CN113787733B - Carbon fiber reinforced aluminum alloy layer pipe member forming process and forming die - Google Patents

Abstract

The invention discloses a forming process and a forming die for a carbon fiber reinforced aluminum alloy layer pipe member, and provides a process route of 'aluminum alloy inner and outer pipe blank heat treatment → aluminum alloy outer pipe blank soft die forming → carbon fiber prepreg and outer layer aluminum alloy pipe forming layer laying → carbon fiber reinforced aluminum alloy layer pipe preform composite pressing → die unloading' for the forming of a fiber metal layer pipe member, can develop a careful composite forming process according to the plasticity and metallurgical bonding performance of different series of aluminum alloys, realize the composite forming integrated preparation scheme of the layered pipe member, is particularly suitable for preparing the fiber metal layered pipe member with the special-shaped section, the forming problem is solved while compounding the part, the problem of difficult secondary processing of the fiber metal layer pipe is solved, the application range of the fiber metal composite material is expanded, and a reference is provided for forming the fiber metal layer pipe composite material with a complex shape.

Description

Carbon fiber reinforced aluminum alloy layer pipe member forming process and forming die

Technical Field

The invention belongs to the technical field of pipe member forming, relates to a carbon fiber reinforced aluminum alloy layer pipe member forming technology, and particularly relates to a carbon fiber reinforced aluminum alloy layer pipe member forming process and a forming die.

Background

The term (a) explains:

fiber metal laminates (FMLs for short): the sandwich material is formed by sequentially paving a metal sheet, a fiber material and a connecting agent and then curing the metal sheet, the fiber material and the connecting agent under the conditions of specific temperature and pressure.

A layer pipe component: the parts with thin wall characteristics are prepared by taking a pipe as an original blank and performing stamping processing.

Carbon fiber prepreg: the epoxy resin is compounded on the carbon fiber through a high-temperature high-pressure technology.

And (3) die forming: putting a certain amount of prepreg into a mold cavity at a forming temperature, and then closing and pressurizing a rigid male mold and a rigid female mold to form and cure the prepreg.

Solid particulate media forming techniques (modes): carrying out soft die forming on the plate by using the solid particles to replace a rigid male die; wherein, the solid particle medium is a tiny particle with strong bearing capacity and good flowing property.

(II) technical background

In light weight design and manufacture, material design and structural design are two basic ideas for realizing light weight. In the aspect of material design, high-quality light alloy materials (such as aluminum alloy, magnesium alloy and titanium alloy) are widely applied, and composite materials are receiving wide attention due to unique properties of the composite materials. In the aspect of structural design, the thin-wall structural part has an obvious light weight effect and is a preferred structure in light weight design. The fiber metal laminate material has the characteristics of both a metal material and a fiber reinforced composite material, the weight of the fiber metal laminate member is reduced by more than 25% compared with an isometric aluminum alloy member, the cost is only about 1/3 of the isometric fiber reinforced composite material member, and the fiber metal laminate member also has good service performances such as high strength, high damage tolerance, corrosion resistance and the like, and has wide application prospects and development potentials in various fields such as aerospace, automobile manufacturing, rail transit, hardware and electronics and the like.

At present, the forming mode of the fiber metal laminate mainly has two process ideas: the first method is to respectively form and process metal and fiber, lay the metal and fiber layer by layer after surface treatment, then bond the metal and fiber layer into a fiber metal laminate by using a connection mode, and then solidify the fiber metal laminate by using an autoclave process to obtain a target structural member; the second method is to bond the metal plate and the fiber layer into a fiber metal laminate, and then process the laminate into the target part by using the traditional plastic forming process (such as stamping forming). The key point of the first forming idea is that an autoclave process is used for curing, but the autoclave investment cost is high, and the production cost for small components with small batch size is too high; and the hydraulic forming process has great difficulty in liquid sealing under the conditions of high temperature and high pressure, and the poor chemical and physical stability of the liquid medium under the high temperature condition brings great potential safety hazard to the process. The second forming idea can exert the advantages of convenience and high efficiency of the traditional stamping process, and an autoclave process, a hot die pressing process and a rolling process are usually adopted, but the large-curvature layer pipe component is difficult to form through secondary processing, and the quality of the large-curvature layer pipe component is still far away from the traditional metal plate stamping forming quality.

At present, the preparation technology of the fiber metal laminate is relatively mature, but the fiber metal laminate prepared by the existing preparation technology generally belongs to semi-finished materials and usually needs secondary processing to prepare usable parts. The traditional metal stamping processing needs to utilize the plastic deformation of a metal material, but the plasticity of the metal material and the plasticity of a fiber material are different, and the fiber in the existing fiber metal laminate/pipe has almost no plasticity, so that the deformation of each layer of the composite laminate/pipe in the secondary processing is difficult to coordinate, the defects of folds, layering, splitting and the like are easily caused, a huge problem is brought to the secondary processing of the product, the application field of the composite layer pipe component which is more wide in trend is limited to a great extent, and the application value can be realized only in a few scenes. Therefore, the preparation technology of the layered pipe member is developed on the basis, and the fiber metal layered pipe member is popularized to more application scenes, so that the method has great significance.

The forming process of the layer pipe member developed at present is a roll bending forming process, a hot press forming process and a stamping forming process. The roll bending forming process has two problems of low forming quality and rebound deformation of a component; the hot-press forming process is easy to generate defects of interface delamination, pores and the like, and laminate peeling can be generated seriously; the press forming process cannot form a small bending radius on a thicker fiber metal laminate, and only can avoid layering and fiber debonding by selecting the process of bonding and curing after the thinnest laminate is pressed step by step. In the actual process, the composite layer pipe member with large curvature and a complex structure cannot be formed due to low fiber elongation.

Disclosure of Invention

The invention aims to provide a forming process and a forming die for a carbon fiber reinforced aluminum alloy layer pipe member, which are used for solving the problems of difficult secondary processing of fiber metal and limited use scene in the prior art, and provide a process route of 'heat treatment of inner and outer pipe blanks of aluminum alloy → soft die forming of outer pipe blanks of aluminum alloy → laying (paving) of carbon fiber prepreg and outer layer aluminum alloy pipe forming member layers → composite pressing of carbon fiber reinforced aluminum alloy layer pipe preforms → die unloading' for forming the fiber metal layer pipe member, so that a delicate composite forming process can be developed according to the plastic property and metallurgical bonding property of different series of aluminum alloys, and an integrated preparation scheme for composite forming of the layer pipe member is realized.

In order to achieve the purpose, the invention provides the following scheme:

the invention provides a forming process of a carbon fiber reinforced aluminum alloy layer pipe member, which comprises the following steps:

carrying out heat treatment on the aluminum alloy outer tube blank and the aluminum alloy inner tube blank;

performing soft die preforming on the aluminum alloy outer tube blank subjected to heat treatment to form an aluminum alloy outer tube preformed piece;

laying carbon fiber prepregs according to the shape of the aluminum alloy outer tube preform, and then placing an aluminum alloy inner tube blank into the aluminum alloy outer tube preform on which the carbon fiber prepregs are laid, so that the carbon fiber prepregs are clamped between the aluminum alloy outer tube preform and the aluminum alloy inner tube blank to form a carbon fiber reinforced aluminum alloy layer tube preform;

carrying out composite pressing on the carbon fiber reinforced aluminum alloy layer pipe preformed piece by adopting a solid particle medium forming technology (mode) to form a carbon fiber reinforced aluminum alloy layer pipe component; after the carbon fiber reinforced aluminum alloy layer pipe component is formed, continuously applying pressure to an aluminum alloy inner pipe of the carbon fiber reinforced aluminum alloy layer pipe component so as to enable resin in the carbon fiber prepreg to completely infiltrate carbon fibers;

after the carbon fiber reinforced aluminum alloy layer pipe member is kept to be formed, continuously applying pressure to the carbon fiber reinforced aluminum alloy layer pipe member, namely, heating and insulating the carbon fiber reinforced aluminum alloy layer pipe member while continuously applying pressure to the carbon fiber reinforced aluminum alloy layer pipe member; in the heating and temperature-rising stage, the resin is melted and fully infiltrated with the carbon fiber; heating to a high temperature stage, curing the resin, and simultaneously realizing artificial aging treatment on the aluminum alloy inner tube forming piece and/or the aluminum alloy outer tube forming piece;

cooling the carbon fiber reinforced aluminum alloy layer pipe component after heat preservation; and after cooling, unloading the aluminum alloy inner tube forming piece, and taking out the carbon fiber reinforced aluminum alloy layer tube member.

Optionally, the heat treatment is performed on the aluminum alloy outer tube blank by adopting a solid solution process.

Optionally, carrying out solution treatment on the aluminum alloy inner tube blank and the aluminum alloy outer tube blank according to heat treatment process parameters of the solution temperature of 450-560 ℃ and the solution time of 15-120 min.

Optionally, before performing composite pressing on the carbon fiber reinforced aluminum alloy layer tube preform, the die is replaced to separately form the aluminum alloy inner tube blank, and forming pressure data of the aluminum alloy inner tube blank is obtained, so that pressure is applied to the carbon fiber reinforced aluminum alloy layer tube preform in a composite pressing stage by referring to the forming pressure data.

Optionally, soft-die preforming is performed on the heat-treated aluminum alloy outer tube blank by adopting a solid particle medium forming technology.

Optionally, the carbon fiber reinforced aluminum alloy layer tube preform is formed outside the mold.

Optionally, after the inner layer of the aluminum alloy outer tube preform is laid, the carbon fiber prepreg is vacuumized between the carbon fiber prepreg and the aluminum alloy outer tube preform by using a vacuum press, so that the carbon fiber prepreg is subjected to semi-curing treatment.

Optionally, after the carbon fiber reinforced aluminum alloy layer pipe member is formed, the curing temperature of the resin is 180-230 ℃, the curing time of the resin is 175-230 min, and the curing pressure applied to the resin is 1-6 MPa.

Optionally, the carbon fiber reinforced aluminum alloy layer pipe member and the composite pressing die are placed in a heating furnace or a heating box for heating and heat preservation.

Optionally, the heating rate of the carbon fiber reinforced aluminum alloy layer pipe member is 3-5 ℃/min.

Optionally, the heating rate when the carbon fiber reinforced aluminum alloy layer pipe member is heated is 1.5 ℃/min.

Optionally, the solid particles adopted when the carbon fiber reinforced aluminum alloy layer pipe preform is subjected to composite pressing are silica particles or ceramic particles with the diameter of 0.3 mm-0.6 mm.

Optionally, before performing composite pressing on the carbon fiber reinforced aluminum alloy layer pipe preform, the temperature of the mold for performing composite pressing is increased to a first temperature, and then after the temperature of the mold is decreased to a second temperature, the carbon fiber reinforced aluminum alloy layer pipe preform is loaded into the mold for performing composite pressing.

Optionally, the first temperature is 90 ℃ to 100 ℃, and the second temperature is 70 ℃ to 80 ℃.

Optionally, before the forming of the carbon fiber reinforced aluminum alloy layer tube preform, the method further comprises: and removing oil stains on the surfaces of the aluminum alloy outer pipe preformed piece and the aluminum alloy inner pipe blank by using acetone.

Optionally, after removing oil stains on the surfaces of the aluminum alloy outer tube preform and the aluminum alloy inner tube blank, the method further comprises the following steps of: sequentially carrying out NaOH alkaline washing and HNO on the aluminum alloy outer tube preformed piece and the aluminum alloy inner tube blank ₃ Deoxidation and phosphoric acid anodic oxidation treatment.

Meanwhile, the invention provides a carbon fiber reinforced aluminum alloy layer pipe member forming die, which is used in the soft die preforming of an aluminum alloy outer pipe blank and the composite pressing process of the carbon fiber reinforced aluminum alloy layer pipe preformed piece, and is characterized by comprising the following steps of:

the die cavity comprises a plurality of die cavity bodies which have different shapes and can be replaced with one another; the die cavity body is used for placing a piece to be pressed and a solid granular medium, wherein the piece to be pressed comprises the aluminum alloy outer tube blank and the carbon fiber reinforced aluminum alloy layer tube preformed piece;

the pressure head is positioned above the cavity die and is used for being matched with the solid granular medium and the corresponding cavity body;

the fastening assembly comprises a fastening bolt, a fastening top plate, a fastening sliding plate, a fastening spring, a fastening bracket and a fastening base which are sequentially arranged from top to bottom; the cavity mold is arranged above the fastening base; the fastening bracket is fixedly arranged above the fastening base and is positioned on the periphery of the cavity die; the fastening sliding plate is slidably sleeved on the fastening support and is positioned above the pressure head; the fastening spring is sleeved on the fastening bracket, and two ends of the fastening spring are respectively abutted against the fastening sliding plate and the fastening base; the fastening top plate is fixed at the top end of the fastening support, the fastening bolt penetrates through the fastening top plate and is in threaded connection with the fastening top plate, and the fastening bolt can push the fastening sliding plate to move downwards to press the pressure head.

Compared with the prior art, the invention has the following technical effects:

the forming process of the carbon fiber reinforced aluminum alloy layer pipe member provided by the invention provides a process route of 'heat treatment of aluminum alloy inner and outer pipe blanks → soft die forming of aluminum alloy outer pipe blanks → layer laying (paving) → composite pressing (including die filling) → die unloading' of carbon fiber reinforced aluminum alloy layer pipe preformed pieces for forming the fiber metal layer pipe member, according to the plasticity and metallurgical bonding performance of different series of aluminum alloys, a careful composite forming process is developed, and a layer pipe component composite forming integrated preparation scheme is realized, so that the method is particularly suitable for preparing fiber metal layer pipe components with special-shaped cross sections, solves the problem of difficulty in secondary processing of fiber metal layer pipes, expands the application range of fiber metal composite materials, provides reference for forming fiber metal layer pipe composite materials with complex shapes, and solves the problem of forming layer pipe components while compounding parts.

In addition, the forming process of the carbon fiber reinforced aluminum alloy layer pipe member provided by the invention performs the metal pipe blank firstly, so that the quality of the formed layer pipe member can be ensured; the design can replace the forming die of different cavity shapes, reduce the product investment, is suitable for the production of the complicated cross-section pipe fittings of small batch; the solid particles are used as pressure transmission medium, and the heat-transfer and pressure-transmission medium has the advantages of uniform heat transfer and pressure transmission, heat resistance, easy sealing and the like. Meanwhile, the solid particle medium forming technology is suitable for the production of small-batch components, the solid particle medium can provide reliable laminate bonding pressure and resin curing pressure for the composite pressing process in all directions, and the particle medium is convenient to load, easy to seal and strong in heat resistance; secondly, the scheme of preforming the metal plate blank and then compositely pressing the fiber layer and the metal layer avoids the problem of coordinated deformation of the metal layer and the fiber layer, can effectively avoid various problems in laminate forming, and has strong practicability; the aging treatment of the aluminum alloy pipe fitting is realized simultaneously in the resin curing process, and the two technical processes are combined into one, so that the energy consumption can be effectively reduced.

The forming die provided by the invention is reasonable in structural arrangement and convenient to disassemble and assemble, can be used for implementing various forming processes of the layered pipe members including the forming process of the carbon fiber reinforced aluminum alloy layered pipe member, and is particularly suitable for preparing the fiber metal layered pipe member with the special-shaped section.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic flow chart of a forming process of a carbon fiber reinforced aluminum alloy layered pipe member disclosed in an embodiment of the invention;

FIG. 2 is a structural schematic diagram of an aluminum alloy outer tube blank disclosed by the embodiment of the invention before being formed;

FIG. 3 is a schematic structural view of a carbon fiber reinforced aluminum alloy laminate tube preform as disclosed in an embodiment of the present invention;

FIG. 4 is a schematic view of a state structure of a composite pressing process according to an embodiment of the present invention;

fig. 5 is a structural schematic diagram of a carbon fiber reinforced aluminum alloy layer pipe member according to an embodiment of the present invention in a resin cured state.

Wherein the reference numbers are: the device comprises a pressure head 1, a cavity die 2, an aluminum alloy outer tube blank 3, a solid particle medium 4, an aluminum alloy outer tube preformed piece 5, a carbon fiber prepreg 6, an aluminum alloy inner tube blank 7, a fastening bolt 8, a fastening top plate 9, a fastening sliding plate 10, a fastening spring 11, a fastening bracket 12, a carbon fiber reinforced aluminum alloy layer tube preformed piece 13, a fastening base 14 and a carbon fiber reinforced aluminum alloy layer tube component 15.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

One of the purposes of the invention is to provide a forming process of a carbon fiber reinforced aluminum alloy layer pipe member, which aims to solve the problems of difficult secondary processing of fiber metal and limited use scene in the prior art, provides a process route of 'metal pipe fitting preforming → fiber layer paving and pasting → layer pipe member composite pressing' for forming the fiber metal layer pipe member, and can develop a detailed composite forming process according to the plastic property and metallurgical bonding property of different series of aluminum alloys to realize an integrated preparation scheme for composite forming of the layer pipe member.

The invention also aims to provide a forming die which can be used for implementing the forming process of the carbon fiber reinforced aluminum alloy layer pipe component.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

Example one

As shown in fig. 1 to 5, the present embodiment provides a forming process of a carbon fiber reinforced aluminum alloy layer tube member, which specifically includes the following process routes:

s1) heat-treating the aluminum alloy outer tubular blank 3 and the aluminum alloy inner tubular blank 7: the aluminum alloy outer tube blank 3 and the aluminum alloy inner tube blank 7 can be subjected to solid solution and water quenching treatment according to the heat treatment process parameters of the solid solution temperature of 450-560 ℃ and the solid solution time of 15-120 min, so that the elongation of the plate is improved, and the deformation resistance is reduced. In this embodiment, the aluminum alloy outer shell 3 and the aluminum alloy inner shell 7 are preferably made of 6-series aluminum alloy.

S2) soft-die preforming the heat-treated aluminum alloy outer tube blank 3: the aluminum alloy outer tube blank 3 is placed in a cavity die 2, a solid particle medium 4 is added into the aluminum alloy outer tube blank 3, a hydraulic press can be used for loading a pressure head 1 to realize soft die preforming of the aluminum alloy outer tube blank, and an aluminum alloy outer tube preformed piece 5 is formed.

S3) obtaining forming pressure data of the aluminum alloy inner pipe: the subsequent composite pressing stage has a large influence on the forming quality, and the applied pressure is too small, so that the forming quality of the aluminum alloy inner tube is influenced; when the forming pressure is too high, the resin is quickly extruded out of the component before the carbon fiber tows are soaked, so that poor soaking is caused, and the carbon fiber prepreg can be broken. Therefore, at this stage, the cavity die 2 needs to be replaced to perform the aluminum alloy inner tube forming on the aluminum alloy inner tube blank in advance and acquire the forming pressure data.

S4) material preparation stage: after assembling the pressure head 1, the cavity die 2 and the fastening assembly, placing the pressure head, the cavity die and the fastening assembly together with the solid particle medium 4 in a heating furnace and heating to 90-100 ℃. Simultaneously, removing oil stains on the surfaces of the aluminum alloy outer tube preformed piece 5 and the aluminum alloy inner tube blank 7 by using acetone, and sequentially performing NaOH alkaline washing and HNO ₃ Deoxidizing and anodizing with phosphoric acid to raise the adhesion strength of the pipe wall.

S5) paving material layers: in order to facilitate the layer laying of the carbon fibers and improve the accuracy of the temperature control of the mold, the layer laying process is carried out outside the forming mold. The carbon fiber prepreg 6 prepared in advance is layered on the inner wall surface of the aluminum alloy outer tube preform 5 according to the shape, and the carbon fiber prepreg 6 can be approximately spread into a formed shape because of certain viscosity. After the 6 layers of the carbon fiber prepreg are laid, in order to prevent solid particle media 4 from entering the bottom of the carbon fiber layer from the edge and prevent the fiber layer from wrinkling in the forming process, a vacuum press can be used for pumping vacuum between the carbon fiber prepreg 6 and the aluminum alloy outer tube preform 5, and semi-curing treatment is carried out. And then placing the aluminum alloy inner pipe blank into an aluminum alloy outer pipe preformed piece 5 on which the carbon fiber prepreg 6 is already laid, so that the carbon fiber prepreg 6 is clamped between the aluminum alloy outer pipe preformed piece 5 and the aluminum alloy inner pipe blank 7 to form a carbon fiber reinforced aluminum alloy layer pipe preformed piece. The aluminum alloy inner tube blank and the aluminum alloy inner tube blank in the process 3) are two different tube blanks, but the shapes to be formed of the two inner tube blanks are the same, and the forming of the aluminum alloy inner tube blank in the process 3) provides parameter reference for the forming of the aluminum alloy inner tube blank in the process 5).

S6) a mold filling stage: and after the material layer is paved, taking the whole forming die assembled in the process 4) out of the heating furnace. In order to initially melt the resin in the carbon fiber prepreg 6 and further bond the resin with the pipe wall of the aluminum alloy pipe fitting, after the forming die is cooled to 80 ℃, the carbon fiber reinforced aluminum alloy layer pipe preformed piece 13 which is well laid is placed into the cavity die 2, and then the solid particle medium 4 and the pressure head 1 are sequentially placed into the aluminum alloy inner pipe blank 7.

S7) composite pressing stage: after the die filling is finished, providing pressure for the pressure head 1 by using a hydraulic machine according to inner tube forming pressure parameters obtained in the mounting process 3), so that the aluminum alloy inner tube blank 7 is formed into an aluminum alloy inner tube matched with the shape of the cavity die 2, and in the process, synchronously forming the carbon fiber prepreg 6 in the carbon fiber reinforced aluminum alloy layer tube preform 13 and the aluminum alloy outer tube preform 5, so that the carbon fiber reinforced aluminum alloy layer tube preform 13 is formed into a corresponding layer tube member, namely a carbon fiber reinforced aluminum alloy layer tube member 15. And then entering a resin curing stage: after the layer tubular member formed, the hydraulic press uninstallation, recycle fastening assembly and provide 1MPa ~6 MPa's pressure for pressure head 1, with pressure head 1, die cavity mould 2, solid particle medium 4 and carbon fiber reinforcement aluminum alloy layer tubular member place in fastening support 12, install fastening spring 11 in proper order, fastening slide 10, fastening roof 9 and fastening bolt 8, exert pressure to fastening slide 10 through rotatory fastening bolt 8, and then exert pressure to pressure head 1, fastening spring 11 is adjustable exerts pressure, avoid pressure too high, fastening spring 11 still plays the effect that resets fastening slide 10 simultaneously. The fastening assembly continuously applies pressure to the carbon fiber reinforced aluminum alloy layer pipe component in situ, so that the resin in the carbon fiber prepreg 6 can be promoted to completely soak the carbon fibers, and the permeation and diffusion effects of the resin on micropores on the surface of the aluminum alloy are improved. Then, the assembled forming die and the fastening assembly are placed in the heating furnace again, in one case, the heating can be carried out to 180 ℃ at the heating rate of 1.5 ℃/min, the temperature is kept for 200min, and the resin in the carbon fiber prepreg 6 is melted at a lower reaction speed in the heating stage and is fully infiltrated with the carbon fibers; in the high-temperature stage, the resin in the carbon fiber prepreg 6 is fully cured, and meanwhile, in the high-temperature stage, the artificial aging treatment of 6-series aluminum alloy pipe fittings, namely the aluminum alloy outer pipe preform 5 and the aluminum alloy inner pipe, can be realized, so that the service strength of the layered pipe member is improved. In another case, the assembled forming mold and fastening assembly are placed in the heating furnace again, and then heated to 190 ℃ at a heating rate of 1.5 ℃/min, and the temperature is maintained for 230 min. In one case, the assembled forming mold and fastening assembly are placed in the heating furnace again, and then heated to 230 ℃ at a heating rate of 2 ℃/min, and the temperature is maintained for 180 min.

S8) demolding: and after the heat preservation of the layer pipe component in the heating furnace is finished, waiting for the cooling of the mold to the normal temperature. After the mold has cooled, the fastening assembly is unloaded, whereby the head 1 can be removed and the solid particulate medium 4 with the formed carbon fiber reinforced aluminum alloy layered tube member can be removed. And finally, trimming the edge of the carbon fiber reinforced aluminum alloy layer pipe member to obtain the final part.

In this embodiment, the curing temperature in the above-described process S7) is preferably in the approximate range of 180 to 230 ℃ and the pressure maintained on the indenter 1 during curing is preferably in the approximate range of 1 to 6MPa, depending on the type of material and the thickness of the pipe.

In this embodiment, in each of the processes S2) and S7), the heat-treated aluminum alloy outer tube blank 3 is preferably subjected to soft-mold preforming and composite press forming by using a solid particle medium forming technique. Among them, the solid particle medium 4 may preferably be silica particles or ceramic particles having a diameter of 0.3mm to 0.6mm, which are introduced into the gaps of the mold during the pressing process, but are finally sealed due to the mutual friction between the solid particles.

In this embodiment, when the cavity mold 2 has a double concave ring structure as shown in fig. 2 and 4, the double convex ring carbon fiber reinforced aluminum alloy layered pipe member can be manufactured, and the application range of the fiber metal layered pipe is expanded. Meanwhile, the aluminum alloy is subjected to solution treatment in the preforming stage, so that the plasticity performance is improved; the curing pressure is kept by utilizing the pressure self-locking device, so that the curing device is simple and convenient; the resin curing and the aluminum alloy artificial aging are fused in the composite pressing process, the aluminum alloy low-temperature deformation heat treatment and the carbon fiber reinforced aluminum alloy layer pipe member preparation technology are ingeniously integrated, the use strength of the composite member is improved, and the forming preparation of the high-quality composite layer pipe member is realized.

In this example, a solid particle medium soft mold forming technique was applied in the composite pressing process. The solid particle medium has uniform heat transfer and pressure transfer, is heat-resistant, is easy to seal, and has fluidity, particles at the position with overlarge pressure flow to the position with lower pressure to prevent overload, and simultaneously, the fluidity is utilized to improve the forming precision of fine parts and avoid the problem of difficulty in filling special-shaped section parts in die forming.

The embodiment designs a composite forming integrated process scheme of a fiber reinforced metal layer pipe member, which is characterized by comprising the steps of heat treatment of aluminum alloy inner and outer pipe blanks → soft die forming of the aluminum alloy outer pipe blank → laying of a carbon fiber prepreg and an outer aluminum alloy pipe forming part layer → composite pressing of a carbon fiber reinforced aluminum alloy layer pipe preform → die unloading. The scheme of pre-forming and then composite pressing avoids the problem of coordinated deformation of the metal layer and the fiber layer, can effectively avoid the problems of fiber layer fracture and the like in laminate forming, and improves the application range of the carbon fiber reinforced aluminum alloy member.

This embodiment is put composite member in the heating furnace of uniform temperature, and this specific temperature had both guaranteed fully to combine between the fibrous layer and between fibrous layer and the aluminum alloy component, and simultaneously under this specific temperature, no matter select for use 7 series aluminum alloy tubular product or 6 series aluminum alloy tubular product in the aluminium alloy inner tube blank and the aluminium alloy outer tube blank, the time-effect temperature that all can reach has guaranteed composite member's service strength.

In the embodiment, the composite pressing of the layered pipe member is realized by adopting a solid particle medium forming technology, and compared with hydraulic forming, the composite pressing has the advantages that sealing is not needed, pollution is avoided, the solid particle medium can be recycled, and the low-carbon and environment-friendly requirements are met; the granular medium soft mold forming process has the advantages of uniform heat transfer and pressure transfer, good sealing performance and the like. Because only different forming dies with cavities of different shapes need to be replaced, the product investment is reduced, and the method can be used for producing small-batch large-curvature components.

The carbon fiber reinforced aluminum alloy layer pipe member forming die related in the embodiment can be used for soft die preforming of an aluminum alloy outer pipe blank, composite pressing of the carbon fiber reinforced aluminum alloy layer pipe preformed piece and resin curing of the carbon fiber reinforced aluminum alloy layer pipe member, and comprises a pressure head 1, a cavity die 2 and a fastening assembly. The cavity die 2 comprises a plurality of cavity bodies which have different shapes and can be replaced with each other; the die cavity body is used for placing a piece to be pressed and a solid granular medium 4, wherein the piece to be pressed comprises an aluminum alloy outer tube blank 3 and a carbon fiber reinforced aluminum alloy layer tube preformed piece 13. The pressure head 1 is positioned above the cavity die 2 and is used for being matched with the solid particle medium 4 and the corresponding cavity body. The fastening assembly comprises a fastening bolt 8, a fastening top plate 9, a fastening sliding plate 10, a fastening spring 11, a fastening bracket 12 and a fastening base 14 which are sequentially arranged from top to bottom; the cavity die 2 is arranged above the fastening base 14; the fastening bracket 12 is fixedly arranged above the fastening base 14, and the fastening bracket 12 is positioned at the periphery of the cavity die 2; the fastening sliding plate 10 is slidably sleeved on the fastening bracket 12, and the fastening sliding plate 10 is positioned above the pressure head 1; the fastening spring 11 is sleeved on the fastening bracket 12, and two ends of the fastening spring 11 are respectively abutted against or connected with the fastening sliding plate 10 and the fastening base 14; the fastening top plate 9 is fixed at the top end of the fastening support 12, the fastening bolt 8 penetrates through the fastening top plate 9 and is in threaded connection with the fastening top plate 9, and the fastening bolt 8 can push the fastening sliding plate 10 to move downwards to press the pressure head 1 downwards.

The carbon fiber reinforced aluminum alloy layer pipe component forming die is reasonable in structural arrangement and convenient to disassemble and assemble, can be used for implementing various layer pipe component forming processes including the carbon fiber reinforced aluminum alloy layer pipe component forming process, and is particularly suitable for preparing special-shaped section fiber metal layer pipe components.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not intended to be construed as limiting the claim concerned.

The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims (9)

1. A carbon fiber reinforced aluminum alloy layer pipe member forming process is characterized by comprising the following steps:

carrying out heat treatment on the aluminum alloy inner pipe blank and the aluminum alloy outer pipe blank;

performing soft die preforming on the aluminum alloy outer tube blank subjected to heat treatment to form an aluminum alloy outer tube preformed piece;

laying carbon fiber prepregs according to the shape of the aluminum alloy outer tube preform, and then placing an aluminum alloy inner tube blank into the aluminum alloy outer tube preform on which the carbon fiber prepregs are laid, so that the carbon fiber prepregs are clamped between the aluminum alloy outer tube preform and the aluminum alloy inner tube blank to form a carbon fiber reinforced aluminum alloy layer tube preform;

carrying out composite pressing on the carbon fiber reinforced aluminum alloy layer pipe preformed piece in a solid particle medium forming mode to form a carbon fiber reinforced aluminum alloy layer pipe component, and continuously keeping applying pressure to an aluminum alloy inner pipe of the carbon fiber reinforced aluminum alloy layer pipe component so as to enable resin in the carbon fiber prepreg to completely infiltrate carbon fibers; before the carbon fiber reinforced aluminum alloy layer tube preform is subjected to composite pressing, replacing a mold to separately form the aluminum alloy inner tube blank, and acquiring forming pressure data of the aluminum alloy inner tube blank so as to apply pressure to the carbon fiber reinforced aluminum alloy layer tube preform in a composite pressing stage according to the forming pressure data;

heating and preserving heat of the carbon fiber reinforced aluminum alloy layer pipe member while continuously applying pressure to the carbon fiber reinforced aluminum alloy layer pipe member;

cooling the carbon fiber reinforced aluminum alloy layer pipe component after heat preservation; and after cooling, unloading the carbon fiber reinforced aluminum alloy layer pipe member, and taking out the carbon fiber reinforced aluminum alloy layer pipe member.

2. The carbon fiber-reinforced aluminum alloy layered pipe member forming process as recited in claim 1, wherein the heat treatment is performed on the aluminum alloy outer shell and the aluminum alloy inner shell by a solid solution process.

3. The forming process of the carbon fiber reinforced aluminum alloy layer tube member as claimed in claim 2, wherein the aluminum alloy outer tube blank and the aluminum alloy inner tube blank are subjected to solution treatment according to heat treatment process parameters of solution temperature of 450-560 ℃ and solution time of 15-120 min.

4. The forming process of the carbon fiber reinforced aluminum alloy layer tube member as claimed in claim 1, wherein the soft die preforming is performed on the aluminum alloy outer tube blank after the heat treatment by adopting a solid particle medium forming mode.

5. The carbon fiber reinforced aluminum alloy layered tube member forming process as recited in claim 1, wherein the carbon fiber reinforced aluminum alloy layered tube preform is formed outside a die for composite pressing.

6. The forming process of the carbon fiber reinforced aluminum alloy layer pipe member according to claim 1, wherein after the inner layer of the aluminum alloy outer pipe preform is laid, vacuum is pumped between the carbon fiber prepreg and the aluminum alloy outer pipe preform to perform semi-solidification treatment on the carbon fiber prepreg.

7. The forming process of the carbon fiber reinforced aluminum alloy layer pipe member according to claim 1, wherein after the carbon fiber reinforced aluminum alloy layer pipe member is formed, the curing temperature of the resin is 180 ℃ to 230 ℃, the curing time of the resin is 175min to 230min, and the curing pressure applied to the resin is 1MPa to 6 MPa.

8. The forming process of the carbon fiber reinforced aluminum alloy layer tube member as claimed in claim 1, wherein the solid particles adopted in the composite pressing of the carbon fiber reinforced aluminum alloy layer tube preform are silica particles or ceramic particles with a diameter of 0.3 mm-0.6 mm.

9. The forming process of the carbon fiber reinforced aluminum alloy layer pipe member according to any one of claims 1 to 8, which is implemented by using a forming mold of the carbon fiber reinforced aluminum alloy layer pipe member, and is characterized in that the forming mold of the carbon fiber reinforced aluminum alloy layer pipe member comprises the following steps:

the die cavity comprises a plurality of die cavity bodies which have different shapes and can be replaced with one another; the die cavity body is used for placing a piece to be pressed and a solid particle medium, wherein the piece to be pressed comprises the aluminum alloy outer tube blank and the carbon fiber reinforced aluminum alloy layer tube preform;

the pressure head is positioned above the cavity die and is used for being matched with the solid granular medium and the corresponding cavity body;

the fastening assembly comprises a fastening bolt, a fastening top plate, a fastening sliding plate, a fastening spring, a fastening bracket and a fastening base which are sequentially arranged from top to bottom; the cavity mold is arranged above the fastening base; the fastening bracket is fixedly arranged above the fastening base and is positioned on the periphery of the cavity die; the fastening sliding plate is slidably sleeved on the fastening support and is positioned above the pressure head; the fastening spring is sleeved on the fastening bracket, and two ends of the fastening spring are respectively abutted against the fastening sliding plate and the fastening base; the fastening top plate is fixed at the top end of the fastening support, the fastening bolt penetrates through the fastening top plate and is in threaded connection with the fastening top plate, and the fastening bolt can push the fastening sliding plate to move downwards to press the pressure head.

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