JPS63143245A - Heat-treatment of al-base alloy containing li and product - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention combines l-i with at least 19 other principal components of FA in the groups CLI, M(+ and zn), and Zr,
Final heat treatment (artificial aging) of M alloys, which essentially contain microcomponents such as Mn, Cr, Ni, If, Ti and Be, and unavoidable impurities such as Fe or S;
ng) and the products obtained thereby.

The problems to be solved by the present invention are as follows for the above alloys)/! A special aging treatment that may seem like a wasted attempt to remove heat from conventional heat treatment F.
I! (Maximum hardening aging or underaging (30113-re
improved transverse mechanical properties (yield strength, tensile strength and elongation), impact strength,
The objective is to achieve improvement in toughness J3, corrosion resistance (intergranular corrosion resistance and stress corrosion resistance), and mechanical properties.

Indeed, M containing 1-i despite possessing attractive properties with respect to low density, high modulus of elasticity and excellent rock mechanical strength.
The alloy has almost the same mechanical strength as the ordinary M alloy (
Compared to the Aluminum Association Standards 2000 or 7000 series), it has less tolerance to fracture (less ductility and toughness) or poorer properties regarding corrosion (intergranular corrosion or stress corrosion). Furthermore, the variability and non-uniformity of mechanical properties for non-recrystallized products are recognized as drawbacks of M-Li alloys for their applications.

Regarding the above-mentioned low ductility, IE, A, 5 TARKE et al.
Journal of Metals, 1981 8
Monthly issue, pp. 24-32), in which some ways to solve this problem are reported;
ilT! - The use of rapid solidification, powder metallurgy and thermo-mechanical processing to produce products with fine grains with fine precipitates and/or non-recrystallized structures; etc. ing.

However, these methods are complex, time consuming and costly.

Structural hardening including 1i (dLIrcisselle
Underaging M alloys with ntStructura+) successfully compromises mechanical strength and ductility or toughness, even at the expense of reduced resistance to lateral intergranular and stress corrosion and high anisotropy of its properties. It is recognized by metallurgists that it leads to results. Excessive aging (su
r-revenu, over-ac+ing)
The coarsening of the type-stable δ-(M3Li) phase within the matrices reduces the mechanical strength, and the expansion of the Q-stable δ'(M3Li > phase precipitation-free region) between the grains. This leads to reduced elongation and toughness.

8, ST 8 to KE Jr and T, H, 5T
ADER3m, C0nf.

Proceedings Met, 6oc, AIHE
Montenay, April 12-16, 1983;
105 pages, 1. See G, PALHER et al., M-Li 8 to l0VST [.

The latter current mulberry contains M-Li containing Cu and/or Ma.
Also experienced in over-aging operations.

At this time, they precipitate the δ' phase in the ground, which is always accompanied by the platelet-like T'1 or T2 (Ai C1IL+) phase, the small-rod-like T'2 or 1 to T
(M6 Ctl L i s ) phase, acicular or band-like 8′ or S (M2Cut Mg) phase and IV2L
Co-precipitation of iMg is performed.

However, in contrast to conventional alloys (2000 and 7000 series), such overaging does not result in high levels of stress corrosion resistance.

Therefore, the final heat treatment that has been used hitherto for all known industrial or experimental M-based alloys containing li is a single temperature of about 170 to 190 °C of the T6 type (to maximize mechanical strength). These included either single aging operations or underaging (for a compromise between tensile strength and elongation or toughness).

Measurement qa and i force At! according to the present invention solves all these drawbacks. -Li (CIJ-MO-Zn) alloy heat treatment is rapid cooling (trempc, qucnchino)
The operation is followed by at least one solution treatment, 0, 5 to 5% plastic deformation carried out by a lifting platform, natural aging and finally at least one aging operation (r
cvcnu, aging operation). This last operation (referred to as “primary statute of limitations”) is
It is carried out at a temperature range of 25 to 270°C for 3 minutes to 10 hours; the preferred range is 230 to 260°C.
℃ and from 5 minutes to 7 hours, generally the highest temperature will be associated with the shortest time.

More precisely, the main aging operation is carried out within a one-hour temperature range of a descending quadrilateral consisting of corner points with the following coordinates on the humidity (°C) logarithmic time diagram: A270°C - 3 minutes. 8210°C - 48 minutes 1225°C - 19 hours 30 minutes 8225°C - 35 minutes preferably E260°C - 5 minutes F 260°C - 1 hour 20 minutes 230°C - 7 hours 1 230°C - 26 minutes.

The temperature of the main aging operation, if this is isothermal, depends on the active chemical composition of the alloy, To (°C) = 65 + 85 (%Li) + 5 (%M
U)→-1,5(%zn): Here, % is lff1%, preferably 1.7≦%l-
i≦2.6. 0.2%≦CLI≦3.4%, MO≦7
, 0% and %7-n≦3%: The range of To-10°C to To+25°C is preferable. It should be noted that TO is independent of the CLI content of the alloy.

The main aging operation time is (for example, during the cooling operation after 0 cooling,
Almost all spherical δ"A
! 3L! The time must be sufficient to substantially dissolve the phase, but typically the coarser particles surrounding the dispersed particles of the spherical M3Zr phase (GAYLE and VAND
ER5ANDE, 5cripta Hetall, Vo
118.1984. p, 473-478) or the very rarely present coarse-grained δ-phase (>25 nm) which is not dissolved even after the main aging operation. From a metallographic perspective, the structure after the main aging operation excluding undissolved particles is a spherical δ with a maximum size of less than 10 nm (preferably less than 5 nm), which was generated during the cooling operation after the main aging operation.
- comprises fine dense precipitates of phases.

The spherical δ-phase is then replaced by the normal hardening phase, i.e. S'1 or S-M CLIM, depending on the chemical composition of the alloy.
(l phase, T-1 or (macho, -M2CU1i phase, u
At least 19 of the MaL; phase, T'1 or T2-M6CuLi3 phase are entrained, which are in the form of needles, plates, bands or rods, especially in the ground.

If the temperature J3 and time of the main aging operation are excessive, the ductility
This results in a loss of mechanical strength with a decrease in toughness or impact strength. On the other hand, if the temperature and time are insufficient, copper intergranular corrosion or stress corrosion resistance will decrease, and isotropy will deteriorate.

Before the main aging operation, a pre-aging operation (pr5rcvenu) may be carried out at a temperature below 200° C. and for a time at most equal to the time corresponding to the T6 state of the alloy in question, which makes it particularly suitable for CIJ-containing alloys. On the other hand, real! It is possible to improve properties related to mechanical strength and corrosion resistance without any decrease in ductility.

The time (to, ·) for this preliminary aging operation is as follows:
In the temperature (°C) logarithmic time (hour) diagram, the formula θ--6
It is limited by a straight line of 0IQ(It', .+260).

This pre-aging operation is preferably carried out in the temperature range from 120 to 180 DEG C. and with a minimum time t'1 of 1 DEG corresponding to the following equation: .theta.( DEG C.) -180-Got', .times.

Before the main aging or pre-aging operation, it is generally subjected to stretching, controlled stretching or compression, stretching, rolling, etc.
, 5 to 5%, the mechanical strength and corrosion resistance can be further improved.

After carrying out the main aging operation, the product corresponds to the characteristics of knee-2024T531 and can be cold-forged without risk of fracture.
mold operation or quenching operation (durcissem)
cnt) or intermediate 1F, corresponding to plastic deformation of 0.5 to 5%, moderate improvement property needs with respect to mechanical strength to enable operation of flattening.
Improved elongation in tension; - especially after quenching and before the main aging operation, S or S'
Particularly improved cross-sectional reduction values obtained when phase-containing alloys are subjected to cold forging operations with rapid cooling; - better homogeneity of the mechanical strength of thick-walled products; - better isotropic needs for mechanical properties; Surface flaking (EXCO test) and intergranular corrosion (桔形屓R90
48), as well as improved resistance to stress corrosion; significant reduction in unfavorable exfoliation failure appearance; and - better 'tF than in the under-aged condition of the same hardness.
It has the characteristics 71, such as:

Processing that includes a main aging operation followed by a supplementary aging operation further improves the mechanical properties and resistance to intergranular and stress corrosion. At this time, the main aging is the temperature (℃)
It is carried out within a one-hour temperature range of a parallelogram consisting of corner points to the right of the following coordinates on a logarithmic time diagram: △: 270°C - 3 minutes B: 270°C - 48 minutes C: 21S°C - 16 hours [): 215°C - 1 hour Preferably, E: 260°C - 5 minutes F: 260°C - 1 hour 20 minutes G: 220°C - 12 hours T1: 220°C - 45 minutes.

Supplementary aging is performed at a temperature (θ) lower than that of the main aging operation;
and θ(℃)-230 in the range of 170 to 210℃
−66IoI] t″ corresponding to m (time)
The time period is greater than m and less than 60 hours. The temperature is preferably in the range of 170 to 210°C.

Too short a time and/or too low a temperature will result in no substantial improvement in corrosion resistance and extreme brittleness after the main aging operation; If the time is too long and/or the temperature is too high, the brittleness increases due to the significant precipitation of l-i-rich intergranular phases and the concomitant increase in the region in which no precipitation of the δ-phase occurs. result. Under these conditions, the size of the spherical δ-phase is greater than 10 nm, which is furthermore than T
= 1 or T1 phase, analytically precipitated in an elongated or semicircular shape at the interface between the S' or S phase and the Al base.

The supplemental aging operation is either performed separately or during a continuous cold LI after the main aging operation. In the case of surface quality, it is possible to carry out 0.5 to 5% cold working operations between the 29 aging operations to improve mechanical properties and corrosion resistance.

It is possible to carry out a preliminary statute of limitations with the conditions given above in line 4≧ before both the main statute of limitations and the supplementary statute of limitations.

The invention will be explained with reference to the following examples with the help of figures: layer <1'r', w? It will be.

Example 1 Alloy 2091 (L i = 2.0%, CLI =
2.0%, Mg=1.4%, Zr=0.1
A flat plate frame H with a cross section of 1100 x 13 was subjected to solution treatment (2 hours,
30°C), quenching and (optionally) 2% controlled tension, followed by a normal aging operation (low temperature tempering or aging in T6 or T651 condition) or main aging treatment at 2.10°C according to the invention. Either was done. Certain treatments are pre-aged in a draft oven to nrI of it! 2! lPI! was held. All main aging operations were performed in a nitrite-Iwi salt bath furnace followed by water cooling. The flat bar had a non-recrystallized structure.

Table 1 shows the tensile mechanical properties (average values of two test pieces taken at half the width of the flat bar in the weft direction or two test pieces taken over the full width in the h1 cross-section direction). ) shows the test piece measurement values regarding yield strength Rpo, 2), tensile strength Pm), elongation to failure (A%) and cross-sectional line (Σ%) at 02% residual deformation.

The table also includes tests based on standard ^Iff 9048 (
Also shown is the susceptibility to intergranular corrosion measured on the core and rough surface of the bar after NaC lithography (continuous immersion in aqueous solution of 202).

For alloy 2091, according to the main aging operation of the present invention, with or without pre-aging carried out before, the mechanical strength and ductility are J3 in the transverse direction (as compared to normal underaging). It is shown that the value is larger than that of the D1 operation, and the value at the quenching peak (T6.T651) is close to that of the normal aging operation.Furthermore, although the mechanical strength in the longitudinal direction is somewhat sacrificed, the 11 The intergranular corrosion resistance in the center and surface of the product was significantly improved, and at the same time, the bond had excellent isotropic mechanical properties.

Moreover, when treated according to the present invention, the bar has very high cross-sectional shrinkage values in the as-is condition after the main aging operation and excellent ductility of the product (when controlled tension is applied after cooling). This value is much larger than that for any under-aged condition or the T6 or T651 condition.Roughly speaking, the as-is condition bar after the main aging operation has almost no secondary cracking in the joint direction of the fracture specimen. It was shown to be completely absent (that is, there is almost no tendency for exfoliation failure).

The diameter of the δ = -VLi phase in the ground measured at high magnification by a transmission electron FI microscope shows that, apart from certain composite particles of the δ--M3L+ phase surrounding spherical particles (about 40 nm in diameter) of the Al3Zr phase, All particles were smaller than 4 mm.

Example 2 A thick rolled plate of alloy 2091 with a thickness of 38.5 m was heated at 530°C.
The specimens were subjected to solution treatment for 2 hours and 30 minutes, followed by controlled tension with a residual deformation of 2% and normal aging operation (under-aging operation or over-aging operation) or main aging treatment according to the present invention. . All of these were carried out in a draft oven and air cooled in order to obtain comparable average values of mechanical strength.

Table 2 shows the tensile strength measured at the center of the wall in the longitudinal direction, transverse longitudinal direction, 60° angle to the longitudinal direction (usually the weak direction for this type of product), and transverse transverse direction. Mechanical properties (Rp O,2, Rm,
Δ%). This table also shows '7tJ'? A
111 in a 3% solution of Na tJ+ 1202 with IR9048! The intergranular corrosion characteristics after subsequent immersion are also shown.

Excellent isotropy of mechanical properties obtained by the treatment of the present invention1. J: Sensitive and, as a result, its mechanical strength ('
1 is equal to the value under aged condition for 12 hours at 135°C in the longitudinal direction (normal alloy 2024-T351
(directly comparable) in the transverse direction is much higher than the value for the slightly underaged condition (between 2 dff1 at 170° C.). The table also shows excellent transverse yield strength and elongation to failure.

This ffi should be stored at a high temperature after aging at 230℃ for 3 hours. (outside the present invention) is higher than the value obtained by 1q. δ--A! The 31-i phase exists in an intragranular form with a diameter smaller than 5% m. In addition, the intergranular corrosion resistance was significantly improved compared to the under-aged material, and the mechanical properties were 11-average (Zr1).

Example 3 Li2.0%, Cu2.0%, MOI, 4%, Zr0.
A thin plate of alloy 2091 having a recrystallized isotropic vs. It was subjected to an aging operation, a controlled bias of 2%, and then either a conventional aging operation (single stage underaging operation) or a special special aging operation according to the invention.

In certain cases, Tong I! One pre-aging operation was carried out in a kite oven before the main aging operation of the present invention carried out in Ifj1. Cooling after the main aging operation was performed in still air.

The thin plate was tested for hardness, longitudinal and transverse longitudinal tensile tests, intergranular feeding test according to TR9048, exfoliation corrosion test (FXCO test) on the center and surface, and 3. Stress corrosion tests were performed using a 5% NaCl solution with repeated immersion-extraction and transverse longitudinal tension. The deformation formed by a steel ball dropped onto a plate or thin plate from an increasing altitude is determined by the ball test used in the aviation industry to evaluate the brittleness of the fuselage. The impact strength (absorbed energy) was also measured by determining the energy required to form a crack in the member from the relationship between Table 3.

Due to the main aging operation of the present invention, treatment 1! ! It is said that the plate or thin plate that has been aged is more resistant to scratches, even when compared with the mechanically filtered, slightly aged condition. Improved impact strength and 16 resistance to intergranular corrosion and stress corrosion (non-destructive stress N of 30 mouth tests conducted in the longitudinal direction of the VL section)
It can be seen that R3Q) is good.

Furthermore, their resistance to flaking corrosion is better at the surface of the plate or sheet than that of undersized temporary or thin sheets, and is acceptable even in the center (Table 3). All thin plates according to the invention are 5-
AI! 2CuMo phase and δ′Aj! Tfj′ with 3Li phase
! shows dense co-precipitation, the latter in the normal state (underaged, T
651, overageing), its diameter is smaller than 5 nm.

Table 3 shows that the aging operation of the present invention has improved resistance to intergranular corrosion than the under-aging operation while having equivalent hardness, and Wi? The strength values also show improved cohesion (which indicates a lack of brittleness).

Third two-front door plate (alloy 2091-t = 1.6mm)
Example 4 Li2.1%-Cu2 with rectangular cross section (eox 30m)
．． 6%-Mo0.4%-Zr0.09%-Fc +S
Extruded rods having a composition of iO,07 were solution treated and water-cooled and then aged under laboratory conditions at various temperatures and for various times. Their resistance to stress corrosion is l? 'l', 3, 5 by AIIt 9048
Measurements were made in the transverse direction on ring C by a test involving repeated immersion and withdrawal with a % NaCl solution.

Surprisingly, the aging treatment FI! according to the invention at 230° C. in an air furnace! As a result of (air cooling), T-
1 or TI-Aj! 2 Dense precipitation of Cu Li phase and δ-Aj! This results in substantial dissolution of the 3L i-phase (large particles of the δ' phase with a size greater than 30 nm are well dispersed and very fine particles of the δ' phase with a diameter of less than 6 nm are highly densified); The result was a satisfactory resistance to stress corrosion, in contrast to normal under-aged or over-aged conditions.

Table 4 * 3NR30: Three test pieces did not break during the 30-mouth test Example 5 100X 13. The cross section shows a non-recrystallized structure (composition is 1i
1.8%, CIJ 2.04%, M (11,52%
, Zr 0.10%, Fe +3i 0.05%, according to atomic absorption spectroscopy).
After being subjected to solution treatment at 28°C for 2 rn, normal aging treatment or aging treatment according to the present invention is performed, and after the aging treatment according to the present invention (in a salt bath furnace), water cooling is performed to reduce residual deformation 2. A controlled pull of .5% was performed. The structure of the heat treatment according to the present invention has no Kumanin δ'-M3[i phase (except around the M3Zr phase particles) and a δ' phase (4n
A very fine precipitate of size smaller than m) and coexistence with it during the aging period described in the present invention.
-Al2 Cu M (precipitation of + phase, J3 J: and T
-M Cut-i3 was a feature.

Table 5 shows the average values of longitudinal mechanical tensile characteristics obtained at half the wall thickness of the flat bar and on specimens taken from the edges.

Table 5: Substantial improvement in elongation up to failure is recognized, but
At the same time, the specimens treated according to the present invention and subjected to tensile processing showed a very slight tendency for exfoliation and intergranular fracture.

Example 6 Alloy 2091 of the same material as described in Examples I J3 and 5, with cross section 10100X13 and compositions Δ and B
After quenching, the extruded flat bar material was optionally cold forged and aged for 1 time, and after being cooled to room temperature, it was subjected to supplementary aging as disclosed in the present invention.

Table 6 shows the improvement in mechanical strength thus obtained, whereby the Togi alloys treated according to the invention:
After a t+fi foot aging operation at 170° or 190°C, mechanical property values comparable to those of the T6 or T651 condition as well as improved resistance to intergranular f/J5 interstices of 1!
? 1. T
It's really hard. The size of the δ''-M3Li phase after supplementary aging is on the order of 20 nm.

Alloy 2091 in the initial state T351 equivalent to Example 3
A thin plate (16M thick) was subjected to a conventional simple aging treatment or a main aging treatment according to the invention followed by a supplementary aging operation. The latter operation was carried out either after lowering the humidity to -n normal humidity (air cooling after main aging) or while controlling cooling in the furnace by introducing outside air (temperature drop rate was 10 - b).

Table 7 shows the values for hardness, impact strength (absorbed energy by ball test) and resistance to intergranular corrosion. 1
Compared to the slightly underaged aging of 12 hours at 70°C, these values are improved in the body.

After quenching and 2% controlled tension, a 38.5M thick rolled plate of alloy 2091 having the same material and composition as that used in Example 2 was subjected to a normal single-stage process. The main aging operation was carried out at 230°C for 3 hours.
A supplementary aging operation of 12 hours at °C was performed in the same furnace, followed by R final cooling from 190 °C to 170 °C at a rate of 20 °C/h, and then left in still air to cool down to room temperature. .

Table 8 shows the results of the performed characteristic value manipulations in the same format as Table 2 (see Example 2).

The aging operation according to the invention significantly improves properties such as the transverse elastic limit and tensile strength, as well as the isotropy of the mechanical properties - the radial values remain acceptable and the core values, and the intergranular It can be seen that the resistance to corrosion is improved.

The structure (,1,
It is characterized by a spherical δ''-M3Li phase (20rvJ: larger size) and a shape that extends along a large number of acicular S--M2CuMg phases in the ground (at the interface).

[Brief explanation of the drawing]

Figure 1 shows the range (AB
CD> and the preferred range (EFGI-1); FIG.
Δ′B−C”D−); and FIG. 3 shows the general and preferred ranges (/
MB'C-Di is shown.

Claims (41)

[Claims] (1) Li and at least one main component element selected from Cu, Mg, and Zn, and in addition to unavoidable impurities such as Fe and Si, Zr, Mn, and N
solution treatment and quenching of an Al alloy containing trace elements such as i, Hf, Ti, and Be, with the remainder being Al; optionally plastic deformation and natural aging; followed by at least one aging. A heat treatment method comprising: The aging operation is carried out in a region defined by a parallelogram whose corner points have the following coordinates in a temperature-logarithmic time diagram. Method: A 270°C - 3 minutes B 270°C - 48 minutes I 225°C - 9 hours 30 minutes J 225°C - 35 minutes. (2) Claim 1, characterized in that the main aging operation is carried out within a temperature region defined by a parallelogram whose corner points have the following coordinates in a temperature-logarithmic time diagram: The method described in: E 260°C-5 minutes F 260°C-1 hour 20 minutes K 230°C-7 hours L 230°C-26 minutes. (3) Isothermal aging operation is To (℃) = 65 + 80 (%Li) + 5 (%Mg) + 1
．． 5(%Zn) (Here, % is weight%, and the alloy is 1.7≦Li≦
2.6%, 0.2≦Cu≦3.4%, Mg≦7% and Zn≦3%) at a temperature in the range of To-10°C to To+25°C. A method according to any one of claims 1 and 2. (4) Before main aging, at a temperature below 200℃ and θ(℃
3. A method as claimed in claim 1, characterized in that preaging is carried out with a maximum time t'M corresponding to ) = 260-60 logt'M (hours). (5) Before main aging, at a temperature below 200℃ and θ(℃
4. A method according to claim 3, characterized in that a preaging is carried out with a maximum time t'M corresponding to ) = 260-60 logt'M (hours). (6) The pre-aging operation is carried out in the temperature range of 120-180°C and for a minimum time t'm corresponding to θ (°C) = 180-60 logt'm (hours). The method described in Section 4. (7) The pre-aging operation is carried out in a temperature range of 120-180°C and for a minimum time t'm corresponding to θ (°C) = 180-60 logt'm (hours). The method described in Section 5. (8) The method according to claim 1 or 2, wherein a plastic deformation of 0.5 to 5% is applied after the quenching operation. (9) A method according to claim 3, characterized in that a plastic deformation of 0.5 to 5% is applied after the quenching operation. (10) The method according to claim 4, wherein a plastic deformation of 0.5 to 5% is applied after the quenching operation. (11) The method according to claim 5, characterized in that a plastic deformation of 0.5 to 5% is applied after the quenching operation. (12) A method according to claim 6, characterized in that a plastic deformation of 0.5 to 5% is applied after the quenching operation. (13) A method according to claim 7, characterized in that a plastic deformation of 0.5 to 5% is applied after the quenching operation. (14) Li and at least one main component element selected from Cu, Mg and Zn, and in addition to unavoidable impurities such as Fe and Si, Zr, Mn,
An Al alloy product containing trace elements such as Ni, Hf, Ta, and Be, with the remainder being Al: The Al base has a fine spherical δ′-(Al_3Li) phase (size <10n).
m) with a dense fine precipitate; T′_1 or T_1(Al_2CuLi) phase, S′ or S(Al_2CuMg) phase, and/or T′_
2 or T_2 (Al_6CuLi_3) phase in the form of plates, needles or rods; and optionally coarse and infrequent particles of the δ' phase with a size exceeding 25 nm. . (15) Product according to claim 14, characterized in that the size of the δ' phase is <5 nm. (16) Li and at least one main component element selected from Cu, Mg and Zn, and in addition to unavoidable impurities such as Fe and Si, Zr, Mn,
solution treatment and quenching of an Al alloy containing trace elements such as Ni, Hf, Ti and Be, with the remainder being Al; optionally plastic deformation and natural aging; followed by at least one aging operation. A heat treatment method comprising: The main aging operation is carried out in a region delimited by a parallelogram whose corner points have the following coordinates in a temperature-logarithmic time diagram, A 270 ° C. -3 minutes B 270°C - 48 minutes C 215°C - 16 hours D 215°C - 1 hour followed by supplementary aging at a temperature in the range 165-215°C below the main aging temperature. (17) Claim 16, characterized in that the main aging operation is performed within a temperature region defined by a parallelogram whose corner points have the following coordinates in a temperature-logarithmic time diagram: The method described in section: E 260°C - 5 minutes F 260°C - 1 hour 20 minutes G 220°C - 12 hours H 220°C - 45 minutes. (18) The time for supplementary aging operation is calculated using the formula θ (℃) = 230-
Claim 1, which is longer than t″m corresponding to 60 logt″m (time) and shorter than 60 hours.
The method according to item 6 or item 17. (19) The method according to claim 16 or 17, characterized in that the temperature of the supplementary aging operation is in the range of 170°C to 210°C. (20) The method according to claim 18, characterized in that the temperature of the supplementary aging operation is in the range of 170°C to 210°C. (21) The method according to claim 16 or 17, wherein the two operations, the main aging operation and the supplementary aging operation, are performed separately. (22) The method according to claim 18, wherein the two operations, the main aging operation and the supplementary aging operation, are performed separately. (23) The method according to claim 19, wherein the two operations, the main aging operation and the supplementary aging operation, are performed separately. (24) The method according to claim 20, wherein the two operations, the main aging operation and the supplementary aging operation, are performed separately. (25) A method according to claim 16 or 17, characterized in that the two operations, the main aging operation and the supplementary aging operation, are separated by a successive cooling step. (26) A method according to claim 18, characterized in that the two operations, the main aging operation and the supplementary aging operation, are separated by a successive cooling step. (27) A method according to claim 19, characterized in that the two operations, the main aging operation and the supplementary aging operation, are separated by a successive cooling step. (28) A method according to claim 20, characterized in that the two operations, the main aging operation and the supplementary aging operation, are separated by a successive cooling step. (29) A method according to claim 21, characterized in that the two operations, the main aging operation and the supplementary aging operation, are separated by a successive cooling step. (30) A method according to claim 22, characterized in that the two operations, the main aging operation and the supplementary aging operation, are separated by a successive cooling step. (31) A method according to claim 23, characterized in that the two operations, the main aging operation and the supplementary aging operation, are separated by a successive cooling step. (32) A method according to claim 24, characterized in that the two operations, the main aging operation and the supplementary aging operation, are separated by a successive cooling step. (33) 0.5 ~ between the main aging operation and the supplementary aging operation
22. Process according to claim 21, characterized in that a 5% cold working operation is carried out. (34) 0.5 ~ between the main aging operation and the supplementary aging operation
23. Process according to claim 22, characterized in that a 5% cold working operation is carried out. (35) 0.5 ~ between the main aging operation and the supplementary aging operation
24. Process according to claim 23, characterized in that a 5% cold working operation is carried out. (36) 0.5 to 5% between main statute of limitations and supplementary statute of limitations operation
25. A method according to claim 24, characterized in that a cold working operation is performed. (37) Before the main aging operation, in the temperature range below 200 °C and θ (°C) = −60 logt′_M (hours) + 260
18. A method according to claim 16, characterized in that a pre-aging operation is carried out with a maximum time t'_M corresponding to . (38) θ(
38. The method according to claim 37, characterized in that it is carried out with a minimum time t'm given by C) = 180-60 logt'm (hours). (39) A method according to claim 37, characterized in that a plastic deformation of 0.5 to 5% is applied after the quenching operation. (40) A method according to claim 38, characterized in that a plastic deformation of 0.5 to 5% is applied after the quenching operation. (41) Li, at least one main component element selected from Cu, Mg and Zn, and in addition to unavoidable impurities such as Fe and Si, Zr, Mn,
A product of an Al alloy containing trace elements such as Ni, Hf, Ti and Be, with the remainder being Al; densely packed T'_1 or T_1 phase, S' or S phase, T_'2 or T_2 phase. In addition to the precipitation, the Al ground is 10n
and a heterogeneous precipitation of an elongated or hemispherical δ' phase at the interface between the T'_1 or T_1 phase, the S' or S phase and the Al ground: In addition to the product or the dense precipitates of the T2 phase, the Al host structure also contains separated spherical δ′ phase precipitates of a size greater than 10 nm; the T′1 or T1 phase, the S′ or A product of an Al-based alloy containing Li, characterized in that the boundary between the S phase and the Al matrix includes an anisotropic precipitated part of an elongated or hemispherical δ'phase; and an Al matrix structure.