Electronic equipment, rotating shaft decorating part and manufacturing method of rotating shaft decorating part

Abstract

The embodiment of the invention discloses electronic equipment, a rotating shaft decorating part and a manufacturing method of the rotating shaft decorating part. The rotating shaft decorating part is used for decorating a rotating shaft of the electronic equipment and comprises an outer shell, an inner shell and a connecting layer, the outer shell is of a long-strip cover body structure, the inner shell is located on the inner side of the outer shell, the connecting layer is located between the inner shell and the outer shell and connects the inner shell and the outer shell, and the outer shell, the connecting layer and the inner shell are an integrally-formed structural part. The outer shell is made of a first metal material, the inner shell is made of a second metal material, the hardness of the first metal material is larger than that of the second metal material, the connecting layer comprises the first metal material and the second metal material, and main components of the first metal material are gradually reduced in the direction from the outer shell to the inner shell. And the content of main group elements of the second metal material is gradually increased in the direction from the outer shell to the inner shell. The rotating shaft decorating part is small in thickness and low in deformation risk.

Description

Technical Field

[0001] The present application relates to the technical field of foldable electronic products, and in particular to an electronic device, a hinge decoration and a manufacturing method thereof. Background Art

[0002] An inward-foldable electronic device generally comprises two housings, a rotating assembly and a rotating shaft decoration. The rotating assembly connects the two housings so that the two housings can be relatively unfolded or folded. The rotating shaft decoration is used to be fixed to the back side of the rotating shaft of the rotating assembly to decorate or cover the rotating shaft, thereby improving the appearance of the electronic device.

[0003] Since the shaft decoration is located on the back side of the shaft and is stacked with the shaft, the thickness of the shaft decoration affects the thickness of the shaft area of ​​the electronic device, and then affects the overall thickness of the electronic device. Therefore, the industry expects to reduce the thickness of the shaft decoration. However, the reduction in the thickness of the shaft decoration will increase the risk of deformation of the shaft decoration and reduce the reliability of the shaft decoration. Therefore, how to achieve a small thickness and low deformation risk of the shaft decoration is a technical problem that needs to be solved at present. Summary of the invention

[0004] The embodiment of the present application provides an electronic device, a rotating shaft decoration and a manufacturing method thereof. The rotating shaft decoration has a small thickness and a low risk of deformation.

[0005] In a first aspect, the implementation of the present application provides a rotating shaft decoration, which is applied to a foldable electronic device and used to decorate the rotating shaft of the electronic device. The rotating shaft decoration can be a long cover structure. Exemplarily, the middle part of the rotating shaft decoration is recessed relative to its periphery, and the rotating shaft decoration forms a receiving space.

[0006] The rotating shaft decoration part includes an outer shell, an inner shell and a connecting layer. The outer shell is a long cover structure, the inner shell is located on the inner side of the outer shell, the connecting layer is located between the inner shell and the outer shell and connects the inner shell and the outer shell, and the outer shell, the connecting layer and the inner shell are an integrally formed structural part. The outer shell adopts a first metal material, the inner shell adopts a second metal material, and the connecting layer includes a first metal material and a second metal material.

[0007] In this implementation, since the outer shell is made of the first metal material, the inner shell is made of the second metal material, the connecting layer includes the first metal material and the second metal material, and the connecting layer is connected between the outer shell and the inner shell, the connecting layer can improve the interface bonding strength between the outer shell and the inner shell, so that the connection strength between the outer shell and the inner shell is high, and the overall structure of the integrated structural member formed by the outer shell, the connecting layer and the inner shell is stable and reliable. At this time, the overall structure of the rotating shaft decorative member is stable and reliable.

[0008] In addition, the inner shell is located on the inner side of the outer shell. The outer shell is mainly used to form the appearance structure of the shaft decoration, and the inner shell is mainly used to form the internal structure of the shaft decoration. Since the first metal material used in the outer shell is different from the second metal material used in the inner shell, the combination of the first metal material and the second metal material can make the appearance structure and internal structure of the shaft decoration meet product requirements and preparation requirements.

[0009] In some possible implementations, the hardness of the first metal material is greater than the hardness of the second metal material.

[0010] In this implementation, the shaft decoration adopts a composite structure of an outer shell and an inner shell, and the outer shell adopts a first metal material with higher hardness, and the material hardness of the outer shell is greater than the material hardness of the inner shell. Compared with the shaft decoration using the same material, the shaft decoration in this implementation can reduce the thickness of the outer shell while keeping the risk of deformation low by increasing the material hardness of the outer shell, thereby reducing the thickness of the large wall structure of the shaft decoration, so that the thickness of the shaft decoration is small and the risk of deformation is low. At this time, the shaft area thickness of the electronic device using the shaft decoration can be designed to be a small value, which is conducive to the thinning of the electronic device. In some possible implementations of the present application, the large wall thickness of the shaft decoration can be less than or equal to 0.35mm, for example, it can be 0.25mm, 0.3mm, etc.

[0011] Furthermore, since the shell is made of a first metal material with higher hardness, the risk of the hinge decoration being scratched by the first shell and the second shell of the electronic device during the unfolding or folding of the electronic device is lower, and the hinge decoration has better scratch resistance and wear resistance.

[0012] In addition, the specific shape of the inner shell is usually formed by mechanical processing. In this implementation, the inner shell adopts a second metal material with lower hardness, which is conducive to reducing the difficulty and processing time of mechanical processing, thereby improving the processing efficiency of the shaft decoration and reducing the difficulty and cost of processing. Since the material hardness of the inner shell is relatively low, although a large area of ​​mechanical processing is required, the residual stress after mechanical processing is small, so the risk of deformation of the inner shell due to stress release is relatively small, which is conducive to the inner shell maintaining a high-precision shape. The inner shell has a high flatness, which makes the production yield of the shaft decoration higher.

[0013] In some possible implementations, the content of the main group elements of the first metal material of the connecting layer gradually decreases from the outer shell to the inner shell, and the content of the main group elements of the second metal material of the connecting layer gradually increases from the outer shell to the inner shell.

[0014] In this implementation, the outer shell is made of a first metal material, and the content of the main group elements of the first metal material of the connecting layer changes from high to low in the direction from the outer shell to the inner shell. The inner shell is made of a second metal material, and the content of the main group elements of the second metal material of the connecting layer changes from low to high in the direction from the outer shell to the inner shell. Therefore, the outer shell and the connecting layer have a good bonding effect, and the inner shell and the connecting layer have a good bonding effect. A higher connection strength can be obtained between the outer shell and the inner shell through the connecting layer, so that the overall structure of the shaft decorative component is more stable and reliable.

[0015] In some possible implementations, the outer shell, the connecting layer and the inner shell are formed by an insert powder metallurgy process. In the preparation process of the insert powder metallurgy process, the insert is first prepared, and then the insert and the powder of the connecting insert are sintered together to finally form an integrally formed structural part. Among them, the outer shell is formed by an insert made of a first metal material, the inner shell is formed by sintering a powder of a second metal material, and the connecting layer is formed by mutual diffusion of the first metal material and the second metal material.

[0016] In this implementation, since the outer shell, connecting layer and inner shell of the rotating shaft decorative part are integrally formed structural parts formed by the insert powder metallurgy process, based on the metal interdiffusion effect during the sintering process, an interdiffusion layer with a composition gradient can be formed between the outer shell formed by the insert and the inner shell formed by the powder, that is, a connecting layer in which the first metal material and the second metal material diffuse with each other is formed. At this time, the formation of the connecting layer significantly improves the interface bonding strength between the outer shell and the inner shell, so that the connection strength between the outer shell and the inner shell is high, and the overall structure of the outer shell, the connecting layer and the inner shell is stable and reliable.

[0017] In addition, the connection layer as the bonding interface is formed during the sintering process due to the metal interdiffusion effect, and the thickness of the connection layer is relatively large, so the connection strength of the outer shell, the inner shell and the connection layer is high. Moreover, during the manufacturing process, the rotating shaft decorative part can control the shape of the bonding interface between the outer shell and the inner shell by controlling the shape of the surface of the insert used to contact the powder. The shape control of the bonding interface is easy to achieve, highly flexible and highly accurate, so that the outer shell, the inner shell and the connection layer have high processing accuracy while having a high connection strength. In addition, since the shape of the bonding interface is easy to control, the actual thickness of the outer shell and the inner shell can be close to or equal to the designed thickness while meeting the design requirements, so that the thickness of the rotating shaft decorative part can be reasonably controlled.

[0018] In some possible implementations, the elastic modulus of the first metal material is greater than the elastic modulus of the second metal material, so that the shell has a stronger ability to resist elastic deformation, thereby reducing the risk of deformation of the rotating shaft decorative component.

[0019] In some possible implementations, the yield strength of the first metal material is greater than the yield strength of the second metal material. In this implementation, the shell of the shaft decoration is made of the first metal material with greater yield strength, so that the shell has a stronger ability to resist slight plastic deformation, thereby reducing the deformation risk of the shaft decoration.

[0020] In some possible implementations, the density of the second metal material is less than that of the first metal material. In this implementation, the inner shell of the shaft decoration piece uses the second metal material with a smaller density, so that the mass of the inner shell is smaller, which is conducive to the lightweight of the shaft decoration piece.

[0021] In some possible implementations, the thermal conductivity of the second metal material is greater than that of the first metal material. In this implementation, the inner shell of the shaft decoration is made of the second metal material with a larger thermal conductivity, so that the inner shell has high thermal conductivity, which is beneficial to improve the heat dissipation performance of the shaft decoration.

[0022] In some possible implementations, the hardness of the first metal material is greater than or equal to 150 HV, and / or the elastic modulus of the first metal material is greater than or equal to 80 GPa, and / or the yield strength of the first metal material is greater than or equal to 200 MPa; and / or the density of the second metal material is less than or equal to 3.5 g / cm 3 ; and / or, the thermal conductivity of the second metal material is greater than or equal to 50 W / m·K.

[0023] In some possible implementations, the first metal material is stainless steel or titanium alloy. In this case, the shell has higher hardness, higher elastic modulus and higher strength.

[0024] In some possible implementations, the second metal material is an aluminum alloy, a particle-reinforced aluminum-based composite material, a magnesium alloy, or a particle-reinforced magnesium-based composite material. In this case, the inner shell has a smaller density and a higher thermal conductivity.

[0025] In some implementations of the present application, the outer shell of the shaft decorative part is made of stainless steel or titanium alloy material, and the inner shell is made of aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material, so that the large-surface wall thickness of the shaft decorative part is smaller, the deformation resistance is better, the wear resistance is better, the strength and rigidity are higher, the processing difficulty is less, the cost is lower, the dimensional accuracy and flatness are higher, the mass is smaller, and the thermal conductivity is better.

[0026] In some possible implementations, the thickness of the connection layer is greater than or equal to 0.1 μm.

[0027] In this implementation, the thickness of the connecting layer is relatively large, that is, the thickness of the bonding interface between the outer shell and the inner shell is relatively large, so that the interface bonding strength between the outer shell and the inner shell is high and the risk of interface cracking is low. Therefore, the connection strength between the outer shell and the inner shell is high, and the overall structure of the outer shell, the connecting layer and the inner shell is stable and reliable.

[0028] In some possible implementations, the thickness of the connection layer is greater than or equal to 2 μm.

[0029] In some possible implementations, the thickness of the connecting layer is in the range of 2 μm to 30 μm. In this case, the shaft decoration can meet the bonding strength requirements between the outer shell and the inner shell, and the preparation time is short and the preparation cost is low, which is conducive to large-scale production.

[0030] In some possible implementations, the connection layer includes a first interface and a second interface, the first interface connects the outer shell, and the second interface connects the inner shell. The first interface and the second interface are visible in the metallographic structure of the rotating shaft decorative part. Since the connection layer is an interdiffusion layer formed during the sintering process, the first metal material of the outer shell and the second metal material of the inner shell are dissimilar metal materials, so the first interface connecting the connection layer and the outer shell, and the first interface connecting the connection layer and the inner shell can be clearly observed in the metallographic structure.

[0031] In some possible implementations, the overall shape of the first interface and the second interface can be designed according to the shape of the rotating shaft decorative part, for example, a curved surface. Among them, since the connecting layer is formed by the metal interdiffusion effect during the sintering process, the multiple regions of the connecting layer arranged in the layer direction (i.e., perpendicular to the thickness direction of the connecting layer) are subjected to a relatively uniform force during the sintering process, so the thickness of the multiple regions is equal or approximately equal, the overall thickness of the connecting layer is equal or approximately equal, and the first interface and the second interface can be parallel or approximately parallel to each other.

[0032] In some possible implementations, in the metallographic structure of the shaft decorative part, the first interface can be parallel to or approximately parallel to the second interface. At this time, since the parts of the connecting layer are of equal thickness, the diffusion degree between the first metal material and the second metal material in the parts of the connecting layer is equal, the bonding strength between the parts of the connecting layer and the outer shell is the same or approximately the same, and the bonding strength between the parts of the connecting layer and the inner shell is also the same or approximately the same, thereby effectively avoiding the shaft decorative part from cracking at the place where the bonding strength between the connecting layer and the outer shell is weak, or cracking at the place where the bonding strength between the connecting layer and the inner shell is weak, which is beneficial to improving the overall structural stability of the shaft decorative part and extending the service life of the shaft decorative part.

[0033] In some possible implementations, the inner shell includes a shell portion and a matching portion, and the outer surface of the shell portion is connected to the connecting layer. The shell portion, the connecting layer and the outer shell form a laminated structure. The shell portion may be a long cover structure, and the shape of the shell portion may be similar to that of the outer shell. The matching portion is provided on the inner surface of the shell portion, and the matching portion includes at least one protrusion and / or at least one groove. The matching portion may be used to achieve connection and matching between the rotating shaft decorative member and the rotating shaft.

[0034] In this implementation, the shell portion of the inner shell, the connecting layer and the outer shell together form a laminated structure, which is the large wall structure of the shaft decoration, and is the main structure of the shaft decoration. The large wall structure can be a long cover structure as a whole. In the implementation of this application, the thickness of the large wall structure of the shaft decoration can be regarded as the thickness of the shaft decoration. By reducing the thickness of the large wall structure of the shaft decoration, the thickness of the shaft decoration can be reduced.

[0035] In some possible implementations, the outer shell includes an outer surface disposed away from the inner shell, and the shaft decoration piece also includes an appearance decoration layer fixed to the outer surface of the outer shell. The appearance decoration layer can decorate the shaft decoration piece in terms of color, pattern, texture, etc.

[0036] In addition, the first metal material used for the shell is titanium alloy or stainless steel, so the appearance decoration layer formed on the outer surface of the shell through PVD treatment has good adhesion to the shell, is not easy to fall off, has high reliability, strong scratch resistance, and long service life.

[0037] In some possible implementations, the inner shell includes an inner surface disposed away from the outer shell, and the rotating shaft decorative member further includes a surface anti-corrosion layer, and the surface anti-corrosion layer is fixed to the inner surface of the inner shell. The surface anti-corrosion layer is used to improve the corrosion resistance and durability of the inner shell, so as to improve the reliability and service life of the rotating shaft decorative member.

[0038] In some implementations, part of the inner surface of the inner shell is a laser-engraved area, which has better surface energy and can enhance the connection strength with adhesives (such as double-sided tape, glue, etc.) to facilitate the fixation of other structural parts.

[0039] In a second aspect, the implementation method of the present application also provides an electronic device, including a screen, a first shell, a second shell, a rotating assembly and a rotating shaft decoration of any of the above items. The rotating assembly connects the first shell and the second shell so that the first shell and the second shell can be relatively unfolded or folded. The screen is fixedly connected to the first shell and the second shell. In this way, the screen can move with the first shell and the second shell. The rotating assembly includes a rotating shaft. The rotating shaft decoration is fixed to the side of the rotating shaft facing away from the screen. Among them, the rotating shaft decoration can be roughly in the form of a long cover structure, so as to cover one side of the rotating shaft.

[0040] In the present application, the hinge decoration of the electronic device has a smaller thickness and a smaller risk of deformation, thereby ensuring mechanical reliability and facilitating the thinning of the shaft area of ​​the electronic device.

[0041] In some possible implementations, when the first shell and the second shell are relatively unfolded to an open state, the shaft decoration is located between the shaft and the first shell and the second shell, and the first shell and the second shell jointly cover the shaft decoration. The shaft decoration is hidden between the rotating assembly and the first shell and the second shell.

[0042] When the first shell and the second shell are folded relative to each other to a closed state, at least part of the rotating shaft decoration is exposed relative to the first shell and the second shell. At this time, the rotating shaft decoration forms a part of the appearance of the electronic device, and the rotating shaft decoration can cover the rotating component and decorate the rotating shaft, thereby improving the appearance consistency and aesthetics of the electronic device and making it easier for users to hold the electronic device.

[0043] In this implementation, when the electronic device is in an open state, the shaft decoration is located between the first shell and the second shell, and the shaft decoration is stacked with the shaft and part of the first shell and the second shell. The thickness of the shaft decoration directly affects the thickness of the shaft area of ​​the electronic device. When the electronic device is in a closed state, the two sides of the shaft decoration are respectively located between the shaft and the first shell and the second shell, and the thickness of the shaft decoration also affects the thickness of the shaft area. The shaft decoration can have a smaller thickness when the risk of its own deformation is small and the reliability is met, so the thickness of the shaft area of ​​the electronic device can be smaller, which is conducive to the thinning of the electronic device.

[0044] In a third aspect, the implementation of the present application further provides a method for manufacturing a rotating shaft decoration, the manufacturing method comprising:

[0045] The metal powder is deposited in the inner space of the initial shell to form a part to be sintered; wherein the initial shell is a long cover structure and is made of a first metal material, and the metal powder is made of a second metal material, and the hardness of the first metal material is greater than that of the second metal material;

[0046] Sintering the to-be-sintered part to form a sintered part; wherein the sintered part comprises a first component, a second component and a transition layer connecting the first component and the second component, the material of the first component is a first metal material, the material of the second component is a second metal material, the material of the transition layer comprises the first metal material and the second metal material, and the content of the main group element of the first metal material gradually decreases from the first component to the second component, and the content of the main group element of the second metal material gradually increases from the first component to the second component; and,

[0047] The sintered part is processed to form a rotating shaft decoration part; wherein the rotating shaft decoration part includes an outer shell, an inner shell and a connecting layer, the outer shell is formed by the first component, the inner shell is formed by the second component, and the connecting layer is formed by the transition layer.

[0048] In the manufacturing method of the rotating shaft decoration part of the implementation mode of the present application, the outer shell, inner shell and connecting layer of the rotating shaft decoration part are integrally formed structural parts through the insert powder metallurgy process. Based on the metal interdiffusion effect during the sintering process, an interdiffusion layer with a composition gradient can be formed between the outer shell formed by the insert (i.e., the initial shell) and the inner shell formed by the powder (i.e., the metal powder), that is, a connecting layer in which the first metal material and the second metal material diffuse with each other is formed. The existence of the connecting layer significantly improves the interface bonding strength between the outer shell and the inner shell, so that the connection strength between the outer shell and the inner shell is high, and the overall structure of the outer shell, the connecting layer and the inner shell is stable and reliable.

[0049] Furthermore, during the manufacturing process of the rotating shaft decorative part, the rotating shaft decorative part can control the shape of the bonding interface between the outer shell and the inner shell by controlling the shape of the surface of the initial shell for contacting the metal powder. The shape control of the bonding interface is easy to achieve, highly flexible, and highly accurate, so that the outer shell, the inner shell, and the connecting layer have high processing accuracy when having a high connection strength. In addition, since the shape of the bonding interface is easy to control, the actual thickness of the outer shell and the inner shell can be close to or equal to the designed thickness when the design requirements are met, so that the thickness of the rotating shaft decorative part can be reasonably controlled.

[0050] In the implementation of the present application, the rotating shaft decoration piece adopts a composite structure of an outer shell and an inner shell, and the outer shell adopts a first metal material with a higher hardness, and the material hardness of the outer shell is greater than the material hardness of the inner shell. Compared with the rotating shaft decoration piece made of the same material, the rotating shaft decoration piece in the present implementation can reduce the thickness of the outer shell while keeping the risk of deformation low by increasing the material hardness of the outer shell, thereby reducing the thickness of the large wall structure of the rotating shaft decoration piece, so that the thickness of the rotating shaft decoration piece is small and the risk of deformation is low. At this time, the shaft area thickness of the electronic device using the rotating shaft decoration piece can be designed to be a small value, which is conducive to the thinning of the electronic device.

[0051] In addition, the inner shell of the rotating shaft decorative part adopts the second metal material with lower hardness, which is conducive to reducing the difficulty and processing time of the mechanical processing of the billet, thereby improving the processing efficiency of the rotating shaft decorative part and reducing the processing difficulty and cost. In addition, since the material hardness of the inner shell is relatively low, although the billet needs to be machined over a large area, the residual stress after machining is relatively small, so the risk of deformation of the inner shell due to stress release is relatively small, which is conducive to the inner shell maintaining a high-precision shape, and the inner shell has a high flatness, so that the manufacturing yield of the rotating shaft decorative part is relatively high.

[0052] In some possible implementations, the elastic modulus of the first metal material is greater than the elastic modulus of the second metal material, and / or the yield strength of the first metal material is greater than the yield strength of the second metal material, and / or the density of the second metal material is less than the density of the first metal material, and / or the thermal conductivity of the second metal material is greater than the thermal conductivity of the first metal material.

[0053] At this time, the outer shell of the shaft decoration has a strong ability to resist elastic deformation and slight plastic deformation, the deformation risk of the shaft decoration is low, the structural reliability is high, and the mass of the inner shell of the shaft decoration is small, which is conducive to the lightweight of the shaft decoration. The thermal conductivity of the inner shell is better, which is conducive to improving the heat dissipation performance of the shaft decoration.

[0054] In some possible implementations, the hardness of the first metal material is greater than or equal to 150 HV, and / or the elastic modulus of the first metal material is greater than or equal to 80 GPa, and / or the yield strength of the first metal material is greater than or equal to 200 MPa; and / or the density of the second metal material is less than or equal to 3.5 g / cm 3 ; and / or, the thermal conductivity of the second metal material is greater than or equal to 50 W / m·K.

[0055] In some possible implementations, the first metal material is stainless steel or titanium alloy; and / or the second metal material is aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material.

[0056] At this time, the outer shell of the shaft decoration is made of stainless steel or titanium alloy, and the inner shell is made of aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material, so that the large-surface wall thickness of the shaft decoration is smaller, the deformation resistance is better, the wear resistance is better, the strength and rigidity are higher, the processing difficulty is less, the cost is lower, the dimensional accuracy and flatness are higher, the mass is smaller, and the thermal conductivity is better.

[0057] In some possible implementations, the step of sintering the part to be sintered includes:

[0058] Sintering the sintered part by hot isostatic pressing;

[0059] The pressure P1 of the hot isostatic pressing sintering process satisfies: P1 ≥ 100 MPa; the temperature T1 of the hot isostatic pressing sintering process satisfies: 500° C. ≤ T1 ≤ 660° C.; and the time t1 of the hot isostatic pressing sintering process satisfies: 2 h ≤ t1 ≤ 5 h.

[0060] In the present implementation, by performing hot isostatic pressing on the sintered part, the mutual diffusion degree of the first metal material and the second metal material is effectively improved, so that the transition layer thickness of the sintered part is larger, and therefore the connecting layer thickness of the shaft decorative part is larger, and the bonding interface thickness between the outer shell and the inner shell is larger, so that the interface bonding strength between the outer shell and the inner shell is high, and the risk of interface cracking is low. Therefore, the connection strength between the outer shell and the inner shell is high, and the overall structure of the outer shell, the connecting layer and the inner shell is stable and reliable.

[0061] In some possible implementations, after the step of forming the part to be sintered and before the step of sintering the part to be sintered, the manufacturing method further includes: cold isostatic pressing the part to be sintered. After the part to be sintered is cold isostatic pressing, the metal powder is pre-pressed to facilitate the subsequent sintering process.

[0062] In some possible implementations, the thickness of the connection layer is greater than or equal to 0.1 μm; or, the thickness of the connection layer is greater than or equal to 2 μm; or, the thickness of the connection layer is in a range of 2 μm to 30 μm.

[0063] In some possible implementations, after the step of forming the sintered part and before the step of processing the sintered part, the manufacturing method further includes: performing a solution treatment on the sintered part; cooling the sintered part; and performing an aging treatment on the sintered part.

[0064] In this implementation, by performing solid solution aging treatment on the sintered part, the yield strength and / or hardness of the second component of the sintered part can be effectively improved, so that the yield strength and / or hardness of the inner shell of the shaft decorative part can be improved, and the shaft decorative part has better deformation resistance and longer service life.

[0065] In some possible implementations, the second metal material is an aluminum alloy or a particle-reinforced aluminum-based composite material. The solution temperature T2 of the solution treatment satisfies: 500°C ≤ T2 ≤ 550°C, and the solution time t2 satisfies: 15min ≤ t2 ≤ 60min; and / or, the aging temperature T3 of the aging treatment satisfies: 170°C ≤ T3 ≤ 200°C, and the aging time t3 satisfies: 4h ≤ t3 ≤ 24h.

[0066] In some possible implementations, the second metal material is a magnesium alloy or a particle-reinforced magnesium-based composite material. The solution temperature T2 of the solution treatment satisfies: 380°C ≤ T2 ≤ 420°C, and the solution time t2 satisfies: 0.5h ≤ t2 ≤ 12h; and / or, the aging temperature T3 of the aging treatment satisfies: 180°C ≤ T3 ≤ 220°C, and the aging time t3 satisfies: 1h ≤ t3 ≤ 8h. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to illustrate the technical solutions in the embodiments of the present application or the background technology, the drawings required for use in the embodiments of the present application or the background technology will be described below.

[0068] Figure 1 is a structural schematic diagram of an electronic device provided by an embodiment of the present application when it is in an open state;

[0069] Figure 2 yes Figure 1 A schematic diagram of the structure of the electronic device shown in the closed state;

[0070] Figure 3 yes Figure 1 A schematic cross-sectional view of a portion of the structure of the electronic device shown;

[0071] Figure 4 yes Figure 2 A schematic cross-sectional view of a portion of the structure of the electronic device shown;

[0072] Figure 5 yes Figure 3 The structure diagram of the rotating shaft decoration in some embodiments is shown;

[0073] Figure 6 yes Figure 5 The cross-sectional structure diagram of the rotating shaft decoration part is shown along AA;

[0074] Figure 7 yes Figure 6 A schematic diagram of the contents of the main group elements of the first metal material and the second metal material at different positions of the connecting layer of the rotating shaft decorative part;

[0075] Figure 8 yes Figure 6 Schematic diagram of metallographic structure of a partial structure of the rotating shaft decoration in some possible implementations;

[0076] Fig. 9 It is a schematic diagram of a process of manufacturing a rotating shaft decoration provided in an embodiment of the present application;

[0077] Fig.10 yes Fig. 9 Schematic diagram of the structure corresponding to some steps in the manufacturing method of the rotating shaft decoration shown Figure 1 ;

[0078] Fig.11 yes Fig. 9 Schematic diagram of the structure corresponding to some steps in the manufacturing method of the rotating shaft decoration shown Figure 2 ;

[0079] Fig.12 yes Fig. 9 Schematic diagram of the structure corresponding to some steps in the manufacturing method of the rotating shaft decoration shown Figure 3 . DETAILED DESCRIPTION

[0080] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0081] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that the two are connected to each other and the relative position relationship remains unchanged after the connection. "Rotational connection" means that the two are connected to each other and can rotate relative to each other after the connection. "Sliding connection" means that the two are connected to each other and can slide relative to each other after the connection.

[0082] The directional terms mentioned in the embodiments of the present application, such as "up", "down", "left", "right", "inside", "outside", etc., are only references to the directions of the drawings. The directional terms used are for the purpose of illustrating and understanding the embodiments of the present application, rather than indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0083] The limitations of the relative positional relationship mentioned in the embodiments of the present application, such as parallel, vertical, etc. These limitations are all for the current state of the art, rather than being absolutely strict limitations, allowing for a small amount of deviation, approximately parallel, approximately vertical, etc. For example, A is parallel to B, which means that A and B are parallel or approximately parallel, and the angle between A and B can be between 0 and 10 degrees. For example, A is perpendicular to B, which means that A and B are perpendicular or approximately perpendicular, and the angle between A and B can be between 80 and 100 degrees.

[0084] In the embodiments of the present application, "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the previous and subsequent associated objects are in an "or" relationship. "Multiple" means at least two. "Include", "Contain", "Have" and their variations all mean "including but not limited to", unless otherwise specifically emphasized.

[0085] Figure 1 is a structural diagram of an electronic device 100 provided in an embodiment of the present application when it is in an open state. Figure 2 yes Figure 1 The structure diagram of the electronic device 100 is shown in FIG. Figure 1As shown, the electronic device 100 may be a mobile phone, a tablet personal computer, a laptop computer, a personal digital assistant (PDA), a camera, a personal computer, a notebook computer, a wearable device, etc. The following description will be made by taking the mobile phone as an example.

[0086] In some embodiments, Figure 1 and Figure 2 As shown, the electronic device 100 includes a housing device 10 and a screen 20, and the screen 20 is installed on the housing device 10. Figure 1 As shown, the housing device 10 can be unfolded to an open state; Figure 2 As shown, the housing device 10 can also be folded to a closed state. The housing device 10 can also be unfolded or folded to an intermediate state, and the intermediate state can be any state between the open state and the closed state.

[0087] The screen 20 moves with the housing device 10, and the housing device 10 can drive the screen 20 to unfold or fold, so that the electronic device 100 can be unfolded to an open state, or folded to a closed state. When the electronic device 100 is in a closed state, the screen 20 is located inside the housing device 10. It should be understood that when the electronic device 100 is in an open state, the various components of the electronic device 100 are correspondingly in an open state; when the electronic device 100 is in a closed state, the various components of the electronic device 100 are correspondingly in a closed state.

[0088] In this embodiment, when the electronic device 100 is in an open state, the screen 20 is flattened, and the screen 20 can be displayed in full screen, so that the electronic device 100 has a larger display area to improve the user's viewing experience and operation experience. When the electronic device 100 is in a closed state, the plane size of the electronic device 100 is small, which is convenient for the user to carry and store.

[0089] In some embodiments, the screen 20 may be integrated with a display function and a touch sensing function. The display function of the screen 20 is used to display images, videos, etc., and the touch sensing function of the screen 20 is used to sense the user's touch action to achieve human-computer interaction. Among them, the flexible display screen can adopt a liquid crystal display (LCD), an organic light-emitting diode (OLED) display screen, an active-matrix organic light-emitting diode or an active-matrix organic light-emitting diode (AMOLED) display screen, a flexible light-emitting diode (FLED) display screen, a MiniLED display screen, a MicroLED display screen, a Micro-OLED display screen, a quantum dot light emitting diode (QLED) display screen, etc.

[0090] In some embodiments, the electronic device 100 may further include multiple components (not shown in the figure), and the multiple components are installed inside the housing device 10. The multiple components may include, for example, a processor, an internal memory, an external memory interface, a universal serial bus (USB) interface, a charging management module, a power management module, a battery, an antenna, a communication module, a camera, an audio module, a speaker, a receiver, a microphone, an earphone interface, a sensor module, a button, a motor, an indicator, and a subscriber identification module (SIM) card interface. Among them, the electronic device 100 may also have more or fewer components than described above, may combine two or more components, or may have different component configurations. Various components may be implemented in hardware, software, or a combination of hardware and software including one or more signal processing and / or application-specific integrated circuits.

[0091] Figure 3 yes Figure 1 A schematic cross-sectional view of a partial structure of the electronic device 100 is shown; Figure 4 yes Figure 2 A schematic cross-sectional diagram of a partial structure of the electronic device 100 is shown.

[0092] In some embodiments, Figures 1 to 4 As shown, the housing device 10 may include a first housing 1 , a second housing 2 , a rotating assembly 3 and a rotating shaft decoration 4 .

[0093] Exemplarily, the rotating assembly 3 connects the first shell 1 and the second shell 2 so that the first shell 1 and the second shell 2 can be relatively unfolded or relatively folded. Wherein, through the movement of the rotating assembly 3, the first shell 1 and the second shell 2 can be relatively unfolded to an open state, or relatively folded to a closed state. Wherein, the screen 20 is fixedly connected to the first shell 1 and the second shell 2, so that the screen 20 can move with the first shell 1 and the second shell 2.

[0094] When the electronic device 100 is in an open state, the angle between the first shell 1 and the second shell 2 can be approximately 180°, and the first shell 1 and the second shell 2 are flat; or, the angle between the first shell 1 and the second shell 2 can also be slightly deviated from 180°, such as 165°, 177° or 185°. When the electronic device 100 is in a closed state, the angle between the first shell 1 and the second shell 2 can be approximately 0°, and the first shell 1 and the second shell 2 are folded; or, the angle between the first shell 1 and the second shell 2 can also be slightly deviated from 0°, such as 3°, 5° or 10°.

[0095] For example, Figure 3 to Figure 4 As shown, the rotating assembly 3 may include a rotating shaft 31, a first connecting portion 32, and a second connecting portion 33. The first connecting portion 32 connects the rotating shaft 31 and the first housing 1, and the second connecting portion 33 connects the rotating shaft 31 and the second housing 2. The first connecting portion 32 can move relative to the rotating shaft 31 and the first housing 1, so that the first housing 1 can move relative to the rotating shaft 31; the second connecting portion 33 can move relative to the rotating shaft 31 and the second housing 2, so that the second housing 2 can move relative to the rotating shaft 31.

[0096] Among them, Figure 3 to Figure 4 As shown, the rotating shaft decoration member 4 is located below the rotating assembly 3 and is fixedly connected to the rotating assembly 3. For example, the rotating shaft decoration member 4 is fixed to the side of the rotating shaft 31 facing away from the screen 20. The rotating shaft decoration member 4 can be roughly in the form of a long cover structure, so as to cover one side of the rotating shaft 31. It can be understood that when the middle part of the structural member is recessed relative to the periphery or both sides of the structural member to form a recessed space, the structural member is considered to be a cover structure, and the embodiment of the present application does not strictly limit the specific size and specific shape of the cover structure.

[0097] like Figure 1 and Figure 3 As shown, when the electronic device 100 is in the open state, the first housing 1 and the second housing 2 jointly cover the rotating shaft decoration 4, and the rotating shaft decoration 4 is hidden between the rotating assembly 3 and the first housing 1 and the second housing 2. Figure 2 and Figure 4As shown, when the electronic device 100 is in a closed state, at least part of the rotating shaft decoration 4 is exposed relative to the first housing 1 and the second housing 2. At this time, the rotating shaft decoration 4 forms a part of the appearance of the electronic device 100, and the rotating shaft decoration 4 can cover the rotating component 3 and decorate the rotating shaft 31, thereby improving the appearance consistency and aesthetics of the electronic device 100, and also making it easier for users to hold the electronic device 100.

[0098] In this embodiment, if Figure 3 As shown, when the electronic device 100 is in the open state, the hinge decoration 4 is located between the first shell 1 and the second shell 2, and the hinge decoration 4 is stacked with the hinge 31 and part of the first shell 1 and the second shell 2. The thickness of the hinge decoration 4 directly affects the thickness of the shaft area of ​​the electronic device 100. Figure 4 As shown, when the electronic device 100 is in a closed state, the two sides of the rotating shaft decoration 4 are respectively located between the rotating shaft 31 and the first shell 1 and the second shell 2, and the thickness of the rotating shaft decoration 4 also affects the thickness of the shaft area of ​​the electronic device 100. Therefore, the embodiment of the present application designs the rotating shaft decoration 4 so that the rotating shaft decoration 4 can have a smaller thickness while the risk of its own deformation is small and the reliability is met, so that the thickness of the shaft area of ​​the electronic device 100 is small, which is conducive to the thinning of the electronic device 100.

[0099] The implementation structure of the rotating shaft decoration part 4 in some embodiments is described below.

[0100] Figure 5 yes Figure 3 The structure diagram of the rotating shaft decoration member 4 in some embodiments is shown in FIG. Figure 6 yes Figure 5 The cross-sectional structure diagram of the rotating shaft decoration member 4 cut along AA is shown in FIG. Figure 7 yes Figure 6 The diagram shows the contents of the main group elements of the first metal material and the second metal material at different positions of the connecting layer of the shaft decoration part 4.

[0101] In some embodiments, Figure 5 and Figure 6 As shown, the shaft decoration member 4 is a long cover structure. For example, the middle part of the shaft decoration member 4 is recessed relative to its periphery, and the shaft decoration member 4 forms a receiving space 41. Figure 3 As shown, the rotating shaft decorative member 4 can accommodate part of the rotating shaft 31 through the accommodating space 41. In some other embodiments, the middle part of the rotating shaft decorative member 4 can also be recessed relative to the two sides thereof. For the convenience of explanation, hereinafter, the side of the rotating shaft decorative member 4 close to the accommodating space 41 is defined as "inner", and the side away from the accommodating space 41 is defined as "outer".

[0102] Exemplarily, the rotating shaft decoration 4 includes an outer shell 42, an inner shell 43 and a connecting layer 44. The outer shell 42 is a long cover structure, and the inner shell 43 is located on the inner side of the outer shell 42. At this time, the above-mentioned accommodating space 41 is located on the inner side of the inner shell 43, and the inner shell 43 is located between the outer shell 42 and the accommodating space 41. The connecting layer 44 is located between the inner shell 43 and the outer shell 42 and connects the inner shell 43 and the outer shell 42. The outer shell 42, the connecting layer 44 and the inner shell 43 are an integrally formed structural member. Among them, the connecting layer 44 includes a first interface 441 and a second interface 442, and the second interface 442 is arranged opposite to the first interface 441. The first interface 441 is connected to the outer shell 42, and the second interface 442 is connected to the inner shell 43. For the convenience of the following description, the direction from the first interface 441 of the connecting layer 44 to the second interface 442 is defined as the thickness direction of the connecting layer 44.

[0103] Exemplarily, the outer shell 42 is made of a first metal material, and the inner shell 43 is made of a second metal material. The second metal material and the first metal material are different materials. The connecting layer 44 includes the first metal material and the second metal material.

[0104] In this embodiment, since the outer shell 42 is made of the first metal material, the inner shell 43 is made of the second metal material, the connecting layer 44 includes the first metal material and the second metal material, and the connecting layer 44 is connected between the outer shell 42 and the inner shell 43, the connecting layer 44 can improve the interface bonding strength between the outer shell 42 and the inner shell 43, so that the connection strength between the outer shell 42 and the inner shell 43 is high, and the overall structure of the integrated structural member formed by the outer shell 42, the connecting layer 44 and the inner shell 43 is stable and reliable. At this time, the overall structure of the rotating shaft decorative member 4 is stable and reliable.

[0105] In addition, the inner shell 43 is located on the inner side of the outer shell 42. The outer shell 42 is mainly used to form the appearance structure of the shaft decoration 4, and the inner shell 43 is mainly used to form the internal structure of the shaft decoration 4. Since the first metal material used in the outer shell 42 is different from the second metal material used in the inner shell 43, the appearance structure and internal structure of the shaft decoration 4 can meet product requirements and preparation requirements through the combination of the first metal material and the second metal material.

[0106] In some embodiments, Figure 7 As shown, Figure 7The diagram shows the variation trend of the content of the main group elements of the first metal material and the content of the main group elements of the second metal material at different positions of the connecting layer 44. The X-axis represents the distance from each part of the connecting layer 44 to the first interface 441 in the thickness direction of the connecting layer 44, and the value X1 corresponds to the distance from the second interface 442 to the first interface 441; the Y-axis represents the content ratio of the main group elements of the material, and the value 1 is 100%. The first metal material and the second metal material are mostly alloy materials, and the main group elements of the alloy material refer to the elements with the highest content in the alloy. In alloys, some other elements are usually added to change their performance and characteristics, but the content of the main group elements is the highest and plays a leading role in the properties of the alloy. The selection and content of the main group elements determine the chemical composition and basic properties of the alloy. For example, for stainless steel, iron is the main group element, and other added elements such as chromium and nickel play a role in improving corrosion resistance. For titanium alloys, titanium is the main group element; for aluminum alloys and particle-reinforced aluminum-based composites, aluminum is the main group element; for magnesium alloys and particle-reinforced magnesium-based composites, magnesium is the main group element.

[0107] The content of the main group element of the first metal material of the connecting layer 44 gradually decreases in the direction from the outer shell 42 to the inner shell 43, and the content of the main group element of the second metal material gradually increases in the direction from the outer shell 42 to the inner shell 43. The direction from the outer shell 42 to the inner shell 43 is parallel to the thickness direction of the connecting layer 44.

[0108] In this embodiment, the outer shell 42 is made of a first metal material, and the content of the main group elements of the first metal material of the connecting layer 44 changes from high to low in the direction from the outer shell 42 to the inner shell 43. The inner shell 43 is made of a second metal material, and the content of the main group elements of the second metal material of the connecting layer 44 changes from low to high in the direction from the outer shell 42 to the inner shell 43. Therefore, the outer shell 42 and the connecting layer 44 have a good bonding effect, and the inner shell 43 and the connecting layer 44 have a good bonding effect. A higher connection strength can be obtained between the outer shell 42 and the inner shell 43 through the connecting layer 44, so that the overall structure of the shaft decorative component 4 is more stable and reliable.

[0109] In some possible implementations, the outer shell 42, the connecting layer and the inner shell 43 can be formed by an insert powder metallurgy process. In the preparation process of the insert powder metallurgy process, an insert is first prepared, and then the insert and the powder of the connecting insert are sintered together to finally form an integrally formed structural member. Among them, the outer shell 42 can be formed by an insert made of a first metal material, the inner shell 43 can be formed by sintering a powder of a second metal material, and the connecting layer can be formed by mutual diffusion of the first metal material and the second metal material.

[0110] In this embodiment, the outer shell 42, the inner shell 43 and the connecting layer 44 are formed into an integrally formed structural part by an insert powder metallurgy process. Based on the metal interdiffusion effect during the sintering process, an interdiffusion layer with a composition gradient can be formed between the outer shell 42 formed by the insert and the inner shell 43 formed by the powder, that is, a connecting layer 44 in which the first metal material and the second metal material diffuse with each other is formed. The existence of the connecting layer 44 significantly improves the interface bonding strength between the outer shell 42 and the inner shell 43, so that the connection strength between the outer shell 42 and the inner shell 43 is high, and the overall structure of the outer shell 42, the connecting layer 44 and the inner shell 43 is stable and reliable.

[0111] Figure 8 yes Figure 6 Schematic diagram of the metallographic structure of a partial structure of the rotating shaft decoration part 4 in some possible implementations.

[0112] like Figure 8 As shown, in some embodiments, the first interface 441 and the second interface 442 are visible in the metallographic structure of the shaft decoration 4. The metallographic structure of the shaft decoration 4 is the internal organizational structure of the shaft decoration 4 seen under a metallographic (optical) microscope. The resolution of the metallographic microscope can be in the micron level, for example, 0.1 micron to 0.5 micron. Since the connecting layer 44 is an interdiffusion layer formed during the sintering process, the first metal material of the outer shell 42 and the second metal material of the inner shell 43 are dissimilar metal materials, the first interface 441 connecting the connecting layer 44 and the outer shell 42, and the first interface 441 connecting the connecting layer 44 and the inner shell 43 can be clearly observed in the metallographic structure.

[0113] Exemplarily, the first interface 441 and the second interface 442 of the connection layer 44 can be relatively smooth interfaces, and slight bumps are allowed on the first interface 441 and the second interface 442. The overall shape of the first interface 441 and the second interface 442 can be designed according to the shape of the shaft decoration 4, for example, it can be a curved surface. Among them, since the connection layer 44 is formed by the metal interdiffusion effect during the sintering process, the multiple regions of the connection layer 44 arranged in its layer direction (i.e., perpendicular to the thickness direction of the connection layer 44) are subjected to more uniform force during the sintering process, so the thickness of the multiple regions is equal or approximately equal, the overall thickness of the connection layer 44 is equal or approximately equal, and the first interface 441 and the second interface 442 can be parallel or approximately parallel to each other.

[0114] like Figure 8As shown, in the metallographic structure of the shaft decorative part 4, the first interface 441 can be parallel to or approximately parallel to the second interface 442. At this time, since the parts of the connecting layer 44 are of equal thickness, the diffusion degree between the first metal material and the second metal material in the parts of the connecting layer 44 is equivalent, the bonding strength between the parts of the connecting layer 44 and the outer shell 42 is the same or approximately the same, and the bonding strength between the parts of the connecting layer 44 and the inner shell 43 is also the same or approximately the same, so that the shaft decorative part 4 can be effectively prevented from cracking at the place where the bonding strength between the connecting layer 44 and the outer shell 42 is weak, or at the place where the bonding strength between the connecting layer 44 and the inner shell 43 is weak, which is beneficial to improve the overall structural stability of the shaft decorative part 4 and extend the service life of the shaft decorative part 4.

[0115] It is understandable that in some other embodiments, the rotating shaft decorative part can also be formed by a stamping and forging process of a heterogeneous metal composite plate. Among them, the heterogeneous metal composite plate is formed by stacking two heterogeneous metal plates together and then forming a composite plate with an integrated structure by means of a rolling mill. Since the heterogeneous metal composite plate presents a plate structure, it needs to be processed by a stamping and forging process to form a product component of a corresponding shape. In this embodiment, the rotating shaft decorative part can be formed of an outer shell and an inner shell by two metals of the heterogeneous metal plate. However, since the bonding interface width of the above-mentioned heterogeneous metal composite structural part is extremely narrow (a structure similar to the previous connection layer is not seen in the metallographic structure), there is a risk of interface cracking between the outer shell and the inner shell during the stamping and forging process, and the shape of the bonding interface is difficult to control, and the dimensional tolerance is large, which easily leads to poor connection strength between the outer shell and the inner shell of the rotating shaft decorative part and low processing accuracy. However, since the shape of the bonding interface is difficult to control, in order to make the metal structures on both sides of the bonding interface meet the design requirements (for example, the outer shell structure is complete, the inner shell structure is complete, the outer shell covers the outer surface of the inner shell, etc.), it is usually necessary to thicken the metal structures on both sides of the bonding interface in the actual product to reduce the occurrence of gaps and fractures that are not required by the design. This will result in a thicker outer shell, a thicker inner shell, and a thicker final shaft decorative part with a heavier weight.

[0116] In the embodiment where the outer shell 42, the inner shell 43 and the connecting layer 44 are formed by the insert powder metallurgy process, the connecting layer 44 as the bonding interface is formed during the sintering process due to the metal interdiffusion effect, and the thickness of the connecting layer 44 is relatively large, so the connection strength of the outer shell 42, the inner shell 43 and the connecting layer 44 is high. In some possible implementations, the shear strength of the connecting layer 44 at the bonding interface between the outer shell 42 and the inner shell 43 is greater than or equal to 100 MPa, and in some implementations it can be as high as 300 MPa, which is much higher than the interface shear strength of the rotating shaft decorative part 4 formed by the stamping and forging process of the heterogeneous metal composite plate. In addition, during the manufacturing process, the rotating shaft decorative part 4 can control the shape of the bonding interface between the outer shell 42 and the inner shell 43 by controlling the shape of the surface of the insert for contacting the powder. The shape control of the bonding interface is easy to implement, highly flexible and highly accurate, so that the outer shell 42, the inner shell 43 and the connecting layer 44 have high processing accuracy while having high bonding strength. In addition, since the shape of the bonding interface is easy to control, the actual thickness of the outer shell 42 and the inner shell 43 can be close to or equal to the designed thickness while meeting the design requirements, so that the thickness of the shaft decoration 4 can be reasonably controlled.

[0117] Exemplarily, the thickness of the connection layer 44 may be greater than or equal to 0.1 μm. For example, the thickness of the connection layer 44 may be greater than or equal to 2 μm, such as 3.6 μm, 5 μm, 6 μm, 8 μm, 12 μm, 15 μm, 20 μm, etc. Alternatively, the thickness of the connection layer 44 may be greater than or equal to 6 μm. Alternatively, the thickness of the connection layer 44 is in the range of 2 μm to 30 μm.

[0118] In this embodiment, the thickness of the connecting layer 44 is relatively large, that is, the thickness of the bonding interface between the outer shell 42 and the inner shell 43 is relatively large, so that the interface bonding strength between the outer shell 42 and the inner shell 43 is high and the risk of interface cracking is low. Therefore, the connection strength between the outer shell 42 and the inner shell 43 is high, and the overall structure of the outer shell 42, the connecting layer 44 and the inner shell 43 is stable and reliable.

[0119] In addition, when the thickness of the connecting layer 44 is less than or equal to 30 μm, the shaft decoration 4 can meet the bonding strength requirements between the outer shell 42 and the inner shell 43 while having a short preparation time and low preparation cost, which is conducive to large-scale production.

[0120] The thickness of the connection layer 44 can be controlled by the sintering process during the manufacturing process of the rotating shaft decorative part 4, for example, by the sintering temperature and the sintering time. When the sintering temperature is higher and the sintering time is longer, the thickness of the connection layer 44 is greater. In addition, the thickness of the connection layer 44 affects the connection strength between the outer shell 42 and the inner shell 43. When no brittle phase is generated in the connection layer 44, the greater the thickness of the connection layer 44, the better. Of course, the thickness design of the connection layer 44 can also take into account the processing efficiency, processing cost and processing difficulty at the same time, and control the thickness of the connection layer 44 within a certain range.

[0121] In some embodiments, Figure 5 and Figure 6 As shown, the inner shell 43 may include a shell portion 431 and a matching portion 432, the outer surface of the shell portion 431 is connected to the connecting layer 44, and the shell portion 431, the connecting layer 44 and the outer shell 42 form a laminated structure. Among them, the shell portion 431 can be a long cover structure, and the shape of the shell portion 431 can be similar to the shape of the outer shell 42. The matching portion 432 is arranged on the inner surface of the shell portion 431, and the inner surface of the shell portion 431 is arranged toward the accommodating space 41, and the matching portion 432 includes at least one protrusion and / or at least one groove. The matching portion 432 can be used to achieve the connection and matching between the rotating shaft decorative part 4 and the rotating shaft. Among them, the matching portion 432 of the inner shell 43 is arranged in a local area of ​​the inner surface of the shell portion 431.

[0122] In this embodiment, the shell portion 431 of the inner shell 43, the connecting layer 44 and the outer shell 42 together form a laminated structure, which is the large wall structure of the shaft decoration 4 and the main structure of the shaft decoration 4. The large wall structure can be a long cover structure as a whole. In the embodiment of the present application, the thickness of the large wall structure of the shaft decoration 4 can be regarded as the thickness of the shaft decoration 4. By reducing the thickness of the large wall structure of the shaft decoration 4, the thickness of the shaft decoration 4 can be reduced.

[0123] In some embodiments, Figure 5 As shown, the mating portion 432 includes at least one protrusion, and the at least one protrusion may include a positioning column 4321 and a fixing column 4322. The positioning column 4321 may be aligned with the rotating shaft 31 (see Figure 3 ), the fixed column 4322 can be used to achieve a fixed connection with the rotating shaft 31.

[0124] In some examples, the matching portion 432 can also be used to increase the structural strength of the rotating shaft decoration 4. For example, at least one protrusion of the matching portion 432 can also include a reinforcing rib 4323, and the reinforcing rib 4323 can enhance the structural strength of the inner shell 43 and the rotating shaft decoration 4. In some other embodiments, at least one protrusion may not include the positioning column 4321, or does not include the fixing column 4322, or does not include the reinforcing rib 4323, and the embodiments of the present application are not strictly limited to this.

[0125] In some embodiments, the hardness of the first metal material is greater than the hardness of the second metal material. Among them, hardness is a performance indicator to measure the hardness of a material, which can be understood as the ability to resist elastic deformation, plastic deformation, residual deformation, resistance and anti-destructive force. Hardness is not a simple physical concept, but the mechanical properties of the material such as elasticity, plasticity, strength and toughness. Exemplarily, the hardness of the first metal material can be greater than or equal to 150HV, for example, 180HV, 200HV, 250HV, 280HV, 300HV, 310HV, 380HV, etc. Among them, HV is the Vickers hardness unit.

[0126] In this embodiment, the rotating shaft decoration 4 adopts a composite structure of an outer shell 42 and an inner shell 43, and the outer shell 42 adopts a first metal material with higher hardness, and the material hardness of the outer shell 42 is greater than the material hardness of the inner shell 43. Compared with the rotating shaft decoration 4 made of the same material, the rotating shaft decoration 4 in this embodiment can reduce the thickness of the outer shell 42 while keeping the risk of deformation low by increasing the material hardness of the outer shell 42, thereby reducing the thickness of the large wall structure of the rotating shaft decoration 4, so that the thickness of the rotating shaft decoration 4 is small and the risk of deformation is low. At this time, the shaft area thickness of the electronic device 100 using the rotating shaft decoration 4 can be designed to be a small value, which is conducive to the thinning of the electronic device 100. In some possible implementations of the present application, the large wall thickness of the rotating shaft decoration 4 can be less than or equal to 0.35mm, for example, it can be 0.25mm, 0.3mm, etc.

[0127] It can be understood that in some embodiments, in a local area of ​​the large wall structure of the hinge decoration 4, the shell portion 431 of the inner shell 43 may be provided with a hollow area, such as forming a groove or a through hole to expose the connecting layer 44 or the outer shell 42 to the accommodating space 41, so that the thickness of the large wall structure in this area is further reduced, so that the hinge decoration 4 can cooperate with other structures of the electronic device 100 to achieve avoidance or other needs.

[0128] like Figure 3 and Figure 4As shown, when the electronic device 100 switches between the open state and the closed state, the first shell 1 and the second shell 2 will both move relative to the hinge decoration 4. In order to make the shaft area thickness of the electronic device 100 smaller, the movable gap between the first shell 1 and the second shell 2 and the hinge decoration 4 is usually also smaller, and the hinge decoration 4 is at risk of being scratched by the first shell 1 and the second shell 2.

[0129] In this embodiment, since the shell 42 is made of a first metal material with higher hardness, the risk of the hinge decoration 4 being scratched by the first shell 1 and the second shell 2 is lower during the unfolding or folding of the electronic device 100, and the hinge decoration 4 has better scratch resistance and better wear resistance.

[0130] In addition, if Figure 6 As shown, after the powder is sintered into an ingot, the inner shell 43 needs to be processed into a specific shape through CNC (Computer numerical control) and other mechanical processing steps. In this embodiment, the inner shell 43 uses a second metal material with a lower hardness, which is beneficial to reduce the difficulty and processing time of the ingot, thereby improving the processing efficiency of the shaft decorative part 4 and reducing the processing difficulty and cost. In addition, since the material hardness of the inner shell 43 is relatively low, although the ingot needs to be machined over a large area, the residual stress after machining is relatively small, so the risk of deformation of the inner shell 43 due to stress release is relatively small, which is beneficial for the inner shell 43 to maintain a high-precision shape. The inner shell 43 has a high flatness, so that the manufacturing yield of the shaft decorative part 4 is relatively high.

[0131] In some embodiments, the elastic modulus of the first metal material is greater than the elastic modulus of the second metal material. Exemplarily, the elastic modulus of the first metal material is greater than or equal to 80GPa, for example, 100GPa, 110GPa, 130GPa, 193GPa, 210GPa, etc. Wherein, 1GPa = 1000MPa (megapascals). Among them, the elastic modulus (Elastic Modulus) refers to the stress required for a material to produce a unit elastic deformation under the action of an external force. It is an indicator of the material's ability to resist elastic deformation. The elastic modulus can be regarded as an indicator of the ease with which a material produces elastic deformation. The larger its value, the greater the stress that causes the material to undergo a certain elastic deformation, that is, the greater the material stiffness, that is, under a certain stress, the smaller the elastic deformation.

[0132] In this embodiment, the shell 42 of the rotating shaft decoration piece 4 is made of a first metal material with a large elastic modulus, so that the shell 42 has a stronger ability to resist elastic deformation, thereby reducing the risk of deformation of the rotating shaft decoration piece 4 .

[0133] In some embodiments, the yield strength of the first metal material is greater than the yield strength of the second metal material. Exemplarily, the yield strength of the first metal material is greater than or equal to 200 MPa (megapascals), such as 400 MPa, 470 MPa, 500 MPa, 600 MPa, 665 MPa, etc. Yield strength is the yield limit of a metal material when yielding occurs, that is, the stress that resists micro plastic deformation.

[0134] In this embodiment, the shell 42 of the rotating shaft decoration component 4 is made of a first metal material with a relatively large yield strength, so that the shell 42 has a relatively strong ability to resist slight plastic deformation, thereby reducing the deformation risk of the rotating shaft decoration component 4 .

[0135] In some embodiments, the density of the second metal material is less than the density of the first metal material. For example, the density of the second metal material is less than or equal to 3.5 g / cm 3 (grams per cubic centimeter), for example, 1.8 g / cm 3 , 1.9g / cm 3 , 2.0g / cm 3 , 2.69g / cm 3 , 2.70g / cm 3 , 2.73g / cm 3 , 2.8g / cm 3 wait.

[0136] In this embodiment, the inner shell 43 of the rotating shaft decoration component 4 is made of a second metal material with a relatively low density, so that the mass of the inner shell 43 is relatively small, which is beneficial to the lightweight of the rotating shaft decoration component 4 .

[0137] In some embodiments, the thermal conductivity of the second metal material is greater than the thermal conductivity of the first metal material. Exemplarily, the thermal conductivity of the second metal material is greater than or equal to 50 W / m·K (watt / meter·degree), for example, 70 W / m·K, 80 W / m·K, 95 W / m·K, 120 W / m·K, 130 W / m·K, 150 W / m·K, 160 W / m·K, 180 W / m·K, etc.

[0138] In this embodiment, the inner shell 43 of the rotating shaft decoration component 4 is made of a second metal material with a large thermal conductivity coefficient, so that the inner shell 43 has a high thermal conductivity property, which is beneficial to improving the heat dissipation performance of the rotating shaft decoration component 4 .

[0139] In some embodiments, the first metal material may be stainless steel or titanium alloy. In this case, the outer shell 42 has a higher hardness, a higher elastic modulus, and a higher strength. Exemplarily, the second metal material may be an aluminum alloy, a particle-reinforced aluminum-based composite material, a magnesium alloy, or a particle-reinforced magnesium-based composite material. In this case, the inner shell 43 has a lower density and a higher thermal conductivity.

[0140] Among them, the particles in the particle-reinforced aluminum-based composite material and the particle-reinforced magnesium-based composite material can be reinforced particles such as silicon carbide, aluminum oxide, boron carbide, carbon nanotubes, graphene, chromium carbide, silicon boride, titanium boride, titanium carbide, etc. For example, the particle-reinforced aluminum-based composite material can be a SiC (silicon carbide) particle reinforcement phase with a mass fraction of 20% + a 6061 aluminum alloy matrix with a mass fraction of 80%, a SiC (silicon carbide) particle reinforcement phase with a mass fraction of 17% + a 6013 aluminum alloy matrix with a mass fraction of 83%, a graphene particle reinforcement phase with a mass fraction of 25% + a 6063 aluminum alloy matrix with a mass fraction of 75%, etc. The particle-reinforced magnesium-based composite material can be a SiC (silicon carbide) particle reinforcement phase with a mass fraction of 20% + an AZ91 magnesium alloy matrix with a mass fraction of 80%, a SiC (silicon carbide) particle reinforcement phase with a mass fraction of 25% + a ZK60 magnesium alloy matrix with a mass fraction of 75%, etc.

[0141] In some embodiments of the present application, the outer shell 42 of the shaft decorative part 4 is made of stainless steel or titanium alloy material, and the inner shell 43 is made of aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material, so that the large-surface wall thickness of the shaft decorative part 4 is smaller, the deformation resistance is better, the wear resistance is better, the strength and rigidity are higher, and the processing difficulty is less, the cost is lower, it has higher dimensional accuracy and flatness, and the weight is smaller and the thermal conductivity is better.

[0142] In the embodiment of the present application, since the thickness of the connecting layer 44 will be affected when the first metal material and the second metal material are combined with different materials, when selecting which metal to combine the first metal material and the second metal material, in addition to considering the requirements described above, the mutual diffusion coefficient between the metals may also be considered to meet the reliability and quantification requirements of the product, so that the connecting layer 44 can achieve a reliable connection between the outer shell 42 and the inner shell 43.

[0143] In some examples, the first metal material is TC4 titanium alloy, and the second metal material is 6013 aluminum alloy. For example, the hardness of TC4 titanium alloy may be approximately in the range of 250HV to 320HV, such as 280HV, the elastic modulus may be approximately 110GPa, the yield strength may be in the range of 800MPa to 1000MPa, such as 880Mpa, and the density may be approximately 4.5g / cm 3, the thermal conductivity can be about 7.95 W / m·K. The hardness of 6013 aluminum alloy (Al-Mg-Si-Cu) can be about 65 HV to 75 HV, the elastic modulus can be about 69 GPa, the yield strength can be about 340 MPa, and the density can be about 2.7 g / cm 3 , the thermal conductivity may be about 160 W / m·K. It is understandable that the above parameters of TC4 titanium alloy and 6013 aluminum alloy may be slightly different due to factors such as specific production process, material state and test method.

[0144] In other examples, the first metal material is SUS316L stainless steel, and the second metal material is AZ31B magnesium alloy. For example, the hardness of SUS316L stainless steel may be approximately in the range of 200HV to 250HV, the elastic modulus may be approximately 193GPa, the yield strength may be approximately in the range of 200Mpa to 300Mpa, for example, 205Mpa, and the density may be approximately 8.0g / cm 3 AZ31B magnesium alloy (Mg-Al-Zn-Mn) may have a hardness of about 60 HV to 70 HV, an elastic modulus of about 45 GPa, a yield strength of about 180 MPa, and a density of about 1.78 g / cm 3 , the thermal conductivity may be about 76.9 W / m·K. It is understandable that the above parameters of SUS316L stainless steel and AZ31B magnesium alloy may be slightly different due to factors such as specific production process, material state and test method.

[0145] In other examples, the first metal material is TC4 titanium alloy, and the second metal material is silicon carbide reinforced aluminum-based composite material. The silicon carbide reinforced aluminum-based composite material may include 1% to 25% SiC and 6013 aluminum alloy, for example, 20% SiC and 80% 6013 aluminum alloy, or 17% SiC and 83% 6013 aluminum alloy. The hardness of the silicon carbide reinforced aluminum-based composite material of 17% SiC + 83% 6013 aluminum alloy may be approximately in the range of 80HV to 140HV, the elastic modulus may be approximately 95GPa, the yield strength may be approximately 500MPa, and the density may be approximately 2.78g / cm 3 , the thermal conductivity may be about 155 W / m·K. It is understandable that the above parameters of the silicon carbide reinforced aluminum matrix composite material may vary slightly due to factors such as specific production process, material state and test method.

[0146] In the above examples, the outer shell 42 of the rotating shaft decoration 4 is made of TC4 titanium alloy or SUS316L stainless steel, and the inner shell 43 is made of 6013 aluminum alloy, AZ31B magnesium alloy or silicon carbide reinforced aluminum-based composite material, which can achieve a small wall thickness (for example, less than or equal to 0.35mm) on the large surface, and at the same time achieve lightness, thinness, high rigidity and high strength. At the same time, the outer shell 42 material has high hardness and good surface scratch resistance, which helps to reduce the gap between the rotating shaft decoration 4 and the first shell 1 and the second shell 2 of the electronic device 100, thereby further reducing the overall thickness of the electronic device 100. In addition, the inner shell 43 material has low hardness, which helps to reduce the difficulty of mechanical processing such as CNC processing, improve processing efficiency, and reduce processing costs.

[0147] In addition, in the example where the outer shell 42 is made of SUS316L stainless steel, the elastic modulus of SUS316L stainless steel is higher than that of TC4 stainless steel, so the outer shell 42 and the rotating shaft decorative part 4 have stronger resistance to elastic deformation and lower risk of deformation. In the example where the inner shell 43 is made of magnesium alloy, the hardness of magnesium alloy is low, which is conducive to CNC processing, improving processing efficiency and reducing processing costs. In the example where the inner shell 43 is made of silicon carbide reinforced aluminum-based composite material, the elastic modulus of silicon carbide reinforced aluminum-based composite material is high, which helps to improve the deformation resistance of the inner shell 43 and the rotating shaft decorative part 4.

[0148] In some embodiments, Figure 6 As shown, the outer shell 42 includes an outer surface 42a, an inner surface 42b and a connection end surface 42c, the outer surface 42a of the outer shell 42 is arranged away from the inner shell 43, the inner surface 42b of the outer shell 42 is arranged toward the inner shell 43, and the connection end surface 42c of the outer shell 42 connects the outer surface 42a of the outer shell 42 and the inner surface 42b of the outer shell 42. Among them, the inner surface 42b of the outer shell 42 is connected to the connection layer 44, and the outer surface 42a of the outer shell 42 and the connection end surface 42c of the outer shell 42 are not connected to the connection layer 44.

[0149] The rotating shaft decoration part 4 further includes an appearance decoration layer 45, which is fixed to the outer surface 42a of the shell 42. The appearance decoration layer 45 can cover the outer surface 42a of the shell 42 to serve as the appearance layer of the rotating shaft decoration part 4, thereby improving the aesthetics of the rotating shaft decoration part 4. The appearance decoration layer 45 can decorate the rotating shaft decoration part 4 in terms of color, texture, texture, etc. In some examples, the appearance decoration layer 45 can also be fixed to and cover the connecting end surface 42c of the shell 42.

[0150] In some embodiments, Figure 6As shown, the inner shell 43 includes an outer surface 43a, an inner surface 43b and a connection end surface 43c. The outer surface 43a of the inner shell 43 is arranged toward the outer shell 42, the inner surface 43b of the inner shell 43 is arranged away from the outer shell 42, and the connection end surface 43c of the inner shell 43 connects the outer surface 43a of the inner shell 43 and the inner surface 43b of the inner shell 43. The outer surface 43a of the inner shell 43 is connected to the connection layer 44, the inner surface 43b of the inner shell 43 and the connection end surface 43c of the inner shell 43 are not connected to the connection layer 44, and the inner surface 43b of the inner shell 43 is arranged toward the accommodation space 41. A part of the inner surface 43b of the inner shell 43 is formed at the shell portion 431, and another part is formed at the matching portion 432.

[0151] The rotating shaft decoration 4 further includes a surface anti-corrosion layer 46, which is fixed to the inner surface 43b of the inner shell 43. The surface anti-corrosion layer 46 may cover a part or all of the inner surface 43b of the inner shell 43. The surface anti-corrosion layer 46 is used to improve the corrosion resistance and durability of the inner shell 43, so as to improve the reliability and service life of the rotating shaft decoration 4. In some examples, the surface anti-corrosion layer 46 may also be fixed to and cover the connection end surface 43c of the inner shell 43.

[0152] In some embodiments, Figure 5 As shown, part of the inner surface 43b of the inner shell 43 is a laser engraved area 47, which has better surface energy and can enhance the connection strength with adhesives (such as double-sided tape, glue, etc.) to facilitate the fixation of other structural parts.

[0153] The above specifically introduces the structure and components of the rotating shaft decoration member 4 in some embodiments. The following will continue to introduce the method for manufacturing the rotating shaft decoration member in conjunction with the relevant drawings.

[0154] Fig. 9 is a flow chart of a method for manufacturing a rotating shaft decoration provided in an embodiment of the present application. Fig.10 yes Fig. 9 Schematic diagram of the structure corresponding to some steps in the manufacturing method of the rotating shaft decoration shown Figure 1 , Fig.11 yes Fig. 9 Schematic diagram of the structure corresponding to some steps in the manufacturing method of the rotating shaft decoration shown Figure 2 ; Fig.12 yes Fig. 9 Schematic diagram of the structure corresponding to some steps in the manufacturing method of the rotating shaft decoration shown Figure 3 .

[0155] In some embodiments, the present application also provides a method for manufacturing a rotating shaft decoration, which can be used for the rotating shaft decoration 4 described above (such as Figure 5 and Figure 6As shown), it can also be used to make a rotating shaft decorative member 4 of other structures. The manufacturing method includes but is not limited to the steps S110 to S130 provided below. Fig. 9 And other related drawings introduce each step:

[0156] Step S110 : depositing the metal powder 51 in the inner space of the initial shell 52 to form the sintered component 5 .

[0157] For example, Fig.10 As shown, the part to be sintered 5 includes a metal powder 51 and an initial shell 52, and the metal powder 51 is accumulated in the inner space of the initial shell 52. At this time, the overall shape of the accumulated metal powder 51 changes with the shape of the initial shell 52. Therefore, by processing the shape of the inner space of the initial shell 52, the overall shape of the accumulated metal powder 51 can be controlled, and the shape of the contact interface between the initial shell 52 and the metal powder 51 can also be controlled. Among them, the accumulation height of the metal powder 51 can be flush with the side wall end face of the initial shell 52, or it can be higher than the side wall end face of the initial shell 52, for example, the middle part of the accumulated metal powder 51 is higher than the side wall end face of the initial shell 52, or it can be lower than the side wall end face of the initial shell 52. The embodiment of the present application does not strictly limit the accumulation shape of the metal powder 51.

[0158] Among them, the initial shell 52 is a long cover structure and is made of a first metal material. The metal powder 51 is made of a second metal material. The hardness of the first metal material is greater than the hardness of the second metal material. In some examples, the initial shell 52 can be obtained by stamping a metal sheet made of the first metal material. In some other examples, the initial shell 52 can also be obtained by other processing methods, and the embodiments of the present application do not strictly limit this. In some examples, the metal powder 51 can be obtained by powder making, powder blending and powder mixing processes. In some other examples, the metal powder 51 can also be obtained by other processing methods, and the embodiments of the present application do not strictly limit this.

[0159] Exemplarily, the elastic modulus of the first metal material is greater than the elastic modulus of the second metal material, and / or the yield strength of the first metal material is greater than the yield strength of the second metal material, and / or the density of the second metal material is less than the density of the first metal material, and / or the thermal conductivity of the second metal material is greater than the thermal conductivity of the first metal material.

[0160] Exemplarily, the hardness of the first metal material is greater than or equal to 150 HV, and / or the elastic modulus of the first metal material is greater than or equal to 80 GPa, and / or the yield strength of the first metal material is greater than or equal to 200 MPa; and / or the density of the second metal material is less than or equal to 3.5 g / cm 3; and / or, the thermal conductivity of the second metal material is greater than or equal to 50 W / m·K.

[0161] Exemplarily, the first metal material may be stainless steel or titanium alloy. For example, the first metal material may be TC4 titanium alloy, SUS316L stainless steel, and the like. At this time, the thickness of the metal sheet used to form the initial shell 52 may be greater than or equal to 0.2 mm, for example, 0.25 mm, 0.3 mm, and the like. The specific thickness of the metal sheet may be adjusted according to product design, material, and processing capability. Exemplarily, the second metal material may be an aluminum alloy, a particle-reinforced aluminum-based composite material, a magnesium alloy, or a particle-reinforced magnesium-based composite material. For example, the second metal material may be 6013 aluminum alloy, AZ31B magnesium alloy, silicon carbide-reinforced aluminum-based composite material, and the like.

[0162] Among them, other solution details of the first metal material and the second metal material can be found in the relevant description above and will not be repeated here.

[0163] Step S120: sintering the part to be sintered 5 to form a sintered part 6.

[0164] For example, Fig.11 As shown, the sintered component 6 includes a first component 61, a second component 62, and a transition layer 63 connecting the first component 61 and the second component 62. The material of the first component 61 is a first metal material, and the shape of the first component 61 corresponds to the shape of the initial shell 52; the material of the second component 62 is a second metal material, and the shape of the second component 62 corresponds to the stacking shape of the metal powder 51; the material of the transition layer 63 includes a first metal material and a second metal material, and the shape of the transition layer 63 corresponds to the shape of the contact interface between the initial shell 52 and the metal powder 51. Among them, the content of the main group element of the first metal material gradually decreases in the direction from the first component 61 to the second component 62, and the content of the main group element of the second metal material gradually increases in the direction from the first component 61 to the second component 62.

[0165] In this embodiment, the sintered part 5 is formed into an integrally formed sintered part 6 by an insert powder metallurgy process. The first component 61 of the sintered part 6 is formed by an initial shell 52, and the second component 62 is formed by a metal powder 51. A transition layer 63 is formed at the contact interface between the initial shell 52 and the metal powder 51, and is formed by the mutual diffusion of the first metal material and the second metal material. The transition layer 63 is an interdiffusion layer with a composition gradient, which can significantly improve the interface bonding strength between the first component 61 and the second component 62, so that the connection strength between the two is high, and the overall structure of the sintered part 6 is stable and reliable.

[0166] Among them, since the transition layer 63 is formed by the metal interdiffusion effect during the sintering process, the multiple regions of the transition layer 63 arranged in the layer direction (i.e., perpendicular to the thickness direction of the transition layer 63) are subjected to relatively uniform force during the sintering process, so the thickness of the multiple regions is equal or approximately equal, the overall thickness of the transition layer 63 is equal or approximately equal, and the two interfaces of the transition layer 63 respectively connecting the first component 61 and the second component 62 can be parallel or approximately parallel to each other. Among them, the two interfaces of the transition layer 63 respectively connecting the first component 61 and the second component 62 can be relatively smooth interfaces, and slight undulations are allowed on the interfaces.

[0167] Exemplarily, the thickness of the transition layer 63 may be greater than or equal to 0.1 μm. For example, the thickness of the transition layer 63 may be greater than or equal to 2 μm, for example, 3.6 μm, 5 μm, 6 μm, 8 μm, 12 μm, 15 μm, 20 μm, etc. Alternatively, the thickness of the transition layer 63 may be greater than or equal to 6 μm. Alternatively, the thickness of the transition layer 63 is in the range of 2 μm to 30 μm.

[0168] Exemplarily, in step S120, the sintered part 5 can be sintered by a hot isostatic pressing process. The pressure P1 of the hot isostatic pressing (HIP) process satisfies: P1 ≥ 100 MPa; the temperature T1 of the hot isostatic pressing process satisfies: 500°C (degrees Celsius) ≤ T1 ≤ 660°C; the time t1 of the hot isostatic pressing process satisfies: 2h (hours) ≤ t1 ≤ 5h. At this time, the mutual diffusion degree between the first metal material and the second metal material is deep, and the thickness of the transition layer 63 is large, for example, greater than or equal to 2 microns, so that the connection strength between the first component 61 and the second component 62 is high.

[0169] Exemplarily, before step S110, when making the initial shell 52, the surface roughness of the inner surface of the initial shell 52 facing its inner space can be increased to increase the contact area between the initial shell 52 and the metal powder 51, thereby increasing the bonding strength between the first component 61 and the second component 62 of the sintered part 6 formed after step S120, so as to improve the overall structural stability of the subsequently formed shaft decorative part 4.

[0170] The surface roughness of the surface can be increased by mechanically grinding the inner surface of the initial shell 52. Alternatively, a rubber-drawing structure such as a round hole or a dovetail groove can be formed by mechanical processing on the inner surface of the initial shell 52, or a steel sheet with a rubber-drawing structure can be welded on the inner surface of the initial shell 52 to form a physical riveting structure on the inner surface of the initial shell 52, thereby increasing the surface roughness of the inner surface of the initial shell 52.

[0171] Exemplarily, after step S110 and before step S120, the manufacturing method may further include: performing cold isostatic pressing on the part to be sintered 5. After the part to be sintered 5 is subjected to cold isostatic pressing (CIP), the metal powder 51 is pre-pressed to facilitate the subsequent sintering process. The pressure during the cold isostatic pressing process may be greater than or equal to 100 MPa, for example, in the range of 100 MPa to 630 MPa, the temperature may be room temperature, and the duration may be between 1 hour and 3 hours. In some other embodiments, after the part to be sintered 5 is subjected to the cold isostatic pressing process, the part to be sintered 5 may also be vacuum degassed to release the residual gas in the part to be sintered 5, thereby facilitating the subsequent sintering process.

[0172] Exemplarily, after step S120, the manufacturing method may further include a step of performing a solution aging treatment on the sintered part 6. In this embodiment, after the sintered part 6 is subjected to the solution aging treatment, the second component 62 of the sintered part 6 can obtain a higher yield strength and / or hardness.

[0173] The solution aging treatment step includes: performing a solution treatment on the sintered part 6; cooling the sintered part 6; and performing an aging treatment on the sintered part 6. For example, the sintered part 6 may be firstly subjected to a solution treatment; then the sintered part 6 subjected to the solution treatment may be water quenched at room temperature to cool the sintered part 6; after the sintered part 6 is cooled to room temperature, it is then subjected to an aging treatment.

[0174] In some examples, the second metal material is an aluminum alloy or a particle-reinforced aluminum-based composite material. In the solution aging treatment, the solution temperature T2 of the solution treatment satisfies: 500°C ≤ T2 ≤ 550°C, and the solution time t2 satisfies: 15min (minutes) ≤ t2 ≤ 60min; and / or, the aging temperature T3 of the aging treatment satisfies: 170°C ≤ T3 ≤ 200°C, and the aging time t3 satisfies: 4h ≤ t3 ≤ 24h.

[0175] In other examples, the second metal material is a magnesium alloy or a particle-reinforced magnesium-based composite material. In the solution aging treatment, the solution temperature T2 of the solution treatment satisfies: 380°C ≤ T2 ≤ 420°C, and the solution time t2 satisfies: 0.5h ≤ t2 ≤ 12h; and / or, the aging temperature T3 of the aging treatment satisfies: 180°C ≤ T3 ≤ 220°C, and the aging time t3 satisfies: 1h ≤ t3 ≤ 8h.

[0176] Step S130: Processing the sintered part 6 to form the shaft decoration part 4.

[0177] For example, Fig.12As shown, in step S130, the step of processing the sintered part 6 may include: machining the sintered part 6 to form an outer shell 42, an inner shell 43 and a connecting layer 44. At this time, through the step of machining, the shape and / or size of the sintered part 6 can be changed to form an outer shell 42, an inner shell 43 and a connecting layer 44 with a designed shape. Among them, the outer shell 42 is formed by the first component 61, the inner shell 43 is formed by the second component 62, and the connecting layer 44 is formed by the transition layer 63. Specifically, the remaining part of the first component 61 after machining forms the outer shell 42, the remaining part of the second component 62 after machining forms the inner shell 43, and the remaining part of the transition layer 63 after machining forms the connecting layer 44. At this time, the material of the outer shell 42 is the first metal material, the material of the inner shell 43 is the second metal material, the material of the connecting layer 44 includes the first metal material and the second metal material, and the content of the main group elements of the first metal material gradually decreases in the direction from the outer shell 42 to the inner shell 43, and the content of the main group elements of the second metal material gradually increases in the direction from the outer shell 42 to the inner shell 43.

[0178] In some examples, the machining step may include CNC machining, mechanical polishing and other steps. For example, CNC machining may be the main machining step, which is used to machine the basic shape and / or size, and then further finishing may be performed by mechanical polishing. Among them, mechanical polishing may adopt processes such as sandblasting, wire drawing, and CD grain processing. Mechanical polishing can make the surface of the subsequently formed shaft decorative part 4 smoother. Among them, in the machining step, the thickness of the sintered part 6 can also be thinned so that the final shaft decorative part 4 has a smaller thickness. In some other examples, the machining step may also not include mechanical polishing, and the embodiments of the present application do not strictly limit this.

[0179] For example, Figure 6 As shown, in step S130, after the sintered part 6 is machined, the step of machining the sintered part 6 may further include: performing PVD treatment on at least part of the surface of the shell 42 to form an appearance decoration layer 45. The appearance decoration layer 45 may decorate the rotating shaft decoration part 4 in terms of color, texture, texture, etc.

[0180] Among them, physical vapor deposition (PVD) technology refers to the technology of using physical methods to vaporize the surface of a material source (solid or liquid) into gaseous atoms or molecules, or partially ionize into ions under vacuum conditions, and deposit a thin film with a special function on the surface of a substrate through a low-pressure gas (or plasma) process. Physical vapor deposition is a surface treatment technology. PVD treatment can be vacuum evaporation coating, vacuum sputtering coating or vacuum ion coating. In this embodiment, the appearance decoration layer 45 can be formed by PVD treatment.

[0181] The appearance decoration layer 45 can be fixed to and cover the outer surface 42a of the shell 42 to serve as the appearance layer of the shaft decoration 4 to improve the aesthetics of the shaft decoration 4. In some examples, the appearance decoration layer 45 can also be fixed to and cover the connecting end surface 42c of the shell 42.

[0182] In addition, since the first metal material used for the shell 42 is titanium alloy or stainless steel, the appearance decoration layer 45 formed on the outer surface of the shell 42 through PVD treatment has good adhesion to the shell 42, is not easy to fall off, has high reliability, strong scratch resistance, and long service life.

[0183] For example, Figure 6 As shown, in step S130, after the sintered part 6 is machined, the step of machining the sintered part 6 may further include: performing surface anti-corrosion treatment on at least part of the surface of the inner shell 43 to form a surface anti-corrosion layer 46. The surface anti-corrosion layer 46 can improve the corrosion resistance and durability of the inner shell 43, so as to improve the reliability and service life of the rotating shaft decorative part 4.

[0184] The surface anti-corrosion treatment may adopt a chemical passivation process to form an anti-corrosion chemical film on the surface of the inner shell 43, that is, the surface anti-corrosion layer 46. The cost of chemical passivation is low. In some other examples, the surface anti-corrosion treatment may also adopt processes such as spraying, electrophoresis, and anodizing to form a coating or plating on the surface of the inner shell 43, which is used as the surface anti-corrosion layer 46.

[0185] The surface anti-corrosion layer 46 may be fixed to and cover a partial area or the entire area of ​​the inner surface 43 b of the inner shell 43 . In some examples, the surface anti-corrosion layer 46 may also be fixed to and cover the connection end surface 43 c of the inner shell 43 .

[0186] For example, in step S130, after the sintered part 6 is machined, the step of machining the sintered part 6 may further include: laser engraving a local area of ​​the inner surface 43b of the inner shell 43 to form a laser engraved area 47 (see Figure 5 The surface energy of the laser engraving area 47 is better, which can enhance the connection strength with the adhesive (such as double-sided tape, glue, etc.) to facilitate the fixing of other structural parts.

[0187] It is understandable that in step S130, the PVD treatment process, the surface anti-corrosion treatment process, and the laser engraving process are all optional processes and non-essential processes. In some other embodiments of the manufacturing method of the rotating shaft decorative part, one or more of these processes may not be included.

[0188] Exemplarily, in step S130, after mechanical processing of the sintered part 6, the step of processing the sintered part 6 may further include: assembling auxiliary materials. The auxiliary materials (not shown in the figure) may be structural parts such as foam, Mylar sheet, and insulating protective cover. When step S130 includes a PVD treatment process, and / or a surface anti-corrosion treatment process, and / or a laser engraving process, the auxiliary material assembly process is performed after these processes. The auxiliary material assembly process is also an optional process and a non-essential process.

[0189] In the manufacturing method of the rotating shaft decoration part of the embodiment of the present application, the outer shell 42, the inner shell 43 and the connecting layer 44 of the rotating shaft decoration part 4 are integrally formed structural parts through the insert powder metallurgy process. Based on the metal interdiffusion effect during the sintering process, an interdiffusion layer with a composition gradient can be formed between the outer shell 42 formed by the insert (i.e., the initial shell 52) and the inner shell 43 formed by the powder (i.e., the metal powder 51), that is, a connecting layer 44 in which the first metal material and the second metal material diffuse with each other is formed. The existence of the connecting layer 44 significantly improves the interface bonding strength between the outer shell 42 and the inner shell 43, so that the connection strength between the outer shell 42 and the inner shell 43 is high, and the overall structure of the outer shell 42, the connecting layer 44 and the inner shell 43 is stable and reliable.

[0190] Furthermore, during the manufacturing process of the rotating shaft decorative part 4, the rotating shaft decorative part 4 can control the shape of the bonding interface between the outer shell 42 and the inner shell 43 by controlling the shape of the surface of the initial shell 52 for contacting the metal powder 51. The shape control of the bonding interface is easy to implement, highly flexible, and highly accurate, so that the outer shell 42, the inner shell 43, and the connecting layer 44 have high processing accuracy when they have high connection strength. In addition, since the shape of the bonding interface is easy to control, the actual thickness of the outer shell 42 and the inner shell 43 can be close to or equal to the designed thickness when the design requirements are met, so that the thickness of the rotating shaft decorative part 4 can be reasonably controlled.

[0191] In addition, by hot isostatic pressing the sintered part 5 in step S120, the mutual diffusion degree of the first metal material and the second metal material is effectively improved, so that the thickness of the transition layer 63 of the sintered part 6 is relatively large, so the thickness of the connecting layer 44 of the rotating shaft decorative part 4 is relatively large, and the thickness of the bonding interface between the outer shell 42 and the inner shell 43 is relatively large, so that the interface bonding strength between the outer shell 42 and the inner shell 43 is high, and the risk of interface cracking is low, so the connection strength between the outer shell 42 and the inner shell 43 is high, and the overall structure of the outer shell 42, the connecting layer 44 and the inner shell 43 is stable and reliable. In some possible implementations, the shear strength of the connecting layer 44 at the bonding interface between the outer shell 42 and the inner shell 43 is greater than or equal to 100MPa, and in some implementations it can be as high as 300MPa, which is much higher than the interface shear strength of the rotating shaft decorative part 4 formed by the stamping and forging process of the heterogeneous metal composite plate.

[0192] In the embodiment of the present application, the rotating shaft decoration 4 adopts a composite structure of an outer shell 42 and an inner shell 43, and the outer shell 42 adopts a first metal material with a higher hardness, and the material hardness of the outer shell 42 is greater than the material hardness of the inner shell 43. Compared with the rotating shaft decoration 4 using the same material, the rotating shaft decoration 4 in this embodiment can reduce the thickness of the outer shell 42 while maintaining a low risk of deformation by increasing the material hardness of the outer shell 42, thereby reducing the thickness of the large wall structure of the rotating shaft decoration 4, so that the thickness of the rotating shaft decoration 4 is small and the risk of deformation is low. At this time, the shaft area thickness of the electronic device 100 using the rotating shaft decoration 4 can be designed to be a small value, which is conducive to the thinning of the electronic device 100.

[0193] In addition, the inner shell 43 of the rotating shaft decorative part 4 is made of a second metal material with a lower hardness, which is conducive to reducing the difficulty and processing time of the mechanical processing of the billet, thereby improving the processing efficiency of the rotating shaft decorative part 4 and reducing the difficulty and cost of processing. In addition, since the material hardness of the inner shell 43 is relatively low, although the billet needs to be mechanically processed over a large area, the residual stress after mechanical processing is relatively small, so the risk of deformation of the inner shell 43 due to stress release is relatively small, which is conducive to the inner shell 43 maintaining a high-precision shape, and the inner shell 43 has a high flatness, so that the manufacturing yield of the rotating shaft decorative part 4 is relatively high.

[0194] In the embodiment of the present application, since the elastic modulus of the first metal material is greater than the elastic modulus of the second metal material, the yield strength of the first metal material is greater than the yield strength of the second metal material, the density of the second metal material is less than the density of the first metal material, and the thermal conductivity of the second metal material is greater than the thermal conductivity of the first metal material, the outer shell 42 of the shaft decoration 4 has a strong ability to resist elastic deformation and a strong ability to resist trace plastic deformation. The deformation risk of the shaft decoration 4 is low and the structural reliability is high. Moreover, the mass of the inner shell 43 of the shaft decoration 4 is small, which is conducive to the lightweight of the shaft decoration 4. The thermal conductivity of the inner shell 43 is better, which is conducive to improving the heat dissipation performance of the shaft decoration 4.

[0195] For example, the outer shell 42 of the shaft decorative part 4 is made of stainless steel or titanium alloy material, and the inner shell 43 is made of aluminum alloy, particle-reinforced aluminum-based composite material, magnesium alloy or particle-reinforced magnesium-based composite material, so that the large-surface wall thickness of the shaft decorative part 4 is smaller, the deformation resistance is better, the wear resistance is better, the strength and rigidity are higher, the processing difficulty is less, the cost is lower, it has higher dimensional accuracy and flatness, and the weight is smaller and the thermal conductivity is better.

[0196] In the embodiment of the present application, by performing solution aging treatment on the sintered part 6 after step S120, the yield strength and / or hardness of the second component 62 of the sintered part 6 can be effectively improved, so that the yield strength and / or hardness of the inner shell 43 of the shaft decorative part 4 can be improved, and the shaft decorative part 4 has better deformation resistance and longer service life.

[0197] All the above drawings are illustrative diagrams of the present application. The drawings mainly illustrate the parts of the product related to the embodiments of the present application. The product may still include other parts not shown in the drawings. In addition, the actual shape, actual position, actual size and proportion, actual structure, actual quantity, etc. of the parts or structures of the product are not limited by the drawings.

[0198] The above embodiments are used to illustrate the technical solutions of the present application rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0199] In the absence of conflict, the embodiments of the present application and the features in the embodiments may be combined with each other, and any combination of features in different embodiments is also within the protection scope of the present application. That is to say, the multiple embodiments described above may also be arbitrarily combined according to actual needs.

Claims

1. A rotating shaft decoration piece, applied to a foldable electronic device, the rotating shaft decoration piece is used to decorate the rotating shaft of the electronic device, characterized in that: The rotating shaft decoration comprises an outer shell, an inner shell and a connecting layer, the outer shell is a long cover structure, the inner shell is located on the inner side of the outer shell, the connecting layer is located between the inner shell and the outer shell and connects the inner shell and the outer shell, and the outer shell, the connecting layer and the inner shell are an integrally formed structural member; The outer shell is made of a first metal material, and the inner shell is made of a second metal material. The hardness of the first metal material is greater than that of the second metal material. The connecting layer includes the first metal material and the second metal material. The content of the main group elements of the first metal material gradually decreases from the outer shell to the inner shell, and the content of the main group elements of the second metal material gradually increases from the outer shell to the inner shell.

2. The rotating shaft decoration according to claim 1, characterized in that: The elastic modulus of the first metal material is greater than the elastic modulus of the second metal material, and / or the yield strength of the first metal material is greater than the yield strength of the second metal material.

3. The rotating shaft decoration according to claim 1 or 2, characterized in that: The density of the second metal material is lower than the density of the first metal material, and / or the thermal conductivity of the second metal material is higher than the thermal conductivity of the first metal material.

4. The rotating shaft decoration according to any one of claims 1 to 3, characterized in that: The hardness of the first metal material is greater than or equal to 150 HV, and / or the elastic modulus of the first metal material is greater than or equal to 80 GPa, and / or the yield strength of the first metal material is greater than or equal to 200 MPa; and / or the density of the second metal material is less than or equal to 3.5 g / cm 3 ; and / or, the thermal conductivity of the second metal material is greater than or equal to 50 W / m·K.

5. The rotating shaft decoration according to any one of claims 1 to 4, characterized in that: The first metal material is stainless steel or titanium alloy; and / or the second metal material is aluminum alloy, particle reinforced aluminum-based composite material, magnesium alloy or particle reinforced magnesium-based composite material.

6. The rotating shaft decoration according to any one of claims 1 to 5, characterized in that: The thickness of the connecting layer is greater than or equal to 0.1 μm; or, the thickness of the connecting layer is greater than or equal to 2 μm; or, the thickness of the connecting layer is in a range of 2 μm to 30 μm.

7. The rotating shaft decoration according to claim 6, characterized in that: The connection layer includes a first interface and a second interface, the first interface connects the outer shell, the second interface connects the inner shell, and the first interface and the second interface are visible in the metallographic structure of the rotating shaft decoration component.

8. The rotating shaft decoration according to any one of claims 1 to 7, characterized in that: The inner shell includes a shell portion and a matching portion, the outer surface of the shell portion is connected to the connecting layer, the shell portion, the connecting layer and the outer shell form a stacked structure, the matching portion is arranged on the inner surface of the shell portion, and the matching portion includes at least one protrusion and / or at least one groove.

9. The rotating shaft decoration according to any one of claims 1 to 8, characterized in that: The outer shell includes an outer surface disposed away from the inner shell, and the rotating shaft decoration also includes an appearance decoration layer, and the appearance decoration layer is fixed to the outer surface of the outer shell; And / or, the inner shell includes an inner surface arranged away from the outer shell, and the rotating shaft decoration also includes a surface anti-corrosion layer, and the surface anti-corrosion layer is fixed to the inner surface of the inner shell.

10. An electronic device, characterized in that: It comprises a screen, a first shell, a second shell, a rotating assembly and a rotating shaft decoration member as claimed in any one of claims 1 to 9; The rotating assembly connects the first shell and the second shell so that the first shell and the second shell can be relatively unfolded or relatively folded, and the rotating assembly includes a rotating shaft; The screen is fixedly connected to the first shell and the second shell, and the rotating shaft decoration is fixed to a side of the rotating shaft facing away from the screen.

11. The electronic device according to claim 10, characterized in that: When the first shell and the second shell are relatively unfolded to an open state, the rotating shaft decoration is located between the rotating shaft and the first shell and the second shell, and the first shell and the second shell jointly cover the rotating shaft decoration; When the first shell and the second shell are folded relative to each other to a closed state, at least a portion of the rotating shaft decoration is exposed relative to the first shell and the second shell.

12. A method for manufacturing a rotating shaft decoration, characterized in that: The production method comprises: The metal powder is deposited in the inner space of the initial shell to form a part to be sintered; wherein the initial shell is a long cover structure and is made of a first metal material, and the metal powder is made of a second metal material, and the hardness of the first metal material is greater than that of the second metal material; Sintering the to-be-sintered part to form a sintered part; wherein the sintered part comprises a first component, a second component and a transition layer connecting the first component and the second component, the material of the first component is a first metal material, the material of the second component is a second metal material, the material of the transition layer comprises a first metal material and a second metal material, and the content of the first metal material gradually decreases from the first component to the second component, and the content of the second metal material gradually increases from the first component to the second component; and, The sintered part is processed to form a rotating shaft decoration part; wherein the rotating shaft decoration part comprises an outer shell, an inner shell and a connecting layer, the outer shell is formed by the first component, the inner shell is formed by the second component, and the connecting layer is formed by the transition layer.

13. The manufacturing method according to claim 12, characterized in that: The elastic modulus of the first metal material is greater than the elastic modulus of the second metal material, and / or the yield strength of the first metal material is greater than the yield strength of the second metal material, and / or the density of the second metal material is less than the density of the first metal material, and / or the thermal conductivity of the second metal material is greater than the thermal conductivity of the first metal material.

14. The production method according to claim 12 or 13, characterized in that: The hardness of the first metal material is greater than or equal to 150 HV, and / or the elastic modulus of the first metal material is greater than or equal to 80 GPa, and / or the yield strength of the first metal material is greater than or equal to 200 MPa; and / or the density of the second metal material is less than or equal to 3.5 g / cm 3 ; and / or, the thermal conductivity of the second metal material is greater than or equal to 50W / mK.

15. The production method according to any one of claims 12 to 14, characterized in that: The first metal material is stainless steel or titanium alloy; and / or the second metal material is aluminum alloy, particle reinforced aluminum-based composite material, magnesium alloy or particle reinforced magnesium-based composite material.

16. The method according to any one of claims 12 to 15, characterized in that: The step of sintering the to-be-sintered part comprises: Sintering the to-be-sintered part by hot isostatic pressing; The pressure P1 of the hot isostatic pressing sintering process satisfies: P1 ≥ 100 MPa; the temperature T1 of the hot isostatic pressing sintering process satisfies: 500° C. ≤ T1 ≤ 660° C.; and the time t1 of the hot isostatic pressing sintering process satisfies: 2h ≤ t1 ≤ 5h.

17. The manufacturing method according to claim 16, characterized in that: After the step of forming the to-be-sintered part and before the step of sintering the to-be-sintered part, the manufacturing method further comprises: The to-be-sintered part is subjected to cold isostatic pressing.

18. The method according to claim 16 or 17, characterized in that: The thickness of the connecting layer is greater than or equal to 0.1 μm; or, the thickness of the connecting layer is greater than or equal to 2 μm; or, the thickness of the connecting layer is in a range of 2 μm to 30 μm.

19. The method according to any one of claims 11 to 18, characterized in that: After the step of forming the sintered part and before the step of processing the sintered part, the manufacturing method further includes: performing a solution treatment on the sintered part; cooling the sintered part; The sintered part is subjected to aging treatment.

20. The manufacturing method according to claim 19, characterized in that: The second metal material is an aluminum alloy or a particle-reinforced aluminum-based composite material; The solution temperature T2 of the solution treatment satisfies: 500°C≤T2≤550°C, and the solution time t2 satisfies: 15min≤t2≤60min; And / or, the aging temperature T3 of the aging treatment satisfies: 170°C≤T3≤200°C, and the aging time t3 satisfies: 4h≤t3≤24h.

21. The method according to claim 19, characterized in that: The second metal material is a magnesium alloy or a particle-reinforced magnesium-based composite material; The solution temperature T2 of the solution treatment satisfies: 380°C≤T2≤420°C, and the solution time t2 satisfies: 0.5h≤t2≤12h; And / or, the aging temperature T3 of the aging treatment satisfies: 180°C≤T3≤220°C, and the aging time t3 satisfies: 1h≤t3≤8h.

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