Deformation-resistant 7XXX aluminum alloy capable of being quenched on line and preparation process of deformation-resistant 7XXX aluminum alloy

Abstract

The invention discloses an anti-deformation 7XXX aluminum alloy capable of being quenched on line and a preparation process of the anti-deformation 7XXX aluminum alloy in the technical field of aluminum alloy material production, and the 7XXX aluminum alloy comprises the following components in percentage by mass: less than or equal to 0.1% of Si, less than or equal to 0.1% of Fe, 0.5-0.55% of Cu, less than or equal to 0.1% of Mn, 2.2-2.5% of Mg, 6.9-7.3% of Zn, 0.05-0.1% of Zr, less than or equal to 0.05% of Ti, 0.02-0.06% of Sc, less than or equal to 0.05% of single other elements, less than or equal to 0.15% of other elements and the balance of Al. The atomic ratio of Zr / Sc is limited to be 1.5-2.0, Sc forms an Al3 (Sc, Zr) core-shell structure, the recrystallization temperature is increased by 80 DEG C, the atomic ratio is limited to ensure that Sc / Zr synergistically inhibits an extrusion deformation texture, and the problem of insufficient grain boundary strengthening caused by ultralow Fe / Si is solved; the 7-series aluminum alloy can be subjected to online quenching, the production cycle of the 7-series aluminum alloy is shortened, and the tensile strength of the 7-series aluminum alloy reaches 550 MPa or above after the 7-series aluminum alloy is subjected to online quenching. And 2, the 7-series aluminum alloy disclosed by the invention can bear rapid extrusion without cracking, and the extrusion deformation degree of the product is small. And 3, the 7-series aluminum alloy has high deformation resistance, the falling degree at the height of 1m is less than 5mm, and the 7-series aluminum alloy does not crack after being bent within 120 degrees.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aluminum alloy material production, in particular to an anti-deformation 7XXX aluminum alloy capable of on-line quenching and a preparation process thereof. BACKGROUND

[0002] With the popularization of portable intelligent devices, product bumping, falling and deformation cannot be avoided, and materials with excellent anti-deformation performance have more advantages in market competition. At the same time, in the fields of aerospace, automobile and other industries, parts need to bear high load and complex stress while reducing weight, and traditional materials are difficult to balance strength and anti-deformation ability, so a kind of aluminum alloy material with high anti-deformation ability is needed.

[0003] Conventional 7XXX series aluminum alloy such as 7075 aluminum alloy is produced through processes such as batching, melting, melt purification, casting, casting rod homogenization, casting rod heating extrusion, off-line quenching, aging, finishing and the like. Off-line quenching is an indispensable process to strengthen the strength of the product, and its production process is complex and time-consuming, and the internal stress of the product will also increase due to deformation, reducing the anti-deformation ability. 7003 alloy has on-line quenching capability, but its strength is only 340MPa.

[0004] A certain device needs a lightweight aluminum alloy material with high anti-deformation performance, which requires high strength, small cross-sectional area, serious extrusion deformation and low yield, resulting in a shortage in the market, and an anti-deformation 7XXX aluminum alloy material with high anti-deformation and excellent extrusion performance is urgently needed.

[0005] Therefore, the present application designs an anti-deformation 7XXX aluminum alloy capable of on-line quenching and a preparation process thereof to solve the above problems. SUMMARY

[0006] The present application aims to provide an anti-deformation 7XXX aluminum alloy capable of on-line quenching and a preparation process thereof to solve the problems raised in the background.

[0007] To achieve the above object, the application provides the following technical scheme: An on-line quenchable anti-deformation 7XXX aluminum alloy, containing, in percentage by mass, Si≤0.1%, Fe≤0.1%, Cu: 0.5%-0.55%, Mn≤0.1%, Mg: 2.2%-2.5%, Zn: 6.9%-7.3%, Zr: 0.05-0.1%, Ti≤0.05%, Sc: 0.02%-0.06%, other elements≤0.05% each and ≤0.15% in total, and the balance being Al. The atomic ratio of Zr / Sc is limited to 1.5-2.0, and Sc forms an Al3(Sc, Zr) core-shell structure to increase the recrystallization temperature by 80°C, and the limited atomic ratio ensures that Sc / Zr cooperatively suppresses the extrusion deformation texture, thereby solving the problem of insufficient grain boundary strengthening caused by ultra-low Fe / Si.

[0008] A preparation process of an on-line quenchable anti-deformation 7XXX aluminum alloy, comprising the following steps:

[0009] 1) The aluminum alloy is prepared by batching and smelting: aluminum ingots, aluminum copper intermediate alloy, aluminum zirconium intermediate alloy, aluminum zinc intermediate alloy, aluminum scandium intermediate alloy and titanium agent are sequentially added to a smelting furnace for smelting; the smelting temperature is set to 740-760°C, after the batching is completely melted, a slagging agent is scattered to perform slagging, and electromagnetic stirring is performed for more than twice; when the temperature rises to 730-750°C, magnesium ingots are pressed into the melt and stirring is performed;

[0010] 2) Refining: the melt obtained in step 1) is refined by using a refining vehicle to pass argon and a refining agent into the melt, an ultrasonic field of 25-30 kHz is applied for 8-10 min, and then slagging is performed; the refining agent is a nanoparticle refining agent, the specific surface area of the adsorbed inclusions is 5 times that of a traditional refining agent, ultrasonic cavitation increases the dispersity of the nanoparticles to 92% (compared with 65% without ultrasonic treatment)-reducing the refining time by 40% and the slag amount by 35%.

[0011] 3) Standing;

[0012] 4) Casting;

[0013] 5) Ingot homogenization: the ingot obtained in step 4) is subjected to homogenization treatment, the homogenization temperature is 450-460°C, the temperature is maintained for 4-5 h, then the temperature is raised to 490-500°C, the temperature is maintained for 18-20 h, and then the furnace is discharged for air cooling; gradient cooling induces η' phase (MgZn2) pre-precipitation as a subsequent aging nucleation point, so that the distribution density of the η phase in the final aging is increased by 50%, thereby breaking through the problem of quenching stress caused by traditional homogenization and fast cooling.

[0014] 6) profile extrusion: the ingot obtained in step 5) is heated at 470-490℃, a profile with a thickness less than 8mm is selected, the profile speed is 3-6m / min, liquid nitrogen atomization spraying cooling is performed, and the cooling rate is ≥300℃ / s; the coarse precipitated phase is inhibited by the ultra-high cooling rate, the surface hardness is increased by 15HV, the fatigue crack initiation life is prolonged by 3 times, and the problem of uneven cooling of thick sections is solved compared with the conventional water cooling with a cooling rate of ≤100℃ / s.

[0015] 7) profile aging: the profile obtained in step 6) is subjected to cryogenic treatment at a temperature of -190℃ for 2h, then room temperature is recovered, and then aging treatment is performed, the heating temperature is 105-115℃, the holding time is 5-6h, then the temperature is increased to 135-145℃, the holding time is 8-10h, and then the furnace is discharged and air cooled; the high-density dislocation is induced by deep cooling, the η phase heterogeneous nucleation site is provided, the yield strength after aging is broken through 650MPa (compared with 610MPa without deep cooling), and the problem of aging response delay of high-Zn alloy is solved.

[0016] 8) deformation resistance test.

[0017] Preferably, the casting in step 4) is to cast the melt obtained in step 3) at a casting speed of 80-100mm / min, and the cooling water flow is controlled at 1000-1200L / min

[0018] Preferably, the standing in step 3) is to heat the melt obtained in step 2) to 750-770℃, and then stand for 30min.

[0019] Preferably, the deformation resistance test in step 8) is to process the profile obtained in step 7) into a standard sample, and perform drop test and bending test.

[0020] Compared with the prior art, the beneficial effects of the present application are:

[0021] 1. The 7-series aluminum alloy of the present application can be subjected to online quenching, the production cycle of the 7-series aluminum alloy is reduced, and the tensile strength after online quenching is above 550MPa.

[0022] 2. The 7-series aluminum alloy of the present application can withstand rapid extrusion without cracking, and the product has a small degree of extrusion deformation.

[0023] 3. The 7-series aluminum alloy of the present application has high deformation resistance, the degree of 1m height drop is less than 5mm, and does not crack within 120° bending.

[0024] Of course, any product implementing the present application does not necessarily need to achieve all the advantages described above at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the description of the embodiments, obviously, the drawings in the following description are only some of the embodiments of the present application, and for those skilled in the art, other drawings can also be obtained without creative labor on the basis of these drawings.

[0026] Figure 1 Inventive structure step block diagram DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application, obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] Embodiment one

[0029] The present application provides a kind of online quenching anti-deformation 7XXX aluminum alloy and its preparation process technical solutions: a kind of online quenching anti-deformation 7XXX aluminum alloy, according to percentage by mass, 7XXX aluminum alloy includes: Si≤0.1%, Fe≤0.1%, Cu: 0.5%~0.55%, Mn≤0.1%, Mg: 2.2%~2.5%, Zn: 6.9%~7.3%, Zr: 0.05~0.1%, Ti≤0.05%, Sc: 0.02% -0.06%, other elements single≤0.05%, other elements total≤0.15%, the rest is Al.

[0030] A kind of preparation process of online quenching anti-deformation 7XXX aluminum alloy, comprising the following steps:

[0031] 1) according to mass fraction, smelting aluminum alloy is prepared: aluminum ingot, aluminum copper intermediate alloy, aluminum zirconium intermediate alloy, aluminum zinc intermediate alloy, aluminum scandium intermediate alloy, titanium agent are sequentially added to smelting furnace for smelting;Smelting temperature is set at 740-760 ℃, after complete melting of ingredients, sprinkle into skimming agent for skimming, and carry out more than 2 times electromagnetic stirring;When the temperature rises to 730-750 ℃, magnesium ingot is pressed into the melt, and stirring is carried out;

[0032] 2) refining: the melt obtained by step 1) is refined by using refining car to pass argon and refining agent into the melt, and 8-10 min of 25-30 kHz ultrasonic field treatment is applied, and then skimming is carried out;

[0033] 3) static setting;The melt obtained by step 2) is heated to 750-770 ℃, and then static setting is carried out for 30 min;

[0034] 4) Casting; the melt obtained in step 3) is subjected to casting, the casting speed is 80-100 mm / min, and the cooling water flow is controlled at 1000-1200 L / min;

[0035] 5) Ingot homogenization: the ingot obtained in step 4) is subjected to homogenization treatment, the homogenization temperature is 450-460 DEG C, the temperature is kept for 4-5 h, then the temperature is raised to 490-500 DEG C, the temperature is kept for 18-20 h, and then the furnace is discharged and air-cooled;

[0036] 6) Profile extrusion: the ingot obtained in step 5) is heated to 470-490 DEG C, a profile with a thickness less than 8 mm is selected as a mold, the profile speed is 3-6 m / min, and the profile is subjected to liquid nitrogen atomization spraying cooling at a cooling rate of greater than or equal to 300 DEG C / s;

[0037] 7) Profile aging: the profile obtained in step 6) is subjected to deep cooling treatment at a temperature of -190 DEG C for 2 h, then the temperature is raised to room temperature, and then the profile is subjected to aging treatment at a heating temperature of 105-115 DEG C for 5-6 h, and then the temperature is raised to 135-145 DEG C for 8-10 h, and then the furnace is discharged and air-cooled;

[0038] 8) Deformation resistance test: the profile obtained in step 7) is processed into a standard sample, and drop test and bending test are performed.

[0039] Example two:

[0040] The application provides an on-line quenchable deformation-resistant 7XXX aluminum alloy and a preparation process thereof.

[0041] The application provides an on-line quenchable deformation-resistant 7XXX aluminum alloy and a preparation process thereof.

[0042] 1) According to the mass fraction, the aluminum alloy is prepared and smelted: aluminum ingots, aluminum copper intermediate alloy, aluminum zirconium intermediate alloy, aluminum zinc intermediate alloy, aluminum scandium intermediate alloy and titanium agent are sequentially added into a smelting furnace for smelting; the smelting temperature is set to 740-760 DEG C, after the ingredients are completely melted, a slagging agent is scattered for slagging, and electromagnetic stirring is performed more than twice; when the temperature rises to 730-750 DEG C, magnesium ingots are pressed into the melt, and stirring is performed;

[0043] 2) Refining: the melt obtained from step 1) is refined by passing argon and a refining agent into the melt using a refining car, applying an ultrasonic field of 25-30 kHz for 8-10 min, after which slagging is performed;

[0044] 3) Resting;

[0045] 4) Casting;

[0046] 5) Ingot homogenization: the ingot obtained from step 4) is subjected to homogenization treatment, the homogenization temperature being 450-460°C, with a holding time of 4-5 h, then the temperature is raised to 490-500°C, with a holding time of 18-20 h, and then the ingot is removed from the furnace and air cooled;

[0047] 6) Profile extrusion: the ingot obtained from step 5) is heated to 470-490°C, a profile with a thickness of less than 8 mm is selected for the mold, the profile speed is 3-6 m / min, and the profile is subjected to liquid nitrogen mist cooling at a cooling rate of ≥300°C / s;

[0048] 7) Profile aging: the profile obtained from step 6) is subjected to cryogenic treatment at a temperature of -190°C for 2 h, then the temperature is raised to room temperature, and then the profile is subjected to aging treatment, the heating temperature being 105-115°C, with a holding time of 5-6 h, then the temperature is raised to 135-145°C, with a holding time of 8-10 h, and then the profile is removed from the furnace and air cooled;

[0049] 8) Profile re-aging: the profile is subjected to re-aging treatment, the heating temperature being 135-140°C, with a holding time of 15-17 h, and then the profile is removed from the furnace and air cooled;

[0050] 9) Deformation resistance test.

[0051] Further, the casting in step 4) is casting the melt obtained from step 3) at a casting speed of 80-100 mm / min, with a cooling water flow rate of 1000-1200 L / min.

[0052] Further, the resting in step 3) is heating the melt obtained from step 2) to 750-770°C, and then resting for 30 min.

[0053] Further, the deformation resistance test in step 9) is processing the profile obtained from step 7) into a standard sample, and then performing a drop test and a bending test.

[0054] Example Three:

[0055] The application provides an on-line quenchable anti-deformation 7XXX aluminum alloy and a preparation process thereof.

[0056] A preparation process of the on-line quenchable anti-deformation 7XXX aluminum alloy comprises the following steps.

[0057] 1) ingredient preparation according to mass fraction, smelting of the aluminum alloy: aluminum ingot, aluminum copper intermediate alloy, aluminum zirconium intermediate alloy, aluminum zinc intermediate alloy, aluminum scandium intermediate alloy and titanium agent are sequentially added into a smelting furnace for smelting; the smelting temperature is set to 740-760 DEG C; after the ingredients are completely melted, a slagging agent is scattered for slagging, and electromagnetic stirring is performed for more than twice; when the temperature rises to 730-750 DEG C, magnesium ingot is pressed into the melt, and stirring is performed;

[0058] 2) refining: the melt obtained in step 1) is refined by using a refining vehicle to pass argon and a refining agent into the melt, and is subjected to ultrasonic field treatment at 25-30 kHz for 8-10 min, and then is subjected to slagging;

[0059] 3) standing;

[0060] 4) casting;

[0061] 5) ingot homogenization: the ingot obtained in step 4) is subjected to homogenization treatment, the homogenization temperature is 450-460 DEG C, the holding time is 4-5 h, then the temperature is raised to 490-500 DEG C, the holding time is 18-20 h, and then the furnace is discharged for air cooling;

[0062] 6) profile extrusion: the ingot obtained in step 5) is heated to 470-490 DEG C, the mold is selected to be a profile with a thickness less than 8 mm, the profile speed is 3-6 m / min, liquid nitrogen atomization spraying cooling is performed, and the cooling rate is greater than or equal to 300 DEG C / s;

[0063] 7) profile aging: the profile obtained in step 6) is subjected to cryogenic treatment at a temperature of -190 DEG C for 2 h, then is subjected to room temperature recovery, and then is subjected to aging treatment, the heating temperature is 105-115 DEG C, the holding time is 5-6 h, then the temperature is raised to 135-145 DEG C, the holding time is 8-10 h, and then the furnace is discharged for air cooling;

[0064] 8) anti-deformation test.

[0065] Further, the casting in step 4) is casting the melt obtained in step 3) at a casting speed of 80-100 mm / min, and the cooling water flow is controlled at 1000-1200 L / min.

[0066] Further, the standing in step 3) is heating the melt obtained in step 2) to 750-770 ℃, and then standing for 30 min.

[0067] Further, the deformation resistance test in step 8) is processing the profile obtained in step 7) into a standard sample, and then performing a drop test and a bending test.

[0068] Example Four:

[0069] The application provides an on-line quenchable deformation-resistant 7XXX aluminum alloy and a preparation process thereof.

[0070] A preparation process of an on-line quenchable deformation-resistant 7XXX aluminum alloy, comprising the following steps:

[0071] 1) dosing according to the mass fraction, smelting the aluminum alloy: aluminum ingots, aluminum copper intermediate alloy, aluminum zirconium intermediate alloy, aluminum zinc intermediate alloy, aluminum scandium intermediate alloy, titanium agent are sequentially added into a smelting furnace for smelting; the smelting temperature is set at 740-760 ℃, after the dosing is completely melted, a slagging agent is scattered for slagging, and electromagnetic stirring is performed for more than twice; when the temperature rises to 730-750 ℃, magnesium ingots are pressed into the melt, and stirring is performed;

[0072] 2) refining: the melt obtained in step 1) is refined by using a refining vehicle to pass argon and a refining agent into the melt, and an ultrasonic field treatment of 25-30 kHz is applied for 8-10 min, and then slagging is performed;

[0073] 3) standing: the melt obtained in step 2) is heated to 750-770 ℃, and then standing for 30 min;

[0074] 4) casting: the melt obtained in step 3) is cast at a casting speed of 80-100 mm / min, and the cooling water flow is controlled at 1000-1200 L / min;

[0075] 5) Ingot homogenization: the ingot obtained in step 4) is subjected to homogenization treatment, the homogenization temperature is 450-460 DEG C, the holding time is 4-5 h, then the temperature is increased to 490-500 DEG C, the holding time is 18-20 h, and then the furnace is discharged and air-cooled;

[0076] 6) Profile extrusion: the ingot obtained in step 5) is heated to 470-490 DEG C, the die is selected to be a profile with a thickness less than 8 mm, the profile speed is 3-6 m / min, and the profile is subjected to liquid nitrogen atomization spraying cooling at a cooling rate of greater than or equal to 300 DEG C / s;

[0077] 7) Profile aging: the profile obtained in step 6) is subjected to cryogenic treatment at a temperature of -190 DEG C for 2 h, then the temperature is increased to room temperature, and then the profile is subjected to aging treatment at a heating temperature of 105-115 DEG C for 5-6 h, and then the temperature is increased to 135-145 DEG C for 8-10 h, and then the furnace is discharged and air-cooled;

[0078] 8) Deformation resistance test: the profile obtained in step 7) is processed into a standard sample, and drop test and bending test are performed.

[0079] Example Five

[0080] The application provides an on-line quenchable deformation-resistant 7XXX aluminum alloy and a preparation process thereof.

[0081] The application provides an on-line quenchable deformation-resistant 7XXX aluminum alloy and a preparation process thereof.

[0082] 1) According to the mass fraction, the aluminum alloy is prepared by melting: the aluminum ingot, the aluminum copper intermediate alloy, the aluminum zirconium intermediate alloy, the aluminum zinc intermediate alloy, the aluminum scandium intermediate alloy and the titanium agent are sequentially added into a melting furnace for melting; the melting temperature is set to be 740-760 DEG C; after the ingredients are completely melted, the skimming agent is scattered for skimming, and electromagnetic stirring is performed more than twice; when the temperature is increased to 730-750 DEG C, the magnesium ingot is pressed into the melt, and stirring is performed;

[0083] 2) Refining: the melt obtained in step 1) is refined by using a refining vehicle to pass argon and a refining agent into the melt for refining, and an ultrasonic field with a frequency of 25-30 kHz is applied for 8-10 min, and then skimming is performed;

[0084] 3) Rest; the melt obtained from step 2) is heated to 750-770°C, and then rested for 30 min;

[0085] 4) Casting; the melt obtained from step 3) is cast at a casting speed of 80-100 mm / min, and the cooling water flow is controlled at 1000-1200 L / min;

[0086] 5) Ingot homogenization; the ingot obtained from step 4) is subjected to homogenization treatment at a homogenization temperature of 450-460°C for 4-5 h, and then raised to 490-500°C for 18-20 h, and then air-cooled after furnace discharge;

[0087] 6) Profile extrusion; the ingot obtained from step 5) is heated to 470-490°C, and a profile with a thickness of less than 8 mm is selected for the mold, and the profile speed is 2-3 m / min, and liquid nitrogen atomization spraying cooling is performed at a cooling rate of ≥300°C / s;

[0088] 7) Profile aging; the profile obtained from step 6) is subjected to cryogenic treatment at a temperature of -190°C for 2 h, and then room temperature is raised, and aging treatment is performed at a heating temperature of 105-115°C for 5-6 h, and then raised to 135-145°C for 8-10 h, and then air-cooled after furnace discharge;

[0089] 8) Deformation resistance test; the profile obtained from step 7) is processed into a standard sample, and drop test and bending test are performed.

[0090] Comparative Example 1, Example 2 and Example 1 are subjected to two different aging strengthening processes, respectively. Example 1 is a peak aging process, and Example 2 is overaging.

[0091] Comparative Example 2, Example 3 and Example 1 are different in that the mass percentage content of Cu and Zn in Example 2 is increased, and the remaining steps are the same.

[0092] Comparative Example 3, Example 4 and Example 1 are different in that Mn and Cr are added in Example 3, and the mass percentage content is increased, and the remaining steps are the same.

[0093] Comparative Example 4, Example 5 and Example 1 are subjected to two different extrusion speeds processes. Example 1 is fast extrusion, and Example 5 is slow extrusion.

[0094] The following table shows the tensile strength and deformation resistance test of each example

[0095] Table 1 shows the detection of different component mass percentages

[0096]

[0097] Table 2 shows the detection of different processes

[0098]

[0099] In the description of the present specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in an appropriate manner.

[0100] The preferred embodiments of the application disclosed above are only used to help explain the application. The preferred embodiments do not describe all the details of the application and limit the application to the specific embodiments described. Obviously, many modifications and variations can be made according to the content of the present specification. The present specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the application, so that those skilled in the art can well understand and utilize the application. The application is limited only by the claims and their full scope and equivalents.

Claims

1. An on-line quenchable, strain resistant 7XXX aluminum alloy characterized in that: The 7XXX aluminum alloy contains, by mass percent: Si≤0.1%, Fe≤0.1%, Cu: 0.5%-0.55%, Mn≤0.1%, Mg: 2.2%-2.5%, Zn: 6.9%-7.3%, Zr: 0.05-0.1%, Ti≤0.05%, Sc: 0.02%-0.06%, other elements≤0.05% individually, other elements≤0.15% in total, and the balance being Al.

2. A process for making an on-line quenchable, strain resistant 7XXX aluminum alloy according to claim 1, characterized in that: The method comprises the following steps: 1) batching according to mass fraction, smelting the aluminum alloy: aluminum ingots, aluminum copper intermediate alloy, aluminum zirconium intermediate alloy, aluminum zinc intermediate alloy, aluminum scandium intermediate alloy, and titanium agent are sequentially added to a smelting furnace for smelting; the smelting temperature is set to 740-760°C; after the ingredients are completely melted, a slagging agent is scattered to perform slagging, and electromagnetic stirring is performed more than twice; when the temperature rises to 730-750°C, magnesium ingots are pressed into the melt and stirring is performed; 2) refining: the melt obtained in step 1) is refined by using a refining vehicle to pass argon and a refining agent into the melt, and an ultrasonic field of 25-30 kHz is applied for 8-10 min, after which slagging is performed; 3) standing; 4) casting; 5) ingot homogenization: the ingot obtained in step 4) is subjected to homogenization treatment, the homogenization temperature is 450-460°C, the holding time is 4-5 h, then the temperature is raised to 490-500°C, the holding time is 18-20 h, and then the furnace is blown and air-cooled; 6) profile extrusion: the ingot obtained in step 5) is heated to 470-490°C, a profile with a thickness of less than 8 mm is selected as the mold, the profile speed is 3-6 m / min, liquid nitrogen atomization spraying cooling is performed, and the cooling rate is ≥300°C / s; 7) profile aging: the profile obtained in step 6) is subjected to cryogenic treatment at a temperature of -190°C for 2 h, then room temperature is recovered, and aging treatment is performed, the heating temperature is 105-115°C, the holding time is 5-6 h, then the temperature is raised to 135-145°C, the holding time is 8-10 h, and then the furnace is blown and air-cooled; 8) deformation resistance test.

3. A process for making an on-line quenchable, strain resistant 7XXX aluminum alloy according to claim 1, characterized in that: The casting in step 4) is casting the melt obtained in step 3), the casting speed is 80-100 mm / min, and the cooling water flow rate is controlled to 1000-1200 L / min.

4. A process for making an on-line quenchable, strain resistant 7XXX aluminum alloy according to claim 1, characterized in that: The standing in step 3) is heating the melt obtained in step 2) to 750-770°C, and then standing for 30 min.

5. An on-line quenchable, strain resistant 7XXX aluminum alloy and process for making the same according to claim 1, characterized in that: The deformation resistance test in step 8) is processing the profile obtained in step 7) into a standard sample, and performing drop test and bending test.

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