CN112522559A - High intergranular corrosion resistance aircraft landing gear aluminum alloy and preparation method thereof - Google Patents
High intergranular corrosion resistance aircraft landing gear aluminum alloy and preparation method thereof Download PDFInfo
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C21/00—Alloys based on aluminium
- C22C21/10—Alloys based on aluminium with zinc as the next major constituent
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C1/00—Making non-ferrous alloys
- C22C1/02—Making non-ferrous alloys by melting
- C22C1/03—Making non-ferrous alloys by melting using master alloys
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- 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
The invention discloses a high intergranular corrosion resistance aircraft landing gear aluminum alloy and a preparation method thereof, wherein the aluminum alloy comprises the following chemical elements in percentage by weight: zn: 9-12.5%; mg: 1.5-4.5%; zr: 0.05-0.25%; and (C) Sc: 0.05-0.2%; cu: 1.0-3.0%; ti: 0.005-0.5%; si: less than or equal to 0.10 percent; fe: less than or equal to 0.20 percent; mn: less than or equal to 0.3 percent; the content of other single impurities is less than or equal to 0.05 percent, the total content of the impurities is less than or equal to 0.15 percent, and the balance is Al; wherein, Ti, Sc, Cu and Zr are intermediate alloy, and the rest is pure alloy, wherein w (Fe) is more than or equal to w (Si) plus 0.05 percent; w (Na) is less than or equal to 5 ppm.
Description
Technical Field
The invention relates to an aluminum alloy and a preparation method thereof, in particular to a high intergranular corrosion resistance aircraft landing gear aluminum alloy and a preparation method thereof.
Background
The landing gear is an important bearing part of a military or civil aircraft, is a key bearing part for the gliding, taking-off, landing, ground moving and parking of the aircraft, bears larger impact load, fatigue load or static load, and needs to have excellent comprehensive properties such as high strength, high fracture toughness, high fatigue resistance, corrosion resistance, high specific strength and the like when being selected.
Along with the improvement of the performance of the airplane and the requirement of light weight and the rapid development of novel alloy materials, the material selection of the airplane landing gear is gradually transited from the traditional low-alloy stainless steel to the superhard aluminum material with higher specific strength. However, the super-hard aluminum alloy has high strength and high toughness, and the corrosion resistance of the super-hard aluminum alloy generally cannot meet the use requirement.
Aiming at the problems, the invention provides the high intergranular corrosion resistance aircraft landing gear aluminum alloy and the preparation process thereof, so that the high strength and the high toughness are obtained, and meanwhile, the high corrosion resistance is obtained, and the performance requirements are met.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides the high intergranular corrosion resistance aircraft landing gear aluminum alloy, which has high strength and high toughness and high corrosion resistance so as to meet the performance requirements.
In order to realize the technical effects, the technical scheme of the invention is as follows: the aircraft landing gear aluminum alloy with high intergranular corrosion resistance comprises the following chemical elements in percentage by weight:
Zn：9～12.5％；
Mg：1.5～4.5％；
Zr：0.05～0.25％；
Sc：0.05～0.2％；
Cu：1.0～3.0％；
Ti：0.005～0.5％；
Si：≤0.10％；
Fe：≤0.20％；
Mn：≤0.3％；
the content of other single impurities is less than or equal to 0.05 percent, the total content of the impurities is less than or equal to 0.15 percent, and the balance is Al;
wherein Ti, Sc, Cu and Zr are intermediate alloys, and the balance is pure alloy
Wherein w (Fe) is not less than w (Si) 0.05%; w (Na) is less than or equal to 5 ppm.
The further improvement is that Cu adopts intermediate alloy AlCu50, Zr adopts intermediate alloy AlZr5, Sc adopts intermediate alloy AlSc2, and Ti adopts grain refiner AlTi5B1.
The effect of transition group and rare earth trace elements on the super-strong aluminum alloy is simultaneously added into the alloy, so that a novel multi-element aluminide coherent disperse phase can be formed, recrystallization can be completely inhibited, the stability of deformation recovery micro-oriented matrix tissues is improved, large-angle crystal boundaries are reduced, and the toughness can be improved simultaneously. The method adopts a low-frequency electromagnetic horizontal casting technology, introduces melt strong shearing and alternating electromagnetic fields in a casting molten pool area, and comprehensively utilizes the high-strength shearing action of a strong shearing device in the center of the melt and the forced convection action of the alternating magnetic field at the edge of the melt, thereby realizing the regulation and control of the grain morphology and macro/micro uniformity in the whole ingot casting range. Strong forced convection is generated in the melt, so that the temperature field and the composition field in the melt are very uniform, and the nucleation of the wall of the crystallizer is promoted.
The induction heating device is adopted to realize the gradient heating of the cast ingot, the mold cooling and other on-line control technologies, and the isothermal deformation is realized. By the method, the aluminum alloy section with high strength and high toughness can be fully and uniformly deformed, and uniform macro/microstructure and performance are obtained.
Fine eta' phase particles are dispersed in multistage aging crystal, the grain boundary is similar to an overaging state, and the good fatigue resistance is compatible with high strength due to the combination of the advantages of T6 and T7; the pre-deformation treatment can effectively eliminate residual stress and ensure the precision of subsequent machining.
The invention aims to overcome the defects in the prior art, and provides another preparation method of the high intergranular corrosion resistance aircraft landing gear aluminum alloy, which can obtain high strength and high toughness and simultaneously obtain high corrosion resistance so as to meet the performance requirements.
In order to realize the technical effects, the technical scheme of the invention is as follows: a preparation method of an aircraft landing gear aluminum alloy with high intergranular corrosion resistance comprises the following steps:
s1: batching, wherein batching is carried out according to the requirements of chemical compositions and weight percentages of the alloy;
s2: casting, namely casting an aluminum alloy round ingot blank by adopting an electromagnetic horizontal continuous casting method, purifying a melt by adopting argon and a sodium-free refining agent, wherein the refining temperature is as follows: the refining time is 10-15min at 730-750 ℃; standing for more than 20min after refining, wherein the electromagnetic intensity is 10-45HZ, the casting temperature is 685-700 ℃, and the casting speed is 40-80 mm/min; pulse water is adopted for cooling, the temperature of cooling water is 20-35 ℃, and the pressure of the cooling water is 0.04-0.08 MPa;
s3: homogenizing, namely transferring the prepared round cast ingot to a homogenizing furnace for three-level homogenizing treatment, wherein the first-level homogenizing temperature: preserving the heat for 18-24 h at 380-400 ℃; second-stage homogenization temperature: keeping the temperature at 450-460 ℃ for 18-24 h; third-stage homogenization temperature: the temperature is 465-475 ℃, and the heat preservation time is 20-24 h;
s4, hot extrusion, ingot casting and peeling, wherein the extrusion temperature is 380-430 ℃, the extrusion ratio is more than or equal to 10, and the extrusion speed is 10-50 mm/S;
s5: carrying out solid solution treatment at the solid solution temperature of 450-465 ℃ for 1-3 h;
s6: carrying out three-stage aging treatment, wherein the first-stage aging temperature is 110-150 ℃, and the aging time is 20-24 h; the secondary aging temperature is 200-250 ℃, and the aging time is 0.5-1 h; the third stage aging temperature is 110-150 ℃, and the aging time is 20-24 h.
In a further improvement, in step S3, the gate part of the ingot is wrapped by ceramic fiber felt and stored transversely for less than 8 h.
In a further improvement, in step S3, after the homogenization treatment, the furnace door is opened by one third and then is suspended for 1 h; then opening the furnace door to two thirds, and pausing for 1 h; and completely opening the furnace door, taking out the cast ingot after 1 hour, and air cooling.
The invention has the advantages and beneficial effects that: the L-direction tensile strength of the bar prepared by the method can reach more than 750MPa, the yield strength reaches more than 700MPa, and the elongation is more than 9 percent; the LT tensile strength can reach more than 700MPa, and the yield strength can reach more than 650 MPa. According to the national standard GB/T7998-2002 (aluminum alloy intercrystalline corrosion determination method), the intercrystalline corrosion depth is 100-120 mu m, and the compressive strength can reach 225MPa at the maximum under the conditions of the deformation temperature of 250 ℃ and the strain rate of 1S-1.
Detailed Description
The following further describes embodiments of the present invention with reference to examples. The following examples are only for illustrating the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.
The first embodiment is as follows:
the high intergranular corrosion resistance aircraft landing gear aluminum alloy is prepared by the following steps:
1. the alloy proportion is Zn: 12%, Mg: 4%, Cu: 3% and Sc: 0.2%, Zr: 0.25 percent and Ti0.032 percent; wherein, 99.70 percent of pure aluminum ingot, pure Zn ingot, pure Mg ingot, intermediate alloy AlCu50, intermediate alloy AlZr5, intermediate alloy AlSc2 and Ti are adopted as grain refiner AlTi5B1.
2. Melting at 690-740 ℃,
3. refining treatment, wherein the refining temperature is 745 ℃, and the refining time is 15 min.
4. Preparing a phi 200mm ingot by electromagnetic horizontal continuous casting: the electromagnetic strength is 45HZ, the casting temperature is 690 ℃, and the casting speed is 80 mm/min; the temperature of the pulse water is 26 ℃, and the pressure of the cooling water is 0.06MPa
5. Carrying out homogenization treatment: first-stage homogenization temperature: keeping the temperature at 400 ℃ for 24 h; second-stage homogenization temperature: keeping the temperature at 460 ℃ for 24 h; third-stage homogenization temperature: keeping the temperature at 470 ℃ for 24h
6. After homogenization treatment, the furnace door is opened by one third, and then the time is suspended for 1 h; then opening the furnace door to two thirds, and pausing for 1 h; and completely opening the furnace door, taking out the cast ingot after 1 hour, and air cooling.
7. Peeling the cast ingot, wherein the peeling depth is 3mm
8. Hot extrusion: the extrusion temperature is 430 ℃, the extrusion ratio is 16, and the extrusion speed is 50mm/s
9. Solution treatment: the solid solution temperature is 460 ℃, and the solid solution time is 1-3 h.
10. And (3) tertiary aging treatment: the first-stage aging temperature is 110 ℃, the aging time is 24 hours, and air cooling is carried out; the secondary aging temperature is 200 ℃, the aging time is 0.5h, and quenching is carried out; the third stage aging temperature is 110 ℃, and the aging time is 20-24 h.
The mechanical properties and the stress corrosion resistance of the bar at room temperature prepared in the first embodiment are as follows:
example two:
the high-stress corrosion cracking resistance aircraft landing gear aluminum alloy is prepared by the following steps:
1. the alloy proportion is Zn: 10%, Mg: 2%, Cu: 1% and Sc: 0.06%, Zr: 0.15 percent and Ti0.028 percent; adopts 99.70 percent pure aluminum ingot, pure Zn ingot, pure Mg ingot, intermediate alloy AlCu50, intermediate alloy AlZr5, intermediate alloy AlSc2 and grain refiner AlTi5B1.
2. Melting was carried out at a temperature of 690-740 ℃.
3. Refining treatment is carried out at a refining temperature of 745 ℃ for 15 min.
4. Preparing a phi 200mm ingot by electromagnetic horizontal continuous casting: the electromagnetic strength is 45HZ, the casting temperature is 690 ℃, and the casting speed is 80 mm/min; the temperature of the pulse water is 27 ℃, and the pressure of the cooling water is 0.06 MPa.
5. Carrying out homogenization treatment: first-stage homogenization temperature: keeping the temperature at 400 ℃ for 24 h; second-stage homogenization temperature: keeping the temperature at 460 ℃ for 24 h; third-stage homogenization temperature: keeping the temperature at 470 ℃ for 24 h.
6. After homogenization treatment, the furnace door is opened by one third, and then the time is suspended for 1 h; then opening the furnace door to two thirds, and pausing for 1 h; and completely opening the furnace door, taking out the cast ingot after 1 hour, and air cooling.
7. And (5) peeling the cast ingot, wherein the peeling depth is 3 mm.
8. Hot extrusion: the extrusion temperature was 430 ℃, the extrusion ratio was 16, and the extrusion speed was 50 mm/s.
9. Solution treatment: the solid solution temperature is 460 ℃, and the solid solution time is 1-3 h.
10. And (3) tertiary aging treatment: the first-stage aging temperature is 110 ℃, the aging time is 24 hours, and air cooling is carried out; the secondary aging temperature is 200 ℃, the aging time is 0.5h, and quenching is carried out; and the third stage aging temperature is 110 ℃, the aging time is 20-24h, and the air cooling is carried out.
The mechanical properties and the stress corrosion resistance of the bar prepared in the second embodiment at room temperature are as follows:
the foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the technical principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (5)
1. The high intergranular corrosion resistance aircraft landing gear aluminum alloy is characterized by comprising the following chemical elements in percentage by weight:
Zn：9~12.5%；
Mg：1.5~4.5%；
Zr：0.05~0.25%；
Sc：0.05~0.2%；
Cu：1.0~3.0%；
Ti：0.005~0.5%；
Si：≤0.10%；
Fe：≤0.20%；
Mn：≤0.3%；
the content of other single impurities is less than or equal to 0.05 percent, the total content of the impurities is less than or equal to 0.15 percent, and the balance is Al;
wherein Ti, Sc, Cu and Zr are intermediate alloys, and the balance is pure alloy
Wherein w (Fe) is not less than w (Si) 0.05%; w (Na) is less than or equal to 5 ppm.
2. The aluminum alloy for aircraft landing gear with high intergranular corrosion resistance as recited in claim 1, wherein Cu is an intermediate alloy AlCu50, Zr is an intermediate alloy AlZr5, Sc is an intermediate alloy AlSc2, and Ti is a grain refiner AlTi5B1.
3. The method for preparing the high intergranular corrosion resistance aluminum alloy for aircraft landing gears according to claim 1, is characterized by comprising the following steps of:
s1: batching, wherein batching is carried out according to the requirements of chemical compositions and weight percentages of the alloy;
s2: casting, namely casting an aluminum alloy round ingot blank by adopting an electromagnetic horizontal continuous casting method, purifying a melt by adopting argon and a sodium-free refining agent, wherein the refining temperature is as follows: the refining time is 10-15min at 730-750 ℃; standing for more than 20min after refining, wherein the electromagnetic intensity is 10-45HZ, the casting temperature is 685-700 ℃, and the casting speed is 40-80 mm/min; pulse water is adopted for cooling, the temperature of cooling water is 20-35 ℃, and the pressure of the cooling water is 0.04-0.08 MPa;
s3: homogenizing, namely transferring the prepared round cast ingot to a homogenizing furnace for three-level homogenizing treatment, wherein the first-level homogenizing temperature: preserving the heat for 18-24 h at 380-400 ℃; second-stage homogenization temperature: keeping the temperature at 450-460 ℃ for 18-24 h; third-stage homogenization temperature: the temperature is 465-475 ℃, and the heat preservation time is 20-24 h;
s4, hot extrusion, ingot casting and peeling, wherein the extrusion temperature is 380-430 ℃, the extrusion ratio is more than or equal to 10, and the extrusion speed is 10-50 mm/S;
s5: carrying out solid solution treatment at the solid solution temperature of 450-465 ℃ for 1-3 h;
s6: carrying out three-stage aging treatment, wherein the first-stage aging temperature is 110-150 ℃, and the aging time is 20-24 h; the secondary aging temperature is 200-250 ℃, and the aging time is 0.5-1 h; the third stage aging temperature is 110-150 ℃, and the aging time is 20-24 h.
4. The method for preparing the aluminum alloy for the landing gear of the aircraft according to the claim 3, wherein in the step S3, the gate part of the ingot is wrapped by ceramic fiber felt and is stored transversely for less than 8 h.
5. The method for preparing the aluminum alloy for landing gears of airplanes according to claim 3, wherein in step S3, after the homogenization treatment, the furnace door is opened by one third, and then the process is suspended for 1 h; then opening the furnace door to two thirds, and pausing for 1 h; and completely opening the furnace door, taking out the cast ingot after 1 hour, and air cooling.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117127071A (en) * | 2023-10-27 | 2023-11-28 | 中铝材料应用研究院有限公司 | Aluminum alloy material and preparation method thereof |
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| CN117127071A (en) * | 2023-10-27 | 2023-11-28 | 中铝材料应用研究院有限公司 | Aluminum alloy material and preparation method thereof |
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