CN114540674A - High strength and high fracture toughness 7XXX series aerospace alloy products - Google Patents
High strength and high fracture toughness 7XXX series aerospace alloy products Download PDFInfo
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- 229910045601 alloy Inorganic materials 0.000 title description 59
- 229910000838 Al alloy Inorganic materials 0.000 claims abstract description 86
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- 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
- C22C21/10—Alloys based on aluminium with zinc 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
- C22F1/002—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working by rapid cooling or quenching; cooling agents used therefor
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- 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
- C22F1/053—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 zinc as the next major constituent
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Abstract
A high strength and high fracture toughness 7xxx series aluminum alloy product including from 6.5 to 7.2 wt.% Zn, from 1.55 to 1.95 wt.% Cu, from 1.75 to 2.15 wt.% Mg, from 0.095 to 0.15 wt.% Zr, impurity elements, and the balance Al. In one embodiment, the aluminum alloy product includes a Mg/Cu ratio in a range of 1.05 to 1.35 and a Zn/Mg ratio in a range of 3.2 to 4.0. The aluminum alloy product can be used for manufacturing plates, extruded or forged products, and is particularly suitable for aerospace structural components.The product has a strength, fracture toughness, K at the point of fatigue crack departure suitable for aerospace applicationsmaxAn excellent combination of different directions of ductility and corrosion resistance.
Description
Cross Reference to Related Applications
According to 35 U.S. c.119(e), the present application claims the benefit of U.S. provisional patent application No. 63/112,294, filed 11/2020, the contents of which are incorporated herein by reference.
Technical Field
The invention relates to a high strength 7xxx series aluminum alloy product. High strength 7 xxx-series aluminum alloys may be used in sheet, extruded or forged products suitable for aerospace structural components, particularly large commercial aircraft wing structure applications, requiring better strength, fracture toughness, fatigue crack deflection resistance, anisotropic ductility, damage tolerance properties, and corrosion resistance.
Background
In order to substantially reduce aircraft weight to improve fuel efficiency, airframe manufacturers and aluminum material manufacturers are actively pursuing higher strength 7xxx aluminum alloys because of their broad combination of material strength, ductility, fracture toughness, fatigue resistance, and corrosion resistance.
The combination of complex, comprehensive and stringent material performance requirements for aerospace applications requires very fine optimization and a very narrow chemical range to meet such requirements for commercial aircraft.
Obviously, strength, fracture toughness and corrosion resistance are the most critical material properties, which are significantly affected by the chemical composition. In the 7xxx series aluminum alloys, zinc is the main alloying element for achieving high strength by age-strengthening. The zinc content in the most commonly used 7050 and 7075 aircraft aluminum alloys ranges from 5.1 to 6.7 weight percent (wt.%). Magnesium is typically added with zinc to form MgZn2 and its variants, the main precipitation hardening phase. Aluminum alloys with higher Zn and Mg contents generally have higher strength. However, higher Zn and Mg contents also negatively impact the resistance to Stress Corrosion Cracking (SCC) and fracture toughness properties. In 7xxx series aluminum alloys, copper is added to improve SCC resistance. Meanwhile, the strength of the material is improved by adding Cu. Most Cu is believed to replace Zn in the metastable MgZn2 phase. Generally, the strength is substantially affected by the amount of Cu and Zn added at the same weight percentage.
To achieve age precipitation strengthening, all added elements must be in solid solution prior to aging. This is typically achieved by a Solution Heat Treatment (SHT) treatment step, followed by rapid quenching. Due to the high Mg, Zn and Cu content, it is difficult to dissolve all the constituent particles consuming a large amount of the added elements into the solid solution. Therefore, it is an extreme challenge to simultaneously achieve high strength, high fracture toughness, and desirable corrosion resistance of 7 xxx-series aluminum alloys.
Another new challenge to increase aircraft component utilization is fatigue crack bifurcation or deflection characteristics. This is a phenomenon in which a crack abruptly changes its propagation direction away from the intended fracture surface under type I fatigue loading conditions. Such crack deviations are a growing concern for aircraft manufacturers because they are difficult to take into account during the structural design process.
In addition to fatigue crack deflection performance, anisotropic ductility of aluminum alloy slabs is another increasingly important feature for aerospace applications, particularly for the most recent monolithic part machining techniques used for fuselage manufacture. Anisotropic ductility refers to a significant change in ductility when the tensile test direction lies between the typical test directions, typically parallel or perpendicular to the material metal flow or microstructure direction, commonly denoted as the rolling direction (L). Ductility generally decreases significantly when the drawing direction is different from the standard direction determined by the metal flow direction.
Another increasingly challenging aspect of aerospace applications is the environmentally-promoted cracking (EAC) properties. This material property is believed to evaluate the ability of the alloy to resist hydrogen embrittlement, which may result in a loss of strength and ductility due to corrosion-like phenomena. The tests were carried out under exceptionally high humidity and temperature and high applied stress. EAC characteristics are also considered to be very sensitive to chemical composition.
In summary, the combination of complex age hardening behaviour and strict and overall material properties requires a very narrow chemical range. Aerospace applications are in urgent need for such high performance alloys to achieve ever increasing fuel efficiency goals.
Disclosure of Invention
A7 xxx-series aluminum alloy product, such as sheets, forgings and extrusions, of high strength, high fracture toughness, high fatigue crack deflection resistance and high anisotropic ductility, suitable for use in the manufacture of aerospace structural components, such as large commercial aircraft wing components, the 7 xxx-series aluminum alloy product comprising 6.5 to 7.2 wt.% Zn, 1.55 to 1.95 wt.% Cu, 1.75 to 2.15 wt.% Mg, 0.095 to 0.15 wt.% Zr, up to 0.15 wt.% of impurity elements, the total of which is no more than 0.35 wt.%, and the balance Al. In one embodiment, the aluminum alloy further comprises: the ratio of Mg/Cu is in the range of 1.05 to 1.35, and the ratio of Zn/Mg is in the range of 3.2 to 4.0.
It has been found that aluminum alloys with optimized chemical ranges, in relation to precise Zn, Mg and Cu contents and Mg/Cu and Zn/Mg ratios, can produce alloys with high strength, desirable fracture toughness, fatigue crack deflection resistance, higher anisotropic ductility, damage tolerance and corrosion resistance properties, an unprecedented combination.
High strength 7xxx series thick plate aluminum alloy products provide promising opportunities for the significant fuel efficiency and cost reduction advantages of commercial aircraft. One example of such an application of the invention is a wing box (wing box) of unitary design, which requires a thick cross-section of a7 xxx-series aluminum alloy product. Material strength is a key design factor to reduce weight. Extensibility, damage tolerance, resistance to stress corrosion and fatigue crack propagation are also important.
Drawings
The features and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments of the invention, taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a graph showing the chemical compositions of Cu and Mg of an alloy of the present invention used to make a7xxx series aluminum alloy product of the present invention;
FIG. 2 is a graph showing the chemical composition of Mg and Zn of the alloys of the present invention used to make the 7xxx series aluminum alloy products of the present invention;
FIG. 3 is a graph showing the chemical compositions of Cu and Mg of an alloy of the present invention used to make a7xxx series aluminum alloy product of the present invention, as compared to a non-inventive alloy;
FIG. 4 is a graph showing the chemical composition of Mg and Zn of the alloys of the present invention used to make the 7xxx series aluminum alloy products of the present invention, as compared to non-inventive alloys;
FIG. 5 is a graph showing the strength of a7xxx series aluminum alloy product of the present invention using the present alloy as compared to a non-present alloy sheet;
FIG. 6 is a graph showing the strength and fracture toughness combination of a7xxx series aluminum alloy product of the present invention using the present alloy as compared to a 3 inch thick plate of a non-present alloy;
FIG. 7 shows the fracture toughness sample orientation relative to the sheet geometry;
FIG. 8 shows the configuration of the bulk sample; b is 6.35 mm; w is 76.2 mm; h is 46 mm; w1 ═ 95 mm;
FIG. 9 is a K-ray illustrating a7xxx series aluminum alloy product of the present invention using the alloy of the present invention as compared to a 4 inch thick plate of the non-present invention alloymax-devA plot of intensity; and
fig. 10 is a graph illustrating the combination of orthotropic strength and ductility of the inventive 7xxx aluminum alloy products using the inventive alloys, as compared to non-inventive alloys.
Detailed Description
The invention includes alternative embodiments wherein the upper or lower limit of the Zn content in the aluminum alloy product can be selected from 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, 7.1, and 7.2 wt.%. In addition to the above-mentioned alternative upper and lower limits of Zn, the present invention also includes alternative embodiments wherein the upper or lower limit of the Cu content may be selected from 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90 and 1.95 wt%. In addition to the above-mentioned alternative upper and lower limits for Zn and Cu, the present invention also includes alternative embodiments wherein the upper or lower limit for the Mg content may be selected from 1.75, 1.80, 1.85, 1.90, 1.95, 2.00, 2.05, 2.10 and 2.15 wt%. In addition to the above-listed alternative upper and lower limits for Zn, Cu and Mg, the present invention also includes alternative embodiments in which the upper or lower limit for the Zr content may be selected from 0.095, 0.10, 0.11, 0.12, 0.13, 0.14 and 0.15 wt%. In addition to the above-listed alternative upper and lower limits for Zn, Cu, Mg and Zr, the present invention also includes alternative embodiments wherein the upper or lower limit for the Mg/Cu ratio can be selected from 1.05, 1.10, 1.15, 1.20, 1.25, 1.30 and 1.35. In addition to the above-listed alternative upper and lower limits for the Zn, Cu, Mg, Zr and Mg/Cu ratios, the present invention also includes alternative embodiments wherein the upper or lower limits for the Zn/Mg ratio may be selected from 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9 and 4.0. In addition to the alternative upper and lower limits enumerated above, the invention also includes alternative embodiments in which the upper limit of the impurity element is 0.15, 0.12, 0.10, 0.08, 0.05, 0.02, and 0.10 weight percent. In addition to the above recited alternative upper and lower limits, the invention also includes alternative embodiments wherein the upper limit of the total impurity elements is 0.35, 0.30, 0.25, 0.20, 0.15, 0.12, 0.10, 0.08, 0.05, 0.02, and 0.10 wt%.
In one embodiment, the aluminum alloy product is a thick plate comprising ≦ 0.12 wt.% Si, preferably ≦ 0.05 wt.% Si. In one embodiment, the aluminum alloy product is a thick plate comprising 0.15 wt.% or less Fe, preferably 0.10 wt.% or less Fe. In one embodiment, the aluminum alloy product is a thick plate comprising Zr in the range of 0.095 to 0.15 wt.%. In one embodiment, the aluminium alloy product is a thick plate comprising ≦ 0.04 wt.% Cr, preferably without adding Cr to the alloy, other than Cr provided as an impurity. In one embodiment, the aluminum alloy product is a thick plate comprising 0.005-0.10 wt.% Ti.
The aluminum alloy products of the present invention may also include low levels of "impurity elements" that are not intentionally included. "impurity element" means any other element than the above-mentioned elements (Al, Zn, Cu, Mg, Zr, Si, Fe, Cr and Ti).
In a preferred embodiment, the aluminum alloy product of the present invention is a thick plate having a thickness of 1 to 10 inches. Alternatively, such plank products can have a thickness of 1-3 inches, 1-5 inches, 3-5 inches, 5-10 inches, 5-8 inches, or 8-10 inches.
Ingots of high strength aluminum alloy products may be cast, homogenized, hot rolled, solution heat treated, cold water quenched, selectively stretched, and aged to a desired temper. The heavy plate high strength aluminum alloy is a sheet product provided in a T7651 or T7451 temper having a thickness in the range of 1 inch to 10 inches. The ingot can be homogenized at a temperature of 454 ℃ to 491 ℃ (849 ° f to 916 ° f). The hot rolling start temperature may be between 385 ℃ to 450 ℃ (725 ° f to 842 ° f). The outlet temperature may be in a similar range as the start-up temperature. The sheet may be solution heat treated in a temperature range of 454 ℃ to 491 ℃ (849 ° f to 916 ° f). The plate is quenched by cold water to room temperature and can be stretched by about 1.5 to 3 percent. The quenched sheet material may be subjected to any aging practice known to those skilled in the art, including but not limited to a two-step aging practice resulting in a final T7651 or T7451 temper. When using a T7651 or T7451 temper, the first stage temperature may be in the range of 100 ℃ to 140 ℃ (212 ° f to 284 ° f) for 4 to 24 hours, and the second stage temperature may be in the range of 135 ℃ to 200 ℃ (275 ° f to 392 ° f) for 5 to 20 hours.
The high strength 7xxx series aluminum alloy sheet products preferably have a tensile strength at Yield (YTS) in the LT direction of 67ksi or more, or 68ksi or more, or 70ksi or more, or 71ksi or more. These 7xxx series aluminum alloy products may also have T-LK1c value is more than or equal to 28ksi-in1 /2Or not less than 29ksi-in1/2Or not less than 30ksi-in1/2. These 7xxx series aluminum alloy products may also have Kmax-devThe value is more than or equal to 33MPa-m1/2Or more than or equal to 34MPa-m1/2Or more than or equal to 35MPa-m1/2Or not less than 36MPa-m1/2Or more than or equal to 37MPa-m1/2Or not less than 38MPa-m1/2. These 7 xxx-series aluminum alloy products may also have an EAC value of 100 days or more, or 110 days or more, or 120 days or more, or 130 days or more, or 140 days or more, or 150 days or more. These 7 xxx-series aluminum alloy sheet products may also have YTS, T-L K1c, K in the LT direction as described abovemax-devAnd the value of EAC in any or all combinations. In one embodiment of the invention, these YTS and K1c values occur in slabs having a thickness of 3 inches or more, or 4 inches or more, and have K as described abovemax-devAnd the value of EAC. Tensile testing was performed according to ASTM B557 specifications, the contents of which are expressly incorporated herein by reference. The in-plane strain fracture toughness (K1c) was measured according to ASTM E399 using CT specimens, the contents of which are expressly incorporated herein by reference. As described below and incorporated herein, Environmental Accelerated Crack (EAC) resistance was evaluated under test conditions of a temperature of 70 ℃, a relative humidity of 85%, and a load stress in the ST direction centered at T/2 (middle of thickness) of 85% of rp 0.2. Deviation from external cracking (K)max-dev) Is based on "any factor that would normally invalidate the E647 FCG assay". The contents of the E647 FCG assay are expressly incorporated herein by reference.
While the following examples illustrate various embodiments of the present invention, those skilled in the art will appreciate how to make additional high strength aluminum alloy products in accordance with the present invention. These examples should not be construed as limiting the scope of protection afforded by the present invention.
Example (factory test)
Fifty (50) pieces of technical grade sheet material were produced by commercial DC (direct cooling) casting, followed by homogenization, hot rolling, solution heat treatment, quenching, drawing and aging of the sheet material at various thicknesses. Table 1 shows the chemical composition of 50 commercial size panels.
Fig. 3 and 4 show the chemical composition differences between the inventive 7 xxx-series aluminum alloy products made from the inventive alloys and the non-inventive alloys.
Table 1: chemical composition of industrial-grade ingot
The ingot is homogenized, hot rolled, solution heat treated, quenched, drawn and aged to obtain a final tempered sheet having a thickness between 1 inch and 8 inches. The ingot is homogenized at a temperature of 465 ℃ to 485 ℃ (869 ° f to 905 ° f). The hot rolling start temperature is from 400 ℃ to 440 ℃ (752 ° F to 824 ° F).
The sheet is solution heat treated in a temperature range of 470 ℃ to 485 ℃ (878 ° f to 905 ° f), cold water quenched to room temperature, and stretched by about 1.5% to 3%. The final T7651 and T7451 tempers were produced using a two-step aging process. The first stage temperature is in the range of 110 ℃ to 130 ℃ (230 ° f to 266 ° f) for 4 to 12 hours, and the second stage temperature is in the range of 145 ℃ to 160 ℃ (293 ° f to 320 ° f) for 8 to 20 hours.
The final sheet produced has strength, fracture toughness, corrosion resistance, fatigue crack deflection resistance, and anisotropic ductility, which are critical for aerospace applications.
Tensile testing is performed according to ASTM B557 specifications, the contents of which are expressly incorporated herein by reference. The in-plane strain fracture toughness (K1c) measurements were made according to ASTM E399 using CT specimens, the contents of which are expressly incorporated herein by reference. Table 2 shows the tensile properties and fracture toughness of aluminum alloy products using inventive and non-inventive alloy samples. The usual terms familiar to the person skilled in the art are used in this table to describe the strength and fracture toughness.
Table 2 shows that the strength of the aluminum alloy products using the alloys of the present invention (samples 1-18) is significantly better than that of the non-inventive alloys. The fracture toughness of the aluminum alloy products of the invention alloy is also better than that of the 7050 non-invention alloy.
Fig. 5 shows that the aluminum alloy product using the alloy of the present invention has higher strength than the alloy of the present invention.
In aerospace applications, both strength and fracture properties must be considered. According to table 2, the strength and fracture toughness combination of the aluminium alloy products made from the alloys of the invention is much better than that of the non-inventive alloys. For example, fig. 6 shows that 3 "thick aluminum alloy sheet made from the alloy of the present invention has a better combination of strength and fracture toughness than the non-inventive alloy.
Table 2: tensile and fracture toughness of aluminum alloy sheet products made from alloys of the present invention and non-present invention
Evaluation of fatigue crack propagation deviation was performed according to ASTM E647, the contents of which are expressly incorporated herein by reference. The specimen orientation is L-S, and the probability of crack deviation is greatest during crack propagation. Fig. 7 shows the orientation of the sample relative to the plate geometry. Fig. 8 illustrates the configuration of the sample used here. The specimens used in this test have a standard compact tensile, i.e., C (T). All test specimens have a size B of 6.35mm and a W of 76.2 mm. The FCGR test procedure generally meets the requirements of ASTM E647, and meets the following specific requirements: (1) r is 0.1, f is 25 Hz; (2) the pre-splitting is carried out at a constant load amplitude, with an initial Δ K of 10MPa m being reached at the end of the pre-splitting1/2The value of (c). After pre-splitting, the test was carried out at constant load amplitude at the same load as the pre-splitting. The test was performed at room temperature. Relative Humidity (RH) is in normal laboratory environment.
The determination of the external crack deviation is based on "any condition that would normally negate the E647 FCG test" (e.g., a crack deviation above 20 ° or more out of plane after exceeding the remaining ligament standards). And after the deviation bifurcation point is determined, calculating the crack length by adopting a three-point weighted average method according to the measurement result of the fractured sample. The formula of the weighted average length is a (front + rear +2 center)/4.
Table 4 shows the fatigue cycles, crack lengths and K at the crack deflection points for the alloy batches according to the invention and not according to the inventionmax-dev. FIG. 9 shows the strength and K of an aluminum alloy product made from the alloy of the present invention and a non-invention alloy sheet material at thicknesses ranging from 4 to 5 inchesmax-devComparison of the combinations.
Table 4: fatigue cycle, crack length and K at crack deflection point for 4 inch thick platemax-dev
The tensile properties, particularly tensile ductility, may vary significantly from test direction to test direction. This anisotropic material behavior is very important for aerospace applications of high strength slabs.
The orthotropic tensile specimen was extracted such that the gauge length was centered at the T/2 position. The stretching direction was deviated 45 degrees from the thickness (ST) direction (ST-45). The test results are shown in table 5. As shown in fig. 10, aluminum alloy products made from the alloys of the present invention have an unexpectedly better combination of orthotropic strength and ductility.
Table 5: anisotropic tensile properties of 4-4.25 inch thick plate alloy batches
Stress corrosion resistance is critical for aerospace applications. The standard stress corrosion cracking test was performed according to the requirements of ASTM G47, the contents of which are expressly incorporated herein by reference, i.e. alternate immersion in 3.5% NaCl solution at constant deflection. Three specimens were tested per sample.
Table 6 gives the SCC test results for T7451 and T7651 tempers. It indicates that the batch designated as T7451 temper passed the 35ksi stress threshold. In addition, most samples at the higher stress level of 40ksi will also pass SCC within 30 days. The batch designated as T7651 temper passed the 25ksi threshold. In addition, they also passed the SCC test at higher stress levels of 30ksi for a duration of 30 days.
Table 6: SCC test Performance of the alloys of the invention
In recent years, other alloys have provided higher yield strength properties than existing alloys (e.g., 7050 and 7075), particularly for thicker sheet applications. However, these alloys have proven to be susceptible to a different failure mechanism known as environmentally-promoted cracking (EAC).
Table 7 shows the chemical composition of such a new high strength 7 xxx-series alloy developed in recent years. These panels are commercial scale panels. The chemical composition not according to the invention, in particular the Zn content, is significantly different compared to the alloy according to the invention.
Table 7: chemical composition of novel high-strength alloy plate for EAC test, not provided by invention
Resistance to environmentally-promoted cracking (EAC) was evaluated under test conditions of 70 ℃ temperature and 85% relative humidity. The load stress in the ST direction was 85% of rp 0.2. Samples were taken in the ST direction centered at T/2 (middle of thickness).
Three coupons (Rep1, Rep2, Rep3) were tested on alloy sheet #18 of the present invention, as well as on some new non-inventive high strength alloy sheets. Table 8 gives the EAC test results. The results show that aluminum alloy products made from the alloys of the present invention have better EAC resistance than other non-inventive high strength alloys. For the alloy sheet ID 18 of the present invention, three specimens failed at 116 days, 150 days, and 159 days, respectively. In contrast, all non-inventive alloy specimens failed the EAC test within 3 to 21 days.
Table 8: EAC test Performance of the alloy at 70 ℃ and 85% relative humidity
Although the present invention has been disclosed in terms of preferred embodiments, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.
Claims (27)
1. A high strength and high fracture toughness 7xxx series aluminum alloy product comprising:
6.5 to 7.2 wt.% Zn, 1.55 to 1.95 wt.% Cu,
1.75 to 2.15 wt.% Mg, 0.095 to 0.15 wt.% Zr,
up to 0.15% by weight of impurity elements, the total amount of these impurity elements not exceeding 0.35% by weight, and
the balance being Al.
2. The aluminum alloy product of claim 1, comprising a Mg/Cu ratio of 1.05 to 1.35.
3. The aluminum alloy product of claim 1, comprising a Zn/Mg ratio of 3.2 to 4.0.
4. The aluminum alloy product of claim 1, further comprising ≦ 0.12 wt.% Si.
5. The aluminum alloy product of claim 4, comprising ≦ 0.05 wt.% Si.
6. The aluminum alloy product of claim 1, further comprising ≦ 0.15 wt.% Fe.
7. The aluminum alloy product of claim 6, comprising ≦ 0.10 wt.% Fe.
8. The aluminum alloy product of claim 1, further comprising ≦ 0.04 wt.% Cr.
9. The aluminum alloy product of claim 1, further comprising 0.005-0.10 wt.% Ti.
10. The aluminum alloy product of claim 1, wherein the aluminum alloy product is a 1-10 inch thick plate, an extruded article, or a forged article.
11. The aluminum alloy product of claim 10, having a tensile strength at Yield (YTS) ≧ 67ksi in the LT direction.
12. The aluminum alloy product of claim 10, having a K1c value ≧ 28ksi-in the T-L direction1/2。
13. The aluminum alloy product of claim 10, having a K1c value ≧ 28ksi-in the T-L direction1/2And a tensile strength at Yield (YTS) in LT direction ≧ 67 ksi.
14. The aluminum alloy product of claim 13, having Kmax-devThe value is more than or equal to 33MP-m1/2。
15. An aluminium alloy product according to claim 13, having an EAC value of 100 days or more.
16. A high strength and high fracture toughness 7xxx series aluminum alloy product comprising:
6.5 to 7.2 wt.% Zn, 1.55 to 1.95 wt.% Cu,
1.75 to 2.15 wt.% Mg, 0.095 to 0.15 wt.% Zr,
a Mg/Cu ratio of 1.05 to 1.35, a Zn/Mg ratio of 3.2 to 4.0,
si of less than or equal to 0.12 weight percent, Fe of less than or equal to 0.15 weight percent,
cr less than or equal to 0.04 wt%, Ti 0.005-0.10 wt%,
up to 0.15% by weight of impurity elements, the total amount of these impurity elements not exceeding 0.35% by weight, and
the balance being Al.
17. The aluminum alloy product of claim 16, comprising ≦ 0.05 wt.% Si.
18. The aluminum alloy product of claim 16, comprising ≦ 0.10 wt.% Fe.
19. The aluminum alloy product of claim 16, wherein the aluminum alloy product is a 1-10 inch thick plate, an extruded article, or a forged article.
20. The aluminum alloy product of claim 19, having a tensile strength at Yield (YTS) ≧ 67ksi in the LT direction.
21. The aluminum alloy product of claim 19, having a K1c value ≧ 28ksi-in the T-L direction1/2。
22. The aluminum alloy product of claim 19, having a K1c value ≧ 28ksi-in the T-L direction1/2And a tensile strength at Yield (YTS) in LT direction ≧ 67 ksi.
23. The aluminum alloy product of claim 22, having Kmax-devThe value is more than or equal to 33MP-m1/2。
24. An aluminium alloy product according to claim 22, having an EAC value of 100 days or more.
25. A method of manufacturing a thick sheet, high strength 7 xxx-series aluminum alloy product, comprising the steps of:
a. an ingot comprising a cast charge of an AA7 xxx-series aluminum alloy of the aluminum alloy product of claim 1;
b. homogenizing the cast billet at a temperature of 454 ℃ to 491 ℃ (849 ° F to 916 ° F);
c. hot working the billet by one or more methods selected from the group consisting of rolling, extruding, and forging at a temperature of 385 ℃ to 450 ℃ (725 ° f to 842 ° f);
d. solution Heat Treating (SHT) the hot worked blank at a temperature in a range of 454 ℃ to 491 ℃ (849 ° f to 916 ° f);
e. cold water quenching the SHT blank; and
h. aging SHT, and quenching in cold water to a required tempering state.
26. The method of claim 25, wherein the aging step comprises a two-step aging procedure in which a first stage lasts for 4 to 24 hours in a temperature range of 100 ℃ to 140 ℃ (212 ° f to 284 ° f) and a second stage lasts for 5 to 20 hours in a temperature range of 135 ℃ to 200 ℃ (275 ° f to 392 ° f).
27. The method of claim 25, further comprising stretching the SHT billet 1.5% to 3% after the cold water quenching step (e) and before the aging step (h).
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| Application Number | Priority Date | Filing Date | Title |
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| US202063112294P | 2020-11-11 | 2020-11-11 | |
| US63/112,294 | 2020-11-11 | ||
| US17/479,211 | 2021-09-20 | ||
| US17/479,211 US20220145439A1 (en) | 2020-11-11 | 2021-09-20 | High Strength and High Fracture Toughness 7xxx Aerospace Alloy Products |
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| US (1) | US20220145439A1 (en) |
| EP (1) | EP4001446A1 (en) |
| CN (1) | CN114540674A (en) |
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| CN116377296A (en) * | 2023-03-31 | 2023-07-04 | 上海华峰铝业股份有限公司 | High-strength and high-toughness Al-Zn-Mg-Cu aluminum alloy plate and preparation method thereof |
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| US20230114162A1 (en) * | 2021-09-27 | 2023-04-13 | Kaiser Aluminum Fabricated Products, Llc | Dispersoids 7XXX Alloy Products With Enhanced Environmentally Assisted Cracking and Fatigue Crack Growth Deviation Resistance |
| CN115961186A (en) * | 2022-11-11 | 2023-04-14 | 蔚来动力科技(合肥)有限公司 | Die-casting aluminum alloy material and preparation method and application thereof |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US5865911A (en) * | 1995-05-26 | 1999-02-02 | Aluminum Company Of America | Aluminum alloy products suited for commercial jet aircraft wing members |
| ATE245207T1 (en) * | 1996-09-11 | 2003-08-15 | Aluminum Co Of America | ALUMINUM ALLOY FOR COMMERCIAL AIRCRAFT WINGS |
| US20050034794A1 (en) * | 2003-04-10 | 2005-02-17 | Rinze Benedictus | High strength Al-Zn alloy and method for producing such an alloy product |
| RU2425902C2 (en) * | 2005-02-10 | 2011-08-10 | АЛКАН РОЛЛД ПРОДАКТС-РЕЙВЕНСВУД ЭлЭлСи | Al-Zn-Cu-Mg ALLOYS ON BASE OF ALUMINIUM, PROCEDURES FOR THEIR PRODUCTION AND IMPLEMENTATION |
| US8840737B2 (en) * | 2007-05-14 | 2014-09-23 | Alcoa Inc. | Aluminum alloy products having improved property combinations and method for artificially aging same |
| CN104532090B (en) * | 2014-12-31 | 2017-01-25 | 中国石油天然气集团公司 | 580Mpa-level aluminum alloy pipe for drill stem and manufacturing method thereof |
| CN104694860B (en) * | 2015-04-07 | 2016-08-24 | 中南大学 | A kind of low-purity Al-Zn-Mg-Cu alloy ageing hot processing method |
| CN110832094A (en) * | 2017-06-21 | 2020-02-21 | 奥科宁克公司 | Improved thick wrought7XXX aluminum alloys and methods of making the same |
| FR3071513B1 (en) * | 2017-09-26 | 2022-02-11 | Constellium Issoire | HIGH STRENGTH AL-ZN-CU-MG ALLOYS AND METHOD OF MANUFACTURING |
| EP3670690A1 (en) * | 2018-12-20 | 2020-06-24 | Constellium Issoire | Al-zn-cu-mg alloys and their manufacturing process |
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- 2021-09-20 US US17/479,211 patent/US20220145439A1/en active Pending
- 2021-10-26 CA CA3135591A patent/CA3135591A1/en active Pending
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| CN116377296A (en) * | 2023-03-31 | 2023-07-04 | 上海华峰铝业股份有限公司 | High-strength and high-toughness Al-Zn-Mg-Cu aluminum alloy plate and preparation method thereof |
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| EP4001446A1 (en) | 2022-05-25 |
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