EP0325937A1 - Aluminium-Lithium-Legierungen - Google Patents

Aluminium-Lithium-Legierungen Download PDF

Info

Publication number
EP0325937A1
EP0325937A1 EP89100355A EP89100355A EP0325937A1 EP 0325937 A1 EP0325937 A1 EP 0325937A1 EP 89100355 A EP89100355 A EP 89100355A EP 89100355 A EP89100355 A EP 89100355A EP 0325937 A1 EP0325937 A1 EP 0325937A1
Authority
EP
European Patent Office
Prior art keywords
alloy
product
strength
toughness
fracture toughness
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP89100355A
Other languages
English (en)
French (fr)
Other versions
EP0325937B1 (de
Inventor
Roberto J. Rioja
Alex Cho
Edward L. Colvin
Asuri Vasudevan
Philip E. Bertz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Howmet Aerospace Inc
Original Assignee
Aluminum Company of America
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US07/149,802 external-priority patent/US5137686A/en
Priority claimed from US07/172,506 external-priority patent/US4961792A/en
Application filed by Aluminum Company of America filed Critical Aluminum Company of America
Publication of EP0325937A1 publication Critical patent/EP0325937A1/de
Application granted granted Critical
Publication of EP0325937B1 publication Critical patent/EP0325937B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon
    • C22F1/057—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon of alloys with copper as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C21/00—Alloys based on aluminium
    • C22C21/12—Alloys based on aluminium with copper as the next major constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
    • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
    • C22F1/04—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of aluminium or alloys based thereon

Definitions

  • This invention relates to aluminum base alloys, and more particularly, it relates to improved lithium containing aluminum base alloys, products made therefrom and methods of producing the same.
  • More desirable alloys would permit increased strength with only minimal or no decrease in toughness or would permit processing steps wherein the toughness was controlled as the strength was increased in order to provide a more desirable combination of strength and toughness. Additionally, in more desirable alloys, the combination of strength and toughness would be attainable in an aluminum-lithium alloy having density reductions in the order of 5 to 15%. Such alloys would find widespread use in the aerospace industry where low weight and high strength and toughness translate to high fuel savings. Thus, it will be appreciated that obtaining qualities such as high strength at little or no sacrifice in toughness, or where toughness can be controlled as the strength is increased would result in a remarkably unique aluminum-lithium alloy product.
  • U.S. Patent 4,626,409 discloses aluminum base alloy consisting of, by wt.%, 2.3 to 2.9 Li, 0.5 to 1.0 Mg, 1.6 to 2.4 Cu, 0.05 to 0.25 Zr, 0 to 0.5 Ti, 0 to 0.5 Mn, 0 to 0.5 Ni, 0 to 0.5 Cr and 0 to 2.0 Zn and a method of producing sheet or strip therefrom.
  • U.S. Patent 4,582,544 discloses a method of superplastically deforming an aluminum alloy having a composi­tion similar to that of U.S. Patent 4,626,409.
  • European Patent Application 210112 discloses an aluminum alloy product containing 1 to 3.5 wt.% Li, up to 4 wt.% Cu, up to 5 wt.% Mg, up to 3 wt.% Zn and Mn, Cr and/or Zr additions.
  • the alloy product is recrystallized and has a grain size less than 300 micrometers.
  • U.S. Patent 4,648,913 discloses aluminum base alloy wrought product having improved strength and fracture toughness combinations when stretched, for example, an amount greater than 3%.
  • the present invention provides an improved lithium containing aluminum base alloys which permit products having improved strength characteristics while retaining high toughness properties.
  • the present invention provides an improved lithium containing aluminum base alloy product which can be processed to improve strength characteristics while retaining high toughness properties or which can be processed to provide a desired strength at a controlled level of toughness.
  • the alloy of the present invention can contain 0.2 to 5.0 wt.% Li, 0.5 to 6.0 wt.% Mg, at least 2.45 wt.% Cu, 0.05 to 12 wt.% Zn, 0.01 to 0.14 wt.% Zr, 0.5 wt.% max. Fe, 0.5 wt.% max. Si, the balance aluminum and incidental impurities.
  • the impurities are preferably limited to about 0.05 wt.% each, and the combination of impurities preferably should not exceed 0.35 wt.%. Within these limits, it is preferred that the sum total of all impurities does not exceed 0.15 wt.%.
  • a preferred alloy in accordance with the present invention can contain 1.5 to 3.0 wt.% Li, 2.5 to 2.95 wt.% Cu, 0.2 to 2.5 wt.% Mg, 0.2 to 11 wt.% Zn, 0.08 to 0.12 wt.% Zr, the balance aluminum and impurities as specified above.
  • a typical alloy composition would contain 1.8 to 2.5 wt.% Li, 2.55 to 2.9 wt.% Cu, 0.2 to 2.0 wt.% Mg, 0.2 to 2.0 wt.% Zn, greater than 0.1 to less than 0.16 wt.% Zr, and max. 0.1 wt.% of each of Fe and Si.
  • a suitable alloy composition would contain 1.9 to 2.4 wt.% Li, 2.55 to 2.9 wt.% Cu, 0.1 to 0.6 wt.% Mg, 0.5 to 1.0 wt.% Zn, 0.08 to 0.12 wt.% Zr, max. 0.1 wt.% of each of Fe and Si, the remainder aluminum.
  • an aluminum base alloy wrought product having improved combinations of strength, fracture toughness and corrosion resistance is provided.
  • the product can be produced in a condition suitable for aging and has the ability to develop improved strength in response to aging treatments without substantially impairing fracture toughness properties or corrosion resistance.
  • the product comprises 0.2 to 5.0 wt.% Li, 0.05 to 6.0 wt.% Mg, at least 2.45 wt.% Cu, 0.05 to 0.16 wt.% Zr, 0.05 to 12 wt.% Zn, 0.5 wt.% max. Fe, 0.5 wt.% max. Si, the balance aluminum and incidental impurities.
  • the product is capable of having imparted thereto a working effect equivalent to stretching so that the product has combinations of improved strength and fracture toughness after aging.
  • a body of a lithium containing aluminum base alloy is provided and may be worked to produce a wrought aluminum product.
  • the wrought product may be first solution heat treated and then stretched or otherwise worked amount equivalent to stretching.
  • the degree of working as by stretching is normally greater than that used for relief or residual internal quenching stresses.
  • the alloy of the present invention can contain 0.2 to 5.0 wt.% Li, 0 to 5.0 wt.% Mg, up to 5.0 wt.% Cu, 0 to 1.0 wt.% Zr, 0 to 2.0 wt.% Mn, 0.05 to 12.0 wt.% Zn, 0.5 wt.% max. Fe, 0.5 wt.% max. Si, the balance aluminum and incidental impurities.
  • the impurities are preferably limited to about 0.05 wt.% each, and the combination of impurities preferably should not exceed 0.15 wt.%. Within these limits, it is preferred that the sum total of all impurities does not exceed 0.35 wt.%.
  • a preferred alloy in accordance with the present invention can contain 0.2 to 5.0 wt.% Li, at least 2.45 wt.% Cu, 0.05 to 5.0 wt.% Mg, 0.05 to 0.16 wt.% Zr, 0.05 to 12.0 wt.% Zn, the balance aluminum and impurities as specified above.
  • a typical alloy composition would contain 1.5 to 3.0 wt.% Li, 2.55 to 2.90 wt.% Cu, 0.2 to 2.5 wt.% Mg, 0.2 to 11.0 wt.% Zn, 0.08 to 0.12 wt.% Zr, 0 to 1.0 wt.% Mn and max. 0.1 wt.% of each of Fe and Si.
  • Zn may be in the range of 0.2 to 2.0 and Mg 0.2 to 2.0 wt.%.
  • lithium is very important not only because it permits a significant decrease in density but also because it improves tensile and yield strengths markedly as well as improving elastic modulus. Additionally, the presence of lithium improves fatigue resistance. Most significantly though, the presence of lithium in combination with other controlled amounts of alloying elements permits aluminum alloy products which can be worked to provide unique combinations of strength and fracture toughness while maintaining meaningful reductions in density.
  • alloying elements such as Cu and Mn, for example. Accordingly, while lithium is the most important element for saving weight, the other elements are important in order to provide the proper levels of strength, fracture toughness, corrosion and stress corrosion cracking resistance.
  • copper should be less than 3.0 wt.%; however, in a less preferred embodiment, copper can be increased to less than 4.0 wt.% and preferably less than 3.5 wt.%.
  • the combination of lithium and copper should not exceed 5.5 wt.% with lithium being at least 1.5wt.% with greater amounts of lithium being preferred.
  • Magnesium is added or provided in this class of aluminium alloys mainly for purposes of increasing strength although it does decrease density slightly and is advantageous from that standpoint. It is important to adhere to the limits set forth for magnesium because excess magnesium, for example, can also lead to interference with fracture toughness, particularly through the formation of undesirable phases at grain boundaries.
  • Zirconium is the preferred material for grain structure control; however, other grain structure control materials can include Cr, V, Hf, Mn, Ti, typically in the range of 0.05 to 0.2 wt.% with Hf and Mn up to typically 0.6 wt.%.
  • the level of Zr used depends on whether a recrystallized or unrecrystallized structure is desired.
  • the use of zinc results in increased levels of strength, particularly in combination with magnesium. However, excessive amounts of zinc can impair toughness through the formation of intermetallic phases.
  • Zinc is important because, in this combination with magnesium, it results in an improved level of strength which is accompanied by high levels of corrosion resistance when compared to alloys which are zinc free.
  • Particularly effective amounts of Zn are in the range of 0.1 to 1.0 wt.% when the magnesium is in the range of 0.05 to 0.5 wt.%, as presently understood. It is important to keep the Mg and Zn in a ratio in the range of about 0.1 to less than 1.0 when Mg is in the range of 0.1 to 1 wt.% with a preferred ratio being in the range of 0.2 to 0.9 and a typical ratio being in the range of about 0.3 to 0.8.
  • the ratio of Mg to Zn can range from 1 to 6 when the wt.% of Mg is 1 to 4.0 and Zn is controlled to 0.2 to 2.0 wt.%, preferably in the range of 0.2 to 0.9 wt.%.
  • Mg/Zn ratio of less than one is important in that it aids in the worked product being less anisotropic or being more isotropic in nature, i.e., properties more uniform in all directions. That is, working with the Mg/Zn ratio in the range of 0.2 to 0.8 can result in the end product having greatly reduced hot worked texture, resulting from rolling, for example, to provide improved properties, for example in the 45° direction.
  • Toughness or fracture toughness as used herein refers to the resistance of a body, e.g. extrusions, forgings, sheet or plate, to the unstable growth of cracks or other flaws.
  • the Mg/Zn ratio less than one is important for another reason. That is, keeping the Mg/Zn ratio less than one, e.g., 0.5, results not only in greatly improved strength and fracture toughness but in greatly improved corrosion resistance. For example, when the Mg and Zn content is 0.5 wt.% each, the resistance to corrosion is greatly lowered. However, when the Mg content is about 0.3 wt.% and the Zn is 0.5 wt.%, the alloys have a high level of resistance to corrosion.
  • Improved combinations of strength and toughness is a shift in the normal inverse relationship between strength and toughness towards higher toughness values at given levels of strength or towards higher strength values at given levels of toughness.
  • going from point A to point D represents the loss in toughness usually associated with increasing the strength of an alloy.
  • going from point A to point B results in an increase in strength at the same toughness level.
  • point B is an improved combination of strength and toughness.
  • going from point A to point C results in an increase in strength while toughness is decreased, but the combination of strength and toughness is improved relative to point A.
  • point C at point C, toughness is improved and strength remains about the same, and the combination of strength and toughness is considered to be improved.
  • toughness is improved and strength has decreased yet the combination of strength and toughness are again considered to be improved.
  • the alloy be prepared according to specific method steps in order to provide the most desirable characteristics of both strength and fracture toughness.
  • the alloy as described herein can be provided as an ingot or billet for fabrication into a suitable wrought product by casting techniques currently employed in the art for cast products, with continuous casting being preferred.
  • the alloy may be roll cast or slab cast to thicknesses from about 0.25 to 2 or 3 inches or more depending on the end product desired.
  • the alloy may also be provided in billet form consolidated from fine particulate such as powdered aluminum alloy having the composi­tions in the ranges set forth hereinabove.
  • the powder or particulate material can be produced by processes such as atomization, mechanical alloying and melt spinning.
  • the ingot or billet may be preliminarily worked or shaped to provide suitable stock for subsequent working operations.
  • the alloy stock Prior to the principal working operation, the alloy stock is preferably subjected to homogenization, and preferably at metal temperatures in the range of 900 to 1050°F for a period of time of at leat one hour to dissolve soluble elements such as Li, Cu, Zn and Mg and to homogenize the internal structure of the metal.
  • a preferred time period is about 20 hours or more in the homogenization temperature range. Normally, the heat up and homogenizing treatment does not have to extend for more than 40 hours; however, longer times are nor normally detrimental.
  • the metal can be rolled or extruded or otherwise subjected to working operations to product stock such as sheet, plate or extrusions or other stock suitable for shaping into the end product.
  • product stock such as sheet, plate or extrusions or other stock suitable for shaping into the end product.
  • a body of the alloy is preferably hot rolled to a thickness ranging from 0.1 to 0.25 inch for sheet and 0.25 to 6.0 inches for plate.
  • the temperature should be in the range of 1000°F down to 750°F.
  • the metal temperature initially is in the range of 850 to 975°F.
  • Such reductions can be to a sheet thickness ranging, for example, from 0.010 to 0.249 inch and usually from 0.030 to 0.10 inch.
  • the sheet or plate or other worked article is subjected to a solution heat treatment to dissolve soluble elements.
  • the solution heat treatment is preferably accomplished at a temperature in the range of 900 to 1050°F and preferably produces an unrecrystallized grain structure.
  • Solution heat treatment can be performed in batches or continuously, and the time for treatment can vary from hours for batch operations down to as little as a few seconds for continuous operations. Basically, solutionizing of the alloy into a single phase field can occur fairly rapidly, for instance in as little as 30 to 60 seconds, once the metal has reached a solution temperature of about 1000 to 1050°F. However, heating the metal to that temperature can involve substantial amounts of time depending on the type of operation involved.
  • solution heat treating can consume one or more hours, for instance one or two hours or more in batch solution treating.
  • the sheet is passed continuously as a single web through an elongated furnace which greatly increases the heat-up rate.
  • the continuous approach is favored in practicing the invention, especially for sheet products, since a relatively rapid heat up and short dwell time at solution temperature is obtained. Accordingly, the inventors contemplate solution heat treating in as little as about 1.0 minute.
  • a furnace temperature or a furnace zone temperature significantly above the desired metal temperature provides a greater temperature head useful in reducing heat-up times.
  • the product should be quenched to prevent or minimize uncontrolled precipita­tion of strengthening phases referred to herein later.
  • the alloy product of the present invention may be artificially aged to provide the combination of fracture toughness and strength which are so highly desired in aircraft member. This can be accomplished by subjecting the sheet or plate or shaped product to a temperature in the range of 150 to 400°F for a sufficient period of time to further increase the yield strength.
  • Some compositions of the product are capable of being artificially aged to a yield strength as high as 95 ksi. However, the useful strengths are in the range of 50 to 85 ksi and corresponding fracture toughnesses for plate products are in the range of 25 to 75 ksi ⁇ in.
  • artificial aging is accomplished by subjecting the alloy product to a temperature in the range of 275 to 375°F for a period of at least 30 minutes.
  • a suitable aging practice contemplate a treatment of about 8 to 24 hours at a temperature of about 325°F.
  • the alloy product in accordance with the present invention may be subjected to any of the typical underaging treatment well known in the art, including natural aging and multi-step agings.
  • multiple aging steps such as two or three aging steps, are contemplated and stretching or its equivalent working may be used prior to or even after part of such multiple aging steps.
  • the improved sheet, plate or extrusion and other wrought products can have a range of yield strength from about 25 to 50 ksi and a level of fracture toughness in the range of about 50 to 150 ksi ⁇ in.
  • fracture toughness can drop considerably.
  • the solution heat treated and quenched alloy product, particularly sheet, plate or extrusion must be stretched, preferably at room temperature, an amount greater than 1%, e.g.
  • stretching or equivalent working is greater than 1%, e.g. about 2% or greater, and less than 14%. Further, it is preferred that stretching be in the range of about 2 to 10%, e.g., 3.7 to 9% increase over the original length with typical increases being in the range of 5 to 8%.
  • the cast material may be subjected to stretching or the equivalent thereof without the intermediate steps or with only some of the intermediate steps to obtain strength and fracture toughness in accordance with the invention.
  • the alloy product of the present invention After the alloy product of the present invention has been worked, it may be artificially aged to provide the combina­tion of fracture toughness and strength which are so highly desired in aircraft members.
  • Specific strength is the tensile yield strength divided by the density of the alloy.
  • Plate products for example, made from alloys in accordance with the invention, have a specific strength of at least 0.75 x 106 ksi in3/lb and preferably at lest 0.80 x 106 ksi in3/lb.
  • the alloys have the capability of producing specific strengths as high as 1.00 x 106 ksi in3/lb.
  • the wrought product in accordance with the invention can be provided either in a recrystallized grain structure form or an unrecrystallized grain structure form, depending on the type of thermomechanical processing used.
  • the alloy is hot rolled and solution heat treated, as mentioned earlier.
  • the Zr is kept to a very low level, e.g., less than 0.05 wt.%, and the thermomechanical processing is carried out at rolling temperatures of about 800 to 850°F with the solution heat treatment as noted above.
  • Zr should be above 0.10 wt.% and the thermomechanical processing is as above except a heat-up rate of not greater than 5°F/min and preferably less than 1°F/min is used in solution heat treatment.
  • the ingot is first hot rolled to slab gauge of about 2 to 5 inches as above. Thereafter, it is reheated to between 700 to 850°F then hot rolled to sheet gauge. This is followed by an anneal at betwen 500 to 850°F for 1 to 12 hours. The material is then cold rolled to provide at least a 25% reduction in thickness to provide a sheet product. The sheet is then solution heat treated, quenched stretched and aged as noted earlier. Where the Zr content is fairly substantial, such as about 0.12 wt.%, a recrystallized grain structure can be obtained if desired.
  • the ingot is hot rolled at a temperature in the range of 800 to 1000°F and then annealed at a temperature of about 800 to 850°F for about 4 to 16 hours. Thereafter, it is cold rolled to achieve a reduction of at least 25% in gauge.
  • the sheet is then solution heat treated at a temperature in the range of 950 to 1020°F using heat-up rates of not slower than about 10°F/min with typical heat-up rates being as fast as 200°F/min with faster heat-up rates giving finer recrystallized grain structure.
  • the sheet may then be quenched, stretched and aged.
  • Wrought products e.g., sheet, plate and forgings, in accordance with the present invention develop a solid state precipitate along the (100) family of planes.
  • the precipitate is plate like and has a diameter in the range of about 50 to 100 Angstroms and a thickness of 4 to 20 Angstroms.
  • the precipitate is primarily copper or copper-magnesium containing; that is, it is copper or copper-magnesium rich. These precipitates are generally referred to as GP zones and are referred to in a paper entitled "The Early Stages of GP Zone Formation in Naturally Aged Al-4 Wt Pct Cu Alloys" by R. J. Rioja and D. E. Laughlin, Metallurgical Transactions A , Vol.
  • the number density of precipitates on the (1 0 0) planes per cubic centimeter ranges from 1 x 1015 to 1 x 1017 with a preferred range being higher than 1 x 1015 and typically as high as 5 x 1016. These precipitates aid in producing a high level of strength without losing fracture toughness, particularly if short aging times, e.g., 15 hours at 350°F, are used for unstretched products.
  • the alloy of the present invention is useful also for extrusions and forgings with improved levels of mechanical properties, as shown in Figure 2, for example.
  • Extrusions and forgings are typically prepared by hot working at temperatures in the range of 600 to 1000°F, depending to some extent on the properties and microstructures desired.
  • alloys of the invention (Table 1) in this Example were cast into ingot suitable for rolling.
  • Alloy A corresponds to AA2090
  • Alloy B corresponds to AA2090 plus 0.3 wt.% Mg
  • Alloy C corresponds to AA2090 plus 0.6 wt.% Mg.
  • Alloys A, B and C were provided for comparative purposes.
  • the ingots were then homogenized at 950°F for 8 hours followed by 24 hours at 1000°F, hot rolled to 1 inch thick plate and solution heat treated for one hour at 1020F.
  • the specimens were quenched and aged. Other specimens were stretched 2% and 6% of their original length at room temperature and then artificially aged. Unstretched samples were aged at 350°F.
  • Alloys A, B, C and D received many ratings of EC (severe exfoliation corrosion) or ED (very severe exfoliation). Alloy C suffered especially severe attack; all four samples received ED ratings after four days exposure to EXCO. Conversely, Alloys E, F and G received ratings that were predominantly EA (mild exfoliation) or EB (moderated exfoliation). Only one specimen from these three alloys was rated worse than EB. This was the 2% stretch 25 hour aging of Alloy E which was rated ED. This data indicates that Al-Cu-Li alloys with Mg to Zn ratios of less than 1 have improved resistance to exfoliation corrosion.
  • Tables 5, 6 and 7 list the strength and toughness exhibited by these alloys at 0, 2 and 6% stretch, respectively.
  • Figure 1 shows the properties of alloys E, F and G which exhibit improved combinations of corrosion resistance, strength and toughness.
  • Table 1 Composition of the Seven Alloys in Weight Percent Alloy Cu Li Mg Zn Zr Si Fe Al A 2.5 2.2 0 0 0.12 0.04 0.07 Balance B 2.5 2.2 0.3 0 0.12 0.04 0.07 Balance C 2.5 2.1 0.6 0 0.12 0.04 0.07 Balance D 2.6 2.2 0.6 0.6 0.12 0.04 0.07 Balance E 2.5 2.2 0.5 1 0.12 0.04 0.07 Balance F 2.6 2.1 0.3 0.5 0.12 0.04 0.07 Balance G 2.6 2.2 0.3 0.9 0.12 0.04 0.07 Balance Table 2 Specific Tensile Yield Strengths (x106 KSI in3/lb) Alloy 0% Stretch 2% Stretch 6% Stretch Calculated Density A 0.71 0.81 0.82 0.0909 B 0.80 0.82 0.88 0.0908 C 0.
  • the alloys of the invention in this example are the same as those from Example 1 except they were hot rolled to 1.5 inch thick plate rather than to 1 inch plate before they were solution heat treated for one hour at 1020F.
  • the specimens were quenched and artificially aged at 350°F for 20 and 30 hours.
  • Alloys E, F and G which had ratios of Mg to Zn of less than 1, had better resistance to stress corrosion cracking (SCC) than Alloys A, B, C and D which either contained no Zn (A, B, C) or had a Zn to Mg ratio of 1 (Alloy D).
  • SCC stress corrosion cracking
  • Alloys A, B, C and D which either contained no Zn (A, B, C) or had a Zn to Mg ratio of 1 (Alloy D).
  • the stress corrosion cracking test results are listed in Table 4 which also contains a description of the test procedures.
  • the forged specimens were solution heat treated from one hour at 1020°F then artificially aged at 350°F for 20 and 40 hours. Alloys E, F and G, which had ratios of Mg to Zn of less than 1, had better resistance to stress corrosion cracking (SCC) than Alloys A, B, C and D which either contained no Zn (A, B, C) or had an Mg to Zn ratio of 1 (Alloy D). Alloys E, F and G all survived 20 days in alternate immersion at 40,000 psi. The stress corrosion cracking results are listed in Table 8. The strength and fracture toughness are shown in Table 9. Table 5 Plate (1" Thick) Tensile Properties at 0% Stretch Aged 25 hr. at 350°F Aged 30 hr.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)
  • Metal Rolling (AREA)
  • Forging (AREA)
EP19890100355 1988-01-28 1989-01-10 Aluminium-Lithium-Legierungen Expired - Lifetime EP0325937B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US149802 1988-01-28
US07/149,802 US5137686A (en) 1988-01-28 1988-01-28 Aluminum-lithium alloys
US07/172,506 US4961792A (en) 1984-12-24 1988-03-24 Aluminum-lithium alloys having improved corrosion resistance containing Mg and Zn
US172506 1988-03-24

Publications (2)

Publication Number Publication Date
EP0325937A1 true EP0325937A1 (de) 1989-08-02
EP0325937B1 EP0325937B1 (de) 1994-03-09

Family

ID=26847044

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890100355 Expired - Lifetime EP0325937B1 (de) 1988-01-28 1989-01-10 Aluminium-Lithium-Legierungen

Country Status (4)

Country Link
EP (1) EP0325937B1 (de)
JP (1) JP3101280B2 (de)
CA (1) CA1338007C (de)
DE (2) DE68913561T2 (de)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991011540A1 (en) * 1990-01-26 1991-08-08 Martin Marietta Corporation Ultra high strength aluminum-base alloys
EP0517884A1 (de) * 1990-12-27 1992-12-16 Aluminum Company Of America Lithiumhaltige stranggepresste aluminiumteile mit niedrigem seitenverhältnis
GB2262744A (en) * 1991-12-26 1993-06-30 Korea Inst Sci & Tech Thermo mechanical treatment method for providing superplasticity to al-li alloy
EP0584271A1 (de) * 1991-05-14 1994-03-02 Reynolds Metals Co Hochfeste al-ci-legierung mit niedriger dichte.
WO1994024329A1 (en) * 1993-04-21 1994-10-27 Alcan International Limited Improvements in or relating to the production of extruded aluminium-lithium alloys
WO1995004837A1 (en) * 1993-08-10 1995-02-16 Martin Marietta Corporation Al-cu-li alloys with improved cryogenic fracture toughness
EP1170394A2 (de) * 2000-06-12 2002-01-09 Alcoa Inc. Aluminiumbleche mit verbesserter Ermüdungsfestigkeit und Verfarhen zu deren Herstellung
DE4123560B4 (de) * 1988-01-28 2006-03-09 Aluminum Company Of America Verfahren zur Herstellung lithiumhaltiger flachgewalzter Produkte auf Basis einer Aluminiumlegierung sowie die dabei erhaltenen Produkte
CN104152753A (zh) * 2014-07-08 2014-11-19 蚌埠市英路光电有限公司 一种led用含改性树木灰的铝基复合散热材料
CN104164597A (zh) * 2014-07-22 2014-11-26 安徽冠宇光电科技有限公司 一种重利用电镀废水的led用铝基复合散热材料
CN106893897A (zh) * 2017-02-27 2017-06-27 广东省材料与加工研究所 一种耐热稀土铝合金导线及其制造方法
US20170292180A1 (en) * 2014-09-29 2017-10-12 Constellium Issoire Wrought product made of a magnesium-lithium-aluminum alloy
WO2018144568A1 (en) * 2017-01-31 2018-08-09 Universal Alloy Corporation Low density aluminum-copper-lithium alloy extrusions
CN108754358A (zh) * 2018-05-29 2018-11-06 江苏理工学院 一种耐低温铝合金复合材料及其制备方法
CN110484792A (zh) * 2019-09-27 2019-11-22 福建省闽发铝业股份有限公司 一种提高铝型材抗压强度的熔铸生产工艺
CN111500901A (zh) * 2020-05-29 2020-08-07 中南大学 一种高锂铝锂合金及其制备方法

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9194028B2 (en) * 2010-09-08 2015-11-24 Alcoa Inc. 2xxx aluminum alloys, and methods for producing the same

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2137227A (en) * 1983-03-31 1984-10-03 Alcan Int Ltd Aluminium-Lithium Alloys
EP0157600A2 (de) * 1984-03-29 1985-10-09 Aluminum Company Of America Aluminium-Lithium-Legierungen
EP0158571A1 (de) * 1984-03-15 1985-10-16 Cegedur Societe De Transformation De L'aluminium Pechiney Al-Cu-Li-Mg-Legierungen mit sehr hohem spezifischen mechanischen Widerstand
EP0214381A1 (de) * 1985-08-20 1987-03-18 The Boeing Company Aluminium-Lithiumlegierung
WO1987003011A1 (en) * 1985-11-19 1987-05-21 Aluminum Company Of America Aluminum-lithium alloys and method of making the same

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA1338007C (en) * 1988-01-28 1996-01-30 Roberto J. Rioja Aluminum-lithium alloys

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2137227A (en) * 1983-03-31 1984-10-03 Alcan Int Ltd Aluminium-Lithium Alloys
EP0158571A1 (de) * 1984-03-15 1985-10-16 Cegedur Societe De Transformation De L'aluminium Pechiney Al-Cu-Li-Mg-Legierungen mit sehr hohem spezifischen mechanischen Widerstand
EP0157600A2 (de) * 1984-03-29 1985-10-09 Aluminum Company Of America Aluminium-Lithium-Legierungen
EP0214381A1 (de) * 1985-08-20 1987-03-18 The Boeing Company Aluminium-Lithiumlegierung
WO1987003011A1 (en) * 1985-11-19 1987-05-21 Aluminum Company Of America Aluminum-lithium alloys and method of making the same

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ACTA METALLURGICA, vol. 33, no. 3, 1985, pages 527-537, Pergamon Press Ltd, GB; P.J.GREGSON et al.: "Microstructural control of toughness in aluminium-lithium alloys" *
PROCEEDINGS OF THE SECOND INTERNATIONAL ALUMINUM-LITHIUM CONFERENCE: ALUMINUM-LITHIUM ALLOYS II, 12th-14th April 1983, Monterey, California, edited by E.A.Starke, Jr., pages 407-418, The Metallurgical Society of AIME, Warrendale, US; J.W.BOHLEN et al.: "Investigation of Al-Li based alloys at northrop" *

Cited By (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4123560B4 (de) * 1988-01-28 2006-03-09 Aluminum Company Of America Verfahren zur Herstellung lithiumhaltiger flachgewalzter Produkte auf Basis einer Aluminiumlegierung sowie die dabei erhaltenen Produkte
US5455003A (en) * 1988-08-18 1995-10-03 Martin Marietta Corporation Al-Cu-Li alloys with improved cryogenic fracture toughness
EP0512056A1 (de) * 1990-01-26 1992-11-11 Martin Marietta Corp Ultra-hochfeste legierungen auf aluminiumbasis.
WO1991011540A1 (en) * 1990-01-26 1991-08-08 Martin Marietta Corporation Ultra high strength aluminum-base alloys
EP0517884A1 (de) * 1990-12-27 1992-12-16 Aluminum Company Of America Lithiumhaltige stranggepresste aluminiumteile mit niedrigem seitenverhältnis
EP0517884A4 (en) * 1990-12-27 1993-06-16 Aluminum Company Of America Low aspect ratio lithium-containing aluminum extrusions
EP0584271A4 (de) * 1991-05-14 1994-03-21 Reynolds Metals Co Hochfeste al-ci-legierung mit niedriger dichte.
EP0584271A1 (de) * 1991-05-14 1994-03-02 Reynolds Metals Co Hochfeste al-ci-legierung mit niedriger dichte.
GB2262744B (en) * 1991-12-26 1995-01-04 Korea Inst Sci & Tech Thermo mechanical treatment method for providing superplasticity to al-li alloy
GB2262744A (en) * 1991-12-26 1993-06-30 Korea Inst Sci & Tech Thermo mechanical treatment method for providing superplasticity to al-li alloy
WO1994024329A1 (en) * 1993-04-21 1994-10-27 Alcan International Limited Improvements in or relating to the production of extruded aluminium-lithium alloys
GB2291431A (en) * 1993-04-21 1996-01-24 Alcan Int Ltd Improvements in or relating to the production of extruded aluminium-lithium alloys
GB2291431B (en) * 1993-04-21 1996-09-04 Alcan Int Ltd Improvements in or relating to the production of extruded aluminium-lithium alloys
US5820708A (en) * 1993-04-21 1998-10-13 Alcan International Limited Production of extruded aluminum-lithium alloys
WO1995004837A1 (en) * 1993-08-10 1995-02-16 Martin Marietta Corporation Al-cu-li alloys with improved cryogenic fracture toughness
EP1170394A2 (de) * 2000-06-12 2002-01-09 Alcoa Inc. Aluminiumbleche mit verbesserter Ermüdungsfestigkeit und Verfarhen zu deren Herstellung
EP1170394A3 (de) * 2000-06-12 2002-03-20 Alcoa Inc. Aluminiumbleche mit verbesserter Ermüdungsfestigkeit und Verfarhen zu deren Herstellung
US6562154B1 (en) 2000-06-12 2003-05-13 Aloca Inc. Aluminum sheet products having improved fatigue crack growth resistance and methods of making same
CN104152753A (zh) * 2014-07-08 2014-11-19 蚌埠市英路光电有限公司 一种led用含改性树木灰的铝基复合散热材料
CN104164597A (zh) * 2014-07-22 2014-11-26 安徽冠宇光电科技有限公司 一种重利用电镀废水的led用铝基复合散热材料
US20170292180A1 (en) * 2014-09-29 2017-10-12 Constellium Issoire Wrought product made of a magnesium-lithium-aluminum alloy
WO2018144568A1 (en) * 2017-01-31 2018-08-09 Universal Alloy Corporation Low density aluminum-copper-lithium alloy extrusions
US10724127B2 (en) 2017-01-31 2020-07-28 Universal Alloy Corporation Low density aluminum-copper-lithium alloy extrusions
CN106893897B (zh) * 2017-02-27 2018-04-10 广东省材料与加工研究所 一种耐热稀土铝合金导线及其制造方法
CN106893897A (zh) * 2017-02-27 2017-06-27 广东省材料与加工研究所 一种耐热稀土铝合金导线及其制造方法
CN108754358A (zh) * 2018-05-29 2018-11-06 江苏理工学院 一种耐低温铝合金复合材料及其制备方法
CN108754358B (zh) * 2018-05-29 2020-03-17 江苏理工学院 一种耐低温铝合金复合材料及其制备方法
CN110484792A (zh) * 2019-09-27 2019-11-22 福建省闽发铝业股份有限公司 一种提高铝型材抗压强度的熔铸生产工艺
CN110484792B (zh) * 2019-09-27 2021-02-26 福建省闽发铝业股份有限公司 一种提高铝型材抗压强度的熔铸生产工艺
CN111500901A (zh) * 2020-05-29 2020-08-07 中南大学 一种高锂铝锂合金及其制备方法

Also Published As

Publication number Publication date
DE68913561T2 (de) 1994-10-20
DE4123560B4 (de) 2006-03-09
JPH01242750A (ja) 1989-09-27
DE68913561D1 (de) 1994-04-14
CA1338007C (en) 1996-01-30
JP3101280B2 (ja) 2000-10-23
DE4123560A1 (de) 1993-01-21
EP0325937B1 (de) 1994-03-09

Similar Documents

Publication Publication Date Title
EP0157600B1 (de) Aluminium-Lithium-Legierungen
US5066342A (en) Aluminum-lithium alloys and method of making the same
EP0247181B1 (de) Aluminium-lithium-legierungen und herstellungsverfahren
US5108519A (en) Aluminum-lithium alloys suitable for forgings
US4816087A (en) Process for producing duplex mode recrystallized high strength aluminum-lithium alloy products with high fracture toughness and method of making the same
US4869870A (en) Aluminum-lithium alloys with hafnium
US4946517A (en) Unrecrystallized aluminum plate product by ramp annealing
US4927470A (en) Thin gauge aluminum plate product by isothermal treatment and ramp anneal
US4988394A (en) Method of producing unrecrystallized thin gauge aluminum products by heat treating and further working
US5151136A (en) Low aspect ratio lithium-containing aluminum extrusions
US4961792A (en) Aluminum-lithium alloys having improved corrosion resistance containing Mg and Zn
EP0325937B1 (de) Aluminium-Lithium-Legierungen
US4797165A (en) Aluminum-lithium alloys having improved corrosion resistance and method
US5061327A (en) Method of producing unrecrystallized aluminum products by heat treating and further working
EP0368005A1 (de) Verfahren zur Herstellung eines nichtkristallisierten, flachgewalzten, dünnen, wärmebehandelten Produktes auf Aluminiumbasis
EP0281076B1 (de) Flachgewalztes Aluminium-Lithium-Produkt
US4795502A (en) Aluminum-lithium alloy products and method of making the same
US5135713A (en) Aluminum-lithium alloys having high zinc
US5137686A (en) Aluminum-lithium alloys
US4921548A (en) Aluminum-lithium alloys and method of making same
JP3540316B2 (ja) アルミニウム−リチウム合金の機械的特性の改良
US4915747A (en) Aluminum-lithium alloys and process therefor
EP0266741B1 (de) Aluminium-Lithium-Legierungen und Verfahren zur Herstellung
GB2257435A (en) Aluminum-lithium alloys and method of making the same
JPH05148597A (ja) アルミニウムおよびリチウム合金およびその製造方法

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19900202

17Q First examination report despatched

Effective date: 19910723

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 68913561

Country of ref document: DE

Date of ref document: 19940414

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20040130

Year of fee payment: 16

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20050802

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20080130

Year of fee payment: 20

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20080129

Year of fee payment: 20

REG Reference to a national code

Ref country code: GB

Ref legal event code: PE20

Expiry date: 20090109

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION

Effective date: 20090109