various types of electronic products according to the specific size and layout of electronic product parts. It has strong versatility and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Below, the preferred embodiments of the present invention will be further described in detail with reference to the accompanying drawings, wherein:

[0021] Figure 1-Figure 3 Micrographs of sample 1, sample 2 and sample 3 of the titanium-aluminum composite structure are shown respectively;

[0022] Figure 4 A photograph showing the energy spectrum analysis result of the intermetallic bonding layer of sample 3;

[0023] Figure 5 A schematic diagram of a high-strength and lightweight composite panel according to an embodiment of the present application is shown;

[0024] Figure 6 Shows this application Figure 5 A partial enlarged view of region A of the embodiment; and

[0025] Figure 7 A cross-sectional view of a high-strength and lightweight composite panel according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] In the following detailed description, reference may be made to the various specification drawings that are part of the present application and are used to illustrate specific embodiments of the present application. In the accompanying drawings, similar reference numerals describe substantially similar components in different figures. The various specific embodiments of the present application are described below in sufficient detail so that a person of ordinary skill in the art with relevant knowledge and skills in the art can implement the technical solutions of the present application. It should be understood that other embodiments may also be used or structural, logical or electrical changes may be made to the embodiments of the present application.

[0028] The utility model provides a new bimetallic bonding material of titanium material and aluminum material, which has unprecedented bonding performance.

[0029] The present application provides a new bimetallic bonding material of titanium material and aluminum material, which has unprecedented bonding performance.

[0030] The titanium material of the present application includes titanium alloys in addition to titanium metal. Titanium alloys include but are not limited to the following materials:

[0031] (1) α (Alpha) alloy, for example, TA5, TA6: This type of alloy has good corrosion resistance and oxidation resistance, but relatively low strength and is suitable for occasions with low operating temperatures.

[0032] (2) β (Beta) alloy, for example, Ti-10V-2Fe-3Al (TB10): This is a high-strength β alloy with excellent formability and weldability, suitable for high-strength structural parts; Ti-15V-3Cr-3Sn-3Al: This alloy has good cold working properties and medium strength, suitable for parts that require cold working.

[0033] (3) α+β alloys, for example, Ti-6Al-4V (TC4): This is the most commonly used titanium alloy, widely used in aerospace, medical equipment and other fields, with good comprehensive properties, including high strength, good corrosion resistance and weldability; Ti-6Al-6V-2Sn: It has high strength and good fatigue resistance and is suitable for applications under high temperatures; Ti-5Al-2.5Sn (TA7): This alloy is not as strong as Ti-6Al-4V, but has good stability and creep resistance and is suitable for temperature environments that are not too demanding.

[0034] The aluminum material of the present application includes aluminum alloys in addition to metal aluminum. The alloys include but are not limited to the following materials:

[0035] (1) 1000 series: pure aluminum, such as 1100 (99% purity) is used for welding and deep drawing, and 1200 (99.1% purity) is used for manufacturing chemical equipment, etc.

[0036] (2) 2000 series: has good strength and corrosion resistance, such as 2014 and 2024, which are often used in aerospace structural parts.

[0037] (3) 3000 series: usually contains manganese, used for food and chemical containers, such as 3003 and 3004.

[0038] (4) 5000 series: Contains magnesium, such as 5052 and 5083, has good corrosion resistance and is used in the manufacture of ships, automobile plates, etc.

[0039] (5) 6000 series: Contains silicon and magnesium, such as 6061 and 6063, which are common structural aluminum alloys used in aviation, aerospace, construction, etc.

[0040] (6) 7000 series: Contains zinc elements, such as 7075, which is a high-strength aluminum alloy used in aerospace and high-performance applications.

[0041] (7) 8000 series: Al-Li (aluminum-lithium alloy) such as 8090, which has low density and high tensile strength and is used in aviation materials.

[0042] 1. Manufacturing of titanium aluminum materials

[0043] 1.1. Pretreatment of titanium alloy frame (aluminum plating)

[0044] (1) A titanium alloy frame is provided, and the titanium alloy frame is pickled to remove an oxide film.

[0045] (2) The solid aluminum or aluminum alloy raw material for hot-dip plating is placed in a crucible and heated to 710-750°C for melting.

[0046] (3) Immerse one surface of the titanium alloy frame in molten aluminum or aluminum alloy solution under inert gas protection. After placing the titanium alloy frame, control the aluminum liquid temperature at 650-680°C and keep it warm for 30-50 minutes.

[0047] (4) Take out the titanium alloy frame and place it on an aluminum silicate fiber blanket to air cool to room temperature.

[0048] 1.2. Pretreatment of titanium alloy frame (evaporation aluminum plating)

[0049] (1) A titanium alloy frame is provided, and the titanium alloy frame is pickled to remove an oxide film.

[0050] (2) Place the aluminum alloy material and the titanium alloy frame in a vacuum chamber.

[0051] (3) The aluminum alloy material is heated to above its melting point to evaporate it into steam, which is then deposited onto one surface of the titanium alloy frame to form an aluminum coating.

[0052] (4) Take out the titanium alloy frame and place it on an aluminum silicate fiber blanket to cool to room temperature.

[0053] In addition to the above methods, aluminum plating on the titanium alloy frame can also be achieved by sputtering aluminum plating or electroplating aluminum. The present application is not limited to the aluminum plating method in the pretreatment process.

[0054] It should be noted that the titanium alloy frame mentioned above is formed by punching or cutting the titanium alloy plate.

[0055] 2. High-pressure liquid compound

[0056] (1) Preheat the metal mold to 200-400°C.

[0057] (2) The aluminum-plated titanium alloy frame is placed into the cavity of a metal mold, with the aluminum-plated surface facing the interior of the metal mold cavity.

[0058] (3) Pour aluminum alloy liquid with a temperature 50 to 100° C. higher than the liquidus temperature into a metal mold so that the aluminum alloy liquid contacts the aluminum-plated surface of the titanium alloy frame.

[0059] (4) The aluminum alloy liquid is pressurized in the mold and maintained at a high pressure of 30 to 200 MPa for a certain period of time, so that interface diffusion occurs between the titanium alloy frame and the aluminum alloy liquid, forming a titanium-aluminum intermetallic compound layer, and firmly combining the titanium alloy frame and the aluminum alloy material.

[0060] 3. Heat strengthening treatment

[0061] The composite titanium-aluminum composite plate is subjected to any one of T5, T6, T7, or T8 heat treatment to obtain a high-strength and lightweight bimetallic composite plate:

[0062] (1) The T5 heat treatment strengthening is performed by heating to 530-540°C and keeping the temperature for 10-18 hours, then cooling to room temperature with water, and then heating to 150-160°C and keeping the temperature for 6-10 hours, then cooling in air;

[0063] (2) The T6 heat treatment strengthening is performed by heating to 530-540°C for 10-18 hours, cooling to room temperature with water, and then heating to 165-175°C for 6-10 hours, and then cooling in air;

[0064] (3) The T7 heat treatment strengthening is performed by heating to 530-540°C for 10-18 hours, cooling to room temperature with water, and then heating to 175-185°C for 6-10 hours, and then cooling in air;

[0065] (4) The T8 heat treatment strengthening is performed by heating to 530-540°C and keeping the temperature for 10-18 hours, then cooling to room temperature with water, compressing the high-strength aluminum alloy core by 5-30%, then heating to 150-175°C and keeping the temperature for 6-10 hours, and then cooling in air.

[0066] Specifically, the present application proposes a titanium-aluminum composite structure with a bonding surface shear strength greater than 50MPa, 60MPa, 70MPa or 80MPa, comprising: a first region of titanium or titanium alloy; a second region of aluminum or aluminum alloy; and an intermetallic bonding layer between the first region and the second region; wherein the thickness of the intermetallic bonding layer is between 5.0-500 microns.

[0067] Optionally, according to an embodiment of the present application, the thickness of the intermetallic bonding layer is between 5.0-300 microns; or, the thickness of the intermetallic bonding layer is between 10-200 microns; or, the thickness of the intermetallic bonding layer is between 20-150 microns.

[0068] Optionally, according to an embodiment of the present application, the intermetallic bonding layer is a metallurgical bonding composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy.

[0069] Optionally, according to an embodiment of the present application, the intermetallic bonding layer is a high-pressure liquid metal composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy.

[0070] Optionally, according to an embodiment of the present application, the morphology of the intermetallic bonding layer is a straight morphology without obvious fluctuations.

[0071] Optionally, according to an embodiment of the present application, the microscopic defect portion in the intermetallic bonding layer includes an intermeshing structure formed when the liquid aluminum or aluminum alloy enters the microscopic defect of the solid titanium or the titanium alloy.

[0072] Optionally, according to an embodiment of the present application, the surface of the first region of the titanium or titanium alloy facing the second region of the aluminum or aluminum alloy includes an artificial concave-convex structure.

[0073] The shear strength of the bonding surface of the present application is greater than 50MPa, 60MPa, 70MPa or 80MPa. The titanium-aluminum composite structure has the characteristics of light weight, low price, good strength and toughness, good heat dissipation performance, etc., and the high-strength and lightweight composite plate made of the above-mentioned titanium-aluminum composite structure can be further processed into middle frames of various types of electronic products according to the specific size and layout of electronic product parts. It has strong versatility and a wide range of applications.

[0074] 2. Samples and performance testing of titanium aluminum materials

[0075] 1. Shear strength test method

[0076] Place and clamp the sample on a universal material testing machine. Apply shear load at a set speed, record the shear force and displacement or deformation, and calculate the shear strength using the following formula: Shear strength = maximum bearing capacity / sample area.

[0077] 2. Yield strength test method

[0078] Place and clamp the sample on the universal material testing machine. Apply tensile load at a set speed, record the tensile force and sample deformation, record the yield point of the sample, that is, the point where significant plastic deformation begins to occur, and calculate the yield strength using the following formula: Yield strength = yield point load / sample cross-sectional area.

[0079] 3. Elongation test method

[0080] Place and clamp the sample on a universal material testing machine. Apply tensile load at a set speed and continue loading until the sample breaks. Measure the final length of the sample after breaking, and calculate the elongation using the following formula: Elongation = (final length - initial length) / initial length × 100%.

[0081] The following table shows the test results of samples of multiple embodiments of the present application.

[0082] Table 1: Test results of multiple samples

[0083]

[0084]

[0085] 3. Microscopic morphology of titanium aluminum materials

[0086] 1. Metallic bonding layer under the microscope

[0087] The titanium-aluminum bonding interface of samples 1, 2 and 3 was observed using a Zeiss (Axioscope 5) microscope. Figure 1-Figure 3 Micrographs of sample one, sample two, and sample three are shown, respectively.

[0088] pass Figure 1 It can be seen that the thickness of the titanium-aluminum intermetallic bonding layer is about 10.4 microns, and it transitions from the metal titanium region to the titanium-aluminum intermetallic compound bonding layer in a relatively straight manner, and then extends from the titanium-aluminum intermetallic bonding layer to the metal aluminum region in a needle-like shape. The bonding layer has a fine structure and no coarse compound phase, forming a strong metallurgical bond. As understood, the so-called "metallurgical bonding" in this application refers to the mutual penetration between two or more metal atoms and the strong bonding in the form of metal bonds.

[0089] pass Figure 2 It can be seen that the thickness of the titanium-aluminum intermetallic bonding layer is about 9.5 microns. Both the metal titanium region side and the metal aluminum region side have achieved metallurgical bonding. Similarly, the internal structure of the titanium-aluminum intermetallic bonding layer is fine and dense, without coarse compound phases.

[0090] pass Figure 3 It can be seen that the thickness of the titanium-aluminum intermetallic bonding layer is about 10.6 microns. Similarly, the titanium-aluminum intermetallic bonding layer achieves metallurgical bonding, fine grains, tight bonding, and no coarse compound phase.

[0091] According to the test results, the shear strength of samples 1, 2 and 3 is greater than 80MPa. According to theoretical calculations, if the thickness of the titanium-aluminum metal bonding layer exceeds 5.0 microns, then its shear strength is enough to reach 50MPa, which is enough to meet the needs of use.

[0092] As understood, with the increase of pressure, temperature and time in the high pressure liquid phase composite process, the metal atoms between titanium and aluminum will be promoted to penetrate, thereby forming a thicker intermetallic bonding layer. According to experimental results, the thickness of the intermetallic bonding layer can reach 150-300 microns. As understood, a thicker intermetallic bonding layer means greater shear strength, greater yield strength and smaller elongation.

[0093] 2. Chemical composition analysis of the intermetallic bonding layer

[0094] The energy spectrum analysis of the titanium-aluminum bonding interface of sample three was carried out using a ZEISS EVO18 scanning electron microscope (equipped with an Oxford X-act energy spectrometer). Figure 4 The energy spectrum analysis results of the metal bonding layer of sample 3 are shown. Figure 4 It can be seen that the chemical composition of the intermetallic bonding layer is neither titanium alloy nor aluminum alloy, but mainly aluminum (66.3%); the titanium, carbon and oxygen in the titanium alloy diffuse into the intermetallic bonding layer; therefore, the intermetallic bonding layer also contains 6.4% titanium, 19.0% carbon, and 5.8% oxygen; at the same time, 1.2% of the copper in the aluminum alloy is retained. The results of the energy spectrum analysis also prove that the titanium-aluminum intermetallic bonding layer is a metallurgical intermetallic compound layer.

[0095] It is not difficult to see from the above embodiments of the present application that the titanium-aluminum bimetallic composite structure of the present application is a high-strength and toughness metallurgical bond, and in all embodiments, the shear strength is greater than 80MPa. As can be understood, since the shear strength of the industrially acceptable titanium-aluminum composite structure in the prior art is less than 50MPa, the present application essentially provides a titanium-aluminum composite structure with a bonding surface shear strength greater than 50MPa, 60MPa, 70MPa or 80MPa.

[0096] On the other hand, the present application also provides a new type of material that is light and inexpensive. The cost of the titanium-aluminum composite plate of the present application is more than 80% lower than that of the full titanium alloy plate; it is equivalent to the cost of the full aluminum plate. Moreover, since the titanium material is replaced by aluminum material, the titanium-aluminum composite plate of the present application has good heat dissipation performance. According to the test results, the thermal conductivity of the titanium-aluminum composite plate of the present application is more than twice that of the titanium alloy, and has a wide range of application prospects.

[0097] The titanium-aluminum bimetallic material of the present application is suitable for application in electronic products. The following takes the manufacture of the middle frame of an electronic product as an example to further illustrate the technical solution of the present application. Of course, as is known, the electronic product or the middle frame of the electronic product is only a specific application of the present application. The application of the present application is not limited to this.

[0098] 4. Examples of high-strength and lightweight composite panels

[0099] 1. Use the following steps to make high-strength and lightweight composite panels:

[0100] (1) providing a titanium alloy sheet, and forming a titanium alloy frame by punching and / or cutting the titanium alloy sheet;

[0101] (2) pickling the titanium alloy frame to remove the oxide film;

[0102] (3) hot-dip coating the inner side of the titanium alloy frame with aluminum alloy to form an intermetallic compound ring;

[0103] (4) placing the titanium alloy frame with the intermetallic compound ring into the accommodating cavity of the manufacturing mold that has been heated to the preheating temperature;

[0104] (5) pouring a predetermined volume of aluminum alloy liquid into the filling cavity surrounded by the titanium alloy frame, and the temperature of the aluminum alloy liquid is at least 50° C. higher than the liquidus temperature, to form an aluminum alloy support plate; wherein the predetermined volume of aluminum alloy liquid can at least cover the filling cavity surrounded by the titanium alloy frame;

[0105] (6) pressurizing the aluminum alloy liquid within a predetermined pressure range and maintaining the pressure for a predetermined time until the aluminum alloy solidifies to form a titanium-aluminum bimetallic composite plate composed of a titanium alloy frame and an aluminum alloy core in the frame; and

[0106] (7) The titanium-aluminum bimetallic composite plate is subjected to heat treatment strengthening treatment, which includes T5 heat treatment, T6 heat treatment, T7 heat treatment or T8 heat treatment.

[0107] Different from the previous embodiments, in order to manufacture a high-strength and lightweight composite plate, a titanium or titanium alloy frame is first provided, and the frame has an inner surface of a certain width to facilitate the composite with aluminum or aluminum alloy. This width is generally equivalent to the height of the electronic product. The aluminum or aluminum alloy and the titanium or titanium alloy frame are composited to form a support plate, so that in a single composite process, not only the titanium-aluminum bimetal composite is achieved, but also the manufacturing of the support plate is achieved, further reducing the cost.

[0108] In some embodiments, the process of hot-dip aluminum alloy plating includes the following steps: placing solid aluminum or aluminum alloy for hot-dip plating in a crucible and heating it to 710-750°C to melt and form an aluminum or aluminum alloy solution; immersing a titanium alloy frame in the aluminum or aluminum alloy solution under the protection of an inert gas and keeping it warm in the temperature range of 650-680°C for 30-50 minutes; taking out the titanium alloy frame with the intermetallic compound ring formed thereon, and placing it on an aluminum silicate fiber blanket for air cooling.

[0109] In some embodiments, the method further comprises the step of alkali washing the titanium alloy frame hot-dip plated with the intermetallic compound ring. In some embodiments, the method further comprises encapsulating the housing cavity containing the titanium alloy frame and continuously introducing an inert gas into the housing cavity.

[0110] In some embodiments, the preheating temperature of the mold is in the range of 200° C.-400° C. In some embodiments, the predetermined pressure is in the range of 30-200 MPa In some embodiments, the predetermined time is in the range of 30-50 min.

[0111] 2. Structure of high-strength and lightweight composite panels

[0112] like Figure 5-Figure 7 As shown, the high-strength and lightweight composite plate of the present application comprises: a frame 1 of titanium or titanium alloy and a support plate 2 of aluminum or aluminum alloy. The frame 1 of titanium or titanium alloy and the support plate 2 of aluminum or aluminum alloy are connected to each other by metallurgical bonding. Figure 6 The titanium or titanium alloy outer frame 1 and the aluminum or aluminum alloy main body 2 include a metal bonding surface 3; wherein the bonding surface shear strength is greater than 50MPa, 60MPa, 70MPa or 80MPa. The titanium-aluminum composite structure is located between the aluminum or aluminum alloy support plate 2 and the titanium or titanium alloy frame 1.

[0113] According to an embodiment of the present application, the thickness of the intermetallic bonding layer is between 5.0 and 500 microns. The thickness of the intermetallic bonding layer may also be between 5.0 and 300 microns; or between 10 and 200 microns; or between 20 and 150 microns.

[0114] According to one embodiment of the present application, the intermetallic bonding layer is a high-pressure liquid metal composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy. The shear strength of the intermetallic bonding layer is greater than 50MPa, 60MPa, 70MPa or 80MPa. The yield strength of the intermetallic bonding layer is greater than 350MPa. The elongation of the intermetallic bonding layer is between 5% and 15%.

[0115] like Figure 5-Figure 7 As shown, the aluminum or aluminum alloy support plate 2 includes a first portion 21 compounded with the titanium or titanium alloy frame 1 and a second portion 22 connected to the first portion 21. Figure 7As shown, the thickness of the first part 21 is greater than the thickness of the second part 22. The first part 21 fits seamlessly with the frame 1. In some embodiments, the side of the first part 21 facing the inside of the frame 1 further includes microstructures such as screw holes, slots, and bosses for installing various parts of electronic products. In some embodiments, the second part 22 of the support plate 2 includes a plurality of regular or irregular holes 23, slots or bosses 24. The high-strength and lightweight composite board of the embodiment of the present application can be used to produce the middle frame of electronic products, and the holes, slots, bosses and other structures on the middle frame can be used to install parts such as cameras, batteries, and motherboards.

[0116] like Figure 5-Figure 7 As shown, the frame 1 of titanium or titanium alloy includes an inner surface 11 and an outer surface 12. The inner surface 11 is compounded with the support plate 2 of aluminum or aluminum alloy. The height or thickness of the inner surface 11 is equal to the height or thickness of the first portion 21 of the main body 2 of aluminum or aluminum alloy. In some embodiments, the height or thickness of the inner surface 11 of the frame 1 of titanium or titanium alloy may be greater than the height or thickness of the first portion 21 of the support plate 2 of aluminum or aluminum alloy.

[0117] Continue to refer Figure 5-Figure 7 In some embodiments, the upper and lower surfaces and the inner and outer surfaces of the titanium or titanium alloy frame 1 have a processing allowance of 0.5 to 1 mm. In some embodiments, the intersection of the titanium or titanium alloy frame 1 and the aluminum or aluminum alloy support plate 2 has a rounded transition. In some embodiments, the outer surface 12 of the titanium or titanium alloy frame 1 is smooth and the inner surface 11 includes one or more concave and convex parts, which are used for positioning or foolproofing the frame of the produced electronic product during the assembly process.

[0118] That is to say, the present application also provides a high-strength lightweight composite plate, including the titanium-aluminum composite structure as described above, wherein the shear strength of the bonding surface is greater than 50 MPa, 60 MPa, 70 MPa or 80 MPa.

[0119] Optionally, according to an embodiment of the present application, comprising a support plate of aluminum or aluminum alloy and a frame of titanium or titanium alloy, the titanium-aluminum composite structure having a shear strength of the bonding surface greater than 50MPa, 60MPa, 70MPa or 80MPa is located between the support plate of aluminum or aluminum alloy and the frame of titanium or titanium alloy.

[0120] Optionally, according to an embodiment of the present application, the aluminum or aluminum alloy support plate includes a first part compounded with the titanium or titanium alloy frame and a second part connected to the first part, and the thickness of the first part is greater than the thickness of the second part.

[0121] Optionally, according to an embodiment of the present application, the second portion of the aluminum or aluminum alloy support plate includes one or more of the following structures: a hole, a slot, and a boss.

[0122] Optionally, according to an embodiment of the present application, the titanium or titanium alloy frame includes an inner surface and an outer surface, and the inner surface is composited with the aluminum or aluminum alloy support plate; the height of the inner surface is the same as or greater than the height of the first part of the aluminum or aluminum alloy support plate.

[0123] Optionally, according to an embodiment of the present application, the outer surface is smooth and the inner surface includes one or more concave and convex parts.

[0124] 3. Performance test of high-strength lightweight composite board embodiment

[0125]

[0126]

[0127] From the performance tests of the three samples in the above table, it can be seen that the middle frame of the electronic product made of the high-strength and lightweight composite board of the present application has high strength, good impact toughness, high resistance to drop damage, and is not easy to be damaged or deformed.

[0128] In summary, the above embodiments of the present application illustrate the following advantages of the present application:

[0129] (1) Wide range of applications: The titanium-aluminum composite structure and high-strength and lightweight composite plate of the present application can be further processed to produce middle frames of various types of electronic products according to the specific size and layout of electronic product parts, and have strong versatility and a wide range of applications.

[0130] (2) Good strength and toughness: The titanium-aluminum composite structure and the middle frame made of high-strength and lightweight composite panels of the present application have high strength, good impact toughness, high resistance to falling damage, and are not easy to be damaged or deformed;

[0131] (3) Lightweight and inexpensive: The titanium-aluminum composite structure and the electronic product middle frame made of high-strength and lightweight composite plates of the present application can be formed as a whole in one step, without welding joints and welding points, with a small processing volume. The cost is more than 80% lower than that of a full titanium alloy middle frame, and 10% lower than that of a mobile phone middle frame processed from aluminum plates.

[0132] (4) Good heat dissipation performance: The titanium-aluminum composite structure of the present application and the middle frame made of high-strength and lightweight composite panels can be widely used in communication electronic products and are not prone to heat.

[0133] The above embodiments are only used to illustrate the present invention, but not to limit the present invention. Ordinary technicians in the relevant technical field can make various changes and modifications without departing from the scope of the present invention. Therefore, all equivalent technical solutions should also fall within the scope of the present invention.

Claims

1. A titanium-aluminum composite structure with a bonding surface shear strength greater than 50MPa, 60MPa, 70MPa or 80MPa, characterized in that: include: A first region of titanium or a titanium alloy; a second region of aluminum or an aluminum alloy; as well as The intermetallic bonding layer between the first region and the second region is a high-pressure liquid metal composite layer; wherein the thickness of the intermetallic bonding layer is between 5.0 and 500 microns.

2. The titanium-aluminum composite structure according to claim 1, wherein the shear strength of the bonding surface is greater than 50MPa, 60MPa, 70MPa or 80MPa, The thickness of the intermetallic bonding layer is between 5.0 and 300 microns; or, the thickness of the intermetallic bonding layer is between 10 and 200 microns; or, the thickness of the intermetallic bonding layer is between 20 and 150 microns.

3. The titanium-aluminum composite structure according to claim 1, wherein the shear strength of the bonding surface is greater than 50MPa, 60MPa, 70MPa or 80MPa. The intermetallic bonding layer is a metallurgical bonding composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy.

4. The titanium-aluminum composite structure with a bonding surface shear strength greater than 50MPa, 60MPa, 70MPa or 80MPa according to claim 3, characterized in that: The intermetallic bonding layer is a high-pressure liquid metal composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy.

5. The titanium-aluminum composite structure with a bonding surface shear strength greater than 50MPa, 60MPa, 70MPa or 80MPa according to claim 4, characterized in that: The intermetallic bonding layer has a straight shape without obvious fluctuations.

6. The titanium-aluminum composite structure with a bonding surface shear strength greater than 50MPa, 60MPa, 70MPa or 80MPa according to claim 5, characterized in that: The microscopic defect portions in the intermetallic bonding layer include meshing structures formed when the liquid aluminum or aluminum alloy enters the microscopic defects of the solid titanium or the titanium alloy.

7. The titanium-aluminum composite structure with a bonding surface shear strength greater than 50MPa, 60MPa, 70MPa or 80MPa according to claim 5, characterized in that: The surface of the first region of the titanium or titanium alloy facing the second region of the aluminum or aluminum alloy includes an artificial concavo-convex structure.

8. A high-strength lightweight composite panel, characterized in that: It comprises a titanium-aluminum composite structure as claimed in any one of claims 1 to 7, wherein the shear strength of the bonding surface is greater than 50 MPa, 60 MPa, 70 MPa or 80 MPa.

9. The high-strength and lightweight composite panel according to claim 8, characterized in that: It comprises an aluminum or aluminum alloy support plate and a titanium or titanium alloy frame, wherein the titanium-aluminum composite structure has a shear strength of the joint surface greater than 50MPa, 60MPa, 70MPa or 80MPa and is located between the aluminum or aluminum alloy support plate and the titanium or titanium alloy frame.

10. The high-strength and lightweight composite panel according to claim 9, characterized in that: The aluminum or aluminum alloy support plate includes a first part compounded with the titanium or titanium alloy frame and a second part connected to the first part, and the thickness of the first part is greater than the thickness of the second part.

11. The high-strength and lightweight composite panel according to claim 10, characterized in that: The second portion of the aluminum or aluminum alloy support plate includes one or more of the following structures: a hole, a slot, and a boss.

12. The high-strength and lightweight composite panel according to claim 10, characterized in that: The titanium or titanium alloy frame includes an inner surface and an outer surface, the inner surface is composited with the aluminum or aluminum alloy support plate; the height of the inner surface is the same as or greater than the height of the first part of the aluminum or aluminum alloy support plate.

13. The high-strength and lightweight composite panel according to claim 12, characterized in that: The outer surface is smooth and the inner surface includes one or more concave and convex portions.

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