• 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 is a laminated and / or forged aluminum-based alloy product comprising, in% by weight, Cu: 3.2-4.0; Li: 0.80 - 0.95; Zn: 0.45-0.70; Mg: 0.15 - 0.7; Zr: 0.07-0.15; Mn: 0.1 - 0.6; Ag: <0.15; Fe + Si ≤ 0.20; at least one of Ti: 0.01 - 0.15; Sc: 0.02 - 0.1; Cr: 0.02 - 0.1; Hf: 0.02-0.5; V: 0.02 - 0.1 other elements ≤ 0.05 each and ≤ 0.15 in total, remains aluminum. In the process for manufacturing the products according to the invention, an aluminum alloy liquid metal bath according to the invention is produced, a raw form is cast from said bath of liquid metal; said raw form is homogenized at a temperature between 450 ° C and 550 °; the raw form is preferably deformed hot and optionally cold, preferably to a thickness of at least 15 mm: it is dissolved between 490 and 530 ° C for 15 min to 8 h and said product is tempered; the product is pulled in a controlled manner with a permanent deformation of 1 to 7% and an income is obtained from said product. The product is advantageous for the manufacture of aircraft structural element.
    公开号:FR3044682A1
    申请号:FR1561852
    申请日:2015-12-04
    公开日:2017-06-09
    发明作者:Ricky Whelchel；Alireza Arbab；Bernard Bes；Christophe Sigli
    申请人:Constellium Issoire SAS；
    IPC主号:
    专利说明:

    Les plaques ont été homogénéisées à environ 500 °C pendant environ 12 heures puis scalpées. Les plaques ont été laminées à chaud pour obtenir des tôles ayant une épaisseur de 50 mm, 102 mm ou 130 mm. Les tôles ont été mises en solution à 527 °C et trempées avec de l’eau froide. Les tôles ont ensuite été tractionnées avec un allongement permanent de 4% ou 6%.
    Les tôles ont subi un revenu à 145 °C ou à 150 °C. Des échantillons ont été prélevés à 1/4-épaisseur pour mesurer les caractéristiques mécaniques statiques en traction et la ténacité dans les directions L, TL, L-T et T-L à 1/2-épaisseur pour mesurer les caractéristiques mécaniques statiques en traction et la ténacité dans les directions TC et S-L. Les éprouvettes utilisées pour la mesure de ténacité étaient des éprouvettes de géométrie CT et avaient des dimensions telles que décrite ci-dessous :
    Les résultats obtenus sont présentés dans le tableau 2 et le tableau 3.
    Tableau 2 : Propriétés mécaniques statiques obtenues pour les différentes tôles.
    Tableau 3 : Propriétés de ténacité K1C
    obtenues pour les différentes tôles.
    Les résultats sont illustrés par les figures 1 à 2 (épaisseur 50 mm) et 3 à 4 (épaisseur 102 mm) et 5 (épaisseur 130 mm).
    Les résultats des essais de corrosion sous contrainte obtenus sont présentés dans le Tableau 4 ci-dessous.
    Tableau 4 : Résultats des essais de corrosion sous contrainte Exemple 2
    Dans cet exemple, plusieurs plaques d’épaisseur 120 mm dont la composition est donnée dans le tableau 5 ont été coulées.
    Tableau 5 : Composition en % en poids Al-Cu-Li coulés sous forme de plaque.
    Les plaques ont été usinée jusqu’à l’épaisseur 100 mm. Les plaques ont été homogénéisées à environ 500 °C pendant environ 12 heures puis scalpées. Après homogénéisation, les plaques ont été laminées à chaud pour obtenir des tôles ayant une épaisseur de 27 mm. Les tôles ont été mises en solution et trempées à l’eau froide ou avec de l’eau à 90 °C de façon à faire varier la vitesse de trempe et tractionnées avec un allongement permanent de 3,5%.
    Les tôles ont subi un revenu compris entre 15 h et 50 h à 155 °C. Des échantillons ont été prélevés à mi-épaisseur pour mesurer les caractéristiques mécaniques statiques en traction
    ainsi que la ténacité Kq. Les éprouvettes utilisées pour la mesure de ténacité dans la direction T - L avaient une largeur W = 50 mm et une épaisseur B = 25 mm. Les critères de validité de Kic ont été remplis pour tous les échantillons. Pour la direction S - L les mesures ont été réalisées sur des éprouvettes de largeur W = 36 mm et d’épaisseur B = 25,4 mm Les résultats obtenus sont présentés dans les tableaux 6 et 7.
    Tableau 6 : Propriétés mécaniques obtenues pour les différentes tôles après trempe à l’eau à 90 °C
    Tableau 7 : Propriétés mécaniques obtenues pour les différentes tôles après trempe à l’eau à 25 °C
    La figure 6 montre la diminution de propriété (résistance mécanique, ténacité) pour une trempe dans de l’eau à 90 °C en pourcentage par rapport à la valeur avec trempe avec de l’eau à 25°C. La composition 61 est la moins sensible à la trempe pour ce qui concerne la ténacité et la composition 58 est la moins sensible à la trempe pour ce qui concerne la limite d’élasticité.
    Exemple 3
    Dans cet exemple, on a étudié l’effet des conditions de traction contrôlée et de revenu sur les résultats de ténacité Kapp et Keff mesurés par une courbe R.
    Des tôles d’épaisseur 50 mm et 102 mm ont été obtenues avec les alliages 56 et 71 du tableau 1. Les tôles ont été mises en solution à 527 °C et trempées avec de l’eau froide. Les tôles en alliage 56 ont ensuite été tractionnées avec un allongement permanent de 4% et les tôles en alliage 71 ont été tractionnées avec un allongement permanent de 6%.
    Les tôles en alliage 56 ont ensuite subi un revenu de 40 heures à 150 °C et le tôles en alliage 71 ont subi un revenu de 20 heures à 150 °C.
    Des échantillons ont été prélevés à '/2 épaisseur pour les tôles d’épaisseur 50 mm et à 1/4-épaisseur pour les tôles d’épaisseur 102 mm et 130 mm, pour mesurer les
    caractéristiques mécaniques statiques en traction et la ténacité en contrainte plane KaPP et Keff dans les directions L, TL, L-T et T-L Pour la ténacité, on a mesuré la courbe R sur des éprouvettes CCT de largeur W = 406 mm et d’épaisseur B = 6,35 mm.
    Les résultats obtenus sont donnés dans le Tableau 8 ci-dessous.
    Tableau 8 : propriétés mécaniques mesurées
    La combinaison d’une traction contrôlée avec une déformation permanente de 6% et de 20 heures à 150 °C est particulièrement avantageuse.
    Lithium copper aluminum alloy has mechanical strength and toughness
    IMPROVED
    FIELD OF THE INVENTION The invention relates to aluminum-copper-lithium alloy products, and more particularly to such products, to their manufacturing and use processes, intended in particular for aircraft and aerospace construction.
    State of the art
    Products, especially thick rolled and / or forged aluminum alloy products are developed to produce by cutting, surfacing or mass machining of high strength parts intended in particular for the aviation industry, the aerospace industry or mechanical construction.
    Aluminum alloys containing lithium are very interesting in this respect, since lithium can reduce the density of aluminum by 3% and increase the modulus of elasticity by 6% for each weight percent of lithium added. For these alloys to be selected in the aircraft, their performance compared to other properties of use must reach that of commonly used alloys, in particular in terms of a compromise between the static mechanical strength properties (yield strength, resistance to rupture) and the properties of damage tolerance (toughness, resistance to the propagation of fatigue cracks), these properties being in general antinomic. For thick products, these properties must in particular be obtained at quarter and at mid-thickness and the products must therefore have a low sensitivity to quenching. A product is said to be quench sensitive if its static mechanical characteristics, such as its yield strength, decrease as the quenching rate decreases. The quenching rate is the average cooling rate of the product during quenching.
    These alloys must also have sufficient corrosion resistance, be able to be shaped according to the usual methods and have low residual stresses so that they can be machined integrally.
    Several Al-Cu-Li alloys are known for which an addition of silver is made.
    No. 5,032,359 discloses a broad family of aluminum-copper-lithium alloys in which the addition of magnesium and silver, in particular between 0.3 and 0.5 percent by weight, makes it possible to increase the mechanical strength.
    US Pat. No. 7,229,509 describes an alloy comprising (% by weight): (2.5-5.5) Cu, (0.1-2.5) Li, (0.2-1.0) Mg, (0, 2-0.8) Ag, (0.2-0.8) Mn, 0.4 max Zr or other grain-refining agents such as Cr, Ti, Hf, Sc, V, especially having Kic toughness ( L)> 37.4 MPaVm for an elastic limit Rpo, 2 (L)> 448.2 MPa (products with a thickness greater than 76.2 mm) and in particular a toughness Kic (L)> 38.5 MPaVm for a limit RpO elastic, 2 (L)> 489.5 MPa (products less than 76.2 mm thick). The AA2050 alloy comprises (% by weight): (3.2-3.9) Cu, (0.7-1.3) Li, (0.20-0.6) Mg, (0.20-0 7) Ag, 0.25max. Zn, (0.20-0.50) Mn, (0.06-0.14) Zr and AA2095 (3.7-4.3) Cu, (0.7-1.5) Li, (0.25-0.8) Mg, (0.25-0.6) Ag, 0.25max. Zn, 0.25 max. Mn, (0.04-0.18) Zr. AA2050 alloy products are known for their quality in terms of static strength and toughness, especially for thick rolled products and are selected in some aircraft.
    The patent application WO2009036953 describes an alloy of composition in% by weight Cu 3.4 to 5.0, Li 0.9 to 1.7, Mg 0.2 to 0.8, Ag 0.1 to 0.8 , Mn 0.1 to 0.9, Zn to 1.5, and one or more elements selected from the group consisting of: (Zr about 0.05 to 0.3, Cr about 0.05 to 0.3 , Ti about 0.03 to 0.3, Sc about 0.05 to 0.4, Hf about 0.05 to 0.4), Fe <0.15, Si <0.5, normal and unavoidable impurities and remains of aluminum.
    US patent application 2009/142222 A1 discloses alloys comprising (in% by weight), 3.4 to 4.2% Cu, 0.9 to 1.4% Li, 0.3 to 0.7% of Ag, 0.1 to 0.6% Mg, 0.2 to 0.8% Zn, 0.1 to 0.6% Mn and 0.01 to 0.6% of at least one element. for the control of the granular structure.
    Patent Application WO2011130180 discloses wrought aluminum alloy products comprising (in% by weight) from 2.75 to 5.0% Cu, from 0.2 to 0.8% Mg, where the ratio between the copper to magnesium ratio (Cu / Mg) in the aluminum alloy is in the range of from about 6.1 to about 17, from 0.1 to 1.10% Li, from 0.3 to 2 0% Ag, 0.5 to 1.5% zinc, up to 1.0% Mn, the remainder being aluminum, optional accessory elements, and impurities.
    The patent application WO2013169901 describes aluminum alloys comprising (in% by weight) of 3.5 to 4.4% Cu, 0.45 to 0.75% of Mg, of 0.45 to 0.75% of Zn, 0.65 -1.15% Li, 0.1 to 1.0% Ag, 0.05 to 0.50. % of at least one grain structure control element, up to 1.0% Mn, up to 0.15% Ti, up to 0.12% Si, up to 0, 15% Fe, up to 0.10. % of all other elements, with the total of these other elements not exceeding 0.35%, the rest being aluminum.
    Al-Cu-Li alloys are known in which the addition of silver is optional or is not mentioned.
    No. 5,455,003 discloses a process for manufacturing Al-Cu-Li alloys which have improved mechanical strength and toughness at cryogenic temperature, in particular through proper work-hardening and tempering. This patent recommends in particular the composition, in percentage by weight, Cu = 3.0-4.5, Li = 0.7-1.1, Ag = 0-0.6, Mg = 0.3-0.6. and Zn = 0 - 0.75.
    US Pat. No. 5,211,910 discloses alloys which may comprise (in% by weight) of 1 to 7% of Cu, of 0.1 to 4% of Li, of 0.01 to 4% of Zn, of 0.05 to 3%. Mg, from 0.01 to 2% Ag, from 0.01 to 2% of a grain refiner selected from Zr, Cr, Mn, Ti, Hf, V, Nb, B and TiB2, the remainder being Al with accidental impurities.
    US Pat. No. 5,234,662 describes alloys of composition (in% by weight), Cu: 2.60 -3.30, Mn: 0.0-0.50, Li: 1.30-1.65, Mg: 0, 0 - 1.8, elements controlling the granular structure selected from Zr and Cr: 0.0 - 1.5.
    US5259897 discloses in one embodiment aluminum-based alloys having the compositions in% by weight in the following ranges: 3.5 to 5.0 Cu, 0.8 to 1.8 Li, 0.25 at 1.0 Mg, from 0.01 to 1.5 grain refiner selected from Zr, Cr, Mn, Ti, Hf, V, Nb, B, TiB2, and mixtures thereof, and the remainder being essentially Al.
    US Pat. No. 7,438,772 describes alloys comprising, in percentage by weight, Cu: 3-5, Mg: 0.5-2, Li: 0.01-0.9 and discourages the use of higher lithium content because of degradation of the compromise between toughness and mechanical strength.
    Patent Application WO2009103899 discloses a substantially non-recrystallized laminated product comprising in% by weight: 2.2 to 3.9% by weight of Cu, 0.7 to 2.1% by weight of Li; 0.2 to 0.8% by weight of Mg; 0.2 to 0.5% by weight of Mn; 0.04 to 0.18% by weight of Zr; less than 0.05% by weight of Zn and, optionally, 0.1 to 0.5% by weight of Ag, the remainder being aluminum and unavoidable impurities, having a low propensity for crack bifurcation when a fatigue test in the direction of LS.
    The patent application WO2010149873 relates to a wrought product such as an extruded, rolled and / or forged, aluminum alloy comprising, in% by weight, Cu: 3.0 -3.9; Li: 0.8 to 1.3; Mg 0.6 to 1.0; Zr: 0.05 to 0.18; Ag: 0.0 to 0.5; Mn: 0.0 to 0.5; Fe + Si <0.20; Zn <0.15; at least one of Ti: 0.01 to 0.15; Sc: 0.05 to 0.3; Cr: 0.05 to 0.3; Hf: 0.05 to 0.5; other elements <0.05 each and <0.15 total, the rest being aluminum.
    Patent Application WO2012112942 products with a thickness of at least 12.7 mm of aluminum alloy containing (in% by weight) from 3.00 to 3.80% Cu, from 0.05 to 0.35. % Mg, from 0.975 to 1.385% of Li, in which the Li content is between -0.3 Mg-0.15Cu + 1.65 and -0.3 Mg-0.15Cu + 1.55, of 0, 0.5 to 0.50% of at least one element permitting control of the granular structure, selected from the group consisting of Zr, Sc, Cr, V, Hf, other rare earth elements, and combinations thereof. ci, up to 1.0% Zn, up to 1.0% Mn, up to 0.12% Si, up to 0.15% Fe, up to 0.15% Ti , up to 0.10% of any other element, with the total of these other elements not exceeding 0.35%, remains aluminum.
    It is found that the products according to the prior art made of alloy containing essentially no silver do not make it possible to obtain properties as advantageous as those of products made with alloys containing silver such as AA2050 alloy. In particular, the advantageous compromise between the mechanical strength and the toughness is not achieved for thick products, in particular having a thickness of at least 12 mm or 40 mm, while maintaining satisfactory corrosion resistance. The addition of silver, which is an unusual element in aluminum alloys, could contaminate other alloys during recycling and affect their properties as it has an effect for low levels. Moreover, the limitation of the quantity of money is economically very favorable. Products having a low sensitivity to quenching would also be particularly advantageous.
    There is a need for aluminum-copper-lithium alloy products, especially thick products, having improved properties over those known products containing essentially no silver, especially in terms of trade-offs between strength properties. static mechanics and properties of damage tolerance, thermal stability, corrosion resistance and machinability, while having a low density.
    Object of the invention
    A first subject of the invention is a rolled and / or forged aluminum alloy product comprising, in% by weight,
    Cu: 3.2 - 4.0;
    Li: 0.80 - 0.95;
    Zn: 0.45-0.70;
    Mg: 0.15-0.7;
    Zr 0.07-0.15;
    Mn: 0.1-0.6;
    Ag: <0.15;
    Fe + Si <0.20; at least one of Ti: 0.01-0.15;
    Sc: 0.02-0.1;
    Cr: 0.02-0.1;
    Hf: 0.02-0.5; V: 0.02-0.1 other elements <0.05 each and <0.15 in total, remaining aluminum.
    A second object of the invention is a method of manufacturing a product according to the invention in which a) is developed a liquid metal bath based on aluminum alloy according to the invention; b) pouring a raw form from said bath of liquid metal; c) homogenizing said crude form at a temperature between 450 ° C and 550 ° and preferably between 480 ° C and 530 ° C for a period of between 5 and 60 hours; d) hot deformed and optionally cold deformed said raw form preferably to a thickness of at least 15 mm and preferably at least 40 mm in a rolled product and / or forged; e) is dissolved between 490 and 530 ° C for 15 min to 8 h and said product quenched; f) controlled pulling said product with a permanent deformation of 1 to 7% and preferably at least 4%; g) yielding said product comprising heating at a temperature between 130 and 170 ° C and preferably between 140 and 150 ° C for 5 to 100 hours and preferably 10 to 5 Oh.
    Yet another object of the invention is an aircraft structural element comprising a product according to the invention.
    Description of figures
    FIG. 1 represents the compromise between the elastic limit Rpo, 2 in the direction TL and the toughness Kic in the direction TL for a thickness of 50 mm.
    FIG. 2 represents the compromise between the elastic limit Rpo, 2 in the direction TC and the toughness Kic in the direction SL for a thickness of 50 mm.
    FIG. 3 represents the compromise between the elastic limit Rpo, 2 in the direction TL and the toughness Kic in the direction TL for a thickness of 102 mm.
    FIG. 4 represents the compromise between the elastic limit Rpo, 2 in the direction TC and the toughness Kic in the direction SL for a thickness of 102 mm.
    FIG. 5 represents the compromise between the elastic limit Rpo, 2 in the direction TC and the toughness Kic in the direction SL for a thickness of 130 mm.
    FIG. 6 shows the difference in toughness for quenching conditions as a function of the difference in yield point for these two quenching conditions for the tests of Example 2.
    Description of the invention
    Unless stated otherwise, all the information concerning the chemical composition of the alloys is expressed as a percentage by weight based on the total weight of the alloy. The expression 1.4 Cu means that the copper content expressed in% by weight is multiplied by 1.4. The designation of alloys is in accordance with the regulations of The Aluminum Association, known to those skilled in the art. The definitions of the metallurgical states are given in the European standard EN 515.
    Unless otherwise stated, static mechanical characteristics, in other words the ultimate tensile strength Rm, the conventional yield stress at 0.2% elongation Rpo, 2 ("yield strength") and elongation at break A%, are determined by a tensile test according to EN 10002-1, the sampling and the direction of the test being defined by EN 485-1.
    The stress intensity factor (Kq) is determined according to ASTM E 399. ASTM E 399 gives the criteria for determining whether Kq is a valid Kic value. For a given specimen geometry, the Kq values obtained for different materials are comparable to each other as long as the elasticity limits of the materials are of the same order of magnitude.
    A curve giving the effective stress intensity factor as a function of the effective crack extension, known as the R curve, is determined according to ASTM E 561. The critical stress intensity factor Kc, in others the intensity factor which makes the crack unstable, is calculated from the curve R. The stress intensity factor Kco is also calculated by assigning the initial crack length at the beginning of the monotonic load, to the critical load . These two values are calculated for a specimen of the required form. Kapp represents the Kco factor corresponding to the specimen that was used to perform the R curve test. Keff represents the Kc factor corresponding to the specimen that was used to perform the R curve test.
    Stress corrosion studies were performed according to ASTM G47 and G49 in the TC and TL directions for mid-thickness samples.
    According to the present invention, a selected class of aluminum alloys which contain specific and critical amounts of copper, lithium, magnesium, zinc, manganese and zirconium but do not substantially contain silver allows for the preparation of wrought products with improved compromise between toughness and strength, and good corrosion resistance.
    The present inventors have found that, surprisingly, it is possible for thick products to obtain a compromise at least equivalent between the static mechanical strength properties and the damage tolerance properties that that obtained with an aluminum-copper-lithium alloy. containing silver, such as alloy AA2050, by carefully selecting the amounts of lithium, copper, magnesium, manganese, zinc and zirconium.
    The copper content of the products according to the invention is between 3.2 and 4.0% by weight. In an advantageous embodiment of the invention, the copper content is at least 3.3 or preferably 3.4% by weight and / or at most 3.8 and preferably 3.7% by weight.
    The lithium content of the products according to the invention is between 0.80 and 0.95% by weight. Advantageously, the lithium content is between 0.84% and 0.93% by weight. Preferably, the lithium content is at least 0.86% by weight.
    The silver content is less than 0.15% by weight and preferably less than 0.05% by weight. The present inventors have found that the advantageous compromise between known mechanical strength and damage tolerance for alloys typically containing 0.3 to 0.4% by weight of silver can be obtained for alloys containing essentially no silver. with the composition selection made.
    The magnesium content of the products according to the invention is between 0.15 and 0.7% by weight and preferably between 0.2 and 0.6% by weight. Advantageously, the magnesium content is at least 0.30% by weight, preferably at least 0.34% by weight and preferably at least 0.38% by weight. The present inventors have found that when the magnesium content is less than 0.30% by weight the advantageous compromise between the mechanical strength and the damage tolerance is not obtained for the highest thicknesses, in particular the thicknesses greater than 76 mm. The present inventors have found that for the lowest levels of magnesium, the presence of a small amount of silver may be advantageous, preferentially the magnesium content is at least 0.3 - 1.5 Ag. In one embodiment of the invention, the magnesium content is at most 0.45% by weight and preferably at most 0.43% by weight.
    The zinc content is between 0.45 and 0.70% by weight. Advantageously, the zinc content is between 0.50 and 0.60% by weight, which can contribute to achieving the desired compromise between toughness and mechanical strength.
    The zirconium content is between 0.07 and 0.15% by weight and preferably between 0.09 and 0.12% by weight.
    The manganese content is between 0.1 and 0.6% by weight. Advantageously, the manganese content is between 0.2 and 0.4% by weight to improve the toughness without compromising the mechanical strength. In the absence of manganese addition, the compromise sought is not achieved.
    The sum of the iron content and the silicon content is at most 0.20% by weight. Preferably, the iron and silicon contents are each at most 0.08% by weight. In an advantageous embodiment of the invention, the iron and silicon contents are at most 0.06% and 0.04% by weight, respectively. The alloy also contains at least one element that can contribute to controlling the grain size selected from V, Cr, Sc, Hf and Ti, the amount of the element, if selected, being from 0.02 to 0 , 1% by weight for V, Cr and Sc, 0.02 to 0.5% by weight for Hf and 0.01 to 0.15% by weight for Ti. Preferably, between 0.02 and 0.10% by weight of titanium is chosen. The alloy according to the invention is particularly intended for the manufacture of thick rolled products. By thick products is meant in the context of the present invention, products whose thickness is at least 12 mm and preferably at least 40 mm.
    In an advantageous embodiment, the rolled products according to the invention have a thickness of at least 76 mm or even at least 121 mm.
    The thick products according to the invention have a compromise between mechanical strength and particularly advantageous toughness.
    The products according to the invention have, in a rolled state, dissolved, quenched, triturated and returned at least one of the following pairs of characteristics for thicknesses between 40 and 75 mm: (i) at quarter-thickness, a limit of elasticity Rpo, 2 (TL)> 480 MPa and preferably
    Rpo, 2 (TL)> 490 MPa and a toughness Kic (TL)> 31 MPaVm and advantageously such that Kic (TL)> - 0.175 Rpo, 2 (TL) + 119.2, preferably Kic (TL)> - 0.175 Rpo, 2 (TL) + 120.5 and preferably Kic (TL)> - 0.175 Rpo, 2 (TL) + 121.5, (ii) at mid-thickness, a yield strength Rpo, 2 (TC) )> 450 MPa and preferably
    Rpo, 2 (TC)> 455 MPa and a Kic (SL) toughness> 24 MPaVm and advantageously such that Kic (SL)> - 0.34 Rpo, 2 (TC) + 185.6, preferably Kic (SL)> - 0.34 Rpo, 2 (TC) + 187.2 and preferably Kic (SL)> - 0.34 RPo, 2 (TC) + 188.7.
    The products according to the invention in which the magnesium content is at least 0.34% by weight and preferably at least 0.38% by weight and the silver content is less than 0.05% by weight are advantageous and exhibit in a laminate state, dissolved, quenched, triturated and returned at least one of the following pairs of characteristics for thicknesses between 76 and 150 mm: (i) for thicknesses of 76 to 120 mm, at quarter-thickness, elasticity limit
    Rpo, 2 (TL)> 460 MPa and preferably Rpo, 2 (TL)> 470 MPa and advantageously a toughness Kic (TL)> 27 MPaVm and such that Kic (TL)> - 0.1 Rpo, 2 (TL) +77, preferably Kic (TL)> 0.1 Rpo, 2 (TL) + 78 and preferably Kic (TL)> 0.1 Rpo, 2 (TL) + 79, (ii) for thicknesses from 76 to 120 mm, at mid-thickness, a yield strength Rpo, 2 (TC)> 435 MPa and preferably Rpo, 2 (TC)> 445 MPa and a toughness Kic (SL)> 23 MPaVm and advantageously such that Kic (SL)> - 0.25 RPo, 2 (TC) + 139.25, preferably Kic (SL)> - 0.25 Rpo, 2 (TC) + 140.85 and preferably Kic (SL)> - 0.25 Rpo, 2 (TC) + 142.45, (iii) for thicknesses from 121 to 150 mm, at mid-thickness, a yield strength Rpo, 2 (TC)> 420 MPa and preferably RPo , 2 (TC)> 425 MPa and a Kic (SL) toughness> 20 MPaVm and advantageously such that Kic (SL)> - 0.25 Rpo, 2 (TC) + 133, preferably Kic (SL)> - 0, Rpo, 2 (TC) + 133, 5 and most preferably Kic (SL)> - 0.25 Rpo, 2 (TC) + 134.
    The products according to the invention also have advantageous properties in terms of toughness as measured according to the ASTM E561 standard. Thus, the products according to the invention have, in a laminated, solution-treated, quenched, triturated and tempered state, at least one of the following pairs of characteristics for thicknesses between 40 and 150 mm, the Kapp plane stress toughness being measured on specimens of the CCT406 type (2ao = 101.6 mm) (i) for thicknesses of 40 to 75 mm Kapp, in the LT direction of at least 105 MPa Vm and preferably at least 110 MPa Vm and a limit of elasticity Rpo, 2 (L) of at least 500 MPa and preferably at least 510 MPa, (ii) for thicknesses of 40 to 75 mm Kapp, in the TL direction of at least 60 MPa Vm, and preferably at least 70 MPa Vm and an elastic limit Rpo, 2 (TL) of at least 480 MPa and preferably at least 490 MPa, (iii) for thicknesses of 76 to 120 mm Kapp, in the LT direction of at least 80 MPa Vm and preferably at least 90 MPa Vm and a yield strength RPo, 2 (L) of at least 475 MPa and preferably at least 485 MPa, (iv) for thicknesses of 76 to 120 mm Kapp, in the TL direction of at least 40 MPa Vm and preferably at least 50 MPa Vm and a yield strength Rpo , 2 (TL) of at least 455 MPa and preferably at least 465 MPa, (v) for thicknesses of 121 to 150 mm KaPP ,, in the LT direction of at least 75 MPa Vm and preferably of at least 80 MPa Vm and an elastic limit Rpo, 2 (L) of at least 470 MPa and preferably at least 480 MPa, (vi) for thicknesses of 121 to 150 mm Kapp, in the TL direction of at least 40 MPa Vm and preferably at least 45 MPa Vm and a yield strength Rpo, 2 (TL) of at least 445 MPa and preferably at least 455 MPa,
    The resistance to stress corrosion of the products of the invention is generally high; advantageously the number of days before failure tested according to the standards ASTM G47 and G49 at mid-thickness for a stress of 350 MPa in the direction TC is at least 30 days and preferably, especially for sheets whose thickness is between 40 and 75 mm, the number of days before failure for a stress of 450 MPa in the TC direction is at least 30 days.
    The manufacturing process of the products according to the invention comprises steps of production, casting, rolling and / or forging, solution, quenching, pulling and tempering.
    In a first step, a bath of liquid metal is produced so as to obtain an aluminum alloy of composition according to the invention.
    The liquid metal bath is then cast in a raw form typically a rolling plate or a forging blank.
    The crude form is then homogenized at a temperature between 450 ° C and 550 ° and preferably between 480 ° C and 530 ° C for a period between 5 and 60 hours.
    After homogenization, the raw form is generally cooled to room temperature before being preheated for hot deformation. Preheating aims to achieve a temperature preferably between 400 and 550 ° C and preferably of the order of 500 ° C allowing the deformation of the raw form.
    The hot deformation is carried out by rolling and / or forging so as to obtain a rolled and / or forged product the thickness of which is preferably at least 12 mm and preferably at least 40 mm. The product thus obtained is then dissolved by heat treatment at 490-550 ° C for 15 minutes to 8 hours, and then typically quenched with water at room temperature. The product then undergoes controlled traction with a permanent deformation of 1 to 7% and preferably of at least 2%. The rolled products preferably undergo a controlled pull with a permanent deformation of at least 4%. In an advantageous embodiment of the invention, which makes it possible in particular to improve the compromise between static mechanical strength and toughness, controlled traction is achieved with a permanent deformation of between 5 and 7%. The preferred metallurgical states are the T84 and T86 states, preferentially T86. Known steps such as rolling, planing, straightening shaping may optionally be performed after solution and quenching and before or after controlled pulling. In one embodiment of the invention, a cold rolling step of at least 7% and preferably at least 9% is carried out before achieving a controlled pull with a permanent deformation of 1 to 3%.
    An income is achieved comprising heating at a temperature between 130 and 170 ° C and preferably between 140 and 150 ° C for 5 to 100 hours and preferably 10 to 50h. The present inventors have found that the compromise between strength and toughness can be improved by achieving income in the preferred area. In an advantageous embodiment, the controlled traction is carried out with a permanent deformation comprised between 5 and 7% and the income is produced at a temperature of between 140 and 150 ° C. for a period of 10 to 30 hours.
    The products according to the invention can advantageously be used in structural elements, in particular aircraft. Here, a "structural element" or "structural element" of a mechanical construction is called a mechanical part for which the static and / or dynamic mechanical properties are particularly important for the performance of the structure, and for which a structural calculation is usually prescribed or realized. These are typically elements whose failure is likely to endanger the safety of said construction, its users, its users or others. In the context of the present invention these aircraft structural elements include bulkheads (bulkheads), the wings (such as the wing skin), the ribs and spars. including tail stabilizers horizontal and vertical stabilizers (horizontal or vertical stabilizers), and doors. The use of a structural element incorporating at least one product according to the invention or manufactured from such a product is advantageous, in particular for aeronautical construction. The products according to the invention are particularly advantageous for producing products that are machined in the mass, such as, in particular, intrados or extrados elements whose skin and stiffeners come from the same starting material, longitudinal members and ribs, and than any other use where the present properties could be advantageous
    These and other aspects of the invention are explained in more detail with the aid of the following illustrative and non-limiting examples.
    Examples
    Example 1
    In this example, several 400 mm thick plates whose composition is given in Table 1 were cast.
    Table 1: Composition in% by weight of Al-Cu-Li alloys cast in plate form.
    The plates were homogenized at about 500 ° C for about 12 hours and then scalped. The plates were hot-rolled to obtain sheets having a thickness of 50 mm, 102 mm or 130 mm. The sheets were dissolved at 527 ° C and quenched with cold water. The sheets were then tractionned with a permanent elongation of 4% or 6%.
    The sheets were tempered at 145 ° C or 150 ° C. Samples were taken at 1/4-thickness to measure tensile static mechanical characteristics and toughness in L, TL, LT and TL directions at 1/2-thickness to measure tensile static mechanical characteristics and toughness in TC and SL directions. The specimens used for the tenacity measurement were CT geometry specimens and had dimensions as described below:
    The results obtained are shown in Table 2 and Table 3.
    Table 2: Static mechanical properties obtained for the different sheets.
    Table 3: K1C toughness properties
    obtained for the different sheets.
    The results are illustrated in Figures 1 to 2 (thickness 50 mm) and 3 to 4 (thickness 102 mm) and 5 (thickness 130 mm).
    The results of stress corrosion tests obtained are shown in Table 4 below.
    Table 4: Results of stress corrosion tests Example 2
    In this example, several plates 120 mm thick whose composition is given in Table 5 were cast.
    Table 5: Composition in weight% Al-Cu-Li cast in plate form.
    The plates have been machined up to 100 mm thickness. The plates were homogenized at about 500 ° C for about 12 hours and then scalped. After homogenization, the plates were hot-rolled to obtain sheets having a thickness of 27 mm. The sheets were dissolved and quenched with cold water or with water at 90 ° C so as to vary the quenching speed and tractionnées with a permanent elongation of 3.5%.
    The sheets were tempered between 15 h and 50 h at 155 ° C. Samples were taken at mid-thickness to measure the static mechanical characteristics in tension
    as well as toughness Kq. The test specimens used for tenacity measurement in the T - L direction had a width W = 50 mm and a thickness B = 25 mm. Kic validity criteria were met for all samples. For the S-L direction, measurements were made on specimens of width W = 36 mm and thickness B = 25.4 mm. The results obtained are shown in Tables 6 and 7.
    Table 6: Mechanical properties obtained for the various sheets after quenching with water at 90 ° C.
    Table 7: Mechanical properties obtained for the various sheets after quenching with water at 25 ° C.
    Figure 6 shows the decrease in property (strength, toughness) for quenching in water at 90 ° C in percent from the quenched value with water at 25 ° C. Composition 61 is the least quench sensitive with respect to toughness and composition 58 is the least quench sensitive with respect to the yield strength.
    Example 3
    In this example, the effect of the conditions of controlled traction and of income on the toughness results Kapp and Keff measured by a curve R.
    Plates with a thickness of 50 mm and 102 mm were obtained with the alloys 56 and 71 of Table 1. The sheets were dissolved at 527 ° C. and quenched with cold water. The alloy sheets 56 were then tractionned with a permanent elongation of 4% and the alloy sheets 71 were tractionned with a permanent elongation of 6%.
    The alloy sheets 56 were then tempered for 40 hours at 150 ° C and the alloy sheets 71 were tempered for 20 hours at 150 ° C.
    Samples were taken at 2 / thickness for 50 mm thick and 1/4-thick sheets for 102 mm and 130 mm thick sheets to measure
    tensile static mechanical characteristics and KaPP and Keff plane stress toughness in the L, TL, LT and TL directions For the tenacity, the curve R was measured on CCT test pieces of width W = 406 mm and thickness B = 6.35 mm.
    The results obtained are given in Table 8 below.
    Table 8: Measured mechanical properties
    The combination of controlled traction with permanent deformation of 6% and 20 hours at 150 ° C is particularly advantageous.
    权利要求:
    Claims (15)
    [1" id="c-fr-0001]
    claims
    1. A rolled and / or forged aluminum alloy product comprising, in% by weight, Cu: 3.2-4.0; Li: 0.80 - 0.95; Zn: 0.45-0.70; Mg: 0.15-0.7; Zr 0.07-0.15; Mn: 0.1-0.6; Ag: <0.15; Fe + Si <0.20; at least one of Ti: 0.01-0.15; Sc: 0.02-0.1; Cr: 0.02-0.1; Hf: 0.02-0.5; V: 0.02-0.1 other elements <0.05 each and <0.15 in total, remaining aluminum.
    [2" id="c-fr-0002]
    2. The product of claim 1 wherein the magnesium content is at most 0.55 - 1.5 Ag.
    [3" id="c-fr-0003]
    3. Product according to claim 1 or claim 2 wherein the copper content is between 3.3 and 3.8% by weight and preferably between 3.4 and 3.7% by weight.
    [4" id="c-fr-0004]
    4. Product according to any one of claims 1 to 3 wherein the zinc content is between 0.50 and 0.60% by weight.
    [5" id="c-fr-0005]
    5. Product according to any one of claims 1 to 4 wherein the manganese content is between 0.2 and 0.4% by weight.
    [6" id="c-fr-0006]
    6. Product according to any one of claims 1 to 5 wherein the lithium content is between 0.84% and 0.93% by weight and preferably the lithium content is at least 0.86% by weight. .
    [7" id="c-fr-0007]
    7. Product according to any one of claims 1 to 6, the thickness of which is at least 12 mm and preferably at least 40 mm.
    [8" id="c-fr-0008]
    8. Product according to any one of claims 1 to 7 in a rolled, dissolved, quenched, quenched and tempered state having at least one of the following pairs of characteristics for thicknesses between 40 and 75 mm: (i) at quarterly thickness, a yield strength Rpo, 2 (TL)> 480 MPa and preferably Rpo, 2 (TL)> 490 MPa and a toughness Kic (TL)> 31 MPaVm and advantageously such that Kic (TL)> - 0.175 Rpo , 2 (TL) + 119.2, preferably Kic (TL)> - 0.175 Rpo, 2 (TL) + 120.5 and most preferably Kic (TL)> - 0.175 Rp0.2 (TL) + 121.5 (ii) at mid-thickness, a yield strength Rpo, 2 (TC)> 450 MPa and preferably Rpo, 2 (TC)> 455 MPa and a toughness Kic (SL)> 24 MPaVm and advantageously such that Kic (SL)> 0.34 Rpo (iiTC) + 185.6, preferably Kic (SL)> 0.34 Rpo, 2 (TC) + 187.2 and preferably Kic (SL)> 0.34 Rpo, 2 (TC) + 188.7.
    [9" id="c-fr-0009]
    9. Product according to any one of claims 1 to 8 having in a rolled state, dissolved, quenched, tractionned and returned at least one of the following pairs of characteristics for thicknesses between 40 and 150 mm, KaPP plane stress toughness being measured on specimens of the CCT406 type, 2ao = 101.6 mm, (i) for thicknesses of 40 to 75 mm KaPP ,, in the LT direction of at least 105 MPa Vm and preferably at least 110 MPa Vm and a yield strength Rpo, 2 (L) of at least 500 MPa and preferably at least 510 MPa, (ii) for thicknesses of 40 to 75 mm KaPP ,, in the TL direction of at least 60 MPa Vm and preferably at least 70 MPa Vm and a yield strength RjjoXTL) of at least 480 MPa and preferably at least 490 MPa, (iii) for thicknesses of 76 to 120 mm Kapp ,, in the LT direction of at least 80 MPa Vm and preferably at least 90 MPa Vm and an elasti limit cited Rpo, 2 (L) of at least 475 MPa and preferably at least 485 MPa, (iv) for thicknesses of 76 to 120 mm Kapp, in the TL direction of at least 40 MPa Vm, and preferably at least 50 MPa Vm and a yield strength Rpo, 2 (TL) of at least 455 MPa and preferably at least 465 MPa, (v) for thicknesses of 121 to 150 mm Kapp, in the LT direction of at least 75 MPa Vm and preferably at least 80 MPa Vm and a yield strength Rpo, 2 (L) of at least 470 MPa and preferably at least 480 MPa, ( vi) for thicknesses from 121 to 150 mm Kapp, in the TL direction of at least 40 MPa Vm and preferably at least 45 MPa Vm and a yield strength Rpo, 2 (TL) of at least 445 MPa and preferably at least 455 MPa,
    [10" id="c-fr-0010]
    The product of any one of claims 1 to 9 wherein the magnesium content is at least 0.34% by weight and the silver content is less than 0.05% by weight.
    [11" id="c-fr-0011]
    11. Product according to claim 10 in a laminate, dissolved, quenched, triturated and tempered state having at least one of the following pairs of characteristics for thicknesses between 76 and 150 mm: (i) for thicknesses of 76 to 120 mm, at quarter thickness, a yield strength Rpo, 2 (TL)> 460 MPa and preferably Rpo, 2 (TL)> 470 MPa and a toughness Kic (TL)> 27 MPaVm and advantageously such that Kic (TL )> 0.1 Rpo, 2 (TL) + 77, preferably Kic (TL)> 0.1 Rpo, 2 (TL) + 78 and preferably Kic (TL)> 0.1 Rp 0.2 (TL) + 79, (ii) for thicknesses of 76 to 120 mm, at mid-thickness, a yield strength RPo, 2 (TC)> 435 MPa and preferably Rpo, 2 (TC)> 445 MPa and Kic (SL) toughness> 23MPaVm and advantageously such that Kic (SL)> 0.25 RPo, 2 (TC) + 139.25, preferably Kic (SL)> -0.25 Rpo, 2 (TC) + 140.85 and preferably Kic (SL)> - 0.25 Rpo, 2 (TC) + 142.45, (iii) for thicknesses from 121 to 150 mm, at mid-thickness, a yield strength Rpo, 2 (TC)> 420 MPa and preferably Rpo, 2 (TC)> 425 MPa and a toughness Kic (SL)> 20 MPaVm and advantageously such that Kic ( SL)> - 0.25 Rpo, 2 (TC) + 133, preferably Kic (SL)> - 0.25 Rpo, 2 (TC) + 133, and preferably Kic (SL)> - 0.25 Rpo, 2 (TC) + 134.
    [12" id="c-fr-0012]
    12. A product according to any one of claims 1 to 11 in a rolled, dissolved, quenched and tempered state having the number of days before failure tested to ASTM G47 and G49 at mid-thickness for a stress of 350 MPa in the TC direction is at least 30 days and preferably, especially for sheets whose thickness is between 40 and 75 mm, the number of days before failure for a stress of 450 MPa in the TC direction is at least 30 days.
    [13" id="c-fr-0013]
    13. A process for manufacturing a laminated and / or forged aluminum alloy product in which a) an aluminum alloy liquid metal bath according to any one of claims 1 to 10 is produced; b) pouring a raw form from said bath of liquid metal; c) homogenizing said crude form at a temperature between 450 ° C and 550 ° and preferably between 480 ° C and 530 ° C for a period of between 5 and 60 hours; d) hot deformed and optionally cold deformed said raw form preferably to a thickness of at least 15 mm and preferably at least 40 mm in a rolled product and / or forged; e) is dissolved between 490 and 530 ° C for 15 min to 8 h and said product quenched; f) controlled pulling said product with a permanent deformation of 1 to 7% and preferably at least 4%; g) yielding said product comprising heating at a temperature between 130 and 170 ° C and preferably between 140 and 150 ° C for 5 to 100 hours and preferably 10 to 5 Oh.
    [14" id="c-fr-0014]
    14. The method of claim 13 wherein the controlled traction is carried out with a permanent deformation of between 5 and 7% and the duration of income is between 10 and 30 hours.
    [15" id="c-fr-0015]
    15. Aircraft structure element, preferably intrados or extrados element whose skin and the stiffeners come from the same starting material, a spar or a rib, comprising a product according to any one of claims 1 to 12.
    类似技术:
    公开号 | 公开日 | 专利标题
    EP2449142B1|2017-05-03|Aluminium-copper-lithium alloy with improved mechanical resistance and toughness
    EP2655680B1|2019-05-22|Aluminium-copper-lithium alloy with improved compressive strength and toughness
    EP3384061B1|2020-02-05|Aluminium-copper-lithium alloy having improved mechanical strength and improved toughness
    EP3201372B1|2021-01-27|Isotropic sheets of aluminium-copper-lithium alloys for the fabrication of fuselages of aircrafts and method of manuacturing same
    CA2798480C|2018-01-16|Aluminum-copper-lithium alloy for lower surface element
    CA2907854C|2021-07-13|Thin sheets made of an aluminium-copper-lithium alloy for producing airplane fuselages
    EP3011068A1|2016-04-27|Extrados structural element made from an aluminium copper lithium alloy
    WO2010055225A1|2010-05-20|Products made of an aluminium-copper-lithium alloy
    EP2981631A1|2016-02-10|Aluminium-copper-lithium alloy sheets for producing aeroplane fuselages
    FR3068370A1|2019-01-04|AL-ZN-CU-MG ALLOYS AND PROCESS FOR PRODUCING THE SAME
    EP3788178A1|2021-03-10|Aluminium-copper-lithium alloy having improved compressive strength and improved toughness
    WO2018189471A1|2018-10-18|Aluminium-copper-lithium alloy products
    WO2019211546A1|2019-11-07|Method for manufacturing an aluminum-copper-lithium alloy with improved compressive strength and improved toughness
    同族专利:
    公开号 | 公开日
    CA3006871A1|2017-06-08|
    EP3384061B1|2020-02-05|
    BR112018010380B1|2021-09-14|
    FR3044682B1|2018-01-12|
    US20180363114A1|2018-12-20|
    EP3384061A1|2018-10-10|
    CN108291281A|2018-07-17|
    WO2017093680A1|2017-06-08|
    CN108291281B|2021-08-06|
    BR112018010380A2|2018-12-04|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    FR2947282A1|2009-06-25|2010-12-31|Alcan Rhenalu|LITHIUM COPPER ALUMINUM ALLOY WITH IMPROVED MECHANICAL RESISTANCE AND TENACITY|
    WO2012112942A2|2011-02-17|2012-08-23|Alcoa Inc.|2xxx series aluminum lithium alloys|WO2019211546A1|2018-05-02|2019-11-07|Constellium Issoire|Method for manufacturing an aluminum-copper-lithium alloy with improved compressive strength and improved toughness|US5455003A|1988-08-18|1995-10-03|Martin Marietta Corporation|Al-Cu-Li alloys with improved cryogenic fracture toughness|
    US5393357A|1992-10-06|1995-02-28|Reynolds Metals Company|Method of minimizing strength anisotropy in aluminum-lithium alloy wrought product by cold rolling, stretching and aging|
    US8673209B2|2007-05-14|2014-03-18|Alcoa Inc.|Aluminum alloy products having improved property combinations and method for artificially aging same|
    CN102021457B|2010-10-27|2012-06-27|中国航空工业集团公司北京航空材料研究院|High-toughness aluminum lithium alloy and preparation method thereof|
    CN101967588B|2010-10-27|2012-08-29|中国航空工业集团公司北京航空材料研究院|Damage-resistant aluminum-lithium alloy and preparation method thereof|
    FR2969177B1|2010-12-20|2012-12-21|Alcan Rhenalu|LITHIUM COPPER ALUMINUM ALLOY WITH ENHANCED COMPRESSION RESISTANCE AND TENACITY|
    FR2981365B1|2011-10-14|2018-01-12|Constellium Issoire|PROCESS FOR THE IMPROVED TRANSFORMATION OF AL-CU-LI ALLOY SHEET|
    US10253404B2|2014-10-26|2019-04-09|Kaiser Aluminum Fabricated Products, Llc|High strength, high formability, and low cost aluminum-lithium alloys|CA3013955A1|2016-02-09|2017-08-17|Aleris Rolled Products Germany Gmbh|Al-cu-li-mg-mn-zn alloy wrought product|
    CA3117862A1|2018-11-07|2020-05-14|Arconic Technologies Llc|2xxx aluminum lithium alloys|
    CN110952011B|2019-11-22|2021-01-05|天津忠旺铝业有限公司|2-series high-damage-tolerance aluminum alloy plate and preparation method thereof|
    CN111304503A|2020-03-12|2020-06-19|江苏豪然喷射成形合金有限公司|Low-density damage-resistant aluminum-lithium alloy for aircraft wheel and preparation method thereof|
    法律状态:
    2016-12-27| PLFP| Fee payment|Year of fee payment: 2 |
    2017-06-09| PLSC| Publication of the preliminary search report|Effective date: 20170609 |
    2017-12-27| PLFP| Fee payment|Year of fee payment: 3 |
    2019-12-26| PLFP| Fee payment|Year of fee payment: 5 |
    2020-12-27| PLFP| Fee payment|Year of fee payment: 6 |
    2021-12-27| PLFP| Fee payment|Year of fee payment: 7 |
    优先权:
    申请号 | 申请日 | 专利标题
    FR1561852|2015-12-04|
    FR1561852A|FR3044682B1|2015-12-04|2015-12-04|LITHIUM COPPER ALUMINUM ALLOY WITH IMPROVED MECHANICAL RESISTANCE AND TENACITY|FR1561852A| FR3044682B1|2015-12-04|2015-12-04|LITHIUM COPPER ALUMINUM ALLOY WITH IMPROVED MECHANICAL RESISTANCE AND TENACITY|
    CN201680071033.2A| CN108291281B|2015-12-04|2016-12-01|Aluminum-copper-lithium alloy with improved mechanical strength and toughness|
    EP16819147.6A| EP3384061B1|2015-12-04|2016-12-01|Aluminium-copper-lithium alloy having improved mechanical strength and improved toughness|
    CA3006871A| CA3006871A1|2015-12-04|2016-12-01|Aluminium-copper-lithium alloy having improved mechanical strength and improved toughness|
    PCT/FR2016/053175| WO2017093680A1|2015-12-04|2016-12-01|Aluminium-copper-lithium alloy having improved mechanical strength and improved toughness|
    BR112018010380-2A| BR112018010380B1|2015-12-04|2016-12-01|LAMINATED AND/OR FORGED PRODUCT IN ALUMINUM ALLOY COPPER LITHIUM WITH IMPROVED MECHANICAL RESISTANCE AND TENACITY, ITS MANUFACTURING PROCESS AND AIRPLANE STRUCTURE ELEMENT|
    US15/780,273| US20180363114A1|2015-12-04|2016-12-01|Aluminum copper lithium alloy with improved mechanical strength and toughness|
    [返回顶部]