Ultrahigh-strength collision energy-absorbing aluminum-magnesium-silicon-copper alloy profile and preparation method thereof

Abstract

The invention discloses an ultrahigh-strength collision energy absorption aluminum-magnesium-silicon-copper alloy profile and a preparation method thereof. The ultrahigh-strength collision energy absorption aluminum-magnesium-silicon-copper alloy profile is prepared from, by mass, 1.2%-1.4% of Si, smaller than or equal to 0.2% of Fe, 0.50%-0.80% of Cu, 0.50%-0.8% of Mn, 1.0%-1.3% of Mg, 0.15%-0.20% of Cr, smaller than or equal to 0.20% of Zn, 0.01%-0.05% of Ti, smaller than or equal to 0.20% of V, 0.10%-0.20% of Zr, smaller than or equal to 0.05% of other single impurities, smaller than or equal to 0.10% of total impurities and the balance Al. Through strict limitation of chemical components, impurity and gas contents and homogenization, extrusion and heat treatment systems, the aluminum alloy has excellent transverse and longitudinal collision energy absorption performance under the condition of sufficient strengthening, the yield strength of the aluminum alloy is larger than 360 MPa, the tensile strength is 390-430 MPa, the transverse bending angle is larger than or equal to 75 degrees, the longitudinal bending angle is larger than or equal to 65 degrees, and the tensile strength is larger than or equal to 390 MPa. After 60% of axial compression, no through crack larger than 10 mm occurs; and meanwhile, the dual requirements of light weight and safety of the automobile are met.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum-magnesium-silicon-copper alloy profiles, and in particular to an ultra-high-strength collision energy-absorbing aluminum-magnesium-silicon-copper alloy profile and a preparation method thereof. Background Art

[0002] As the most widely used aluminum alloy, 6 series aluminum-magnesium-silicon (copper) alloy has excellent mechanical properties, corrosion resistance and weldability, and is very suitable for automotive body structural parts. In 6 series alloys, strength is mainly related to the degree of alloying, heat processing technology and heat treatment status. The higher the degree of alloying, the more precipitated phase content is available for strengthening, and the corresponding strength level is also higher. However, as the degree of alloying increases, the extrudability decreases, and the processing technology window that can meet the comprehensive performance of strength and collision energy absorption becomes narrower.

[0003] Existing energy-absorbing aluminum alloy materials used to manufacture automobile structures, such as CN109468502A, disclose that the aluminum alloy belongs to the Al-Mg-Si-Mn alloy system, contains main alloying elements Mg, Si, Mn and trace elements Cr, Er, La, Sr, Ti, B, and its manufacturing method includes smelting and preparing aluminum alloy liquid, furnace blowing refining, online refinement and modification, online degassing and filtration, semi-continuous casting, ingot homogenization, heating and extrusion, online quenching and artificial aging; the aluminum alloy materials in the prior art have low collision strength when used for automobile structures or structural beams or automobile energy-absorbing devices, and cannot meet the collision safety requirements of automobiles in daily use.

[0004] Therefore, those skilled in the art are in urgent need of improving an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile and a preparation method thereof to improve the safety of automobile collisions. Summary of the invention

[0005] The purpose of the present invention is to provide an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile and a preparation method thereof, so as to solve the problems existing in the above-mentioned prior art.

[0006] An ultra-high-strength collision energy-absorbing aluminum-magnesium-silicon-copper alloy profile and a preparation method thereof, comprising the following components in mass percentage: Si: 1.2-1.4%, Fe≤0.2%, Cu: 0.50-0.80%, Mn: 0.50-0.8%, Mg: 1.0-1.3%, Cr: 0.15-0.20%, Zn≤0.20%, Ti: 0.01-0.05%, V≤0.20%, Zr: 0.10-0.20%, other single impurities≤0.05%, total impurities≤0.10%, and the balance is Al.

[0007] Preferably, it is composed of the following components in mass percentage: Si: 1.31%, Fe: 0.07%, Cu: 0.64%, Mn: 0.75%, Mg: 1.09%, Cr: 0.16%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, total impurities ≤ 0.10%, and the balance is Al.

[0008] Preferably, it is composed of the following components in mass percentage: Si: 1.23%, Fe: 0.07%, Cu: 0.55%, Mn: 0.56%, Mg: 1.01%, Cr: 0.17%, Zn: 0.17%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, total impurities ≤ 0.10%, and the balance is Al.

[0009] Preferably, it is composed of the following components in mass percentage: Si: 1.34%, Fe: 0.08%, Cu: 0.76%, Mn: 0.76%, Mg: 1.25%, Cr: 0.17%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, total impurities ≤ 0.10%, and the balance is Al.

[0010] The technical solution also provides a method for preparing a recycled aluminum alloy material for an automobile energy absorption box, comprising the following steps:

[0011] S1: Ingredients; Ingredients are prepared according to the mass percentage of alloy elements, wherein Si is in the form of industrial crystalline silicon or Al-Si or Mg-Si master alloy; Mn and Zr are in the form of aluminum-containing master alloy; Ti is in the form of AlTi or AlTiB master alloy and is used as a grain refining additive;

[0012] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 760-790℃ to melt the raw materials;

[0013] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0014] S4: casting; casting the liquid aluminum alloy at 680-700° C. to obtain a round ingot with a diameter of 178-259 mm;

[0015] S5: homogenization treatment: the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 400-450°C for 5-10 hours, and the second stage homogenization treatment is performed at 530-570°C for 5-10 hours, followed by strong air cooling or water mist cooling;

[0016] S6: extrusion; preheat the homogenized ingot to 490±20°C by induction heating, extrude at an extrusion speed of 2.0-4.0 mm / s, an extrusion ratio of 20-50, and an extrusion outlet temperature of 530-550°C;

[0017] S7: Quenching; the quenching temperature is ≥530℃, and the quenching is carried out at a cooling rate of not less than 500℃ / min;

[0018] S8: stretching; control the stretching rate range from 0.5% to 1.5%;

[0019] S9: Aging: Perform artificial aging to obtain ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profiles.

[0020] Preferably, the parking time interval from the end time of the quenching to the start time of the artificial aging is within 8 hours.

[0021] Preferably, the artificial aging adopts T7 treatment, the aging temperature is controlled at 200-210° C., and the insulation time is 4 to 7 hours.

[0022] Preferably, the preheating time for extrusion is 120S.

[0023] Preferably, the extrusion ratio of the extrusion is 35, and the extrusion outlet temperature is 530-535°C.

[0024] Preferably, the stretching ratio of the stretching is in the range of 0.5%.

[0025] Compared with the prior art, the present invention provides an ultra-high-strength collision energy-absorbing aluminum-magnesium-silicon-copper alloy profile and a preparation method thereof, which has the following beneficial effects:

[0026] 1. By strictly limiting the chemical composition, impurity and gas content, homogenization, extrusion and heat treatment system, the aluminum alloy can obtain excellent transverse and longitudinal collision energy absorption under the condition of sufficient strengthening. Its yield strength is greater than 360MPa, tensile strength is 390-430MPa, transverse bending angle is ≥75°, longitudinal bending angle is ≥65°, and no through cracks greater than 10mm appear after axial compression of 60%.

[0027] 2. Meet the dual requirements of automobile lightweight and safety at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0029] Figure 1 Schematic diagram of the relationship between axial compression displacement and force value of the profiles prepared in Examples 1-6 and Comparative Examples 1-3 of the present invention;

[0030] Figure 2 This is a schematic diagram of the axial compression of the sample obtained in Example 4 of the present invention;

[0031] Figure 3 This is a schematic diagram of the axial compression of the sample prepared in Comparative Example 2 of the present invention;

[0032] Figure 4 This is a schematic diagram of the dispersed phase distribution of the homogeneous sample of Example 4 of the present invention;

[0033] Figure 5 This is a schematic diagram of the distribution of strengthening precipitation phases after aging in Example 4 of the present invention. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] The technical solution of the present invention is achieved in this way:

[0037] An ultra-high-strength collision energy-absorbing aluminum-magnesium-silicon-copper alloy profile is composed of the following components in percentage by mass: Si: 1.2-1.4%, Fe≤0.2%, Cu: 0.50-0.80%, Mn: 0.50-0.8%, Mg: 1.0-1.3%, Cr: 0.15-0.20%, Zn≤0.20%, Ti: 0.01-0.05%, V≤0.20%, Zr: 0.10-0.20%, other single impurities≤0.05%, total impurities≤0.10%, and the balance is Al.

[0038] A method for preparing an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile, which is used to prepare an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile, comprises the following steps:

[0039] S1: Ingredients; Ingredients are prepared according to the mass percentage of alloy elements, wherein Si is in the form of industrial crystalline silicon or Al-Si or Mg-Si master alloy; Mn and Zr are in the form of aluminum-containing master alloy; Ti is in the form of AlTi or AlTiB master alloy and is used as a grain refining additive;

[0040] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 760-790℃ to melt the raw materials;

[0041] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0042] S4: casting; casting the liquid aluminum alloy at 680-700° C. to obtain a round ingot with a diameter of 178-259 mm;

[0043] S5: homogenization treatment: the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 400-450℃ for 5-10h, and the second stage homogenization treatment is performed at 530-570℃ for 5-10h, followed by strong wind cooling or water mist cooling;

[0044] S6: extrusion; preheat the homogenized ingot to 490±20°C by induction heating, extrude at an extrusion speed of 2.0-4.0 mm / s, an extrusion ratio of 20-50, and an extrusion outlet temperature of 530-550°C;

[0045] S7: Quenching; the quenching temperature is ≥530℃, and the quenching is carried out at a cooling rate of not less than 500℃ / min;

[0046] S8: stretching; control the stretching rate range from 0.5% to 1.5%;

[0047] S9: Aging: Perform artificial aging to obtain ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profiles.

[0048] In the present invention, Mn and Zr are in the form of an aluminum-containing master alloy; the aluminum-containing master alloy is an alloy form formed by adding Mn and Zr to aluminum as a matrix; pure aluminum, Mn and Zr are added into a melting furnace in a certain proportion, heated and melted at a high temperature, and each element is fully mixed and uniformly mixed by stirring and other means, and then cooled and solidified to obtain an aluminum-containing master alloy.

[0049] The artificial aging in the present invention adopts T7, i.e., solution treatment plus stabilization treatment; solution treatment: heating the alloy to a high-temperature single-phase region and maintaining the temperature at a constant temperature, so that the excess phase is fully dissolved into the solid solution and then rapidly cooled to obtain a supersaturated solid solution; stabilization treatment: during artificial aging, the strength is made to pass the highest peak point on the aging curve, and the alloy is kept at a certain temperature for a period of time, so as to promote the decomposition of the supersaturated solid solution in the alloy and form a relatively stable organizational state, so as to improve the dimensional stability of the alloy, reduce the residual stress, and enhance the corrosion resistance.

[0050] The artificial aging temperature is controlled at 200-210°C, and the holding time is 4-7h; the parking time interval from the end of quenching to the start of artificial aging is within 8 hours.

[0051] The present invention is suitable for automobile structural parts, especially structural beams with special requirements for lateral and longitudinal collision safety in limited space; by strictly limiting the chemical composition, impurity and gas content, homogenization, extrusion and heat treatment system, the aluminum alloy can obtain excellent lateral and longitudinal collision energy absorption under the condition of sufficient strengthening, and its yield strength is greater than 360MPa, tensile strength is 390-430MPa, lateral bending angle is greater than 75°, longitudinal bending angle is greater than 65°, and no through cracks greater than 10mm appear after axial compression of 60%; at the same time, the dual requirements of automobile lightweight and safety are met.

[0052] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below; if no specific conditions are specified in the embodiments, the process is carried out according to conventional conditions or conditions recommended by the manufacturer; if the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0053] The following is a detailed description of an embodiment of an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile and a preparation method thereof according to the present invention.

[0054] Embodiment 1:

[0055] S1: ingredients; Si: 1.25%, Fe: 0.07%, Cu: 0.55%, Mn: 0.54%, Mg: 1.04%, Cr: 0.17%, Zn: 0.18%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, each unavoidable impurity element is less than 0.05%, the total amount of impurities is less than 0.10%, and the balance is Al, among which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0056] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 780°C to melt the raw materials;

[0057] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0058] S4: casting; casting the liquid aluminum alloy at 685-690° C. to obtain a round ingot with a diameter of 254±2 mm;

[0059] S5: homogenization treatment; the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 420°C for 6 hours, the second stage homogenization treatment is performed at 560°C for 8 hours, and then cooled by strong air cooling;

[0060] S6: Extrusion: preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.5mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0061] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0062] S8: stretching; the profile is stretched by 0.5%;

[0063] S9: Aging: artificial aging of the profile at 205℃ for 4h, with a storage time of <5h;

[0064] After aging is completed, performance analysis is performed.

[0065] Embodiment 2:

[0066] S1: ingredients; Si: 1.23%, Fe: 0.07%, Cu: 0.55%, Mn: 0.56%, Mg: 1.01%, Cr: 0.17%, Zn: 0.17%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, each unavoidable impurity element is less than 0.05%, the total impurity is less than 0.10%, the balance is Al, of which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0067] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 780°C to melt the raw materials;

[0068] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0069] S4: casting; casting the liquid aluminum alloy at 685-690° C. to obtain a round ingot with a diameter of 254±2 mm;

[0070] S5: homogenization treatment; the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 420°C for 6 hours, the second stage homogenization treatment is performed at 560°C for 8 hours, and then cooled by water mist;

[0071] S6: Extrusion: preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.5mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0072] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0073] S8: stretching; the profile is stretched by 0.5%;

[0074] S9: Aging: artificial aging of the profile at 205℃ for 6h, with a storage time of <5h;

[0075] After aging is completed, performance analysis is performed.

[0076] Embodiment 3:

[0077] S1: ingredients; Si: 1.31%, Fe: 0.07%, Cu: 0.64%, Mn: 0.76%, Mg: 1.12%, Cr: 0.16%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.17%, each unavoidable impurity element is less than 0.05%, the total amount of impurities is less than 0.10%, and the balance is Al, among which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0078] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 775°C to melt the raw materials;

[0079] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0080] S4: casting; casting the liquid aluminum alloy at 685-690° C. to obtain a round ingot with a diameter of 254±2 mm;

[0081] S5: homogenization treatment; the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 420°C for 6 hours, the second stage homogenization treatment is performed at 540°C for 8 hours, and then cooled by strong air cooling;

[0082] S6: Extrusion: preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.5mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0083] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0084] S8: stretching; the profile is stretched by 0.5%;

[0085] S9: Aging: artificial aging of the profile at 205℃ for 4h, with a storage time of <5h;

[0086] After aging is completed, performance analysis is performed.

[0087] Embodiment 4:

[0088] S1: ingredients; Si: 1.31%, Fe: 0.07%, Cu: 0.64%, Mn: 0.75%, Mg: 1.09%, Cr: 0.16%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, each unavoidable impurity element is less than 0.05%, the total amount of impurities is less than 0.10%, and the balance is Al, among which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0089] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 775°C to melt the raw materials;

[0090] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0091] S4: casting; casting the liquid aluminum alloy at 685-690° C. to obtain a round ingot with a diameter of 254±2 mm;

[0092] S5: homogenization treatment; the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 420°C for 6 hours, the second stage homogenization treatment is performed at 540°C for 8 hours, and then cooled by water mist;

[0093] S6: Extrusion: preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.5mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0094] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0095] S8: stretching; the profile is stretched by 0.5%;

[0096] S9: Aging: artificial aging of the profile at 205℃ for 6h, with a storage time of <5h;

[0097] After aging is completed, performance analysis is performed.

[0098] Embodiment 5:

[0099] S1: ingredients; Si: 1.37%, Fe: 0.08%, Cu: 0.73%, Mn: 0.79%, Mg: 1.22%, Cr: 0.17%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, each unavoidable impurity element is less than 0.05%, the total amount of impurities is less than 0.10%, and the balance is Al, among which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0100] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 770°C to melt the raw materials;

[0101] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0102] S4: casting; casting the liquid aluminum alloy at 680-685° C. to obtain a round ingot with a diameter of 254±2 mm;

[0103] S5: homogenization treatment; the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 440°C for 6 hours, the second stage homogenization treatment is performed at 560°C for 8 hours, and then cooled by water mist;

[0104] S6: Extrusion; preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.0mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0105] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0106] S8: stretching; the profile is stretched by 0.5%;

[0107] S9: Aging: artificial aging of the profile at 205℃ for 4h, with a storage time of <5h;

[0108] After aging is completed, performance analysis is performed.

[0109] Embodiment 6:

[0110] S1: ingredients; Si: 1.34%, Fe: 0.08%, Cu: 0.76%, Mn: 0.76%, Mg: 1.25%, Cr: 0.17%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, each unavoidable impurity element is less than 0.05%, the total amount of impurities is less than 0.10%, and the balance is Al, among which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0111] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 770°C to melt the raw materials;

[0112] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0113] S4: casting; casting the liquid aluminum alloy at 680-685° C. to obtain a round ingot with a diameter of 254±2 mm;

[0114] S5: homogenization treatment; the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 440°C for 6 hours, the second stage homogenization treatment is performed at 530°C for 8 hours, and then cooled by water mist;

[0115] S6: Extrusion; preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.0mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0116] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0117] S8: stretching; the profile is stretched by 0.5%;

[0118] S9: Aging: artificial aging of the profile at 205℃ for 6h, with a storage time of <5h;

[0119] After aging is completed, performance analysis is performed.

[0120] Comparative Example 1:

[0121] S1: ingredients; Si: 1.65%, Fe: 0.07%, Cu: 0.54%, Mn: 0.55%, Mg: 1.02%, Cr: 0.17%, Zn: 0.18%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, each unavoidable impurity element is less than 0.05%, the total amount of impurities is less than 0.10%, and the balance is Al, among which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0122] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 780°C to melt the raw materials;

[0123] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0124] S4: casting; casting the liquid aluminum alloy at 685-690° C. to obtain a round ingot with a diameter of 254±2 mm;

[0125] S5: homogenization treatment; the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 420°C for 6 hours, the second stage homogenization treatment is performed at 560°C for 8 hours, and then cooled by strong air cooling;

[0126] S6: Extrusion: preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.5mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0127] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0128] S8: stretching; the profile is stretched by 0.5%;

[0129] S9: Aging: artificial aging of the profile at 205℃ for 4h, with a storage time of <5h;

[0130] After aging is completed, performance analysis is performed.

[0131] Comparative Example 2:

[0132] S1: ingredients; Si: 1.35%, Fe: 0.07%, Cu: 0.65%, Mn: 0.75%, Mg: 1.10%, Cr: 0.16%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.17%, each unavoidable impurity element is less than 0.05%, the total amount of impurities is less than 0.10%, the balance is Al, of which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0133] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 775°C to melt the raw materials;

[0134] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0135] S4: casting; casting the liquid aluminum alloy at 685-690° C. to obtain a round ingot with a diameter of 254±2 mm;

[0136] S5: homogenization treatment; the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 420°C for 6 hours, the second stage homogenization treatment is performed at 560°C for 8 hours, and then cooled by strong air cooling;

[0137] S6: Extrusion: preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.5mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0138] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0139] S8: stretching; the profile is stretched by 0.5%;

[0140] S9: Aging: artificial aging of the profile at 205℃ for 6h, and storage time for 48h;

[0141] After aging is completed, performance analysis is performed.

[0142] Comparative Example 3:

[0143] S1: ingredients; Si: 1.35%, Fe: 0.08%, Cu: 0.75%, Mn: 0.76%, Mg: 1.24%, Cr: 0.17%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.17%, each unavoidable impurity element is less than 0.05%, the total amount of impurities is less than 0.10%, and the balance is Al, among which Ti element is added by online wire feeding during the casting process, and Zr element is controlled to reach the target composition within 30 minutes before heat preservation;

[0144] S2: Melting: Add the prepared raw materials into the melting furnace and heat to 770°C to melt the raw materials;

[0145] S3: Degassing and filtering: online degassing and online filtering of the melt;

[0146] S4: casting; casting the liquid aluminum alloy at 680-685° C. to obtain a round ingot with a diameter of 254±2 mm;

[0147] S5: homogenization treatment: the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 500°C for 8 hours, the second stage homogenization treatment is performed at 550°C for 8 hours, and then water mist cooling is used;

[0148] S6: Extrusion; preheat the homogenized ingot and then extrude it. The preheating temperature is 500°C, the preheating time is 120s, the extrusion speed is controlled at 2.0mm / s, the extrusion ratio is 35, and the profile outlet temperature is 530-535°C;

[0149] S7: Quenching: the extruded profile is quenched online at a quenching rate of 630°C / min;

[0150] S8: stretching; the profile is stretched by 0.5%;

[0151] S9: Aging: artificial aging of the profile at 205℃ for 2h, storage time <5h;

[0152] After aging is completed, performance analysis is performed.

[0153] The following is a detailed description of the above embodiments 1-6 and comparative examples 1-3:

[0154] like Figure 1 As shown, the profiles prepared in Examples 1-6 and Comparative Examples 1-3 are Japanese-shaped profiles with a nominal wall thickness of 3 mm and a cross-section of 150 mm×80 mm. The mechanical properties and bending tests of the profiles prepared in the above Examples and Comparative Examples were performed according to GB / T228.1 and GB / T232, and the test results are shown in Table 1.

[0155] The axial compression performance of the profiles prepared in Examples 1-6 and Comparative Examples 1-3 was tested. The samples were axially compressed from 200 mm to 80 mm at a deformation rate of 100 mm / min. The maximum crack length values ​​were shown in Table 1. The compression displacement-force curves are shown in Table 1. Figure 1 shown.

[0156] like Figure 1 As shown, the strength levels of Examples 1, 3, and 5 are lower than those of Comparative Examples 1, 2, and 3 with similar chemical compositions, while the transverse and longitudinal bending properties and axial compression properties are improved.

[0157] like Figure 1-5 As shown, the transverse and longitudinal bending and axial compression performances of Examples 2, 4, and 6 are further improved. The transverse and longitudinal bending angles of Examples 4 and 6 reach 81° / 68° and 80° / 69° respectively when the yield strength is greater than 360 MPa, and no through cracks of 10 mm or more appear during axial compression. Figure 2 shown.

[0158] like Figure 1-5 As shown, after homogenization, there are a large number of dispersed phases with a size of 20-500 nm in the tissues of Examples 4 and 6. The distribution of the dispersed phase in the homogenized state of the sample of Example 4 is as follows: Figure 4 As shown; it can inhibit recrystallization during the extrusion, quenching and aging processes and improve the strength of the alloy.

[0159] Table 1- Aluminum-magnesium-silicon-copper alloy profile performance table

[0160] Yield strength / Mpa Tensile strength / Mpa Elongation / % Horizontal bending angle Longitudinal bending angle Maximum crack length / mm Embodiment 1 374 403 11 77 65 10-20 Embodiment 2 355 395 11 81 71 <10 Embodiment 3 380 410 11 75 67 20-30 Embodiment 4 362 396 11 81 68 <10 Embodiment 5 382 415 11 77 66 10-20 Embodiment 6 363 399 11 80 69 <10 Comparative Example 1 388 412 12 68 42 ＞50 Comparative Example 2 390 421 12 65 45 ＞50 Comparative Example 3 392 425 12 61 39 ＞50

[0161] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0162] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. An ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile, characterized in that: The following mass percentage components Composition: Si: 1.2-1.4%, Fe≤0.2%, Cu: 0.50-0.80%, Mn: 0.50-0.8%, Mg: 1.0-1.3%, Cr: 0.15-0.20%, Zn≤0.20%, Ti: 0.01-0.05%, V≤0.20%, Zr: 0.10-0.20%, other single impurities ≤0.05%, total impurities ≤0.10%, the balance is Al.

2. The ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile according to claim 1 is characterized in that: The following mass percentage components Composition: Si: 1.31%, Fe: 0.07%, Cu: 0.64%, Mn: 0.75%, Mg: 1.09%, Cr: 0.16%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, total impurities ≤ 0.10%, the balance is Al.

3. The ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile according to claim 1 is characterized in that: The following mass percentage components Composition: Si: 1.23%, Fe: 0.07%, Cu: 0.55%, Mn: 0.56%, Mg: 1.01%, Cr: 0.17%, Zn: 0.17%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, total impurities ≤ 0.10%, the balance is Al.

4. The ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile according to claim 1 is characterized in that: The following mass percentage components Composition: Si: 1.34%, Fe: 0.08%, Cu: 0.76%, Mn: 0.76%, Mg: 1.25%, Cr: 0.17%, Zn: 0.07%, Ti: 0.03%, V: 0.02%, Zr: 0.16%, total impurities ≤ 0.10%, the balance is Al.

5. A method for preparing an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile, characterized in that: The preparation method is used to prepare an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile as described in any one of claims 1 to 4. The following steps are included: S1: Ingredients; Ingredients are prepared according to the mass percentage of alloy elements, wherein Si is in the form of industrial crystalline silicon or Al-Si or Mg-Si master alloy; Mn and Zr are in the form of aluminum-containing master alloy; Ti is in the form of AlTi or AlTiB master alloy and is used as a grain refining additive; S2: Melting: Add the prepared raw materials into the melting furnace and heat to 760-790℃ to melt the raw materials; S3: Degassing and filtering: online degassing and online filtering of the melt; S4: casting; casting the liquid aluminum alloy at 680-700° C. to obtain a round ingot with a diameter of 178-259 mm; S5: homogenization treatment: the round ingot is placed in a soaking furnace for heating and heat preservation, and the first stage homogenization treatment is performed at 400-450°C for 5-10 hours, and the second stage homogenization treatment is performed at 530-570°C for 5-10 hours, followed by strong air cooling or water mist cooling; S6: extrusion; preheat the homogenized ingot to 490±20°C by induction heating, extrude at an extrusion speed of 2.0-4.0 mm / s, an extrusion ratio of 20-50, and an extrusion outlet temperature of 530-550°C; S7: Quenching; the quenching temperature is ≥530℃, and the quenching is carried out at a cooling rate of not less than 500℃ / min; S8: stretching; control the stretching rate range from 0.5% to 1.5%; S9: Aging: Perform artificial aging to obtain ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profiles.

6. The method for preparing an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile according to claim 5, characterized in that: The parking time interval from the end time of the quenching to the start time of the artificial aging is within 8 hours.

7. The method for preparing an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile according to claim 5, characterized in that: The artificial aging adopts T7 treatment, the aging temperature is controlled at 200-210° C., and the insulation time is 4-7 hours.

8. The method for preparing an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile according to claim 5, characterized in that: The preheating time for the extrusion is 120S.

9. The method for preparing an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile according to claim 8, characterized in that: The extrusion ratio of the extrusion is 35, and the extrusion outlet temperature is 530-535°C.

10. The method for preparing an ultra-high strength collision energy absorbing aluminum-magnesium-silicon-copper alloy profile according to claim 5, characterized in that: The stretching ratio of the stretching is in the range of 0.5%.

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