CN116140757A

CN116140757A - Welding structural member, forming method thereof and electronic equipment

Info

Publication number: CN116140757A
Application number: CN202111376071.8A
Authority: CN
Inventors: 纪大伟; 蔡明�; 黄学龙
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-11-19
Filing date: 2021-11-19
Publication date: 2023-05-23
Also published as: WO2023088334A1

Abstract

The application provides a welding structural member, a forming method thereof and electronic equipment, wherein the welding structural member comprises a first structural member and a second structural member, the first structural member is provided with a through hole, and the through hole comprises a first opening and a second opening; at least a portion of the second structural member passes through the through-hole; the welded structure further includes: a first welding part welded with the first structural member and the second structural member; the first welding part is the same as the material main body of the second structural part, and at least part of the first welding part is positioned in the first concave area; and/or a second welding part welded with the first structural member and the second structural member; wherein, the second welding part is the same as the material main body of the first structural part; at least a portion of the second weld is located within the second recessed region. The welding structure provided by the application can effectively improve the welding stability of dissimilar metals and improve the connection strength of the structure.

Description

Welding structural member, forming method thereof and electronic equipment

[ field of technology ]

The present invention relates to the field of electronic devices, and in particular, to a welded structure, a method for forming the welded structure, and an electronic device.

[ background Art ]

Titanium and titanium alloy are widely applied to the fields of aviation, aerospace, deep diving, chemical industry and the like due to high mechanical strength and light weight, and are increasingly applied to the fields of wearing equipment, mobile phones and the like. However, titanium alloys are not as wear resistant as steel. At present, some structural members of electronic products need to have weight reduction, high mechanical strength and wear resistance, and in general, titanium or titanium alloy and steel are used for preparing the structural members together, so that the structural members have weight reduction and wear resistance.

Because the thermal expansion coefficient and the thermal conductivity of titanium and steel are greatly different, the welding heating and cooling cause the joint to generate larger internal stress. Secondly, in the weld, the steel is prone to precipitate out forming a large number of intermetallic compounds, such as brittle TiFe, tiFe ₂ And the quality of the welding head is compromised, so that the welding part is easy to break under the action of external force, and the connection strength of the structural part is reduced.

[ invention ]

The invention aims to provide a welding structural member, a forming method thereof and electronic equipment, which can effectively improve the welding stability of dissimilar metals and improve the connection strength of the structural member.

In a first aspect, the present application provides a welded structure, the welded structure including a first structure and a second structure, the first structure and the second structure being different in material;

The first structural member is provided with a through hole, and the through hole comprises a first opening and a second opening; at least a portion of the second structural member passes through the through hole;

the welded structure further includes:

a first welded portion welded to the first structural member and the second structural member; the first structural member is provided with a first concave region, the first concave region comprises a third opening and a fourth opening, and the fourth opening is communicated with the first opening; the first welding part is the same as the material main body of the second structural part, and at least part of the first welding part is positioned in the first concave area; and/or the number of the groups of groups,

a second welded portion welded to the first structural member and the second structural member; wherein, the second structural member is also provided with an inclined structure, and the inclined structure is matched with the first structural member to form a second concave area; the second welding part is the same as the material main body of the first structural part; at least a portion of the second weld is located within the second recessed region.

The fact that the first structural member and the second structural member are identical in material body means that the elements with a mass ratio of 50% or more in the two materials are identical, and preferably the fact that the elements with a mass ratio of 80% or more in the two materials are identical. More preferably, the first structural member and the second structural member are made of the same material, i.e. the mass content of each element in the two materials is the same. For example, the titanium metal has a titanium metal mass ratio of 90% or more and the titanium alloy has a titanium metal mass ratio of 50% or more, and it is possible to consider two materials in which the titanium metal and the titanium alloy are the same as each other.

In the scheme, the welding seam between the second structural member and the second welding part is a welding interface formed by welding the same materials, so that the metal fusion welding strength is high, and intermetallic compounds are not easy to form; and, first structure is equipped with the sunk area, can prevent effectively that the second structure from deviating from in the through-hole, can promote the mechanical strength of welded structure spare. The welding structural member of this scheme can effectively improve dissimilar metal's welding stability, improves the joint strength of structural member.

In some embodiments, at least a portion of the second structural member protrudes into a raised portion in a first recessed region relative to the first structural member prior to welding with the first structural member, the first weld being formed by fusion welding of the raised portion.

In the scheme, in the welding process, the second structural member is welded in a melting way to form the first welding part, and as the first welding part is formed by melting and cooling the protruding part of the second structural member, the first welding part is made of the same material, is not easy to form intermetallic compounds in the welding process, and has stronger overall structural stability. The first welding part is accommodated in the first concave area, so that the clamping process and the welding process can be fused, the welding stability of dissimilar metals can be further improved, and the connection strength of the structural part is further improved.

In some embodiments, the first structural member is provided with a transition layer near the side wall surface of the first concave region, and the first welding part and the first structural member are welded through the transition layer.

In the scheme, the transition layer is used for welding metals of two different materials, so that intermetallic compounds are generated in the welding process, and the mechanical strength of the welded structural part is improved.

In some embodiments, the first weld mates with the first recessed region.

In the scheme, the first welding part is matched with the first concave area, so that the whole structure is more compact and tidy, the first welding part does not protrude relative to the first structural part, and the arrangement of other components is not affected.

In some embodiments, the surface of the inclined structure is provided with a transition layer, and the second welding part and the inclined structure are welded and connected through the transition layer.

In the above scheme, the second welding part and the inclined structure are welded through the transition layer, so that intermetallic compounds generated in the welding process can be reduced, and the mechanical strength of the welded structural part is improved.

In some embodiments, the second weld mates with the second recessed region.

In the scheme, the second welding part is matched with the second concave area, so that the whole structure is more compact and tidy, the second welding part does not protrude relative to the first structural part, and the arrangement of other components is not affected.

In some embodiments, the through hole is a stepped hole, the through hole comprises a first pore canal and a second pore canal which are communicated, and the pore diameter of the first pore canal is smaller than that of the second pore canal; the second structural member comprises a main body part and clamping parts formed by extending from two sides of the main body part, the main body part penetrates through the first pore canal, and the clamping parts are clamped in the second pore canal.

In the scheme, the clamping part of the second structural member can be clamped in the second pore canal of the first structural member, so that the mechanical strength of the welding structural member can be improved, and the connection strength of the structural member is improved.

In some embodiments, the second welding portion is connected to a side of the engagement portion of the second structural member that is remote from the side proximate to the second opening.

In some embodiments, a portion of the second welded portion is fusion welded to the first structural member, and a portion of the second welded portion is welded to the engagement portion of the second structural member by a transition layer.

In the above scheme, the material of the second welding part is the same as the material main body of the first structural member, for example, titanium or titanium alloy, and the second welding part is partially melted through a spot welding process, so that the second concave region formed by matching the inclined structure with the first structural member can be closed, the second welding part with the same material as the first structural member is used for welding, the formation of intermetallic compounds can be avoided, the second structural member can be prevented from falling out of the through hole, and the overall stability is improved.

In some embodiments, the material of the first structural member and the second welded portion is at least one selected from titanium metal, titanium alloy, aluminum alloy, magnesium alloy, and carbon fiber; the material of the second structural member and the first welding part is at least one selected from carbon steel, stainless steel, cobalt alloy and nickel alloy.

In some embodiments, the material of the transition layer is at least one selected from copper, nickel, zinc, silver, and chromium.

In some embodiments, the transition layer has a thickness of 10 μm to 100 μm.

In a second aspect, the present application provides a method of forming a welded structure comprising the steps of:

providing a first structural member and a second structural member, wherein the first structural member and the second structural member are made of different materials; wherein the first structural member is provided with a through hole, and the through hole comprises a first opening and a second opening

Passing at least a portion of the second structural member through the through hole;

welding the first structural member and the second structural member by the following method A and/or method B;

the method A comprises the following steps:

forming a first welding part in a first concave area on the first structural part to realize welding of the first structural part and the second structural part, wherein the first concave area comprises a third opening and a fourth opening, and the fourth opening is communicated with the first opening; the first welding part and the second structural part are the same in material main body;

the method B comprises the following steps:

forming a second welding part in a second concave region to realize the welding of the first structural member and the second structural member, wherein an inclined structure is arranged on the second structural member, and the inclined structure is matched with the first structural member to form the second concave region; the second welding part is the same as the material main body of the first structural part.

In the scheme, the first structural member and the second structural member which are different in material are welded and connected through the welding part, welding between dissimilar metals is converted into welding between the same metals, the welding stability of the dissimilar metals can be effectively improved, and the connection strength of the structural members is improved.

In some embodiments, at least a portion of the second structural members of the welded structural members protrude into a first recessed area relative to the first structural members to form a bulge prior to welding with the first structural members, the forming a first weld in the first recessed area on the first structural members comprising:

the projecting portion is melted to form the first welded portion.

In some embodiments, the forming a first weld in a first recessed region on the first structural member to effect welding of the first structural member to the second structural member comprises:

forming a transition layer on the side wall of the first structural member in the first concave region;

and welding one end, close to the first concave area, of the second structural member in a fusion mode to form a first welding part, and welding the first welding part with the first structural member through the transition layer. In some embodiments, the first weld mates with the first recessed region.

In some embodiments, the through hole is a stepped hole, the through hole comprises a first pore canal and a second pore canal which are communicated, and the pore diameter of the first pore canal is smaller than that of the second pore canal; before the welding the first welded portion to the first structural member and the second structural member, the method further includes:

processing the second structural member to ensure that the second structural member comprises a main body part and clamping parts formed by extending from two sides of the main body part;

the main body part of the second structural member passes through the first pore canal of the first structural member, and the clamping part is clamped in the second pore canal.

In some embodiments, the forming a second weld in the second recessed region to effect welding of the first structural member to the second structural member includes:

forming an inclined structure on one side of the clamping part of the second structural member, which is close to the second opening, and forming a transition layer on the inclined structure;

and welding a second welding part with the first structural part in a fusion way, and welding and connecting the second welding part with the second structural part through the transition layer.

In some embodiments, the second weld mates with the second recessed region.

In a third aspect, the present application provides a welded structure formed by the method of the second aspect described above.

In a fourth aspect, the present application provides an electronic device comprising the welded structure according to the first aspect or the welded structure according to the third aspect. The electronic equipment is foldable electronic equipment, the foldable electronic equipment comprises a rotating shaft assembly, and the welding structural part is located on the rotating shaft assembly.

Compared with the prior art, the application has at least the following beneficial effects:

the application provides a welded structure spare and electronic equipment through converting dissimilar intermetallic welding into same intermetallic welding between the structure spare with different materials, same metal fuses welding strength height, is difficult to form intermetallic compound, can effectively improve dissimilar metal's welding stability, improves the joint strength of structure spare.

[ description of the drawings ]

FIG. 1a is a schematic diagram of a prior art dissimilar metal welding structure.

FIG. 1b is a schematic diagram of another prior art dissimilar metal welding configuration.

Fig. 2 is a perspective view of a welded structure provided in an embodiment of the present application prior to welding.

Fig. 3a is a schematic cross-sectional view of a first structural member according to an embodiment of the present application.

Fig. 3b is a schematic cross-sectional view of a second structural member provided in an embodiment of the present application.

Fig. 4a is a schematic structural diagram of a first structural member according to an embodiment of the present application.

Fig. 4b is another schematic structural view of the first structural member according to the embodiment of the present application

Fig. 4c is another schematic structural view of the first structural member according to the embodiment of the present application.

Fig. 4d is another schematic structural view of the first structural member according to the embodiment of the present application.

Fig. 5a is a schematic structural diagram of a first structural member according to an embodiment of the present application.

Fig. 5b is another schematic structural view of the first structural member according to the embodiment of the present application.

Fig. 5c is another schematic structural view of the first structural member according to the embodiment of the present application.

Fig. 6a is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application prior to welding.

Fig. 6b is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application after welding.

Fig. 6c is a partial enlarged view of the area a shown in fig. 6 b.

Fig. 7 is a perspective view of another welded structure provided in an embodiment of the present application.

Fig. 8a is another schematic cross-sectional view of a first structural member provided in an embodiment of the present application.

Fig. 8b is a schematic cross-sectional view of a second structural member provided in an embodiment of the present application.

Fig. 8c is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application prior to welding.

Fig. 8d is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application after welding.

Fig. 8e is a partial enlarged view of the area B shown in fig. 8 d.

Fig. 9 is a schematic cross-sectional view of another welded structure provided in an embodiment of the present application.

Fig. 10 is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application.

Fig. 11 is a schematic cross-sectional view of another welded structure provided in an embodiment of the present application in an exploded state after welding.

Fig. 12a is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application prior to welding.

Fig. 12b is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application after welding.

Fig. 13a is a schematic cross-sectional view of another welded structure provided in an embodiment of the present application, prior to welding.

Fig. 13b is a schematic cross-sectional view of another welded structure provided in an embodiment of the present application.

Fig. 13C is a partial enlarged view of the area C shown in fig. 13 b.

Fig. 14 is a schematic structural diagram of a rotating shaft assembly in an electronic device according to an embodiment of the present application.

[ detailed description ] of the invention

It should be understood that the described embodiments are merely some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the description of embodiments of the present invention, it should be understood that the terms "length," "thickness," "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," and the like indicate or are based on the orientation or positional relationship shown in the drawings, merely to facilitate description of embodiments of the present invention and to simplify description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be configured and operated in a particular orientation, and thus should not be construed as limiting embodiments of the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless explicitly defined otherwise.

In describing embodiments of the present invention, it should be noted that the term "coupled" should be interpreted broadly, unless otherwise indicated and limited thereto, such as being either fixedly coupled, detachably coupled, or integrally coupled; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements or interaction relationship between the two elements. The specific meaning of the above terms in the embodiments of the present invention can be understood by those of ordinary skill in the art according to specific circumstances.

The existing titanium and titanium alloy have high mechanical strength and light weight, are widely applied in the fields of aviation, aerospace, deep diving, chemical industry and the like, and are increasingly applied in the fields of wearing equipment, mobile phones and the like. However, titanium alloys are not as wear resistant as steel. Some structural members of the current electronic products need to have weight reduction, high mechanical strength and wear resistance. The structural member is prepared by titanium or titanium alloy and steel together, so that the structural member has weight reduction and wear resistance.

Fig. 1a is a schematic structural diagram of dissimilar metal welding in the prior art, as shown in fig. 1a, a pre-drilled hole 31 can be obtained at a joint of an aluminum plate 4 and a steel plate 2 to be connected, and then a rivet 3 is inserted into the pre-drilled hole 31, so that the end face of a nut of the rivet 3 is flush with the surface of the aluminum plate 4, and the other end of the rivet is higher than the surface of the steel plate 2; finally, the rivet higher than the surface of the steel plate 2 is pressed down by the rotary needleless stirring head 1, so that the end face of the needleless stirring head 1 is contacted with the surface of the steel plate 2; and then continuing to perform friction welding after the second pressing. However, the welding structure needs a rotary stirring head for friction welding, is only suitable for welding plates with large plane structures, and cannot be suitable for blind hole structures.

At present, when titanium or titanium alloy and steel are used for preparing the same structural member, as shown in fig. 1b, a welding transition layer 11' of copper, niobium, tantalum and the like is generally arranged between a part of a structure 10' of titanium (titanium alloy) material and another part of a structure 20' of steel material, so that the quality of a titanium steel welding joint is improved. However, the mode of welding the transition layer has low weld strength and unstable welding.

In order to improve the welding stability of the dissimilar metals, fig. 2 is a perspective view of a welded structure before welding, as shown in fig. 2, where the welded structure 100 includes a first structural member 10 and a second structural member 20, and the materials of the first structural member 10 and the second structural member 20 are different.

In some embodiments, the material of the first structural member 10 is at least one selected from titanium, titanium alloy, aluminum alloy, magnesium alloy and carbon fiber, and the material of the second structural member 20 is at least one selected from carbon steel, stainless steel, cobalt alloy and nickel alloy. The specific preparation process may be die casting, machining, powder metallurgy, etc., and is not limited herein. The first structural member 10 may be rectangular parallelepiped, or may have other irregular three-dimensional structures, which are not limited herein. The second structure 20 may be a column, rod, shaft, or other irregular solid structure. Illustratively, by welding the first structural member 10 of titanium metal to the second structural member 20 of steel, the welded structural member can be made to have both wear resistance of the steel and low density, high mechanical strength of the titanium metal or titanium alloy.

The heating and cooling during welding can lead to larger internal stress due to the larger difference in thermal expansion coefficient and thermal conductivity between titanium and steel. And, during the welding process, the content of iron in the steel in the welding line greatly exceeds the solubility, and a large amount of intermetallic compounds such as TiFe and TiFe are easily precipitated ₂ The welding structural part is easy to break under the action of external force, and the welding stability is poor.

Fig. 3a is a schematic cross-sectional view of a first structural member according to an embodiment of the present application, as shown in fig. 3a, the first structural member 10 is provided with a through hole 13, the through hole 13 includes a first opening 131 and a second opening 132, and at least part of the second structural member 20 passes through the through hole 13.

The first structural member 10 is further provided with a first concave region 11, the first concave region 11 includes a third opening 111 and a fourth opening 112, and the fourth opening 112 is communicated with the first opening 131.

Specifically, the first structural member 10 includes oppositely disposed first and

second surfaces

101, 102; in some embodiments, the first and

second surfaces

101, 102 may be flat surfaces. In other embodiments, the first surface 101 and the second surface 102 may also be surfaces with a certain radian or gradient, which is not limited herein. The present application describes a solution with the first surface 101 and the second surface 102 as planes, but the present application is not limited thereto. The first structural member 10 is made of titanium or titanium alloy, and the titanium alloy can be a dual-phase alloy, so that the dual-phase alloy has good structural stability, good toughness, plasticity and high-temperature deformation performance, and can be better subjected to hot pressing. The titanium alloy can be titanium aluminum vanadium alloy (Ti-6 Al-4V, TC4) or TA2 titanium alloy. The first surface 101 of the first structural member 10 is recessed to form a first recessed region 11.

The through holes 13 may be circular holes, square holes, or other regular or irregular shapes, and are not limited herein. In a specific embodiment, as shown in fig. 3a, the through hole 13 may be a stepped hole, and the through hole 13 includes a first pore canal 13a and a second pore canal 13b that are communicated, where the pore diameter of the first pore canal 13a is smaller than the pore diameter of the second pore canal 13 b. The step holes are formed on the first structural member 10, and the clamping connection of the first structural member and the second structural member can be realized through the step holes, so that the connection strength of the whole structure is improved.

Fig. 3b is a schematic cross-sectional view of the second structural member according to the embodiment of the present application, as shown in fig. 3b, the second structural member 20 includes a main body portion 21 and engaging portions 22 formed by extending from two sides of the main body portion 21, and at least part of the main body portion 21 passes through the through hole 13. Specifically, the main body 21 passes through the first hole 13a, and the engaging portion 22 is engaged with the second hole 13 b. The main body 21 may have a cylindrical shape, a prismatic shape, or other columnar structure, which is not limited herein. In this embodiment, the main body 21 is cylindrical, the diameter of the main body 21 of the second structural member 20 is 0.6 mm-2.0 mm, and the material of the second structural member 20 is stainless steel, which has strong wear resistance.

Fig. 4a is a schematic structural view of a first structural member according to an embodiment of the present application, and the first recess region 11 may be a C-shaped groove. Fig. 4b is another schematic structural view of the first structural member provided in the embodiment of the present application, as shown in fig. 4b, the cross section of the first concave region 11 may be rectangular, for example, the first concave region 11 may be a rectangular groove or a cylindrical groove; fig. 4c is another schematic structural view of the first structural member according to the embodiment of the present application, and as shown in fig. 4c, the first concave region 11 may be an arc-shaped groove. Fig. 4d is another schematic structural view of the first structural member according to the embodiment of the present application, as shown in fig. 4d, the first concave region 11 may also be a composite structure with several shapes as described above, which is not limited herein.

Fig. 5a to 5b are schematic views of another structure of the first structural member according to the embodiment of the present application, where, as shown in fig. 5a, the through hole 13 may be a stepped hole, and the specific structure may be that, as shown in fig. 5a to 5b, the hole wall of the through hole 13 may be an inclined plane, a vertical plane or an arc shape. Fig. 5c is a schematic structural diagram of the first structural member according to the embodiment of the present application, where the through hole 13 may be formed by connecting 3 or more holes with different diameters, which is not limited herein.

Fig. 6a is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application before welding, and fig. 6b is a schematic cross-sectional view of a welded structure provided in an embodiment of the present application after welding; as shown in fig. 6a and 6b, the welded structure further includes a first welded portion 30, the first welded portion 30 is welded to the first structural member 10 and the second structural member 20, the first welded portion 30 is the same as the material body of the second structural member 20, and at least part of the first welded portion 30 is located in the first recessed region 11. The first welding portion 30 may be used to prevent the second structural member 20 from being removed from the through hole 13, and the first welding portion 30 may be formed by welding using a fusion welding process, which is the same as the main body of the second structural member 20.

In some embodiments, at least a portion of the second structural member 20 protrudes into the first recessed region 11 of the first structural member 10 to form a protruding portion 21a prior to welding with the first structural member 10. Specifically, the protruding portion 21a may be formed by extending the main body portion 21 of the second structural member 20. As shown in fig. 6b, during the welding process, the second structural member 20 is melted and welded at one end (which may be the convex portion 21 a) of the first concave region 11 to form a liquid metal or liquid alloy filled into the first concave region 11, thereby forming the first welded portion 30. In this embodiment, the first welding portion 30 and the second structural member 20 are connected to form a riveted structure, and since the first welding portion 30 is formed by melting and cooling a part of the second structural member 20 and is made of the same material, intermetallic compounds are not easily formed in the welding process, and the overall structural stability is stronger. During the actual welding process, the first surface 101 of the first structural member 10 may be blown flat by a protective atmosphere (e.g., nitrogen, argon) to form a smooth riveted structure. In other embodiments, the first welding portion 30 may be disposed on the second surface 102 of the first structural member 10 in a protruding manner, which is not limited herein.

In other embodiments, the first welding portion 30 may be formed by directly welding with the same solder as the material body of the second structural member, so that the solder and the second structural member 20 are fusion-welded and filled into the first recess 11. Since the first welded portion 30 is the same as the material body of the second structural member 20, the connection structure between the two is stable.

In order to improve the welding stability, the first welded portion 30 and the second structural member 20 are welded by a transition layer. Fig. 6c is an enlarged view of a portion of the area a shown in fig. 6b, and as shown in fig. 6c, a transition layer 222 is disposed on a surface of the side wall 12 of the first structural member 10 adjacent to the first recess 11, and the first welding portion 30 is welded to the side wall 12 of the first structural member 10 through the transition layer 222. The material of the transition layer 222 may be at least one of copper, nickel, zinc, silver, and chromium. The provision of the transition layer is advantageous for improving the welding strength between the first structural member 10 and the second structural member 20 of the dissimilar materials.

Specifically, the second structural member 20 is made of stainless steel, the second structural member 20 is welded by a fusion welding process, a welding seam between the second structural member 20 made of stainless steel and the first welding portion 30 is a welding interface formed by welding the same material, the metal fusion welding strength is high, and intermetallic compounds are not easy to form; in addition, the first welded portion 30 and the side wall 12 of the first structural member 10 are welded by the transition layer 222, so that intermetallic compound generation during welding can be reduced, and mechanical strength of the welded structural member can be improved. The clamping connection, riveting and welding processes are fused, so that the whole welding structural member has the abrasion resistance of steel materials and the low density and high mechanical strength of titanium metal or titanium alloy.

The welding process of the welded structure may further include the steps of:

providing a first structural member 10 and a second structural member 20, wherein the first structural member 10 and the second structural member 20 are made of different materials; wherein the first structural member 10 is provided with a through hole 13, and the through hole 13 comprises a first opening 131 and a second opening 132;

passing at least part of the second structural member 20 through the through hole 13;

forming a first welding part 30 in a first concave region 11 on a first structural member 10 to realize welding of the first structural member 10 and the second structural member 20, wherein the first concave region 11 comprises a third opening 111 and a fourth opening 112, and the fourth opening 112 is communicated with the first opening 131; the first welded portion 30 is made of the same material as the second structural member 20.

In the concrete processing process, the method mainly comprises the following steps: firstly, pretreatment of a structural member: firstly, milling the first structural member 10 to form a first concave region 11 and a through hole 13, wherein the first concave region 11 can be a C-shaped concave region or a rectangular concave region; processing the second structural member 20 so that the second structural member 20 includes a main body portion 21 and engagement portions 22 extending from both sides of the main body portion 21; and the main body 21 of the second structural member 20 passes through the first duct 13a of the first structural member 10, and the engaging portion 22 is engaged with the second duct 13 b. A transition layer 222 (which may be, for example, a nickel layer) is formed on the sidewall 12 of the first structural member 10.

Second, welding treatment: the main body portion 21 (may be the protruding portion 21 a) of the second structural member 20 is spot-welded and melted, the melted metal melt fills the first concave region 11 to form a first welded portion 30, and the first welded portion 30 is connected with the second structural member 20 to form a riveted structure; wherein a weld interface (steel-steel) of the same metal is formed between the first weld 30 and the second structural member 20; the first weld 30 is welded to the side wall 12 of the first structural member 10 by a transition layer 222 to form a weld interface (titanium-nickel-steel).

Thirdly, improving the quality of the welding seam through heat treatment, and removing the internal stress at the joint through annealing treatment; and then polishing to form a smooth welding surface.

The welding process used in the present application may be laser spot welding, argon arc welding or other welding processes, and is not limited herein. In the welding process, the molten metal liquid can be blown flat by using the shielding gas to fill up the grooves, so that the surface with the smooth riveting structure is formed. In other embodiments, the first welding portion 30 may be disposed on the first surface 101 of the first structural member 10 in a protruding manner, which is not limited herein.

By converting the welding of dissimilar metals (e.g., stainless steel and titanium) to welding of the same metal (stainless steel and stainless steel, titanium and titanium), the formation of intermetallic compounds during the welding process can be reduced, and internal stresses at the welded joint can be reduced; meanwhile, the rivet structure formed by welding can enhance the stability and mechanical strength of the welded structural member. The welding interface between dissimilar metals is welded through the transition layer, so that the welding interface with transition metals can be formed, the generation of intermetallic compounds can be reduced, and the composite welding structural member with firm structure can be formed.

The welded structure member manufactured by the embodiment has a riveting structure and a clamping structure, and the structural stability can be improved through the composite action of the two structures.

Fig. 7 is a perspective view of another welded structure provided in an embodiment of the present application, and as shown in fig. 7, the welded structure 100 includes a first structural member 10 and a second structural member 20.

Fig. 8a is a schematic cross-sectional view of a first structural member according to an embodiment of the present application, as shown in fig. 8a, where the first structural member 10 is provided with a through hole 13, and the through hole 13 includes a first opening 131 and a second opening 132, and at least a portion of the second structural member 20 passes through the through hole 13.

second surfaces

101, 102; in some embodiments, the first and

second surfaces

101, 102 may be flat surfaces. In other embodiments, the first surface 101 and the second surface 102 may also be surfaces with a certain radian or gradient, which is not limited herein. The present application describes a solution with the first surface 101 and the second surface 102 as planes, but the present application is not limited thereto. The first structural member 10 is made of titanium or titanium alloy, and the titanium alloy can be a dual-phase alloy, so that the dual-phase alloy has good structural stability, good toughness, plasticity and high-temperature deformation performance, and can be better subjected to hot pressing. The titanium alloy can be titanium aluminum vanadium alloy (Ti-6 Al-4V, TC4) or TA2 titanium alloy.

The through holes 13 may be circular holes, square holes, or other regular or irregular shapes, and are not limited herein. In a specific embodiment, the through hole 13 may be a stepped hole, and the through hole 13 includes a first pore canal 13a and a second pore canal 13b that are communicated, where the pore diameter of the first pore canal 13a is smaller than the pore diameter of the second pore canal 13 b. The step holes are formed on the first structural member 10, and the clamping connection of the first structural member 10 and the second structural member 20 can be realized through the step holes, so that the connection strength of the whole structure is improved.

Fig. 8b is a schematic cross-sectional view of the second structural member according to the embodiment of the present application, as shown in fig. 8b, the second structural member 20 includes a main body portion 21 and engaging portions 22 formed by extending from two sides of the main body portion 21, and at least part of the main body portion 21 passes through the through hole 13. Specifically, the main body 21 passes through the first hole 13a, and the engaging portion 22 is engaged with the second hole 13 b.

Fig. 8c is a schematic cross-sectional view of a welded structure before welding, as shown in fig. 8b and 8c, where the second structure 20 is provided with an inclined structure 221, the inclined structure 221 cooperates with the first structure 10 to form a second concave area 23, and the second concave area 23 is configured to receive at least part of the second welded portion 40. Specifically, the inclined structure 221 and the inner wall of the first structural member 10 together define a second concave region 23, and the opening direction of the second concave region 23 is the same as the opening direction of the second opening 132 (i.e. the downward direction in fig. 8 c).

Fig. 8d is a schematic cross-sectional view of a welded structure after welding, and fig. 8e is a partial enlarged view of a region B shown in fig. 8d, and as shown in fig. 8d and 8e, the welded structure further includes a second welding portion 40, where the second welding portion 40 is welded to the first structural member 10 and the second structural member 20, the second welding portion 40 is the same as the material body of the first structural member 10, and at least part of the second welding portion 40 is located in the second recessed area 23. The second welding portion 40 may be used to prevent the second structural member 20 from being removed from the through hole 13, and the second welding portion 40 may be formed by welding using a fusion welding process, which is the same as the main body of the first structural member 10.

Preferably, the second welding portion 40 is matched with the second concave region 23, that is, the second welding portion 40 is filled in the second concave region 23, and the second welding portion 40 and the second surface 102 of the first structural member 10 form a flat surface, so that subsequent assembly with other components is facilitated.

At least a portion of the second welded portion 40 is welded to the side wall of the first structural member 10 adjacent to the second recessed area 23, and at least a portion of the second welded portion 40 is welded to the inclined structure 221 of the second structural member 20.

Specifically, the engaging portion 22 of the second structural member 20 is provided with an inclined structure 221 on a side close to the second recess 23, a transition layer 222 is provided on a surface of the inclined structure 221, and the transition layer 222 may be formed on the surface of the inclined structure 221 by an electroless plating or electroplating process. Specifically, the thickness of the transition layer 222 is 10 μm to 100 μm.

With continued reference to fig. 8e, a bevel is disposed on a side of the second welding portion 40 away from the first structural member 10, the sidewall of the second welding portion 40 is welded to the sidewall of the first structural member 10 near the second recess 23, and the bevel of the second welding portion 40 is welded to the inclined structure 221 through a transition layer 222. In other embodiments, the second welded portion 40 may be directly welded to the inclined structure 221. Specifically, the second welding portion 40 is made of titanium or titanium alloy, the first structural member 10 and the second welding portion 40 are connected and fixed together through a fusion welding process, and a welding seam between the first structural member 10 made of titanium or titanium alloy and the second welding portion 40 is a welding seam formed by melting and then cooling the same material, so that the metal fusion welding strength is high, intermetallic compounds are not formed, and the connection is firm.

The inclined structure 221 of the second structural member 20 is welded with the second welding portion 40 through the transition layer 222, so that intermetallic compound generated in the welding process can be reduced, and the mechanical strength of the welded structural member can be improved. In addition, the engaging portion 22 of the second structural member 20 can be engaged with the second hole 13b of the through hole 13 of the first structural member 10, so that the overall structural stability of the welded structural member is improved, and the welded structural member has both wear resistance of steel and low density and high mechanical strength of titanium metal or titanium alloy.

The welding process of the welding structural part mainly comprises the following steps:

forming a second weld 40 in the second recessed area 23 to effect welding of the first structural member 10 to the second structural member 20; wherein, the second structural member 20 is provided with an inclined structure 221, and the inclined structure 221 cooperates with the first structural member 10 to form the second recessed area 23; the second welded portion 40 is made of the same material as the first structural member 10.

During the course of a particular welding process,

firstly, pretreatment of a structural member: firstly, milling the first structural member 10 to form a through hole 13; machining the second structural member 20 to form an engaging portion 22, and performing milling on one side of the engaging portion 22, which is close to the second opening 132, to form an inclined structure 221; a transition layer 222 (which may be, for example, a copper layer) is formed on the surface of the inclined structure 221. Note that the formation of the transition layer 222 may be performed by electroplating, coating, spraying, or the like, which is not limited herein.

Second, welding treatment: melting and welding the second welding part 40 with the side wall of the first structural member 10, which is close to the second concave region 23, by adopting laser spot welding, filling molten metal in the second concave region 23, and welding the formed second welding part 40 with the inclined structure 221 of the second structural member 20 through the transition layer 222, wherein a part of the surface of the second welding part 40 and the side wall of the first structural member 10, which is close to the second concave region 23, are welded to form a welding interface (titanium-titanium) between the same metals; another part of the surface of the second welded portion 40 is welded with the inclined surface of the inclined structure 221 of the second structural member 20 to form a welded interface (titanium-copper-steel) with a transition metal.

Fig. 9 is a schematic cross-sectional view of another welded structure provided in an embodiment of the present application before welding, fig. 10 is a schematic cross-sectional view of another welded structure provided in an embodiment of the present application after welding, and fig. 11 is a schematic cross-sectional view of an exploded welded structure provided in an embodiment of the present application, as shown in fig. 9 to 11, where the welded structure 100 includes a first structural member 10 and a second structural member 20.

The first structural member 10 is provided with a through hole 13, and the through hole 13 comprises a first opening 131 and a second opening 132; at least part of the second structural member 20 passes through the through hole 13; the first structural member 10 is further provided with a first concave region 11, the first concave region 11 includes a third opening 111 and a fourth opening 112, and the fourth opening 112 is communicated with the first opening 131.

The second structural member 20 includes a main body 21 and engaging portions 22 extending from both sides of the main body 21, and at least a part of the main body 21 passes through the through hole 13. The second structural member 20 is provided with an inclined structure 221, and the inclined structure 221 cooperates with the first structural member 10 to form a second concave region 23.

The welded structure further comprises a first welded portion 30, the first welded portion 30 is welded to the first structural member 10 and the second structural member 20, the first welded portion 30 is the same as the material body of the second structural member 20, and at least part of the first welded portion 30 is located in the first concave region 11. The first welding portion 30 may be used to prevent the second structural member 20 from being removed from the through hole 13, and the first welding portion 30 may be formed by welding using a fusion welding process, which is the same as the material body of the first structural member 10.

The welded structure further comprises a second welded portion 40, the second welded portion 40 is welded to the first structural member 10 and the second structural member 20, the second welded portion 40 is the same as the material body of the first structural member 10, and at least part of the second welded portion 40 is located in the second recessed area 23. The second welding portion 40 may be used to prevent the second structural member 20 from being removed from the through hole 13, and the second welding portion 40 may be formed by welding using a fusion welding process, which is the same as the main body of the first structural member 10.

In a specific embodiment, one end of the main body portion 21 of the second structural member 20 passes through the through hole 13, and one end of the main body portion 21 protrudes to form a protruding portion 21a relative to the first recessed region 11 of the first structural member 10, and the engaging portion 22 of the second structural member 20 is engaged in the through hole 13. In the present embodiment, the first welded portion 30 formed by melting the convex portion 21a of the main body portion 21 is matched with the first concave region 11; the engaging portion 22 is processed on a side close to the second opening 132 to form an inclined structure 221, a transition layer 222 may be disposed on a surface of the inclined structure 221, and the transition layer 222 may be at least one of copper, nickel, zinc, silver, and chromium.

As shown in fig. 10 and 11, the protruding portion 21a of the main body 21 is melted to form a liquid metal or liquid alloy, and the liquid metal or liquid alloy is filled into the first concave region 11 to form a first welded portion 30, and the first welded portion 30 forms a riveted structure with the second structural member 20.

Specifically, the first welding part 30 and the second structural part 20 may be made of steel, the second structural part 20 and the first welding part 30 are welded by a fusion welding process, the welding seam between the second structural part 20 made of steel and the first welding part 30 is a welding seam formed by welding the same materials, the metal fusion welding strength is high, and intermetallic compounds such as TiFe and TiFe are not easy to form ₂ And the mechanical strength of the welding structural part is improved. The surface of the first structural member 10, which is close to the side wall 12 of the first concave region 11, is provided with a transition layer 222, and the first welding part 30 is welded and connected with the side wall 12 of the first structural member 10 through the transition layer 222.

The materials of the first structural member 10 and the second welding part 40 are titanium or titanium alloy, the second welding part 40 is welded with the side wall of the first structural member 10 close to the second concave region 23 in a melting way, the second welding part 40 is welded with the inclined structure 221 of the second structural member 20 through the transition layer 222, intermetallic compounds generated in the welding process can be reduced, and the mechanical strength of the welded structural member is improved. In addition, since the second structural member 20 can be engaged with the through hole 13 of the first structural member 10, the overall structural stability of the welded structural member is improved, and the welded structural member has both the abrasion resistance of steel and the low density and high mechanical strength of titanium metal or titanium alloy.

As shown in fig. 12a and 12b, the second welding portion 40 may be integrally formed with the first structural member 10, or may be welded to the second surface 102 along the edge of the second opening 132 of the through hole 13. After the first welded portion 30 is formed by fusion welding the protruding portion 21a of the second structural member 20, the first welded portion 30 is filled in the first recessed area 11, and then the second welded portion 40 is fused such that at least part of the second welded portion 40 covers the surface of the second structural member on the side close to the second opening 132.

In other embodiments, the second welded portion 40 may be formed by welding the first structural member 10 with a stainless steel electrode and then filling the second recessed region 23 with the electrode.

In the concrete processing process, the method mainly comprises the following steps:

firstly, pretreatment of a structural member:

firstly, milling the first structural member 10 to form a through hole 13 and a first concave region 11, wherein the first concave region 11 can be a C-shaped concave region or a rectangular concave region; milling the first structural member 10 to form an inclined structure 221, wherein the inclined structure 221 is matched with the first structural member 10 to form a second concave region 12, and the first concave region 11 and the second concave region 12 can be C-shaped grooves or rectangular grooves;

processing the second structural member 20 so that the second structural member 20 includes a main body portion 21 and engagement portions 22 extending from both sides of the main body portion 21; and the main body 21 of the second structure 20 is inserted through the through hole 13 of the first structural member 10, and the engaging portion 22 is engaged with the through hole 13.

A transition layer 222 (which may be, for example, a nickel layer) is formed on a surface of the sidewall of the first structural member 10 adjacent to the first recess region 11.

An inclined structure 221 is formed on a side of the engaging portion 22 of the second structural member 20 near the second opening 132, and a transition layer 222 is formed on the inclined structure 221.

Second, welding treatment: spot welding and melting the convex portion 21a of the second structural member 20 (for example, a second structural member of stainless steel material), and filling the molten metal into the first concave region 11 to form a C-shaped first welded portion 30; wherein a weld interface (steel-steel) of the same metal is formed between the first weld 30 and the second structural member 20; the first welded portion 30 is welded to the side wall of the first structural member 10 by a transition layer 222 to form a welded interface (titanium-copper-steel).

Thirdly, welding treatment: welding the welding metal with the side wall of the first structural member 10 close to the second opening 132 by adopting laser spot welding, filling the melted metal in the second concave region 23 to form a second welding part 40, and welding the second welding part 40 with the inclined structure 221 of the second structural member 20 through a transition layer, wherein a part of the surface of the second welding part 40 is welded with the first structural member 10 to form a same metal welding interface (titanium-titanium); another portion of the surface of the second welded portion 40 is welded with the second structural member 20 to form a welded interface (titanium-nickel-steel) with a transition metal.

Fourthly, improving the quality of the welding seam through heat treatment, and removing the internal stress at the joint through annealing treatment; and then polishing to form a smooth weld surface, thereby obtaining the welded structural member with double-sided riveting.

In this embodiment, the main body portion 21 of the second structural member is cylindrical with a diameter of 0.9mm; the second structural member 20 and the first welding part 30 form a riveting structure, and the second welding part 40 is filled in the second concave region 23, so that double-sided riveting welding can be realized, the stability of the welding structural member in a long-term use state can be ensured, the welding structural member is durable, larger internal stress caused by welding among different metals can be avoided, the occurrence probability of fracture of the welding structural member is reduced, and the mechanical strength of the whole welding structure is improved. Through drawing test, the drawing force of the welded structural part riveted on the two sides is more than or equal to 100N.

Fig. 13a is a schematic cross-sectional view of another welding structure before welding, as shown in fig. 13a, where the welding structure 100 includes a first structural member 10 and a second structural member 20. The main body 21 of the second structural member 20 is inserted through the through hole 13, wherein the engaging portion 22 of the second structural member 20 is engaged in the through hole 13, and at least part of the second structural member 20 protrudes to form a protruding portion 21a in the first recessed area 11 opposite to the first structural member 10 before being welded to the first structural member 10.

Fig. 13b is a schematic cross-sectional view of another welded structure provided in the embodiment of the present application, as shown in fig. 13b, unlike the embodiment shown in fig. 10, in this embodiment, the inclined structure 221 formed on the side of the second structure 20 near the second opening 132 is a plane, and the inclined structure 221 cooperates with the first structure 10 to form the second recess 23. That is, the thickness of the engaging portion 22 is smaller than the depth of the second duct 13 b; the inclined structure 221 of the second structural member 20 is formed with a transition layer 222, thereby improving the strength of the dissimilar metal welding.

Fig. 13C is an enlarged view of a portion of the area C shown in fig. 13b, as shown in fig. 13C, the side wall of the second welding portion 40 is welded to the side wall of the first structural member 10 near the second recess region 23, and the second welding portion 40 is welded to the engaging portion 22 through the transition layer 222, so that intermetallic compounds are generated during the welding process, and the mechanical strength of the welded structural member is improved. Specifically, the second welding portion 40 is made of titanium or titanium alloy, the first structural member 10 and the second welding portion 40 are welded by a fusion welding process, the welding seam between the first structural member 10 and the second welding portion 40 made of titanium or titanium alloy is formed by welding the same material, the metal fusion welding strength is high, and intermetallic compounds such as TiFe, tiFe are not easy to form ₂ And the mechanical strength of the welding structural part is improved. In addition, since the second structural member 20 can be engaged with the through hole 13, the structural stability of the welded structural member as a whole is improved, and the welded structural member has both the abrasion resistance of steel and the low density and high mechanical strength of titanium metal or titanium alloy.

Fig. 14 is a schematic structural diagram of a rotating shaft assembly in an electronic device according to an embodiment of the present application, and as shown in fig. 14, the present invention further provides an electronic device, including a rotating shaft assembly 200, where the rotating shaft assembly 200 of the electronic device includes the above-mentioned welding structure member 100, and by adopting the above-mentioned welding method, the overall structural stability is improved, and the welding structure member has both wear resistance of steel material and low density and high mechanical strength of titanium metal or titanium alloy, so that the service life of the electronic device can be prolonged. In particular, the electronic device may be a foldable electronic device, which includes a spindle assembly 200, and the welding structure 100 is located on the spindle assembly 200.

The electronic device of the present application may be a foldable mobile phone, a notebook, a foldable wearable device, etc., without limitation.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims

1. The welding structure is characterized by comprising a first structure and a second structure, wherein the first structure and the second structure are made of different materials;

the welded structure further includes:

2. The welded structure of claim 1, wherein at least a portion of the second structure protrudes into a bulge in a first recessed region relative to the first structure prior to welding with the first structure, the first weld being formed by fusion welding of the bulge.

3. The welded structure of claim 1, wherein the first structure is provided with a transition layer adjacent to a sidewall surface of the first recessed area, and the first welded portion is welded to the first structure by the transition layer.

4. The welded structure according to claim 1 or 2, wherein the first weld is mated with the first recessed area.

5. The welded structure according to claim 1, characterized in that the surface of the inclined structure is provided with a transition layer, and the second welded part and the inclined structure are welded together by the transition layer.

6. The welded structure according to claim 1 or 5, wherein the second weld is mated with the second recessed area.

7. The welded structure according to any one of claims 1 to 6, wherein the through hole is a stepped hole, the through hole includes a first duct and a second duct that are communicated, and the aperture of the first duct is smaller than the aperture of the second duct; the second structural member comprises a main body part and clamping parts formed by extending from two sides of the main body part, the main body part penetrates through the first pore canal, and the clamping parts are clamped in the second pore canal.

8. The welded structure according to claim 7, wherein the second welded portion is connected to a side of the engagement portion of the second structure that is away from the side near the second opening.

9. The welded structure according to claim 7, wherein a portion of the second welded portion is fusion welded to the first structure, and a portion of the second welded portion is welded to the engagement portion of the second structure via a transition layer.

10. The welded structure according to any one of claims 1 to 9, wherein the material of the first and second welded portions is at least one selected from the group consisting of titanium metal, titanium alloy, aluminum alloy, magnesium alloy, and carbon fiber; the material of the second structural member and the first welding part is at least one selected from carbon steel, stainless steel, cobalt alloy and nickel alloy.

11. The welded structure according to claim 3 or 5, wherein the material of the transition layer is at least one selected from copper, nickel, zinc, silver, chromium.

12. The welded structure according to claim 11, wherein the transition layer has a thickness of 10 μm to 100 μm.

13. A method of forming a welded structure comprising the steps of:

providing a first structural member and a second structural member, wherein the first structural member and the second structural member are made of different materials; the first structural member is provided with a through hole, and the through hole comprises a first opening and a second opening;

the method A comprises the following steps:

The method B comprises the following steps:

14. The method of claim 13, wherein at least a portion of the second structural members of the welded structural members protrude into a first recessed area relative to the first structural members to form a bulge prior to welding with the first structural members, the forming a first weld in the first recessed area on the first structural members comprising:

the projecting portion is melted to form the first welded portion.

15. The method of claim 13, wherein forming a first weld in a first recessed area on the first structural member to effect welding of the first structural member to the second structural member comprises:

and welding one end, close to the first concave area, of the second structural member in a fusion mode to form a first welding part, and welding the first welding part with the first structural member through the transition layer.

16. The method of claim 15, wherein the first weld mates with the first recessed area.

17. The method according to any one of claims 13 to 16, wherein the through hole is a stepped hole, the through hole comprises a first pore canal and a second pore canal which are communicated, and the pore diameter of the first pore canal is smaller than that of the second pore canal; before the welding the first welded portion to the first structural member and the second structural member, the method further includes:

18. The method of claim 17, wherein forming a second weld in a second recessed area to effect welding of the first structural member to the second structural member comprises:

19. The method of claim 17 or 18, wherein the second weld mates with the second recessed area.

20. A welded structure, characterized in that it is formed by the method according to any one of claims 13-19.

21. An electronic device comprising the welded structure according to any one of claims 1 to 12 or the welded structure according to claim 20.

22. The electronic device of claim 21, wherein the electronic device is a foldable electronic device comprising a spindle assembly, the welding structure being located on the spindle assembly.