• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The invention relates to a method of producing an integrated monolithic aluminium structure, the method comprising the steps of: (a) providing an aluminium alloy plate with a predetermined thickness of at least 38.1 mm, wherein the aluminium alloy plate is a 7xxx—series alloy provided. in an F—temper‘ or an O—temper; (b) optionally pre—machining' of the aluminiunl alloy plate to an intermediate machined structure; (c) high—energy hydroforming of the plate or optional intermediate machined structure against a forming surface of a rigid die having a contour in accordance with a desired curvature of the integrated monolithic aluminium structure, the high—energy hydroforming causing the plate or the intermediate machined structure to conform to the contour of the forming surface to at least one of a uniaxial curvature and a biaxial curvature; (d) solution heat—treating and cooling of the high—energy hydroformed structure; (e) machining and (f) ageing of the final integrated monolithic aluminium structure.
    公开号:NL2023766A
    申请号:NL2023766
    申请日:2019-09-04
    公开日:2020-04-24
    发明作者:Meyer Philippe；Khosla Sunil；Bürger Achim；Maria Spangel Sabine；Harald Bach Andreas
    申请人:Aleris Rolled Prod Germany Gmbh；
    IPC主号:
    专利说明:

    Method of producing a high-energy hydroformed structure from a 7xxx-series alloy
    FIELD OF THE INVENTION
    The invention relates to a method of producing an integrated monolithic aluminium alloy structure, and can have a complex configuration, that is machined to nearnet-shape out of a plate material. More specifically, the invention relates to a method of producing an integrated monolithic aluminium alloy structure made from a 7xxxseries alloy, and can have a complex configuration, that is machined to near-net-shape out of a plate material. The invention relates also to an integrated monolithic aluminium alloy structure produced by the method of this invention and to several intermediate semi-finished products obtained by said method.
    BACKGROUND TO THE INVENTION
    US patent no. 7,610,669-B2 (Aleris) discloses a method for producing an integrated monolithic aluminium structure, in particular an aeronautical member, comprising the steps of:
    (a) providing an aluminium alloy plate with a predetermined thickness, said plate having been stretched after quenching and having been brought to a first temper selected from the group consisting of T4, T73, T74 and T76, wherein said aluminium alloy plate is produced from a AA7xxx-series aluminium alloy having a composition consisting of, in wt. %: 5.0-8.5% Zn, 1.0-2.6% Cu, 1.0-2.9% Mg, <0.3% Fe, <0.3% Si, optionally one or more elements selected from the group of Cr, Zr, Mn, V, Hf, Ti, the total of the optional elements not exceeding 0.6%, incidental impurities and the balance aluminium, (b) shaping said alloy plate by means of bending to obtain a predetermined shaped structure having a premachining thickness in the range of 10 to 220 mm, said alloy plate in said first temper selected from the group consisting of T4, T73, T74 and T76 to form the shaped structure having a built-in radius, (c) heat-treating said shaped structure, wherein said heat-treating comprises artificially aging said shaped structure to a second temper selected from the group consisting of T6, T79, T78, T77, T76, T74, T73 or T8, (d) machining said shaped structure to obtain an integrated monolithic aluminium structure as said aeronautical member for an aircraft, wherein said machining of said shaped structure occurs after said artificial ageing.
    It is suggested that the disclosed method can be applied also to AA5xxx, AA6xxx and AA2xxx-series aluminium alloys .
    Patent document US-2018/0230583-A1 discloses a method of forming a tubular vehicle body reinforcement, comprising providing a seam welded or extruded 7xxx aluminium tube, solution heat-treating by heating tube to at least 450°C, quenching the tube to less than 300°C at a minimum rate of 300°C/s with no more than a 20 second delay between the heating and the quenching, preferably a pre-bending and a pre-forming operation to form the tube along its length to a desired shape, and hydroforming the tube within 8 hours of quenching, trimming and artificially ageing of the tube to provide a yield strength of more than 470 MPa. The tube may have an outer diameter of less than 5 inches and a wall thickness greater than 1.5 mm and less than 4 mm.
    There is a demand for forming integrated monolithic aluminium structures of more complex configuration from a thick plate product.
    DESCRIPTION OF THE INVENTION
    As will be appreciated herein, except as otherwise indicated, aluminium alloy designations and temper designations refer to the Aluminium Association designations in Aluminium Standards and Data and the Registration Records, as published by the Aluminium Association in 2018 and are well known to the person skilled in the art. The temper designations are laid down in European standard EN515.
    For any description of alloy compositions or preferred alloy compositions, all references to percentages are by weight percent unless otherwise indicated.
    As used herein, the term about when used to describe a compositional range or amount of an alloying addition means that the actual amount of the alloying addition may vary from the nominal intended amount due to factors such as standard processing variations as understood by those skilled in the art.
    The term up to and up to about and <, as employed herein, explicitly includes, but is not limited to, the possibility of zero weight-percent of the particular alloying component to which it refers. For example, up to 0.5% Ag may include an aluminium alloy having no Ag.
    Monolithic is a term known in the art meaning comprising a substantially single unit which may be a single piece formed or created without joint or seams and comprising a substantially uniform whole.
    It is an object of the invention to provide a method of producing an integrated monolithic aluminium alloy structure of complex configuration that is machined to near-net-shape .
    It is an object of the invention to provide a method of producing an integrated monolithic 7xxx~series aluminium alloy structure of complex configuration that is machined to near-net-shape out of thick gauge plate material.
    These and other objects and further advantages are met or exceeded by the present invention providing a method of producing an integrated monolithic aluminium structure, the method comprising the process steps of, providing an aluminium alloy plate with a predetermined thickness of at least 38.1 mm (1.5 inches), wherein the aluminium alloy plate is a 7xxx-series alloy provided in an F-temper or an O-temper;
    optionally pre-machining of the aluminium alloy plate to an intermediate machined structure;
    high-energy hydroforming of the plate or the intermediate machined structure into a high-energy hydroformed structure against a forming surface of a rigid die having a contour at least substantially in accordance with a desired curvature of the integrated monolithic aluminium structure, the high-energy hydroforming causing the plate or the intermediate machined structure to substantially conform to the contour of the forming surface to at least one of a uniaxial curvature and a biaxial curvature;
    solution heat-treating and cooling of the resultant high-energy hydroformed structure;
    machining or mechanical milling of the solution heattreated high-energy formed structure to a near-final or final machined integrated monolithic aluminium structure; and ageing of the integrated monolithic aluminium structure to a desired temper to develop the required strength and other engineering properties relevant for the intended application of the integrated monolithic aluminium structure.
    It is an important feature of this invention that the 7xxx-series starting plate product employed is provided in an F-temper or in an O-temper.
    F-temper means that the 7xxx-series starting plate product is as-fabricated, optionally incorporating a small stretching operation of up to about 1% to improve product flatness, and there are no mechanical properties specified. In the case at hand this means that the plate material has been cast into a rolling ingot, pre-heated and/or homogenised, hot-rolled, and optionally coldrolled, to final gauge as is regular in the art but without or devoid of any further purposive annealing, solution heat-treatment or artificial ageing.
    As is well-known in the art, O-temper means that the 7xxx-series starting plate product has been annealed to obtain lowest strength temper having more stable mechanical properties. In the case at hand this means that the plate material has been cast into a rolling ingot, pre-heated and/or homogenised, hot-rolled, and optionally cold-rolled, to final gauge as is regular in the art, optionally incorporating a small stretching operation of up to about 1% to improve product flatness. As is known in the art, a recommended annealing to obtain lowest strength temper typically comprises soaking for about 2 to 3 hours at about 405°C, cooling to about 205°C or lower, reheat to about 232°C, and soak for about 4 hours, followed by cooling to ambient temperature and whereby the cooling rate to ambient temperature is not critical.
    An F-temper or O-temper plate product as a starting material is favourable as it provides significantly more ductility during a subsequent high-energy hydroforming operation. Whereas high-energy hydroforming of plate material in for example a T6 or T7 temper having a higher strength and lower ductility, will lead to more springback and residual stress after the high-energy hydroforming operation .
    In an embodiment in a next process step the 7xxxseries plate material is pre-machined, such as by turning, milling, and drilling, to an intermediate machined structure. Preferably the ultra-sonic dead-zone is removed from the plate product. And depending on the final geometry of the integrated monolithic aluminium structure some material can be removed to create one or more pockets in the plate material and a more near-net-shape to the forming die. This may facilitate the shaping during the subsequent high-energy hydroforming operation.
    In an embodiment of the method according to this invention the high-energy hydroforming step is by means of explosive forming. The explosive forming process is a high-energy-rate plastic deformation process performed in water or another suitable liquid environment, e.g. an oil, to allow ambient temperature forming of the aluminium alloy plate. The explosive charge can be concentrated in one spot or distributed over the metal, ideally using detonation cords. The plate is placed over a die and preferably clamped at the edges. In an embodiment the space between the plate and the die may be vacuumed before the forming process.
    Explosive-forming processes may be equivalently and interchangeably referred to as explosion-moulding, explosive moulding, explosion-forming or high-energy hydroforming (HER) processes. An explosive-forming process is a metalworking process where an explosive charge is used to supply the compressive force (e.g. a shockwave) to an aluminium plate against a form (e.g. a mould) otherwise referred to as a die. Explosive-forming is typically conducted on materials and structures of a size too large for forming such structures using a punch or press to accomplish the required compressive force. According to one explosive-forming approach, an aluminium plate, up to several inches thick, is placed over or proximate to a die, with the intervening space, or cavity, optionally evacuated by a vacuum pump. The entire apparatus is submerged into an underwater basin or tank, with a charge having a predetermined force potential detonated at a predetermined distance from the metal workpiece to generate a predetermined shockwave in the water. The water then exerts a predetermined dynamic pressure on the workpiece against the die at a rate on the order of milliseconds. The die can be made from any material of suitable strength to withstand the force of the detonated charge such as, for example, concrete, ductile iron, etc. The tooling should have higher yield strength than the metal workpiece being formed.
    In an embodiment of the method according to this invention the high-energy hydroforming step is by means of electrohydraulic forming. The electrohydraulic forming process is a high-energy-rate plastic deformation process preferably performed in water or another suitable liquid environment, e.g. an oil, to allow ambient temperature forming of the aluminium alloy plate. An electric arc discharge is used to convert electrical energy to mechanical energy and change the shape of the plate product. A capacitor bank delivers a pulse of high current across two electrodes, which are positioned a short distance apart while submerged in a fluid. The electric arc discharge rapidly vaporizes the surrounding fluid creating a shock wave. The plate is placed over a die and preferably clamped at the edges. In an embodiment the space between the plate and the die may be vacuumed before the forming process.
    A coolant is preferably used during the various premachining and machining or mechanical milling processes steps to allow for ambient temperature machining of the aluminium alloy plate or an intermediate product. Preferably wherein the pre-machining and the machining to near-final or final machined structure comprises highspeed machining, preferably comprises numericallycontrolled (NC) machining.
    Following the high-energy hydroforming step the resultant structure is solution heat-treated and cooled to ambient temperature. One of the objects is to heat the structure to a suitable temperature, generally above the solvus temperature, holding at that temperature long enough to allow soluble elements to enter into solid solution, and cooling rapidly enough to hold the elements as much as feasible in solid solution. The suitable temperature is alloy dependent and is commonly in a range of about 400°C to 560°C and can be performed in one step or as a multistep solution heat-treatment. The solid solution formed at high temperature may be retained in a supersaturated state by cooling with sufficient rapidity to restrict the precipitation of the solute atoms as coarse, incoherent particles.
    The solution heat-treatment followed by cooling is important because of obtaining an optimum microstructure that is substantially free from grain boundary precipitates that deteriorate corrosion resistance, strength and damage tolerance properties and to allow as much solute to be available for subsequent strengthening by means of ageing.
    For the 7xxx“Series alloys having a purposive addition of Cu of at least 1.0%, the solution heat treatment temperature should be at least about 400°C. A preferred minimum temperature is about 450°C, and more preferably about 460°C, and most preferably 470°C. The solution heattreatment temperature should not exceed 560°C. A preferred maximum temperature is about 530°C, and preferably not more than about 520°C.
    In the embodiment of the 7xxx-series alloys having Cu up to 0.3%, the solution heat treatment temperature should be at least about 400°C. A preferred minimum temperature is about 430°C, and more preferably about 470°C. The solution heat-treatment temperature should not exceed 560°C. A preferred maximum temperature is about 545°C, and preferably not more than about 530°C.
    In an embodiment of the method according to this invention following the solution heat-treatment the intermediate product is stress relieved, preferably by an operation including a cold compression type of operation, else there will be too much residual stress impacting a subsequent machining operation.
    In an embodiment the stress relieve via a cold compression of operation is by performing one or more next high-energy hydroforming steps. Preferably applying a milder shock wave compared to the first high-energy hydroforming step creating the initial high-energy hydroformed structure.
    In one embodiment the solution heat-treated highenergy formed intermediate structure, and optionally also stress relieved, is, in that order, next machined or mechanically milled to a near-final or final machined integrated monolithic aluminium structure and followed by ageing to a desired temper to achieve final mechanical properties .
    In another more preferred embodiment the solution heat-treated high-energy formed intermediate structure, and optionally also stress relieved, is, in that order, aged to a desired temper to achieve final mechanical properties and followed by machining or mechanical milling to a near-final or final machined integrated monolithic aluminium structure. Thus said machining occurs after said ageing.
    In both embodiments the ageing to a desired temper to achieve final mechanical properties is selected from the group of: T4, T5, T6, and T7. The ageing step preferably includes at least one ageing step at a temperature in the range of 120°C to 210°C for a soaking time in a range of 4 to 30 hours.
    In a preferred embodiment the ageing to a desired temper to achieve final mechanical properties is to a T7 temper, more preferably an T73, T74 or T76 temper, more preferably an T7352, T7452 or T7652 temper.
    In an embodiment the ageing is to a Tx54 temper and where x is equal to 3, 6, 73, 74 or 76, which represents a stress relieved temper with combined stretching and compression .
    In an embodiment the final aged near-final or final machined formed integrated monolithic aluminium structure has a tensile strength of at least 300 MPa. In an embodiment the tensile strength is at least 360 MPa, and more preferably at least 400 MPa.
    In an embodiment the final aged near-final or final machined formed integrated monolithic aluminium structure has a substantially unrecrystallized microstructure to provide to better balance in mechanical and corrosion properties .
    In an embodiment the predetermined thickness of the aluminium alloy plate is at least 50.8 mm (2.0 inches), and preferably at least 63.5 mm (2.5 inches). In an embodiment the predetermined thickness of the aluminium alloy plate is at most 127 mm (5 inches), and preferably at most 114.3 mm (4.5 inches).
    In an embodiment the 7xxx-series aluminium alloy has a
    composition comprising,in wt. % : Zn5.0% to9.8%,preferably 5.5% to 8.7%,Mg1.0% to3.0%, Cuup to 2. 5%, Preferably 1.0% to2.5%,andoptionally oneor more elementsselected from thegroup consistingof:Zrupto0.3%, Crupto0.3%, Mnupto0.45%, Tiupto0.15%, preferablyup to 0.1%, Scupto0.5%, Agupto0.5%, Feup to 0.25%rpreferably up to 0. 15%,
    Si up to 0.25%, preferably up to 0.12%, impurities and balance aluminium. Typically, such impurities are present each <0.05% and total <0.15%.
    The Zn is the main alloying element in 7xxx-series alloys, and for the method according to this invention it should be in a range of 5.0% to 9.7%. A preferred lowerlimit for the Zn-content is about 5.5%, and more preferably about 6.2%. A preferred upper-limit for the Zncontent is about 8.7%, and more preferably about 8.4%.
    Mg is another important alloying element and should be
    present in arange of1.0% to3.0%. A preferredlower-limitfortheMgcontentisabout1.2%. A preferredupper-limitfortheMgcontentisabout2.6%. A preferredupper-limitfortheMgcontentisabout2.4% . Cucan. bepresent inthe 7xxx-series alloy up to* about
    2.5%. In one embodiment Cu is purposively added to increase in particular the strength and the SCC resistance and is present in a range of 1.0% to 2.5%. A preferred lower-limit for the Cu-content is 1.25%. A preferred upper-limit for the Cu-content is 2.3%.
    In another embodiment the 7xxx-series alloy has a low Cu level of up to about 0.3%, providing a slight decrease in strength and SCC resistance, but increasing fracture toughness and ST-elongation .
    The iron and silicon contents should be kept significantly low, for example not exceeding about 0.15% Fe, and preferably less than 0.10% Fe, and not exceeding about 0.15% Si and preferably 0.10% Si or less. In any event, it is conceivable that still slightly higher levels of both impurities, at most about 0.25% Fe and at most about 0.25% Si may be tolerated, though on a less preferred basis herein.
    The 7xxx-series aluminium alloy comprises optionally one or more dispersoid forming elements to control the grain structure and the quench sensitivity selected from the group consisting of: Zr up to 0.3%, Cr up to 0.3%, Mn up to 0.45%, Ti up to 0.15%, Sc up to 0.5%, Ag up to 0.5%.
    A preferred maximum for the Zr level is 0.25%. A suitable range of the Zr level is about 0.03% to 0.25%, and more preferably 0.05% to 0.18%. Zr is the preferred dispersoid forming alloying element in the aluminium alloy product according to this invention.
    The addition of Sc is preferably not more than about 0.5% and more preferably not more than 0.3%, and more preferably not more than about 0.25%. A preferred lower limit for the Sc addition is 0.03%, and more preferably 0.05% .
    In an embodiment, when combined with Zr, the sum of Sc + Zr should be less than 0.35%, preferably less than 0.30%.
    Another dispersoid forming element that can be added, alone or with other dispersoid formers is Cr. Cr levels should preferably be below 0.3%, and more preferably at a maximum of about 0.25%. A preferred lower limit for the Cr would be about 0.04%.
    In another embodiment of the aluminium alloy wrought product according to the invention it is free of Cr, in practical terms this would mean that it is considered an impurity and the Cr-content is up to 0.05%, and preferably up to 0.04%, and more preferably only up to 0.03%.
    Mn can be added as a single dispersoid former or in combination with any one of the other mentioned dispersoid formers. A maximum for the Mn addition is about 0.4%. A practical range for the Mn addition is in the range of about 0.05% to 0.4%, and preferably in the range of about 0.05% to 0.3%. A preferred lower limit for the Mn addition is about 0.12%. When combined with Zr, the sum of Mn plus Zr should be less than about 0.4%, preferably less than about 0.32%, and a suitable minimum is about 0.12%.
    In another embodiment of the aluminium alloy wrought product according to the invention it is free of Mn, in practical terms this would mean that it is considered an impurity and the Mn-content is up to 0.05%, and preferably up to 0.04%, and more preferably only up to 0.03%.
    In another embodiment each of Cr and Mn are present only at impurity level in the aluminium alloy wrought product . Preferably the combined presence of Cr and Mn is only up to 0.05%, preferably up to 0.04%, and more preferably up to 0.02%.
    Silver (Ag) in a range of up to 0.5% can be purposively added to further enhance the strength during ageing. A preferred lower limit for the purposive Ag addition would be about 0.05% and more preferably about 0.08%. A preferred upper limit would be about 0.4%.
    In an embodiment the Ag is an impurity element and it can be present up to 0.05%, and preferably up to 0.03%.
    Ti can be present in particular to act as a grain refiner during the casting of rolling feedstock. Ti based grain refiners such as those containing titanium and boron, or titanium and carbon, may also be used as is well-known in the art. The Ti-content in the aluminium alloy is up to 0.15%, and preferably up to 0.1%, and more preferably in a range of 0.01% to 0.05%.
    In an embodiment the 7xxx-series aluminium alloy has a composition consisting of, in wt. %: Zn 5.0% to 9.8%, Mg 1.0% to 3.0%, Cu up to 2.5%, and optionally one or more elements selected from the group consisting of: (Zr up to 0.3%, Cr up to 0.3%, Mn up to 0.45%, Ti up to 0.15%, Sc up to 0.5%, Ag up to 0.5%), Fe up to 0.25%, Si up to 0.25%, balance aluminium and impurities each <0.05% and total <0.15%, and with preferred narrower compositional ranges as herein described and claimed.
    In a further aspect the invention relates to an integrated monolithic aluminium structure manufactured by the method according to this invention.
    In a further aspect the invention relates to an intermediate semi-finished product formed by the intermediate machined structure prior to the high-energy hydro forming operation.
    In a further aspect the invention relates to an intermediate semi-finished product formed by the intermediate, and optionally pre-machined, structure having been high-energy hydroformed formed and having at least one of a uniaxial curvature and a biaxial curvature by the method according to this invention.
    In a further aspect the invention relates to an intermediate semi-finished product formed by the intermediate, and optionally pre-machined, structure then high-energy hydroformed and having at least one of a uniaxial curvature and a biaxial curvature, and then solution heat-treated and cooled to ambient temperature.
    In a further aspect the invention relates to an intermediate semi-finished product formed by the intermediate, and optionally pre-machined, structure then high-energy hydroformed and having at least one of a uniaxial curvature and a biaxial curvature, then solution heat-treated and cooled, stress relieved in a cold compression operation, and aged prior to machining into a near-final or final formed integrated monolithic aluminium structure, the ageing is to a desired temper to develop the required strength and other engineering properties relevant for the intended application of the integrated monolithic aluminium structure.
    The aged and machined final integrated monolithic aluminium structure can be part of a structure like a fuselage panel with integrated stringers, cockpit of an aircraft, lateral windshield of a cockpit, integral lateral windshield of a cockpit, an integral frontal windshield of a cockpit, front bulkhead, door surround, nose landing gear bay, and nose fuselage. It can also be as part of an underbody structure of an armoured vehicle providing mine blast resistance, the door of an armoured vehicle, the engine hood or front fender of an armoured vehicle, a turret.
    In a further aspect the invention relates to the use of a 7xxx-series aluminium alloy plate in an F-temper or an O-temper, having a composition of, in wt.%, Zn 5.0% to 9.8%, Mg 1.0% to 3.0%, Cu up to 2.5%, and optionally one or more elements selected from the group consisting of: (Zr up to 0.3%, Cr up to 0.3%, Mn up to 0.45%, Ti up to 0.15%, Sc up to 0.5%, Ag up to 0.5%), Fe up to 0.25%, Si up to 0.25%, balance aluminium and impurities each <0.05% and total <0.15%, and with preferred narrower compositional ranges as herein described and claimed, and a gauge in a range of 38.1 mm to 127 mm in a high-energy hydroforming operation according to this invention, and preferably to produce an aircraft structural part.
    DESCRIPTION OF THE DRAWINGS
    The invention shall also be described with reference to the appended drawings, in which:
    Fig. 1 shows a flow chart illustrating one embodiment of the method according to this invention; and
    Fig. 2 shows a flow chart illustrating another embodiment of the method according to this invention.
    Figs. 3A, 3B and 3C show cross-sectional side-views of an aluminium plate progressing through stages of a forming process from a rough-shaped metal plate into a shaped, near-finally shaped and finally-shaped workpiece, according to aspects of the present invention.
    In Fig. 1 the method comprises, in that order, a first process step of providing an 7xxx-series aluminium alloy plate material in an F-temper or O-temper and having a predetermined thickness of at least 38.1mm. In a next process step the plate material is pre-machined (this is an optional process step) into an intermediate machined structure and subsequently high-energy hydroformed, preferably by means of explosive forming or electrohydraulic forming, into a high-energy hydroformed structure with least one of a uniaxial curvature and a biaxial curvature. In a next process step there is solution heat-treating (SHT) and cooling of said highenergy hydroformed structure. In a preferred embodiment following SHT and cooling the intermediate product is stress relieved, more preferably in an operation including in a cold compression type of operation.
    Then there is either machining or mechanical milling of the solution heat-treated high-energy formed structure to a near-final or final machined integrated monolithic aluminium structure, followed by ageing of said machined integrated monolithic aluminium structure to a desired temper to develop the required strength and other engineering properties relevant for the intended application of the integrated monolithic aluminium structure .
    Or in an alternative embodiment there is firstly ageing of intermediate integrated monolithic aluminium structure to a desired temper to develop the required strength and other engineering properties relevant for the intended application of the integrated monolithic aluminium structure, for example an T7452 or T7652 temper, followed by machining or mechanical milling of the aged high-energy formed structure into a near-final or final machined integrated monolithic aluminium structure.
    The method illustrated in Fig. 2 is closely related to the method illustrated in Fig. 1, except that in this embodiment there is a first high-energy hydroforming step, followed by a solution heat-treatment and cooling. Then at least one second high-energy hydroforming step is performed the purpose of which is at least stress relief, followed by the ageing and machining as in the method illustrated in Fig. 1.
    Figs. 3A, 3B and 3C show a series in progression of exemplary drawings illustrating how an aluminium plate may be formed during an explosive forming process that can be used in the forming processes according to this invention. According to explosive forming assembly 80a, a tank 82 contains an amount of water 83. A die 84 defines a cavity and a vacuum line 87 extends from the cavity 85 through the die 84 to a vacuum (not shown). Aluminium plate 86a is held in position in the die 84 via a hold-down ring or other retaining device (not shown). An explosive charge 88 is shown suspended in the water 83 via a charge detonation line 89, with charge detonation line 19a connected to a
    detonator(not shown). As shownin Fig. 3B,thecharge 88(showninFig.3A) has been detonatedinexplosiveformingassembly80bcreating ashock waveAemanatingfrom agasbubbleB, with theshock wave Ά causing the
    deformation of the aluminium plate 86b into cavity 85 until the aluminium plate 86c is driven against (e.g., immediately proximate to and in contact with) the inner surface of die 84 as shown in Fig. 3C.
    The present application also discloses the following items :
    Item 1. A method of producing an integrated monolithic aluminium structure, the method comprising the steps of: (i) providing an aluminium alloy plate with a predetermined thickness of at least 38.1 mm, wherein the aluminium alloy plate is a 7xxx-series alloy provided in an F-temper or an O-temper; (ii) optionally pre-machining of the aluminium alloy plate to an intermediate machined structure; (iii) high-energy hydroforming of the plate or optional intermediate machined structure into a highenergy hydroformed structure against a forming surface of a rigid die having a contour in accordance with a desired curvature of the integrated monolithic aluminium structure, the high-energy hydroforming causing the plate or the intermediate machined structure to conform to the contour of the forming surface to at least one of a uniaxial curvature and a biaxial curvature; (iv) solution heat-treating and cooling of the high-energy hydroformed structure; (v) machining of the solution heat-treated high-energy formed structure to a final machined integrated monolithic aluminium structure; (vi) ageing of the final integrated monolithic aluminium structure to a desired temper.
    Item 2. Method according to item 1, wherein the highenergy hydro-forming step is by explosive forming.
    Item 3. Method according to item 1, wherein the highenergy hydro-forming step is by electrohydraulic forming.
    Item 4. Method according to any one of items 1 to 3, wherein following solution heat-treating and cooling of the high-energy hydroformed structure, in that order, the solution heat-treated high-energy formed structure is machined to a final machined integrated monolithic aluminium structure and then aged to a desired temper.
    Item 5. Method according to any one of items 1 to 3, wherein following solution heat-treating and cooling of the high-energy hydroformed structure, in that order, the solution heat-treated high-energy formed structure is aged to a desired temper and then machined to a final machined integrated monolithic aluminium structure.
    Item 6. Method according to any one of items 1 to 5, wherein following solution heat-treating and cooling of the high-energy hydroformed structure, said structure is stress-relieved, preferably by compressive forming, followed by machining and ageing to a desired temper of the integrated monolithic aluminium structure.
    Item 7. Method according to any one of items 1 to 6, wherein following solution heat-treating and cooling of the high-energy hydroformed structure, said structure is stress-relieved, preferably by compressive forming in a next high-energy hydroforming step, followed by machining and ageing to a desired temper of the integrated monolithic aluminium structure.
    Item 8. Method according to any one of items 1 to 7, wherein the predetermined thickness of the aluminium alloy plate is at least 50.8 mm, and preferably at least 63.5 mm.
    Item 9. Method according to any one of items 1 to 8, wherein the predetermined thickness of the aluminium alloy plate is at most 127 mm, and preferably at most 114.3 mm.
    Item 10. Method according to any one of items 1 to 9, wherein the ageing of the integrated monolithic aluminium structure is to a desired temper selected from the group of: T4, T5, T6, and T7.
    Item 11. Method according to any one of items 1 to 9, wherein the ageing of the integrated monolithic aluminium structure is to a T7 temper, preferably an T73, T74 or T76 temper .
    Item 12. Method according to any one of items 1 to 11, wherein the 7xxx-series aluminium alloy has a composition comprising, in wt. %: Zn 5.0% to 9.8%, Mg 1.0% to 3.0%, Cu up to 2.5% .
    Item 13. Method according to any one of items 1 to 12, wherein the 7xxx-series aluminium alloy has a composition comprising, in wt . %: Zn 5.0% to 9.8%, Mg 1.0% to 3.0%, Cu up to 2.5%, and optionally one or more elements selected from the group consisting of: (Zr up to 0.3%, Cr up to 0.3%, Mn up to 0.45%, Ti up to 0.15%, preferably up to
    0.1%, Sc up to0.5%, Agupto 0.5%) , Fe upto0.25%,preferably up to0.15%, Siupto 0.25%, preferably up to0.12%, impuritiesand balance aluminium. Item 14. Methodaccordingtoany one of items1to 13,wherein the 7xxx--series aluminium alloy has aCu--contentof 1.0% to 2.5% . Item 15. Methodaccordingtoany one of items1to 13,wherein the 7xxx-series aluminium alloy has aCu-contentof up to 0.3%. Item 16. Methodaccordingtoany one of items1to 15,wherein the solution heat-treatment is at a temperature ina range of 400°Cto 560 °C .Item 17 . Methodaccordingtoany one of items1to 16,wherein the pre-machiningandfinal machiningcomprises
    high-speed machining, preferably comprises numericallycontrolled (NC) machining.
    Item 18, An integrated monolithic aluminium structure manufactured by the method according to any one of items 1 to 17.
    Item 19. Use of a 7xxx-series aluminium alloy plate in an F-temper or an 0-temper, having a composition of, in wt.%,
    Zn 5.0% to 9.8%,Mg 1.0 %to 3.0%, Cu up to2.5%,andoptionally oneormoreelements selectedfromthegroupconsisting of:(Zr upto0.3%, Cr up to0.3%,Mnupto0.45%, Ti up to0. 15%,Scup to 0.5%, Agup to0.5ί0 ,Feup to 0.25%, Siupto0.25%, balancealuminiumandimpurities, andagaugeina range of 38.1mm to127mm. in
    a high-energy hydroforming operation according to any one of items 1 to 17 .
    Item 20. Use of a 7xxx-series aluminium alloy plate in an F-temper or an O-temper, having a composition of, in wt.%,
    Zn 5.0% to 9.8%,Mg 1. 0%to 3.0%, Cu up to2.5%,andoptionally one ormoreelements selected fromthe groupconsisting of: (Zr upto0.3%, Cr up to 0.3%,Mn upto0.45%, Ti up to 0.15%,Scup to 0.5%, Ag up to0.5%),Feup to 0.25%, Siupto0.25%, balance aluminiumandimpurities, and agaugeina range of 38.1 mm to12 7 mm. in
    a high-energy hydroforming operation according to any one of items 1 to 17 to produce an aircraft structural part.
    Having now fully described the invention, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made without departing from the spirit or scope of the invention as herein described.
    权利要求:
    Claims (5)
    [1]
    A method of manufacturing an integrated monolithic aluminum construction, the method comprising the following steps:
    providing an aluminum alloy plate with a predetermined thickness of at least 38.1 mm, and wherein the aluminum alloy plate is of a 7xxx series alloy in an F condition or an O condition;
    optional pre-machining of the aluminum alloy sheet to a machined intermediate;
    high-energy hydroforming of the sheet or the machined intermediate into a high-energy hydroformed construction against a deformation surface of a rigid die with a contour corresponding to a desired curvature of the integrated monolithic aluminum construction, whereby the high-energy hydroforming of the sheet whether the machining intermediate causes it to conform to the shape of the deformation surface to at least one of a uniaxial or a biaxial curvature;
    solution annealing and cooling of the high-energy hydroformed construction;
    machining of the solution-annealed high-energy hydroformed construction into a final machined integrated monolithic aluminum construction;
    aging the end-machined integrated monolithic aluminum construction to a desired condition.
    [2]
    The method of claim 1, wherein the high energy hydroforming step is by explosive shaping.
    5
    [3]
    The method of claim 1, wherein the high energy hydroforming step is by electrohydraulic conversion.
    [4]
    Method according to any one of claims 1 to 3,
    10 wherein following the solution annealing and cooling of the high-energy hydroformed construction, in this order, the solution-annealed high-energy hydroformed construction is machined into a final machined integrated
    15 monolithic aluminum construction and then aged to a desired condition.
    A method according to any one of claims 1 to 3, wherein following the solution annealing and cooling of the high energy hydroformed construction, in this order, the solution annealed high energy hydroformed construction is aged to a desired condition and then machined to an end-machined integrated 25 monolithic aluminum construction.
    The method of any one of claims 1 to 5, wherein after the annealing and cooling of the high-energy hydroformed construction, the structure is de-stressed, preferably by compression molding, followed by machining and aging to a desired condition. of the integrated monolithic aluminum construction.
    35
    The method of any one of claims 1 to 6, wherein after the annealing and cooling of the high-energy hydroformed construction, the construction is de-stressed, preferably by compressive deformation in a subsequent high-energy hydroforming step, and then machining machining and aging to a desired condition of the integrated monolithic aluminum construction.
    The method of any one of claims 1 to 7, wherein the predetermined thickness of the aluminum alloy sheet is at least 50.8 mm, and preferably at least 63.5 mm.
    The method of any one of claims 1 to 8, wherein the predetermined thickness of the aluminum alloy sheet is at most 127 mm, and preferably at most 114.3 mm.
    A method according to any one of claims 1 to 9, wherein for aging the integrated monolithic aluminum construction to a desired condition is selected from the group: T4, T5, T6 and T7.
    The method of any one of claims 1 to 10, wherein aging the integrated monolithic aluminum structure to a desired condition is a T7 condition, preferably a T73, T74 or a T76 condition.
    The method of any one of claims 1 to 11, wherein the 7xxx series aluminum alloy has a composition comprising, in weight percent:
    Zn 5.0% -9.8%,
    Mg 1.0% -3.0%,
    Cu <2.5%.
    Mg
    Cu
    The method of any one of claims 1 to 12, wherein the 7xxx ~ series aluminum alloy has a composition comprising, in weight percent:
    Zn 5.0% -9.8%, preferably 5.5% -8.7%,
    5 Mg 1.0% -3.0%,
    Cu d 2.5%, preferably 1.0% -2.5%, optionally one or more elements selected from the
    group existing from: Sr <0.3%, 10 Cr <0.3%,Mn <0.45%,Ti <0.15%, preferably <0.1% Sc <0.5%,Ag <0.5%, 15 Fe < 0.25%, bee preference <0.15%, Si < 0.25%, bee preference <0.12%, contaminants and balance aluminum.
    A method according to any one of claims 1 to 13,
    20 wherein the 7xxx series aluminum alloy has a Cu content of 1.0% -2.5%.
    The method of any one of claims 1 to 13, wherein the 7xxx series aluminum alloy has a Cu content
    25 has <0.3%.
    The method of any one of claims 1 to 15, wherein the solution annealing is done at a temperature in a range from 400 ° C to 560 ° C.
    A method according to any one of claims 1 to 16, wherein the pre-machining and the final machining comprises high-speed machining, preferably numerically controlled (NC) machining.
    An integrated monolithic aluminum construction manufactured by the method of any one of claims 1 to 17.
    19. A semi-finished intermediate product comprising a 7xxx ~ series aluminum alloy sheet in an F-condition or an O-condition with a thickness of at least 3 mm, preferably in a range from 38.1 mm to 127 mm, wherein the 7xxx series aluminum alloy has a composition 10 comprising, in wt%: Zn 5.0% -9.8%, preferably
    [5]
    5.5% -8.7%, Mg 1.0% -3.0%, Cu <2.5%, preferably 1.0% 2.5%, optionally one or more elements selected from the group consisting of: (Zr < 0.3%, Cr <0.3%, Mn <0.45%, Ti <0.15%, Sc <0.5%, Ag <0.5%), Fe <0.25%, Si < 0.25%, 15 impurities and balance aluminum, optionally pre-machined, and high-energy hydroformed into a high-energy hydroformed construction with at least one-axis or two-axis curvature.
    类似技术:
    公开号 | 公开日 | 专利标题
    EP2324137B1|2013-01-16|Process for forming aluminium alloy sheet components
    EP1783235B1|2009-01-07|Titanium-based alloy
    GB2430937A|2007-04-11|Aluminium-copper-magnesium-manganese alloy
    CN102834502A|2012-12-19|2xxx series aluminum lithium alloys having low strength differential
    Ismail et al.2016|Review on sheet metal forming process of aluminium alloys
    US20180148815A1|2018-05-31|High-strength hot-forged aluminum alloy
    NL2023766B1|2020-07-14|Method of producing a high-energy hydroformed structure from a 7xxx-series alloy
    NL2023971B1|2020-05-13|Method of producing a high-energy hydroformed structure from a 7xxx-series alloy
    NL2023765B1|2020-05-01|Method of producing a high-energy hydroformed structure from a 2xxx-series alloy
    US20220002853A1|2022-01-06|Method of producing a high-energy hydroformed structure from a 7xxx-series alloy
    NL2024300B1|2020-06-09|Method of producing a high-energy hydroformed structure from an Al-Mg-Sc alloy
    US20220056562A1|2022-02-24|Method of producing a high-energy hydroformed structure from a 2xxx-series alloy
    EP3789507A1|2021-03-10|Clad 2xxx-series aerospace product
    EP3783125A1|2021-02-24|Clad 2xxx-series aerospace product
    EP3904073A1|2021-11-03|Clad 2xxx-series aerospace product
    KR20210126107A|2021-10-19|Clad 2XXX-Series Aerospace Products
    Erisov et al.2019|Structure and Anisotropy of the Mechanical Properties of Hot-and Cold-Rolled Semi-Finished Products from Aluminium-Lithium Alloys
    CA3146405A1|2021-02-25|Clad 2xxx-series aerospace product
    CA3146252A1|2021-03-11|Clad 2xxx-series aerospace product
    同族专利:
    公开号 | 公开日
    US20210340655A1|2021-11-04|
    WO2020049027A1|2020-03-12|
    CN112840059A|2021-05-25|
    EP3847292A1|2021-07-14|
    NL2023766B1|2020-07-14|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    JP2003154407A|2001-11-19|2003-05-27|Honda Motor Co Ltd|Aluminum extruded material for hydroforming and method of manufacturing the same|
    US7093470B2|2002-09-24|2006-08-22|The Boeing Company|Methods of making integrally stiffened axial load carrying skin panels for primary aircraft structure and fuel tank structures|
    CA2519139C|2003-03-17|2010-01-05|Corus Aluminium Walzprodukte Gmbh|Method for producing an integrated monolithic aluminium structure and aluminium product machined from that structure|
    CA2615852C|2005-07-21|2015-02-24|Achim Buerger|A wrought aluminum aa7000-series alloy product and method of producing said product|
    WO2008003503A2|2006-07-07|2008-01-10|Aleris Aluminum Koblenz Gmbh|Method of manufacturing aa2000 - series aluminium alloy products|
    KR20140134315A|2012-03-07|2014-11-21|알코아 인코포레이티드|Improved 7xxx aluminum alloys, and methods for producing the same|
    US9249487B2|2013-03-14|2016-02-02|Alcoa Inc.|Methods for artificially aging aluminum-zinc-magnesium alloys, and products based on the same|
    FR3031056B1|2014-12-31|2017-01-20|Adm28 S Ar L|ENCLOSURE FOR ELECTRO-HYDRAULIC FORMING|
    DE102016008941A1|2016-07-25|2018-01-25|Fachhochschule Südwestfalen|Apparatus and method for hydraulic high speed high pressure forming|
    US10570489B2|2017-02-15|2020-02-25|Ford Global Technologies, Llc|Heat treatment and tube forming process for high strength aluminum tube body structure reinforcements|
    法律状态:
    2021-05-19| PD| Change of ownership|Owner name: AIRBUS SAS; FR Free format text: DETAILS ASSIGNMENT: CHANGE OF OWNER(S), ASSIGNMENT; FORMER OWNER NAME: ALERIS ROLLED PRODUCTS GERMANY GMBH Effective date: 20210413 |
    优先权:
    申请号 | 申请日 | 专利标题
    EP18192734|2018-09-05|
    [返回顶部]