Middle frame of electronic product

Abstract

The utility model relates to a middle frame of an electronic product. The middle frame comprises a titanium or titanium alloy frame body; a support plate of aluminum or aluminum alloy; the supporting plate and the frame body are connected with each other through metallurgical bonding, and an intermetallic bonding layer is arranged between the supporting plate and the frame body; wherein the thickness of the intermetallic bonding layer ranges from 5.0 micrometers to 500 micrometers. The process is simple and reasonable, and the manufactured middle frame of the electronic product is light in weight, low in cost, good in obdurability and good in heat dissipation performance.

Description

Technical Field

[0001] This application relates to the field of electronic products, and particularly to a middle frame of an electronic product. Background Art

[0002] The middle frame of an electronic product needs to meet the dual requirements of high strength and toughness and light weight at the same time. The existing all-titanium middle frames and all-aluminum middle frames cannot meet such requirements. Metallic titanium is a lightweight metal material with good corrosion resistance. Titanium has many good advantages. The density of titanium is relatively low, close to that of aluminum, but it has higher strength and 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 the properties of high melting point and difficult processing, and has relatively high requirements for processing equipment and processes. Moreover, titanium is expensive, and its production and processing costs are higher compared to general structural metals. Metallic 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 its strength is not high.

[0003] Therefore, how to better combine titanium and aluminum to propose a new middle frame for electronic products is a technical problem to be solved urgently. Utility Model Content

[0004] In view of the technical problems existing in the prior art, this application proposes a middle frame for an electronic product, with a simple and reasonable processing technology, and the middle frame of the manufactured electronic product is light in weight, low in price, good in strength and toughness, and good in heat dissipation performance.

[0005] The middle frame of the electronic product includes: a frame body made of titanium or a titanium alloy; a support plate made of aluminum or an aluminum alloy; the support plate and the frame body are connected to each other by metallurgical bonding, wherein there is an intermetallic bonding layer between the support plate and the frame body; wherein, the thickness of the intermetallic bonding layer is between 5.0 and 500 microns.

[0006] Optionally, 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.

[0007] Optionally, the intermetallic bonding layer is a high-pressure liquid-phase metal composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy.

[0008] Optionally, the shear strength of the intermetallic bonding layer is greater than 50 MPa, 60 MPa, 70 MPa, or 80 MPa.

[0009] Optionally, the yield strength of the intermetallic bonding layer is greater than 350 MPa.

[0010] Optionally, the elongation of the intermetallic bonding layer is between 5% and 15%.

[0011] Optionally, the support plate includes a first part compounded with the frame body 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.

[0012] Optionally, the second part of the support plate includes one or more of the following structures: holes, card slots, and bosses.

[0013] Optionally, the frame body includes an inner surface and an outer surface, the inner surface is compounded with the support plate; the height of the inner surface is greater than or equal to the height of the first part of the support plate.

[0014] Optionally, the outer surface of the frame body is smooth and the inner surface includes one or more concave and convex parts.

[0015] In summary, the middle frames of various types of electronic products processed and manufactured in this application can be applicable to a wide range according to the specific sizes and layouts of the parts of the electronic products; the middle frames have high strength, good impact toughness, high anti-drop failure ability, and are not easily damaged and deformed; the middle frames can be integrally formed at one time, without welding joints and solder joints, with small processing amount, and the cost is reduced by more than 80% compared with the all-titanium alloy middle frames, and the cost is reduced by 10% compared with the mobile phone middle frames processed by aluminum plates; they can be widely used in communication electronic products and are not prone to heat generation. Description of the Drawings

[0016] Next, the preferred embodiments of the present application will be further described in detail with reference to the drawings, where:

[0017] Figures 1 - 3 The scanning electron microscope photos of Sample 1, Sample 2, and Sample 3 are respectively shown.

[0018] Figure 4 The transmission electron microscope photo of Sample 3 is shown.

[0019] Figure 5 The schematic diagram of the electronic middle frame of an embodiment of the present application is shown.

[0020] Figure 6 It is a partial enlarged view of an embodiment of the present application.

[0021] Figure 7 The sectional view of the electronic middle frame according to an embodiment of the present application is shown. Detailed Description of the Embodiments

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0023] In the following detailed description, reference can be made to the various specification drawings that form a part of this application and illustrate specific embodiments of this application. In the drawings, like reference numerals generally describe substantially similar components in different figures. The various specific embodiments of this application have been described in sufficient detail below so that those of ordinary skill in the relevant art and technology can implement the technical solutions of this application. It should be understood that other embodiments can also be used, or structural, logical, or electrical changes can be made to the embodiments of this application.

[0024] This application proposes a new bimetallic composite material of titanium material and aluminum material, which has unprecedented bonding properties.

[0025] The titanium material of this application includes titanium alloys in addition to metallic titanium. Titanium alloys include, but are not limited to, the following materials:

[0026] (1) α (Alpha) alloys, such as TA5, TA6: These alloys have good corrosion resistance and oxidation resistance, but relatively low strength, and are suitable for occasions with lower working temperatures.

[0027] (2) β (Beta) alloys, such as Ti-10V-2Fe-3Al (TB10): This is a high-strength β alloy with excellent formability and weldability, and is suitable for high-strength structural parts; Ti-15V-3Cr-3Sn-3Al: This alloy has good cold working performance and medium strength, and is suitable for parts that require cold working forming.

[0028] (3) α + β alloys, such as Ti-6Al-4V (TC4): This is the most commonly used titanium alloy, widely used in the fields of aerospace, medical devices, etc., and has 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 at high temperatures; Ti-5Al-2.5Sn (TA7): The strength of this alloy is not as high as that of Ti-6Al-4V, but it has good stability and creep resistance, and is suitable for temperature environments with not too high requirements.

[0029] The aluminum material of this application includes aluminum alloys in addition to metallic aluminum. Alloys include, but are not limited to, the following materials:

[0030] (1) Series 1000: Pure aluminum, such as 1100 (99% purity) for welding and deep drawing, and 1200 (99.1% purity) for manufacturing chemical equipment, etc.

[0031] (2) Series 2000: With good strength and corrosion resistance, such as 2014 and 2024 are commonly used in aerospace structural components.

[0032] (3) Series 3000: Usually contains manganese and is used for food and chemical containers, such as 3003 and 3004.

[0033] (4) Series 5000: Contains magnesium, such as 5052 and 5083, with good corrosion resistance, and is used for manufacturing ships, automotive sheets, etc.

[0034] (5) Series 6000: Contains silicon and magnesium, such as 6061 and 6063 are common structural aluminum alloys, and are used in aviation, aerospace, construction, etc.

[0035] (6) Series 7000: Contains zinc element, such as 7075 is a high-strength aluminum alloy, and is used in aerospace and high-performance applications.

[0036] (7) Series 8000: Al-Li (aluminum-lithium alloy) such as 8090, with low density and high tensile strength, and is used for aviation materials.

[0037] I. Preparation of Titanium-Aluminum Materials

[0038] 1.1. Pretreatment of Titanium Alloy Frame (Aluminum Coating on Aluminum Liquid)

[0039] (1) Provide a titanium alloy frame, and pickling the titanium alloy frame to remove the oxide film.

[0040] (2) Place the 7075 aluminum alloy material in a crucible and heat it to 710 - 750 °C to melt.

[0041] (3) Under the protection of inert gas, immerse one surface of the titanium alloy frame into the molten aluminum liquid. After placing the titanium alloy frame, control the temperature of the aluminum liquid at 650 - 680 °C and keep it warm for 30 - 50 minutes.

[0042] (4) Take out the titanium alloy frame and place it on the aluminosilicate fiber blanket to cool to room temperature.

[0043] 1.2. Pretreatment of Titanium Alloy Frame (Vacuum Evaporation Aluminum Coating)

[0044] (1) Provide a TC4 titanium alloy frame, and pickling the titanium alloy frame to remove the oxide film.

[0045] (2) Place the aluminum alloy material and the titanium alloy frame in a vacuum chamber.

[0046] (3) Heat the aluminum alloy material to a temperature above its melting point to evaporate it into vapor, and then deposit it on one surface of the titanium alloy frame to form an aluminum coating;

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

[0048] In addition to the above methods, aluminizing on the titanium alloy frame can also be achieved by sputtering aluminizing or electroplating aluminizing. This application is not limited to the method of aluminizing during the pretreatment process.

[0049] 2. High - pressure Liquid - phase Composite

[0050] (1) Preheat the metal mold to 200 - 400 °C.

[0051] (2) Place the aluminized titanium alloy frame into the cavity of the metal mold, with the aluminized surface facing the inside of the metal mold cavity.

[0052] (3) Pour the aluminum alloy liquid at a temperature 50 - 100 °C above the liquidus temperature into the metal mold, so that the 7075 aluminum alloy liquid contacts the aluminized surface of the titanium alloy frame.

[0053] (4) Apply pressure to the aluminum alloy liquid in the mold and maintain it under a high pressure of 30 - 200 MPa for a certain period of time, so that interfacial diffusion occurs between the titanium alloy frame and the aluminum alloy liquid, forming a titanium-aluminum intermetallic compound layer and firmly bonding the titanium alloy frame and the aluminum alloy material together.

[0054] 3. Thermal Strengthening Treatment

[0055] Perform any one of the heat treatments of T5, T6, T7, or T8 on the composite titanium-aluminum composite plate to obtain a high-strength and lightweight bimetallic composite plate:

[0056] (1) For the T5 heat treatment strengthening, heat to 530 - 540 °C, hold for 10 - 18 h, then water-cool to room temperature, and then heat to 150 - 160 °C, hold for 6 - 10 h, and then air-cool;

[0057] (2) For the T6 heat treatment strengthening, heat to 530 - 540 °C, hold for 10 - 18 h, then water-cool to room temperature, and then heat to 165 - 175 °C, hold for 6 - 10 h, and then air-cool;

[0058] (3) For the T7 heat treatment strengthening, heat to 530 - 540 °C, hold for 10 - 18 h, then water-cool to room temperature, and then heat to 175 - 185 °C, hold for 6 - 10 h, and then air-cool;

[0059] (4) The T8 heat treatment strengthening: heating to 530 - 540 °C, holding for 10 - 18 h, then water-cooling to room temperature. After subjecting the high-strength aluminum alloy core to 5 - 30% compressive deformation, it is reheated to 150 - 175 °C, held for 6 - 10 h, and then air-cooled.

[0060] II. Samples and Performance Testing of Titanium-Aluminum Materials

[0061] 1. Test Method for Shear Strength

[0062] On a universal material testing machine, place and clamp the sample well. 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.

[0063] 2. Test Method for Yield Strength

[0064] On a universal material testing machine, place and clamp the sample well. Apply tensile load at a set speed, record the tensile force and sample deformation, record the yield point of the sample, i.e., the point where significant plastic deformation begins, and calculate the yield strength using the following formula: Yield strength = yield point load / sample cross-sectional area.

[0065] 3. Test Method for Elongation

[0066] On a universal material testing machine, place and clamp the sample well. Apply tensile load at a set speed and continue loading until the sample fractures. Measure the final length of the sample after fracture, and calculate the elongation using the following formula: Elongation = (final length - initial length) / initial length × 100%.

[0067] The following table shows the test results of the samples in multiple embodiments of this application.

[0068] Table 1: Test Results of Multiple Samples

[0069]

[0070]

[0071] III. Microscopic Morphology of Titanium-Aluminum Materials 1. Intermetallic Bonding Layer under Microscope

[0072] The titanium-aluminum bonding interfaces of Sample 1, Sample 2, and Sample 3 were observed using a Zeiss (Axioscope 5) microscope. Figures 1 - 3 Micrographs of Sample 1, Sample 2, and Sample 3 are shown respectively.

[0073] Through Figure 1It can be seen that the thickness of the intermetallic bonding layer of titanium-aluminum is approximately 10.4 microns. It transitions relatively smoothly from the region of metallic titanium to the bonding layer of titanium-aluminum intermetallic compound, and then extends in a needle-like shape from the titanium-aluminum intermetallic bonding layer into the region of metallic aluminum. The structure within the bonding layer is fine and dense, without coarse compound phases, forming a firm metallurgical bond. As understood, the so-called "metallurgical bond" in this application refers to the firm bonding together of two or more metal atoms through mutual penetration and mainly in the form of metallic bonds.

[0074] Through Figure 2 It can be seen that the thickness of the titanium-aluminum intermetallic bonding layer is approximately 9.5 microns. Metallurgical bonding is achieved on both the metallic titanium region side and the metallic aluminum region side. Similarly, the internal structure of the titanium-aluminum intermetallic bonding layer is fine and dense, without coarse compound phases.

[0075] Through Figure 3 It can be seen that the thickness of the titanium-aluminum intermetallic bonding layer is approximately 10.6 microns. Similarly, the titanium-aluminum intermetallic bonding layer has achieved metallurgical bonding, with fine grains, close bonding, and no coarse compound phases.

[0076] According to the test results, the shear strengths of Sample 1, Sample 2, and Sample 3 are all greater than 80 MPa. According to theoretical calculations, if the thickness of the titanium-aluminum intermetallic bonding layer exceeds 5.0 microns, then its shear strength will be sufficient to reach 50 MPa, which is sufficient to meet the usage requirements.

[0077] As understood, with the increase in pressure, temperature, and time during the high-pressure liquid-phase composite process, the penetration of metal atoms between titanium and aluminum will be promoted, thereby forming an intermetallic bonding layer with a greater thickness. According to the experimental results, the thickness of the intermetallic bonding layer can reach 150 - 300 microns. As understood, a greater thickness of the intermetallic bonding layer means greater shear strength, greater yield strength, and smaller elongation.

[0078] 2. Chemical composition analysis of the intermetallic bonding layer

[0079] Energy-dispersive spectroscopy analysis was performed on the titanium-aluminum bonding interface of Sample 3 using a ZEISS EVO18 scanning electron microscope (equipped with an Oxford X-act energy-dispersive spectrometer). Figure 4 Shows the energy-dispersive spectroscopy analysis results of the intermetallic bonding layer of Sample 3. Through Figure 4 It can be seen that the chemical composition of the intermetallic bonding layer is neither a titanium alloy nor an aluminum alloy, but mainly metallic aluminum (66.3%); metallic 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-dispersive spectroscopy analysis also prove that the titanium-aluminum intermetallic bonding layer is an intermetallic compound layer with a metallurgical bond.

[0080] It can be easily seen from the above embodiments of the present application that the titanium-aluminum bimetallic composite structure of the present application has the characteristics of high strength and toughness. In all embodiments, the shear strength is greater than 80 MPa. As understood, since the shear strength of titanium-aluminum bonding acceptable in the prior art is less than 50 MPa, the present application provides a titanium-aluminum composite structure with a shear strength of the bonding surface greater than 50 MPa, 60 MPa, 70 MPa, or 80 MPa.

[0081] On the other hand, the present application also provides a new material that is light in weight and low in cost. The cost of the titanium-aluminum composite plate of the present application is reduced by more than 80% compared with that of the all-titanium alloy frame; it is comparable to the cost of the all-aluminum plate. Moreover, since the aluminum material replaces the titanium material, the titanium-aluminum composite plate of the present application has good heat dissipation performance. According to the test results, the heat conduction ability of the titanium-aluminum composite plate of the present application is more than twice that of the titanium alloy, and it has broad application prospects.

[0082] The titanium-aluminum bimetallic material of the present application is suitable for use in electronic products. Taking the preparation of the middle frame of electronic products as an example, the technical solution of the present application will be further described below. Of course, as is understood, the middle frame of electronic products or mobile phones of electronic products is only a specific application of the present application. The application of the present application is not limited thereto.

[0083] IV. Embodiments of the Middle Frame of Electronic Products

[0084] 1. The middle frame of electronic products is made by the following steps:

[0085] (1) Provide a titanium alloy plate, and form the titanium alloy frame by punching or cutting the titanium alloy plate;

[0086] (2) Pickle the titanium alloy frame to remove the oxide film;

[0087] (3) Hot dip aluminum alloy on the inner side surface of the titanium alloy frame to form an intermetallic compound ring;

[0088] (4) Place the titanium alloy frame with the intermetallic compound ring into the inner part of the accommodating cavity of the preparation mold that has been heated to the preheating temperature;

[0089] (5) Pour a predetermined volume of aluminum alloy solution into the filling cavity surrounded by the titanium alloy frame, and the temperature of the aluminum alloy solution is at least 50 °C higher than the liquidus temperature, for making and forming an aluminum alloy support plate; wherein, the predetermined volume of aluminum alloy liquid can at least cover the filling cavity surrounded by the titanium metal frame

[0090] (6) Pressurize the aluminum alloy liquid within a predetermined pressure range and maintain it for a predetermined time until the aluminum alloy solidifies, forming a titanium-aluminum bimetallic composite plate composed of the titanium alloy frame and the aluminum alloy core body inside the frame.

[0091] (7) Perform heat treatment strengthening on the titanium-aluminum bimetal composite plate, which includes T5 heat treatment, T6 heat treatment, T7 heat treatment, or T8 heat treatment.

[0092] Among them, the process of hot-dip aluminizing includes the following steps: placing solid aluminum or aluminum alloy for hot-dip aluminizing in a crucible and heating it to 710 - 750 °C to melt and form an aluminum or aluminum alloy solution; immersing the titanium alloy frame in the aluminum or aluminum alloy solution under the protection of an inert gas and keeping it warm within the temperature range of 650 - 680 °C for 30 - 50 minutes; taking out the titanium alloy frame with the formed intermetallic compound ring and air-cooling it on a silica-aluminum fiber blanket.

[0093] In some embodiments, it further includes the step of alkali-washing the titanium alloy frame hot-dip aluminized with the intermetallic compound ring. In some embodiments, it further includes encapsulating the accommodation cavity containing the titanium alloy frame and continuously introducing an inert gas into the accommodation cavity.

[0094] In some embodiments, the preheating temperature range of the mold is 200 °C - 400 °C. In some embodiments, the range of the predetermined pressure is 30 - 200 Mpa. In some embodiments, the range of the predetermined time is 30 - 50 min.

[0095] 2. Structure of the middle frame of electronic products

[0096] Figure 5 Shows a schematic diagram of the electronic middle frame according to an embodiment of the present application. Figure 6 Is a partial enlarged view of an embodiment of the present application. Figure 7 Shows a cross-sectional view of the electronic middle frame according to an embodiment of the present application. As Figures 5 - 7 Shown, the middle frame of the electronic product of the present application includes: a frame body 1 made of titanium or titanium alloy and a support plate 2 made of aluminum or aluminum alloy. The support plate 2 and the frame body 1 are connected to each other through metallurgical bonding. Refer to Figure 6 , there is an intermetallic bonding layer 3 between the support plate 2 and the frame body 1; wherein, the thickness of the intermetallic bonding layer is between 5.0 - 500 microns.

[0097] According to an embodiment of the present application, the thickness of the intermetallic bonding layer can also be between 5.0 - 300 microns; or, between 10 - 200 microns; or, between 20 - 150 microns.

[0098] According to an embodiment of the present application, the intermetallic bonding layer is a high-pressure liquid-phase 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 50 MPa, 60 MPa, 70 MPa, or 80 MPa. The yield strength of the intermetallic bonding layer is greater than 350 MPa. The elongation rate of the intermetallic bonding layer is between 5% and 15%.

[0099] Reference Figure 7 , the support plate includes a first part 21 composite with the frame body and a second part 22 connected to the first part 21. As shown in the figure, the thickness of the first part 21 is greater than the thickness of the second part 22. The first part 21 is seamlessly attached to the frame body 1. In some embodiments, the side of the first part 21 facing the inside of the frame body further includes microstructures such as screw holes, card slots, and bosses for installing various parts of the electronic product. In some embodiments, the second part 22 of the support plate 2 includes a plurality of regular or irregular vertical holes 23, grooves or bosses 24 for installing parts such as cameras, batteries, and main boards.

[0100] Reference Figure 7 , the frame body 1 includes an inner surface 11 and an outer surface 12. The inner surface 11 is composite with the support plate 2. The height of the inner surface 11 is equal to the height of the first part 21 of the support plate 2. In some embodiments, the height of the inner surface 11 of the frame body 1 can be greater than the height of the first part 21 of the support plate 2.

[0101] In some embodiments, there is a machining allowance of 0.5 - 1 mm on the upper and lower surfaces and the inner and outer surfaces of the frame body. In some embodiments, the intersection of the outer frame and the support plate has a rounded transition. In some embodiments, the outer surface of the frame body is smooth and the inner surface includes one or more concave and convex parts.

[0102] In other words, the present application provides a middle frame of an electronic product, including: a frame body made of titanium or titanium alloy; a support plate made of aluminum or aluminum alloy; the support plate and the frame body are interconnected by metallurgical bonding, wherein there is an intermetallic bonding layer between the support plate and the frame body; wherein, the thickness of the intermetallic bonding layer is between 5.0 - 500 microns.

[0103] Optionally, 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.

[0104] Optionally, the intermetallic bonding layer is a high-pressure liquid-phase metal composite layer between the titanium or titanium alloy and the aluminum or aluminum alloy.

[0105] Optionally, the shear strength of the intermetallic bonding layer is greater than 50 MPa, 60 MPa, 70 MPa, or 80 MPa.

[0106] Optionally, the yield strength of the intermetallic bonding layer is greater than 350 MPa.

[0107] Optionally, the elongation of the intermetallic bonding layer is between 5% and 15%.

[0108] Optionally, the support plate includes a first part composite with the frame body and a second part connected to the first part, and the thickness of the first part is greater than that of the second part.

[0109] Optionally, the second part of the support plate includes one or more of the following structures: holes, card slots, and bosses.

[0110] Optionally, the frame body includes an inner surface and an outer surface, the inner surface is composite with the support plate; the height of the inner surface is greater than or equal to the height of the first part of the support plate.

[0111] Optionally, the outer surface of the frame body is smooth and the inner surface includes one or more concave-convex parts.

[0112] 3. Performance Test of the Middle Frame Embodiment of Electronic Products

[0113]

[0114]

[0115] In summary, the above embodiments of the present application illustrate the following advantages of the present application:

[0116] (1) Wide application range: The titanium-aluminum bimetal structure of the present application can be further processed according to the specific dimensions and layouts of electronic product parts to manufacture middle frames of various types of electronic products, with strong versatility and wide application range.

[0117] (2) Good strength and toughness: The middle frame made of the titanium-aluminum bimetal plate of the present application has high strength, good impact toughness, high anti-drop failure ability, and is not easily damaged and deformed;

[0118] (3) Light weight and low cost: The middle frame made of the titanium-aluminum bimetal plate of the present application can be integrally formed at one time, without welding joints and solder joints, with small processing amount, and the cost is reduced by more than 80% compared with the all-titanium alloy middle frame, and the cost is reduced by 10% compared with the mobile phone middle frame processed by the aluminum plate.

[0119] (4) Good heat dissipation performance: The middle frame made of the titanium-aluminum bimetal plate of the present application can be widely used in communication electronic products and is not easily heated.

[0120] The above embodiments are only for illustrating the present application and are not intended to limit the present application. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the scope of the present application. Therefore, all equivalent technical solutions should also fall within the scope of the disclosure of the present application.

Claims

1. A middle frame of an electronic product, characterized in that: include: Frame of titanium or titanium alloy; Aluminum or aluminum alloy support plate; The support plate and the frame are connected to each other through metallurgical bonding, wherein a metal bonding layer is included between the support plate and the frame; wherein the thickness of the metal bonding layer is between 5.0 and 500 microns.

2. The middle frame of the electronic product according to claim 1, characterized in that: 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 middle frame of the electronic product according to claim 1, 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.

4. The middle frame of the electronic product according to claim 1, characterized in that: The shear strength of the metal-to-metal bonding layer is greater than 50 MPa, 60 MPa, 70 MPa, or 80 MPa.

5. The middle frame of the electronic product according to claim 1, characterized in that: The yield strength of the intermetallic bonding layer is greater than 350MPa.

6. The middle frame of the electronic product according to claim 1, characterized in that: The elongation of the metal bonding layer is between 5% and 15%.

7. The middle frame of the electronic product according to claim 1, characterized in that: The support plate includes a first part compounded with the 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.

8. The middle frame of the electronic product according to claim 7, characterized in that: The second portion of the support plate includes one or more of the following structures: a hole, a slot, and a boss.

9. The middle frame of the electronic product according to claim 7, characterized in that: The frame includes an inner surface and an outer surface, and the inner surface is compounded with the support plate; the height of the inner surface is greater than or equal to the height of the first portion of the support plate.

10. The middle frame of the electronic product according to claim 9, characterized in that: The outer surface of the frame is smooth and the inner surface includes one or more concave and convex parts.

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