Hydraulic actuator shell and preparation method thereof

Abstract

The invention discloses a hydraulic actuator shell and a preparation method thereof, relates to the technical field of metal material preparation, and aims at solving the problems that an existing hydraulic actuator shell is weak in pressure resistance and poor in vibration and noise reduction capacity. The hydraulic actuator shell comprises a foam metal sandwich composite pipe, a foam metal sandwich flange and a foam metal sandwich end cover; the foam metal sandwich composite pipe is connected with one end of the foam metal sandwich flange, and the foam metal sandwich end cover is connected with the other end of the foam metal sandwich flange; the foam metal sandwich composite pipe comprises a first metal pipe layer, a first foam metal layer and a second metal pipe layer which are sequentially arranged from inside to outside. And a first bonding interface among the first metal pipe layer, the first foam metal layer and the second metal pipe layer is a metallurgical bonding interface. The hydraulic actuator shell is used for improving the pressure resistance, the corrosion resistance and the vibration and noise reduction capacity of the hydraulic actuator shell.

Description

Technical Field

[0001] The present invention relates to the technical field of metal material preparation, and in particular to a hydraulic actuator housing and a preparation method thereof. Background Art

[0002] As the core transmission component of deep-sea operations and ocean exploration, deep-sea hydraulic actuators not only need to withstand harsh conditions such as high pressure, high temperature, and high humidity, but also need to cope with the dual challenges of seawater corrosion and mechanical vibration. In order to ensure the survivability of equipment under high hydrostatic pressure in the deep sea, the shell of marine equipment must have excellent pressure resistance. At the same time, in order to expand the scope of application, these shells must also have multiple functions under the coupling of complex multi-physical fields such as force, sound, and electromagnetic.

[0003] Bimetallic composite materials and bimetallic composite plates combine the advantages of two different metal elements and have unique properties such as light weight, high strength, corrosion resistance, fatigue resistance, and impact resistance. They have been widely used in aerospace, shipbuilding, petrochemical and other fields. However, their high density, high rigidity and strong physical properties cause sound waves to tend to reflect rather than absorb when they contact their surface, especially in terms of absorbing high-frequency sound waves. In addition, the multi-layer interface inside the composite structure may also cause complex reflection and refraction of sound waves, further weakening its sound absorption performance.

[0004] With its unique pore structure, metal foam has shown significant advantages in terms of light weight, high strength, energy absorption and vibration reduction, good thermal conductivity and excellent acoustic performance. Especially in the field of acoustics, the efficient sound insulation and sound absorption effects of metal foam make it a rising star in the field of sound absorbing materials. However, the lower strength of metal foam limits its load-bearing capacity and energy absorption characteristics. Therefore, metal foam is usually used to fill thin-walled structures to improve the stability, high strength and buffering and vibration reduction capabilities of the overall structure. However, at present, metal foam composite materials are mainly based on mechanical bonding, which is difficult to meet the high standards of high strength, high stability and high corrosion resistance.

[0005] Therefore, there is an urgent need for a hydraulic actuator housing and a preparation method thereof. Summary of the invention

[0006] The object of the present invention is to provide a hydraulic actuator housing and a preparation method thereof, which are used to improve the pressure resistance, corrosion resistance and vibration and noise reduction capabilities of the hydraulic actuator housing during deep-sea operations and ocean exploration.

[0007] In order to achieve the above object, the present invention provides the following technical solutions: In a first aspect, the present invention provides a hydraulic actuator housing, comprising a foam metal sandwich composite tube, a foam metal sandwich flange, and a foam metal sandwich end cover; The foam metal sandwich composite tube is connected to one end of the foam metal sandwich flange, and the foam metal sandwich end cover is connected to the other end of the foam metal sandwich flange; The foam metal sandwich composite tube comprises a first metal tube layer, a first foam metal layer and a second metal tube layer arranged in sequence from the inside to the outside; the first bonding interface between the first metal tube layer, the first foam metal layer and the second metal tube layer is a metallurgical bonding interface.

[0008] Optionally, the foam metal sandwich flange is an annular cylindrical structure, the foam metal sandwich end cover is a cylindrical structure, the outer diameter of the foam metal sandwich flange is the same as the diameter of the foam metal sandwich end cover, a plurality of first through holes are evenly arranged along the circumferential direction on the annular surface of the foam metal sandwich flange, and a plurality of second through holes corresponding to the first through holes are arranged on the circular surface of the foam metal sandwich end cover.

[0009] Optionally, the foam metal sandwich end cover and the foam metal sandwich flange are obtained by cutting a foam metal sandwich composite plate, and the foam metal sandwich composite plate includes, from top to bottom, a first corrugated metal layer, a second foam metal layer and a second corrugated metal layer, and the bonding interface between the first corrugated metal layer, the second corrugated metal layer and the second foam metal layer is a second bonding interface of metallurgical bonding, and the second bonding interface is a corrugated interface.

[0010] Compared with the prior art, the present invention provides a hydraulic actuator housing, comprising a foam metal sandwich composite tube, a foam metal sandwich flange and a foam metal sandwich end cover; the foam metal sandwich composite tube comprises a first metal tube layer, a first foam metal layer and a second metal tube layer arranged in sequence from the inside to the outside; the first bonding interface between the first metal tube layer, the first foam metal layer and the second metal tube layer is a metallurgical bonding interface; the foam metal sandwich composite tube in this scheme is a foam metal sandwich material and the bonding interface of each structure is a metallurgical bonding interface, the foam metal sandwich composite tube material has high strength, high stability, high corrosion resistance, and excellent sound absorption and vibration reduction performance, the hydraulic actuator housing prepared from this material not only has light weight, high strength and excellent sound absorption and vibration reduction performance, but also can maintain excellent performance in extreme environments such as deep sea high pressure, low temperature, high salt, etc., thereby meeting the urgent demand for high-performance functional housing materials for deep-sea hydraulic actuators.

[0011] In a second aspect, the present invention provides a method for preparing a hydraulic actuator housing, which is used to prepare the hydraulic actuator housing, and the method comprises: A tube blank composite blank is provided; the tube blank composite blank comprises, from inside to outside, a first metal tube layer, an annular prefabricated foam blank and a second metal tube layer; The tube blank composite blank is heated to a target temperature, and the tube blank composite blank is extruded to form a shape, during which the temperature of the first contact interface between the structures of the tube blank composite blank is raised to a preset temperature, the preset temperature being greater than or equal to the melting point temperature of the annular prefabricated foam blank, the first contact interface is remelted to form a metallurgically bonded first bonding interface, and a target composite tube blank is obtained; the target temperature is less than the melting point temperature; Placing the target composite tube blank in a heating furnace to foam the middle layer of the target composite tube blank to form a first foam metal layer, thereby obtaining a foam metal sandwich composite tube; The foam metal sandwich composite tube, the foam metal sandwich flange and the foam metal sandwich end cover are assembled to form a hydraulic actuator housing.

[0012] Optionally, the target temperature includes a first target temperature and a second target temperature; the step of heating the tube blank composite blank to the target temperature, and extruding the tube blank composite blank to form the tube blank composite blank, during which the temperature of the first contact interface between the structures of the tube blank composite blank is raised to a preset temperature, the preset temperature is greater than or equal to the melting point temperature of the annular prefabricated foam blank, the first contact interface is remelted to form a metallurgically bonded first bonding interface, and obtaining the target composite tube blank includes: Putting the tube blank composite blank into a first annular inner cavity formed by an extrusion inner die and an extrusion outer die; Fix the extrusion outer die by an extruder, start a first induction heating coil arranged on the extrusion inner die to heat the first metal tube layer to a first target temperature; start a second induction heating coil arranged on the extrusion outer die to heat the second metal tube layer to a second target temperature; The pressure head pushes one end of the extrusion inner die to move axially along the tube blank composite billet, so that the tube blank composite billet is extruded from the extrusion end of the first annular inner cavity, and the temperature of the first contact interface rises to a preset temperature during the extrusion process, and the preset temperature is greater than or equal to the melting point temperature. The first contact interface is remelted to form a metallurgically bonded first bonding interface to obtain a target composite tube blank, and the extrusion end is used to apply radial pressure to the tube blank composite billet.

[0013] Optionally, before assembling the foam metal sandwich composite tube, the foam metal sandwich flange and the foam metal sandwich end cover to form the hydraulic actuator housing, the step further includes: preparing a foam metal sandwich flange and a foam metal sandwich end cap; The preparation of the foam metal sandwich flange and the foam metal sandwich end cover comprises: A composite plate blank is provided; the composite plate blank comprises, from top to bottom, a first corrugated metal layer, a square prefabricated foam blank and a second corrugated metal layer; the first corrugated metal layer and the second corrugated metal layer are corrugated metal plates with a corrugated interface on one side; Heating the composite slab, heating the first corrugated metal layer to a first target temperature, and heating the second corrugated metal layer to a second target temperature, to obtain a different-temperature composite slab; The different-temperature composite sheet blank is subjected to rolling treatment, so that the first corrugated metal layer, the square prefabricated foam blank layer and the second corrugated metal layer are tightly bonded, and during the deformation process, the temperature of the second contact interface between the structures of the different-temperature composite sheet blank is increased to a preset temperature, the preset temperature is greater than or equal to the melting point temperature, and the second contact interface is remelted to form a metallurgically bonded second bonding interface, so as to obtain a target composite sheet; Placing the target composite panel in a heating furnace at a third target temperature for a preset time, so that the middle layer of the target composite panel is foamed to form a second foam metal layer, thereby obtaining a foam metal sandwich composite panel; The foam metal sandwich composite panel is cut according to preset dimensions to obtain two foam metal sandwich flanges and two foam metal sandwich end covers.

[0014] Optionally, before providing a composite slab, the method further includes: preparing a composite slab; The preparation of the composite slab comprises: Two metal plates are provided; Putting the second foaming powder into a square mold and pressing the second foaming powder to obtain a square prefabricated foam blank; The two metal plates are rolled using a corrugated rolling mill to obtain a first corrugated metal layer and a second corrugated metal layer; the upper roll of the corrugated rolling mill is a corrugated roll, and the lower roll is a flat roll; The square prefabricated foam blank is placed between the first corrugated metal layer and the second corrugated metal layer to assemble the blank to obtain a composite plate blank.

[0015] Optionally, the foam metal sandwich composite tube is prepared by an extrusion tool, and the extrusion tool comprises: An extrusion inner mold, the extrusion inner mold comprises an inner mold cylinder body of a T-shaped structure, the inner mold cylinder body comprises a head and a tail, the tail is provided with a cylindrical inner cavity, a first induction heating coil is provided in the cylindrical inner cavity, an inner mold insulating pad is provided between the first induction heating coil and the cylindrical inner cavity, an inner mold end cap is provided at one end of the cylindrical inner cavity away from the head, the inner mold end cap is connected to the inner mold cylinder body through an inner mold fastening screw, and the inner mold end cap is used to form a closed space in the cylindrical inner cavity; An extrusion outer die, wherein a second induction heating coil is arranged in the extrusion outer die, the inner wall of the extrusion outer die comprises a large diameter section, a slope section and a small diameter section, the large diameter section and the small diameter section are transitionally connected by the slope section, the large diameter section of the extrusion outer die is sleeved with the head of the inner die cylinder body, a first annular inner cavity is formed between the inner wall of the extrusion outer die and the tail of the extrusion inner die, and an end of the first annular inner cavity close to the small diameter section is an extrusion end; An extruder, used for clamping and fixing the outer wall of the extrusion outer die; The pressure head is used to push the extrusion inner die to make the tube blank composite blank move axially and extrude it from the extrusion end of the first annular inner cavity.

[0016] Optionally, the main body of the extrusion outer die is an outer die cylinder body, a second annular inner cavity is arranged between the inner wall and the outer wall of the large diameter section, a second induction heating coil is arranged in the second annular inner cavity, the second induction heating coil and the second annular inner cavity are separated by an outer die insulating pad, an outer die end cover is arranged at one end of the second annular inner cavity away from the small diameter section, and the outer die end cover is connected to the outer die cylinder body to form a closed space for the second annular inner cavity.

[0017] Optionally, before providing a tube blank composite blank, the process further includes: preparing a tube composite billet; The preparation of the tube blank composite blank comprises: Mixing metal powder, tackifier and foaming agent powder in a preset ratio to obtain foaming powder; the foaming powder includes a first foaming powder and a second foaming powder; Pour the first foaming powder into the third annular inner cavity formed by the tube blank forming outer mold and the tube blank forming inner mold, start the first oscillating base of the tube blank set mold, and use an annular pressing head to press the foaming powder into an annular prefabricated foam blank during the oscillation process of the first oscillating base; The annular prefabricated foam blank is placed in the gap between the first metal tube layer and the second metal tube layer of the tube blank composite blank to obtain the tube blank composite blank.

[0018] Compared with the prior art, the method for preparing a hydraulic actuator housing provided by the present invention is to heat a tube blank composite blank to a target temperature, and to extrude the tube blank composite blank, and at the same time, the deformation heat under the extrusion composite deformation action causes the temperature of the first contact interface between the structures of the tube blank composite blank to rise to a preset temperature, the preset temperature is greater than or equal to the melting point temperature of the annular prefabricated foam blank, and the first contact interface is remelted to form a metallurgically bonded first bonding interface to obtain a target composite tube blank. Since the temperature of the first contact interface is the preset temperature reached by the action of deformation heat, the temperature rise will not be particularly large, and the temperature of the first contact interface can reach the melting point temperature but not reach the foaming temperature of the middle layer of the tube blank composite blank. The middle layer of the tube blank composite blank will not foam during the extrusion composite process, so the structures of the tube blank composite blank are more tightly bonded under the action of extrusion; then the target composite tube blank is placed in a heating furnace to foam the middle layer of the target composite tube blank, thereby obtaining a foam metal sandwich composite tube. Then, the foam metal sandwich composite tube, the foam metal sandwich flange and the foam metal sandwich end cover are assembled to obtain a hydraulic actuator housing. This method achieves precise control over the foaming process by remelting the first contact interface of the tube-blank composite billet during the extrusion process to form a metallurgical bond, while preventing the foaming of the middle layer of the tube-blank composite billet in advance, effectively solving the existing problem of difficulty in achieving a tight metallurgical bond between the foam metal and the base metal. The foam metal sandwich composite tube material prepared by this method has high strength, high stability, high corrosion resistance, and excellent sound absorption and vibration reduction performance. The hydraulic actuator housing prepared based on this material not only has light weight, high strength and excellent sound absorption and vibration reduction performance, but also can maintain excellent performance in extreme environments such as deep-sea high pressure, low temperature, and high salt, thereby meeting the urgent demand for high-performance functional housing materials for deep-sea hydraulic actuators. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 A schematic structural diagram of a hydraulic actuator housing provided by the present invention; Figure 2 A top view of the foam metal sandwich composite tube provided by the present invention; Figure 3 A schematic diagram of the structure of the foam metal sandwich composite panel provided by the present invention; Figure 4 A top view of the foam metal sandwich flange provided by the present invention; Figure 5 A cross-sectional view of the foam metal sandwich flange provided by the present invention; Figure 6A top view of the foam metal sandwich end cap provided by the present invention; Figure 7 A cross-sectional view of the foam metal sandwich end cap provided by the present invention; Figure 8 A flow chart of a method for preparing a hydraulic actuator housing is provided for the present invention; Fig. 9 A schematic diagram of the structure of the tube composite blank provided by the present invention; Fig.10 A schematic diagram of the formation of the annular prefabricated foam blank provided by the present invention; Fig.11 A cross-sectional schematic diagram of the extrusion inner die provided by the present invention; Fig.12 A cross-sectional schematic diagram of the extrusion outer die provided by the present invention; Fig.13 A schematic diagram of the extrusion forming of the target composite tube provided by the present invention; Fig.14 A schematic diagram of preparing a square prefabricated foamed blank layer provided by the present invention; Fig.15 A schematic diagram of the rolling process of the corrugated metal plate provided by the present invention; Fig.16 A schematic diagram of the structure of the induction heating device for the foam metal sandwich composite panel provided by the present invention; Fig.17 This is a schematic diagram of the rolling forming of the composite slab provided by the present invention.

[0020] Reference numerals: 1-foam metal sandwich composite tube, 11-first metal tube layer, 12-first foam metal layer, 13-second metal tube layer, 14-annular prefabricated foam blank, 2-foam metal sandwich flange, 21-first through hole, 3-foam metal sandwich end cover, 31-second through hole, 4-foam metal sandwich composite plate, 41-first corrugated metal layer, 42-second foam metal layer, 43-second corrugated metal layer, 101-tube blank forming inner mold, 102-tube blank forming outer mold, 103-first oscillation base, 104 annular pressure head, 5-extrusion inner mold, 51-inner mold cylinder, 52-inner mold circular insulating gasket, 53-first induction heating coil, 54-inner mold end cover, 55-inner mold strip insulating rubber pad, 56-inner mold fastening screw, 6-extrusion outer mold, 61-outer mold cylinder, 62-second induction heating coil, 63-outer mold end cover, 64-outer mold fastening screw, 65-outer mold strip insulating rubber pad, 66-outer mold annular insulating gasket, 7-extruder, 8-pressing head, 9-graphite gasket, 10-target composite tube blank, 141-square pressing head, 142-square mold, 143-second oscillation base, 144-square prefabricated foam blank, 161-third induction heating coil, 162-fourth induction heating coil. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0023] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. The meaning of "several" is one or more, unless otherwise clearly and specifically defined.

[0024] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "front", "back", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0026] As onshore and coastal resources become increasingly depleted, the world's marine powers have shifted their development focus from offshore to deep-sea areas. The rapid progress of deep-sea equipment has made it possible to develop and utilize deep-sea resources on a large scale. However, the extreme environment of the deep sea, such as high pressure, low temperature, and high salt, poses severe challenges to the shell design of marine equipment. The existing deep-sea hydraulic brake shell is usually prepared with foam metal sandwich materials that are mainly mechanically bonded, which is difficult to meet the requirements of high strength, high stability, and high corrosion resistance.

[0027] In order to solve the above problems, the present invention provides a hydraulic actuator housing and a preparation method thereof, which will be described below with reference to the accompanying drawings.

[0028] See also Figure 1 , a hydraulic actuator housing provided by the present invention comprises a foam metal sandwich composite tube 1, a foam metal sandwich flange 2 and a foam metal sandwich end cover 3; The foam metal sandwich composite tube 1 is connected to one end of the foam metal sandwich flange 2, and the foam metal sandwich end cover 3 is connected to the other end of the foam metal sandwich flange 2; See also Figure 2 The foam metal sandwich composite tube includes a first metal tube layer 11, a first foam metal layer 12 and a second metal tube layer 13 arranged in sequence from the inside to the outside; the first bonding interface between the first metal tube layer 11, the first foam metal layer 12 and the second metal tube layer 13 is a metallurgical bonding interface.

[0029] The bonding interface between the various structures of the foam metal sandwich flange 2 is a metallurgical bonding interface, and the bonding interface between the various structures of the foam metal sandwich end cover 3 is a metallurgical bonding interface.

[0030] The first bonding interface is formed when the temperature of the first contact interface rises to a preset temperature under extrusion and the interface is remelted. The first contact interface is the contact interface between the structures of the tube blank composite blank.

[0031] The materials of the first metal tube layer 11 and the second metal tube layer 13 in the above structure can both be seamless metal tubes.

[0032] It can be seen from the above structure that the hydraulic actuator housing provided by the present invention is composed of a foam metal sandwich composite tube, a foam metal sandwich flange, and a foam metal sandwich end cover, which can effectively meet the performance requirements of vibration reduction and sound absorption. At the same time, a variety of outer layer coated metals, titanium / stainless steel, titanium / aluminum, titanium / copper and other foam metal sandwich composite tubes, flanges and end covers can be selected according to different needs. The foam metal sandwich composite tube, foam metal sandwich flange, and foam metal sandwich end cover are all foam metal sandwich materials and the bonding interface of each structure is a metallurgical bonding interface. Materials such as the foam metal sandwich composite tube, foam metal sandwich flange and foam metal sandwich end cover have high strength, high stability, high corrosion resistance, and excellent sound absorption and vibration reduction performance. The hydraulic actuator housing prepared from these materials not only has light weight, high strength and excellent sound absorption and vibration reduction performance, but also can maintain excellent performance in extreme environments such as deep sea high pressure, low temperature, and high salt, thereby meeting the urgent demand for high-performance functional housing materials for deep-sea hydraulic actuators.

[0033] See also Figure 3 The foam metal sandwich flange 2 and the foam metal sandwich end cover 3 in the above structure are obtained by cutting the foam metal sandwich composite plate 4, such as Figure 3 As shown, the foam metal sandwich composite panel 4 includes a first corrugated metal layer 41, a second foam metal layer 42 and a second corrugated metal layer 43 from top to bottom, the bonding interface between the first corrugated metal layer 41 and the second foam metal layer 42 and the bonding interface between the second corrugated metal layer 43 and the second foam metal layer 42 are collectively referred to as the second bonding interface, the second bonding interface is a metallurgical bonding interface, and the second bonding interface is a corrugated interface. The material of the first corrugated metal layer is the same as that of the first metal tube layer, and the material of the second corrugated metal layer is the same as that of the second metal tube layer.

[0034] See also Figures 4 to 7 The foam metal sandwich flange 2 in the above structure is an annular cylindrical structure, the foam metal sandwich end cover 3 is a cylindrical structure, the outer diameter of the foam metal sandwich flange 2 is the same as the diameter of the foam metal sandwich end cover 3, the inner diameter of the foam metal sandwich flange 2 is the same as the inner diameter of the foam metal sandwich composite tube 1, and a plurality of first through holes 21 are evenly arranged on the annular surface of the foam metal sandwich flange 2 along the circumferential direction, and a plurality of second through holes 31 corresponding to the first through holes 21 are arranged on the circular surface of the foam metal sandwich end cover 3.

[0035] Combination Figure 1The number of the foam metal sandwich flange and the foam metal sandwich end cover constituting the hydraulic actuator housing are both 2, one foam metal sandwich flange is welded to one end of the foam metal sandwich composite tube, and the other foam metal sandwich flange is welded to the other end of the foam metal sandwich composite tube, and the foam metal sandwich flange and the foam metal sandwich end cover are fastened by bolts, and the bolts pass through the first through hole and the second through hole.

[0036] The metal in the first foam metal layer and the second foam metal layer in the above structure can be aluminum, copper, iron, nickel, titanium or stainless steel, etc., which are metals or alloys that can form stable bubbles by heating and foaming.

[0037] Foam metal has high efficiency in sound insulation and sound absorption effects, but the strength of foam metal is relatively low, which limits its load-bearing capacity and energy absorption characteristics. Currently, a method of adding thin-walled structures to foam metal is usually adopted to improve the stability, strength and buffering and vibration reduction capabilities of the overall structure. However, the structures are only mechanically combined, and the obtained foam metal sandwich composite material cannot meet the high standard requirements of high strength, high stability and high corrosion resistance in extreme deep-sea environments; and the existing preparation of foam metal composite materials makes it difficult to achieve a close metallurgical bond between the foam metal and the base metal.

[0038] To solve this technical problem, the present invention also provides a method for preparing a hydraulic actuator housing, which is used to prepare the above-mentioned hydraulic actuator housing, such as Figure 8 As shown, a method for preparing a hydraulic actuator housing comprises the following steps: Step S1: providing a tube composite blank; like Fig. 9 As shown, the tube blank composite blank includes, from inside to outside, a first metal tube layer 11 , an annular prefabricated foam blank 14 and a second metal tube layer 13 .

[0039] The first metal tube layer and the second metal tube layer are two different high-strength and corrosion-resistant seamless metal tubes.

[0040] Step S2: heating the tube blank composite blank to a target temperature, and extruding the tube blank composite blank to raise the temperature of the first contact interface between the structures of the tube blank composite blank to a preset temperature during the forming process, wherein the preset temperature is greater than or equal to the melting point temperature of the annular prefabricated foam blank, and the first contact interface is remelted to form a metallurgically bonded first bonding interface to obtain a target composite tube blank; The melting point temperature is the melting point temperature of the annular prefabricated foam blank, and the target temperature is less than the melting point temperature; Step S2 also includes calculating the target temperature according to formula (1), as shown in formula (1): (1) in, is the target temperature, is the melting point temperature of the annular prefabricated foam blank, is the density of the first metal tube layer or the density of the second metal tube layer, is the specific heat capacity of the first metal tube layer or the specific heat capacity of the second metal tube layer.

[0041] When the materials of the first metal tube layer and the second metal tube layer are different, the heating temperatures are different. The target temperature calculated according to the density and specific heat capacity of the first metal tube layer is the first target temperature, and the target temperature calculated according to the density and specific heat capacity of the second metal tube layer is the second target temperature; both the first target temperature and the second target temperature are lower than the melting point temperature.

[0042] Step S3: placing the target composite tube blank in a heating furnace to foam the middle layer of the target composite tube blank to form a first foam metal layer, thereby obtaining a foam metal sandwich composite tube; Specifically, the target composite tube blank is placed in a heating furnace at a third target temperature for a certain period of time, during which the foaming agent decomposes to generate bubbles, and the annular prefabricated foam blank in the middle layer of the target composite tube blank forms a second metal foam layer, and after the insulation is completed, a foam metal sandwich composite tube with a metallurgical bonding interface is obtained. The third target temperature is greater than or equal to the foaming temperature of the annular prefabricated foam blank.

[0043] Step S4: Assembling the foam metal sandwich composite tube, the foam metal sandwich flange and the foam metal sandwich end cover to form a hydraulic actuator housing.

[0044] It should be noted that the foam metal sandwich composite tube is prepared by heating, extruding, heat-insulating and foaming the tube blank composite blank.

[0045] In the preparation method of a hydraulic actuator housing provided by the present invention, since the temperature of the first contact interface is a preset temperature reached by the action of deformation heat, the temperature rise will not be particularly large, and the temperature of the first contact interface can reach the melting point temperature but not reach the foaming temperature of the annular prefabricated foaming blank of the tube blank composite blank. The middle layer of the tube blank composite blank will not foam during the extrusion composite process, so the various structures of the tube blank composite blank are more tightly bonded under the action of extrusion; then the target composite tube blank is placed in a heating furnace to foam the middle layer of the target composite tube blank, thereby obtaining a foam metal sandwich composite tube. Then, the foam metal sandwich composite tube, the foam metal sandwich flange and the foam metal sandwich end cover are assembled to obtain a hydraulic actuator housing. The method realizes precise control of the foaming process by remelting the first contact interface of the tube blank composite blank to form a metallurgical bond during the extrusion process, while avoiding the premature foaming of the annular prefabricated foaming blank of the middle layer of the tube blank composite blank, and effectively solves the problem of the difficulty in achieving a tight metallurgical bond between the foam metal and the base metal. The foam metal sandwich composite tube material prepared by this method has two highly corrosion-resistant seamless metal tubes as inner and outer layers, and the core layer is filled with foam metal. This foam metal sandwich composite tube has high strength, high stability, high corrosion resistance, and excellent sound absorption and vibration reduction performance. The hydraulic actuator shell prepared based on this material not only has light weight, high strength and excellent sound absorption and vibration reduction performance, but also can maintain excellent performance in extreme environments such as deep sea high pressure, low temperature, high salt, etc., thus meeting the urgent demand for high-performance functional shell materials for deep-sea hydraulic actuators.

[0046] Based on the above method, the present invention also provides some specific implementation methods, which are described in detail below.

[0047] As an optional method, before providing a tube blank composite blank, the method further includes: Prepare a tube blank composite blank by using a tube blank set die; See also Fig.10 The above-mentioned tube blank set mold includes a tube blank forming inner mold 101, a tube blank forming outer mold 102, an annular pressure head 104, and a first oscillating base 103. The tube blank forming inner mold 101 is a cylindrical structure. The tube blank forming outer mold 102 is sleeved on the outer surface of the tube blank forming inner mold 101. A third annular inner cavity is formed between the tube blank forming inner mold 101 and the tube blank forming outer mold 102. The lower surface of the tube blank forming inner mold 101 and the lower surface of the tube blank forming outer mold 102 are connected to the upper surface of the first oscillating base 103. The annular pressure head 104 includes a head and a tail. The head of the annular pressure head 104 can be a metal plate with circular upper and lower surfaces. The tail of the annular pressure head 104 is an annular cylinder. The tail of the annular pressure head 104 is sleeved with the third annular inner cavity. The preparation of the tube blank composite blank includes the following steps: Mixing metal powder, tackifier and foaming agent powder in a preset ratio to obtain foaming powder; Since the foaming powder used to prepare the first foamed metal layer of the foamed metal sandwich composite tube and the second foamed metal layer of the foamed metal sandwich panel is made of the same material, the foaming powder is divided into a first foaming powder and a second foaming powder; Pour the first foaming powder into the third annular inner cavity formed by the tube blank forming outer mold 102 and the tube blank forming inner mold 101, start the first oscillating base 103, and use the annular pressing head 104 to press the foaming powder into an annular prefabricated foam blank 14 during the oscillation of the first oscillating base 103; The annular prefabricated foam blank 14 is placed in the gap between the first metal tube layer 11 and the second metal tube layer 13 of the tube blank composite blank to obtain a tube blank composite blank.

[0048] As an optional method, when the materials of the first metal tube layer and the second metal tube layer in the above step S2 are different, the target temperature includes the first target temperature and the second target temperature; the target composite tube blank in step S2 can be prepared by using an extrusion tool, firstly placing the tube blank composite billet into the first annular inner cavity between the extrusion inner die and the extrusion outer die, heating the first metal tube layer of the tube blank composite billet to the first target temperature, heating the second metal tube layer of the tube blank composite billet to the second target temperature, and then pushing one end of the extrusion inner die to drive the tube blank composite billet to be extruded from the extrusion end of the first annular inner cavity, so that the temperature of the first contact interface between the structures of the tube blank composite billet is increased to a preset temperature, the preset temperature is greater than or equal to the melting point temperature, the first contact interface is remelted to form a metallurgical bonding first bonding interface, and the target composite tube blank is obtained.

[0049] See also Figure 11-13 , the extrusion tooling used in the above steps includes: Extrusion inner mold 5, such as Fig.11 As shown, the extrusion inner mold 5 includes an inner mold cylinder body 51 of a T-shaped structure, the inner mold cylinder body 51 includes a head and a tail, the tail is provided with a cylindrical inner cavity, a first induction heating coil 53 is provided in the cylindrical inner cavity, an inner mold insulating pad is provided between the first induction heating coil 53 and the cylindrical inner cavity, the inner mold insulating pad includes an inner mold circular insulating pad 52 and an inner mold strip insulating rubber pad 55, the inner mold circular insulating pad 52 and the inner mold strip insulating rubber pad 55 separate the first induction heating coil from the inner surface of the inner mold cylinder body to avoid contact and conduction; an inner mold end cover 54 is provided at one end of the cylindrical inner cavity away from the inner mold cylinder head, the inner mold end cover 54 is connected to the inner mold cylinder body 51 through an inner mold fastening screw 56, and the inner mold end cover 54 is used to form a closed space in the cylindrical inner cavity; The extrusion outer die 6 is provided with a second induction heating coil 62. The inner wall of the extrusion outer die 6 includes a large diameter section, a slope section and a small diameter section. The large diameter section and the small diameter section are transitionally connected by the slope section. Fig.13As shown, the large diameter section of the extrusion outer die 6 is sleeved with the head of the inner die cylinder body, and a first annular inner cavity is formed between the inner wall of the extrusion outer die 6 and the tail of the extrusion inner die, and the end of the first annular inner cavity close to the small diameter section is the extrusion end; like Fig.12 As shown, the main body of the extrusion outer die 6 in the above structure is the outer die cylinder body 61, and a second annular inner cavity is arranged between the inner wall of the large diameter section of the outer film cylinder body and the outer wall of the outer film cylinder body, and a second induction heating coil 62 is arranged in the second annular inner cavity, and the second induction heating coil 62 is separated from the second annular inner cavity by an outer die insulating pad, and the outer die insulating pad includes an outer die strip insulating rubber pad 65 and an outer die annular insulating gasket 66, and an outer die end cover 63 is arranged at one end of the second annular inner cavity away from the small diameter section, and the outer die end cover 63 is connected to the outer die cylinder body 61 through an outer die fastening screw 64 to form a closed space for the second annular inner cavity.

[0050] An extruder 7, used for clamping and fixing the outer wall of the extrusion outer die 6; The pressure head 8 is used to push the extrusion inner die 5 to make the tube blank composite blank move axially and be extruded from the extrusion end of the first annular inner cavity. A graphite gasket 9 is arranged between the pressure head 8 and the extrusion inner die 5.

[0051] Specifically, step S2 can be implemented based on the following steps: Step S21: placing the tube blank composite blank into a first annular inner cavity formed by an extrusion inner die and an extrusion outer die; Step S22: fixing the extrusion outer die 6 by the extruder 7, starting the first induction heating coil 53 provided on the extrusion inner die 5 to heat the first metal tube layer of the tube blank composite billet to the first target temperature; starting the second induction heating coil 62 provided on the extrusion outer die 6 to heat the second metal tube layer of the tube blank composite billet to the second target temperature; The first target temperature and the second target temperature are set to be lower than and close to the melting point of the annular prefabricated foam blank.

[0052] Step S23: Pushing one end of the extrusion inner die to move axially along the tube blank composite billet through a pressure head, so that the tube blank composite billet is extruded from the extrusion end of the first annular inner cavity, and the temperature of the first contact interface rises to a preset temperature during the extrusion process, and the preset temperature is greater than or equal to the melting point temperature. The first contact interface is remelted to form a metallurgical bonding first bonding interface to obtain a target composite tube blank, and the extrusion end is used to apply radial pressure to the tube blank composite billet.

[0053] The above method uses an extrusion tool to prepare the target composite tube blank. The extrusion tool uses an independent induction heating coil to perform induction heating on different metal tube layers at the same time, achieving precise temperature control, ensuring that the material of the first metal tube layer and the material of the second metal tube layer at high temperature are similar to the deformation resistance of the annular prefabricated foam blank at room temperature, effectively avoiding oxidation of the first contact surface to be composited during the heating process, and achieving coordinated deformation, greatly improving the success rate and stability of the preparation of the target composite tube blank. When extruding the tube blank composite blank, the electromagnetic induction frequency can be adjusted according to the extrusion speed, achieving precise online temperature control, and further improving production efficiency and stability. In addition, the extrusion tool realizes the preparation of the target composite tube blank through electromagnetic temperature control and extrusion gap matching, so that the target composite tube blank has a metallurgical bonding interface, which effectively solves the problem of difficult forming of the tube blank composite blank with gap matching sleeve.

[0054] As an optional method, before assembling the foam metal sandwich composite tube, the foam metal sandwich flange and the foam metal sandwich end cover to form the hydraulic actuator housing, the method further includes: preparing a foam metal sandwich flange and a foam metal sandwich end cap; The preparation of the foam metal sandwich flange and the foam metal sandwich end cover comprises the following steps: Step S31: providing a composite blank; the composite blank comprises, from top to bottom, a first corrugated metal layer, a square prefabricated foam blank layer and a second corrugated metal layer; the first corrugated metal layer and the second corrugated metal layer are corrugated metal plates with a corrugated interface on one side; the first corrugated metal layer and the first metal tube layer are made of the same material, and the second corrugated metal layer and the second metal tube layer are made of the same material; See also Figure 14-16 , the steps of preparing the composite slab are: Two metal plates are provided; like Fig.14 As shown, the second foaming powder is placed in the square inner cavity formed by the square mold 142, the second oscillating base 143 is started, and the second foaming powder is pressed by the square pressing head 141. The second foaming powder is formed into a square prefabricated foam blank 144 under the action of continuous vibration of the second oscillating base and extrusion of the square pressing head; The two metal plates are rolled by a flat rolling mill to obtain a first corrugated metal layer and a second corrugated metal layer; Fig.15 As shown, the upper roll of the flat rolling mill is a corrugated roll, and the lower roll is a flat roll; the first corrugated metal layer and the second corrugated metal layer are corrugated metal layers with a corrugated interface on one side; The square prefabricated foam blank is placed between the first corrugated metal layer and the second corrugated metal layer for assembly to obtain a composite blank. The square prefabricated foam blank is in contact with the corrugated interface of the two corrugated metal layers, and the composite blank is a sandwich structure.

[0055] Step S32: using a foam metal sandwich composite panel induction heating device to heat the composite panel blank, such as Fig.16 As shown, the first corrugated metal layer is heated to a first target temperature by a third induction heating coil 161 disposed at the top, and the second corrugated metal layer is heated to a second target temperature by a fourth induction heating coil 162 disposed at the bottom, to obtain a different-temperature composite slab; Step S33: Fig.17 As shown, the different-temperature composite plate blank is rolled to make the first corrugated metal layer, the square prefabricated foam blank and the second corrugated metal layer tightly bonded, and the temperature of the second contact interface between the structures of the different-temperature composite plate blank is increased to a preset temperature, and the preset temperature is greater than or equal to the melting point temperature, and the second contact interface is remelted to form a metallurgically bonded second bonding interface to obtain a target composite plate; the square prefabricated foam blank and the annular prefabricated foam blank are made of the same material, have the same melting point, and have the same foaming temperature.

[0056] The target composite panel is placed in a heating furnace at a third target temperature and kept warm for a preset time, so that the square prefabricated foam blanks in the middle layer of the target composite panel are foamed to form a second foam metal layer, thereby obtaining a foam metal sandwich composite panel; the third target temperature is greater than or equal to the foaming temperature; The above steps S32 and S33 use a separate induction heating coil to heat the first corrugated metal layer and the second corrugated metal layer of the composite plate blank to different temperatures, achieving precise control of the temperature before rolling and compounding, ensuring that the first corrugated metal layer and the second corrugated metal layer at high temperature are close to the deformation resistance of the square prefabricated foam blank at room temperature, effectively avoiding oxidation of the surface to be compounded due to heating, achieving coordinated deformation, and greatly improving the success rate and stability of the preparation of the foam metal sandwich composite board. The surface layers of the foam metal sandwich flange and the foam metal sandwich end cap prepared by the above steps are two high-strength and corrosion-resistant metal sheets, and the core layer is filled with foam metal, which has high strength, high stability, high corrosion resistance, and excellent sound absorption and vibration reduction performance.

[0057] The foam metal sandwich composite panel is cut according to preset dimensions to obtain two foam metal sandwich flanges and two foam metal sandwich end covers.

[0058] Next, a method for preparing a hydraulic actuator housing provided by the present invention is described in detail by way of example.

[0059] A TA1 / 304 aluminum foam sandwich shell for deep-sea hydraulic actuators is composed of a TA1 / 304 metal foam sandwich composite tube, a TA1 / 304 metal foam sandwich flange, and a TA1 / 304 metal foam sandwich end cover. The TA1 / 304 metal foam sandwich composite tube and the TA1 / 304 metal foam sandwich flange are welded, and the TA1 / 304 metal foam sandwich flange and the TA1 / 304 metal foam sandwich end cover are connected by bolts and a sealing gasket. The preparation method thereof consists of two parts: The first part is a method for preparing a TA1 / 304 foam metal sandwich composite tube, wherein the material of the first metal layer of the foam metal sandwich composite tube is a TA1 seamless tube, and the material of the second metal layer is a 304 stainless steel seamless tube, and the method comprises the following steps: Step 11: Preparation of foaming powder: Select metal Ca as a tackifier and titanium metal hydride as a foaming agent powder, perform pre-oxidation treatment on the foaming agent powder to delay its decomposition rate during the heating and foaming process, mix the aluminum alloy powder, the tackifier and the foaming agent powder at a mass percentage of 95%, 3% and 2% to obtain the foaming powder, then pour the foaming powder into the third annular inner cavity formed by the tube blank forming outer mold and the tube blank forming inner mold, and use an annular pressing head to press it into an annular prefabricated foam blank with an outer diameter of 178 mm, a wall thickness of 18 mm and a length of 500 mm. During the pressing process, the first oscillation base works continuously to ensure that a compact foam aluminum annular prefabricated foam blank is obtained; Step 12: Assembly: Select TAI seamless tubes with an outer diameter of 200 mm, a wall thickness of 10 mm, and a length of 500 mm and 304 stainless steel seamless tubes with an outer diameter of 140 mm, a wall thickness of 10 mm, and a length of 500 mm, use alcohol to clean and remove oil stains, then grind the inner surface of the TA1 seamless tube and the outer surface of the 304 stainless steel seamless tube, and assemble the TA1 seamless tube, annular prefabricated foaming blank, and 304 stainless steel seamless tube in order to obtain a TA1 / 304 foam aluminum sandwich tube composite blank; Step 13: Calculate the first target temperature and the second target temperature according to formula (1), wherein the density of the TA1 seamless tube in the TA1 / 304 aluminum foam sandwich tube composite billet is 4.51 g / cm3, the specific heat capacity is 0.526 J / g, the density of the 304 stainless steel seamless tube in the TA1 / 304 aluminum foam sandwich tube composite billet is 7.93 g / cm3, the specific heat capacity is 0.5 J / g, and the melting point temperature of the annular prefabricated foam blank is 660°C. Substituting these data into formula (1), it can be obtained that the first target temperature of the TA1 seamless tube is 550°C, and the second target temperature of the 304 stainless steel seamless tube is 600°C.

[0060] Step 13: Electromagnetic temperature control extrusion compounding: insert the TA1 / 304 tube composite billet into the extrusion inner die with an outer diameter of 110 mm, and send the extrusion inner die and the tube composite billet into the undeformed area of ​​the extrusion outer die together, then start the induction heating coils set in the extrusion inner die and the extrusion outer die, heat the TA1 seamless pipe and the 304 stainless steel seamless pipe to 550°C and 600°C respectively, turn off the induction heating coil, and start the extruder at the same time. The pressure head pushes the extrusion inner die to drive the tube composite billet through the extrusion outer die with an inner diameter of 170 mm in the forming area, and extrude the seamless metal composite tube billet from the extrusion mold; before starting the extrusion compounding, the TA1 seamless pipe and the 304 stainless steel seamless pipe are heated to 550°C and 600°C respectively, and the temperature is lower than the pre- The melting point of the foaming blank is 660℃. After the induction heating is completed, the temperature of the annular prefabricated foam blank in the middle layer of the tube blank composite blank is lower than that of the seamless tube. Since titanium has a lower thermal conductivity and a higher thermal expansion coefficient, it is easier to absorb heat and heat up rapidly during plastic deformation. Under the same conditions, titanium usually heats up faster than stainless steel. Therefore, the TA1 seamless tube is set with a higher starting temperature than the 304 stainless steel seamless tube. Under the action of extrusion composite deformation, the deformation heat causes the contact interface temperature of the TA1 seamless tube and the 304 stainless steel seamless tube with the annular prefabricated foam blank to rise to a temperature exceeding the melting point of the annular prefabricated foam blank, achieving interface remelting to form a metallurgical bond, but the annular prefabricated foam blank does not reach the foaming temperature of 550℃ and pre-foaming will not occur. Step 14: Insulation foaming: The target composite tube blank prepared in step 13 is placed in a heating furnace at a temperature of 550° C. and insulated for 3 minutes. During the heating process, the annular prefabricated foam blank is decomposed to generate bubbles, and the prefabricated foam blank of the middle layer forms foamed metal aluminum. After the insulation foaming is completed, the end is cut off to obtain a TA1 / 304 foamed aluminum sandwich composite tube with interface metallurgical bonding; The second part is a method for preparing a TA1 / 304 foam aluminum sandwich flange and a TA1 / 304 foam aluminum sandwich end cover, which comprises the following steps: Step 21: Preparing a prefabricated foaming blank: using metal Ca as a viscosity enhancer and titanium metal hydride as a foaming agent powder, pre-oxidizing the foaming agent powder to delay its decomposition rate during the heating and foaming process, mixing the aluminum alloy powder, the viscosity enhancer and the foaming agent powder at a mass percentage of 95%, 3% and 2% to obtain a foaming powder, and then using a square mold to press the foaming powder to obtain a square prefabricated foamed aluminum blank with a size of 250 mm*250 mm*10 mm; Step 22: Prefabricate corrugated metal plates: Use a corrugated roller as the upper roller and a flat roller as the lower roller to roll a TA1 titanium plate and a 304 stainless steel plate with a size of 250*250mm*5mm to obtain two TA1 titanium plates and 304 stainless steel plates with a corrugated interface on one side; Step 23: Grinding and assembling: Use a wire brush to grind the corrugated interface of the TA1 titanium plate and the 304 stainless steel plate to remove the oxide on the corrugated interface, and then stack the TA1 titanium plate, the square prefabricated foamed aluminum blank, and the 304 stainless steel plate in this order to obtain a TA1 / 304 foamed aluminum sandwich panel composite blank. During the assembly, ensure that the corrugated interface is in contact with the square prefabricated foamed aluminum blank. Step 24: Electromagnetic induction heating of composite blanks: Place the TA1 / 304 aluminum foam sandwich panel composite blank into the induction heating device, turn on the top and bottom induction heating coils, and heat the TA1 titanium plate and 304 stainless steel plate to the target temperatures of 550°C and 600°C, respectively. The target temperatures are both lower than the melting point of the square prefabricated foam blank, 660°C. Since titanium has a lower thermal conductivity and a higher thermal expansion coefficient, it is easier to absorb heat and heat up quickly during the rolling process. Under the same conditions, titanium usually heats up faster than stainless steel, so the TA1 titanium plate is heated to a higher temperature than the 304 stainless steel plate. Step 25: rolling and compounding: the heated TA1 / 304 aluminum foam sandwich panel composite blank is sent to a two-roll flat rolling mill for rolling and compounding, and finally a composite metal plate blank is obtained after cooling. Under the action of rolling deformation, the deformation heat causes the contact interface temperature of the TA1 titanium plate and the 304 stainless steel plate with the square prefabricated foam blank to rise to a temperature exceeding the melting point of the square prefabricated foam blank, so that the interface is remelted to form a metallurgical bond, but the square prefabricated foam blank does not reach the foaming temperature of 550°C and no pre-foaming occurs; Step 26: Insulation foaming: The composite metal sheet blank is placed in a heating furnace at a temperature of 550°C for 3 minutes. During the heating process, the square prefabricated foam blank is decomposed to generate bubbles, and the square prefabricated foam blank in the middle layer forms foamed metal aluminum. After the insulation foaming is completed, a foamed aluminum sandwich composite plate is obtained, wherein the material of the first corrugated metal layer is TA1, and the material of the second corrugated metal layer is 304 stainless steel. The foamed aluminum sandwich composite plate is cut and processed to obtain a TA1 / 304 foamed aluminum sandwich flange and a TA1 / 304 foamed aluminum sandwich end cap with a corrugated metallurgical bonding interface. The outer diameter of the foamed metal sandwich flange is 240mm, the inner diameter is 100mm, and the thickness is 15mm. The diameter of the foamed metal sandwich end cap is 240mm and the thickness is 15mm. Six through holes with a diameter of 8mm are processed on the circumference of the foamed metal sandwich flange and the foamed metal sandwich end cap with a diameter of 230mm, and bolts are fastened through the through holes.

[0061] Finally, the prepared TA1 / 304 aluminum foam sandwich composite tube, TA1 / 304 aluminum foam sandwich flange and TA1 / 304 aluminum foam sandwich end cover are cleaned, and then the TA1 / 304 aluminum foam sandwich flange is welded to both ends of the TA1 / 304 aluminum foam sandwich composite tube, and the TA1 / 304 aluminum foam sandwich flange and the TA1 / 304 aluminum foam sandwich end cover are connected with bolts for sealing to obtain the required TA1 / 304 aluminum foam sandwich shell.

[0062] In the description of the above embodiments, specific features, structures, materials or characteristics may be combined in a suitable manner in any one or more embodiments or examples.

Claims

1. A hydraulic actuator housing, characterized in that: It includes a foam metal sandwich composite tube, a foam metal sandwich flange and a foam metal sandwich end cover; The foam metal sandwich composite tube is connected to one end of the foam metal sandwich flange, and the foam metal sandwich end cover is connected to the other end of the foam metal sandwich flange; The foam metal sandwich composite tube comprises a first metal tube layer, a first foam metal layer and a second metal tube layer arranged in sequence from the inside to the outside; the first bonding interface between the first metal tube layer, the first foam metal layer and the second metal tube layer is a metallurgical bonding interface.

2. The hydraulic actuator housing according to claim 1, characterized in that: The foam metal sandwich flange is an annular cylindrical structure, the foam metal sandwich end cover is a cylindrical structure, the outer diameter of the foam metal sandwich flange is the same as the diameter of the foam metal sandwich end cover, a plurality of first through holes are evenly arranged along the circumferential direction on the annular surface of the foam metal sandwich flange, and a plurality of second through holes corresponding to the first through holes are arranged on the circular surface of the foam metal sandwich end cover.

3. The hydraulic actuator housing according to claim 1, characterized in that: The foam metal sandwich end cover and the foam metal sandwich flange are obtained by cutting a foam metal sandwich composite plate, and the foam metal sandwich composite plate includes a first corrugated metal layer, a second foam metal layer and a second corrugated metal layer from top to bottom. The bonding interface between the first corrugated metal layer, the second corrugated metal layer and the second foam metal layer is a second bonding interface of metallurgical bonding, and the second bonding interface is a corrugated interface.

4. A method for preparing a hydraulic actuator housing, characterized in that: A method for preparing a hydraulic actuator housing according to any one of claims 1 to 3, comprising: A tube blank composite blank is provided; the tube blank composite blank comprises, from inside to outside, a first metal tube layer, an annular prefabricated foam blank and a second metal tube layer; The tube blank composite blank is heated to a target temperature, and the tube blank composite blank is extruded to form the tube blank composite blank, so that the temperature of the first contact interface between the structures of the tube blank composite blank is increased to a preset temperature during the forming process, and the preset temperature is greater than or equal to the melting point temperature of the annular prefabricated foam blank, and the first contact interface is remelted to form a metallurgically bonded first bonding interface to obtain a target composite tube blank; the target temperature is less than the melting point temperature; Placing the target composite tube blank in a heating furnace to foam the middle layer of the target composite tube blank to form a first foam metal layer, thereby obtaining a foam metal sandwich composite tube; The foam metal sandwich composite tube, the foam metal sandwich flange and the foam metal sandwich end cover are assembled to form a hydraulic actuator housing.

5. The method for preparing a hydraulic actuator housing according to claim 4, characterized in that: The target temperature includes a first target temperature and a second target temperature; the tube blank composite blank is heated to the target temperature, and the tube blank composite blank is extruded to form the tube blank composite blank, so that the temperature of the first contact interface between the structures of the tube blank composite blank is increased to a preset temperature during the forming process, and the preset temperature is greater than or equal to the melting point temperature of the annular prefabricated foam blank, and the first contact interface is remelted to form a metallurgically bonded first bonding interface, and the target composite tube blank is obtained, comprising: Putting the tube blank composite blank into a first annular inner cavity formed by an extrusion inner die and an extrusion outer die; Fix the extrusion outer die by an extruder, start a first induction heating coil arranged on the extrusion inner die to heat the first metal tube layer to a first target temperature; start a second induction heating coil arranged on the extrusion outer die to heat the second metal tube layer to a second target temperature; The pressure head pushes one end of the extrusion inner die to move axially along the tube blank composite billet, so that the tube blank composite billet is extruded from the extrusion end of the first annular inner cavity, and the temperature of the first contact interface rises to a preset temperature during the extrusion process, and the preset temperature is greater than or equal to the melting point temperature. The first contact interface is remelted to form a metallurgically bonded first bonding interface to obtain a target composite tube blank, and the extrusion end is used to apply radial pressure to the tube blank composite billet.

6. The method for preparing a hydraulic actuator housing according to claim 4, characterized in that: Before assembling the foam metal sandwich composite tube, the foam metal sandwich flange and the foam metal sandwich end cover to form the hydraulic actuator housing, the method further includes: preparing a foam metal sandwich flange and a foam metal sandwich end cap; The preparation of the foam metal sandwich flange and the foam metal sandwich end cover comprises: A composite plate blank is provided; the composite plate blank comprises, from top to bottom, a first corrugated metal layer, a square prefabricated foam blank and a second corrugated metal layer; the first corrugated metal layer and the second corrugated metal layer are corrugated metal plates with a corrugated interface on one side; Heating the composite slab, heating the first corrugated metal layer to a first target temperature, and heating the second corrugated metal layer to a second target temperature, to obtain a different-temperature composite slab; The different-temperature composite sheet blank is subjected to rolling treatment, so that the first corrugated metal layer, the square prefabricated foam blank layer and the second corrugated metal layer are tightly combined, and the temperature of the second contact interface between the structures of the different-temperature composite sheet blank is increased to a preset temperature during the forming process, and the preset temperature is greater than or equal to the melting point temperature, and the second contact interface is remelted to form a metallurgically bonded second bonding interface, so as to obtain a target composite sheet; Placing the target composite panel in a heating furnace at a third target temperature for a preset time, so that the middle layer of the target composite panel is foamed to form a second foam metal layer, thereby obtaining a foam metal sandwich composite panel; The foam metal sandwich composite panel is cut according to preset dimensions to obtain two foam metal sandwich flanges and two foam metal sandwich end covers.

7. The method for preparing a hydraulic actuator housing according to claim 6, characterized in that: Before providing a composite slab, the method further comprises: preparing a composite slab; The preparation of the composite slab comprises: Two metal plates are provided; Putting the second foaming powder into a square mold and pressing the second foaming powder to obtain a square prefabricated foam blank; The two metal plates are rolled using a corrugated rolling mill to obtain a first corrugated metal layer and a second corrugated metal layer; the upper roll of the corrugated rolling mill is a corrugated roll, and the lower roll is a flat roll; The square prefabricated foam blank is placed between the first corrugated metal layer and the second corrugated metal layer to assemble the blank to obtain a composite plate blank.

8. The method for preparing a hydraulic actuator housing according to claim 4, characterized in that: The foam metal sandwich composite tube is prepared by an extrusion tool, and the extrusion tool comprises: An extrusion inner mold, the extrusion inner mold comprises an inner mold cylinder body of a T-shaped structure, the inner mold cylinder body comprises a head and a tail, the tail is provided with a cylindrical inner cavity, a first induction heating coil is provided in the cylindrical inner cavity, an inner mold insulating pad is provided between the first induction heating coil and the cylindrical inner cavity, an inner mold end cap is provided at one end of the cylindrical inner cavity away from the head, the inner mold end cap is connected to the inner mold cylinder body through an inner mold fastening screw, and the inner mold end cap is used to form a closed space in the cylindrical inner cavity; An extrusion outer die, wherein a second induction heating coil is arranged in the extrusion outer die, the inner wall of the extrusion outer die comprises a large diameter section, a slope section and a small diameter section, the large diameter section and the small diameter section are transitionally connected by the slope section, the large diameter section of the extrusion outer die is sleeved with the head of the inner die cylinder body, a first annular inner cavity is formed between the inner wall of the extrusion outer die and the tail of the extrusion inner die, and an end of the first annular inner cavity close to the small diameter section is an extrusion end; An extruder, used for clamping and fixing the outer wall of the extrusion outer die; The pressure head is used to push the extrusion inner die to make the tube blank composite blank move axially and extrude it from the extrusion end of the first annular inner cavity.

9. The method for preparing a hydraulic actuator housing according to claim 8, characterized in that: The main body of the extrusion outer die is the outer die cylinder body, a second annular inner cavity is arranged between the inner wall and the outer wall of the large diameter section, a second induction heating coil is arranged in the second annular inner cavity, the second induction heating coil and the second annular inner cavity are separated by an outer die insulating pad, an outer die end cover is arranged at one end of the second annular inner cavity away from the small diameter section, and the outer die end cover is connected to the outer die cylinder body to form a closed space for the second annular inner cavity.

10. The method for preparing a hydraulic actuator housing according to claim 4, characterized in that: Before providing a tube composite blank, the method further includes: preparing a tube composite billet; The preparation of the tube blank composite blank comprises: Mixing metal powder, tackifier and foaming agent powder in a preset ratio to obtain foaming powder; the foaming powder includes a first foaming powder and a second foaming powder; Pour the first foaming powder into the third annular inner cavity formed by the tube blank forming outer mold and the tube blank forming inner mold, start the first oscillating base of the tube blank set mold, and use an annular pressing head to press the foaming powder into an annular prefabricated foam blank during the oscillation process of the first oscillating base; The annular prefabricated foam blank is placed in the gap between the first metal tube layer and the second metal tube layer of the tube blank composite blank to obtain the tube blank composite blank.

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