Aluminum alloy material recycled and reconstructed from waste aluminum template and preparation method of aluminum alloy material

Abstract

The invention discloses a reconstituted aluminum alloy material obtained by recycling waste aluminum templates and a preparation method of the reconstituted aluminum alloy material. The reconstituted aluminum alloy material obtained by recycling the waste aluminum templates comprises the following chemical components in percentage by mass: 0.05-0.20% of Cu, 0.50-0.70% of Si and Znlt. The aluminum alloy comprises 0.10% of aluminum, 0.04%-0.17% of Mn, 0.70%-0.90% of Mg, 0.15%-0.50% of Fe, 0.05%-0.20% of Cr, 0.01%-0.07% of Ni, 0.01%-0.07% of V, smaller than or equal to 0.05% of Ti and the balance aluminum and impurity elements, each impurity element is smaller than or equal to 0.05%, and the total content is smaller than or equal to 0.20%. The sum of the mass fractions of Mg, Si and Cu is 1.6-1.8%, the mass fraction ratio of Mg to Si is 1.2-1.5, the sum of the mass fractions of Fe, Mn and Cr is 0.35-0.65%, the mass fraction ratio of (Mn + Cr) to Fe is 0.35-0.65, meanwhile, trace elements such as Ni and V are added, a super grain refiner is adopted, and the grain structure and the morphology / size / distribution of a second phase are optimized by combining regulation and control such as casting, homogenization and extrusion processes. And it is ensured that the aluminum bar still has excellent extrudability and uniform deformability under the high impurity tolerance, and the obtained aluminum profile is bright in surface and good in age hardening effect.

Description

Technical Field

[0001] The invention relates to the technical field of waste aluminum recycling and reuse, and in particular to an aluminum alloy material recycled from waste aluminum templates and a preparation method thereof. Background Art

[0002] Aluminum alloy formwork is a type of lightweight structural product used in the field of construction for concrete pouring in residential buildings, replacing traditional bamboo plywood, wooden formwork, steel formwork, etc. It has the advantages of high strength, corrosion resistance, high precision, high recycling rate, and short cycle, but it also has disadvantages such as multiple specifications, large one-time investment, and uneven product levels. According to the requirements of the construction industry standard "JG / T522-2017 Aluminum Alloy Formwork" and the national standard "GB / T 6892-2023 General Industrial Aluminum and Aluminum Alloy Extrusion Profiles", aluminum formwork is made of 6061 or 6082 aluminum alloy, and has clear requirements for surface quality and mechanical properties, such as smooth surface, no / few burrs, T6 state yield strength not less than 240 MPa, tensile strength not less than 260 MPa, and elongation at break not less than 7%. However, after the aluminum formwork is scrapped and remelted by different manufacturers, the quality of aluminum formwork products is uneven, and the composition of some scrap aluminum formwork products has exceeded the 6061 or 6082 aluminum alloy composition range specified in the standard. At the same time, the waste aluminum formwork is also mixed with aluminum die-castings, iron plates, iron pipes, iron nails, bolts, iron wires, and concrete residues on the surface or in the holes. In addition, the corrosion products remaining on the surface of the aluminum formwork after repeated use lead to complex composition of the waste aluminum formwork, long melting time, high energy consumption, and large amount of slag removal during remelting. Usually, only 30-50% of waste aluminum formwork materials are added during casting, and it is difficult to achieve 100% recycling of waste aluminum formwork to manufacture new aluminum formwork. This is because the complex composition of the waste aluminum formwork leads to high impurity content, large Mg and Si burnout after remelting, especially the impurity Fe content is very easy to exceed the internal control standards of the enterprise, which significantly affects the production efficiency and the yield rate of extruded profiles, and makes the subsequent recycling and remanufacturing more difficult. How to achieve 100% recycling of waste aluminum formwork to manufacture new aluminum formwork or other aluminum components has become a major challenge facing the recycling and reuse of waste aluminum formwork, and is also a key technology that needs to be broken through to achieve grade preservation or upgraded utilization of waste aluminum formwork.

[0003] In order to achieve the addition and reuse of a high proportion of waste aluminum templates, the present invention has achieved 100% recycling of waste aluminum templates to manufacture new aluminum templates and other aluminum components by overall optimization of aluminum alloy composition, aluminum rod casting quality, homogenization and extrusion process, while ensuring that the mechanical properties of extruded aluminum profiles meet the use requirements, so as to support the application demand for high-performance, low-carbon aluminum materials in the development of industries such as construction and new energy vehicles. Summary of the invention

[0004] The purpose of the present invention is to provide an aluminum alloy material recycled from waste aluminum templates and a preparation method thereof, so as to solve the problems raised in the above-mentioned background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: an aluminum alloy material recycled from waste aluminum templates, wherein the chemical composition of the aluminum alloy is (mass percentage, %): Cu 0.05-0.20, Si 0.50-0.70, Zn<0.10, Mn 0.04-0.17, Mg 0.70-0.90, Fe 0.15-0.50, Cr0.05-0.20, Ni 0.01-0.07, V 0.01-0.07, and the remainder is aluminum and impurity elements, wherein each impurity element is ≤0.05 and the total content is ≤0.20.

[0006] As a further improvement of the present invention, the mass fraction of Mg+Si+Cu is 1.6-1.8%, the mass fraction ratio of Mg / Si is 1.2-1.5%, the mass fraction of Fe+Mn+Cr is 0.35-0.65%, and the mass fraction ratio of (Mn+Cr) / Fe is 0.30-0.65%.

[0007] As a further improvement of the present invention, the profile tensile strength of the aluminum alloy material is ≥270 MPa, the yield strength is ≥240 MPa, and the elongation after fracture is ≥10%.

[0008] As a further improvement of the present invention, the profile tensile strength of the aluminum alloy material is ≥310 MPa, the yield strength is ≥300 MPa, and the elongation after fracture is ≥10%.

[0009] The present invention also discloses a preparation method for recycling the aluminum alloy material from the waste aluminum template, and the preparation method comprises the following steps: S1. Collect and pre-treat waste aluminum formwork materials to ensure that there is no iron products, concrete, etc. residue on the surface, and dry the waste aluminum formwork; S2. The dried waste aluminum template is melted in an industrial furnace to obtain an aluminum alloy solution, which is then refined. After degassing and slagging, the aluminum solution is filtered to remove oxides and other inclusions; S3, casting the filtered aluminum liquid into aluminum rods by hot top casting; S4, aluminum rod homogenization treatment; S5, the homogenized aluminum rod is preheated and then extruded; S6, extruded aluminum profiles are quenched and pre-straightened online; S7. Aluminum alloy components are obtained after aging treatment of aluminum profiles.

[0010] As a further improvement of the present invention, the specific steps of the refining treatment in step S2 are: when the temperature of the aluminum liquid is about 730°C, a high-precision refining agent is introduced into the aluminum alloy liquid using an inert gas, the amount of the refining agent added is 90 kg (added three times), the inert gas is nitrogen or argon, the gas introduction amount is 40-50 kg / furnace (calculated by the weight of the liquid gas), and refining is performed three times, each refining time is 10-20 minutes.

[0011] As a further improvement of the present invention, the specific steps of melting in step S2 are: adding the pretreated and dried waste aluminum template into the industrial furnace in stages and melting them completely, refining them once when the aluminum liquid temperature is 710-730°C, then sampling and analyzing the chemical composition of the aluminum liquid, adding the required dried pure metals or intermediate alloys such as Cu, Mn, Cr, Si, Ni, V, etc. in turn, and after they are completely dissolved, refining them for the second time when the aluminum liquid temperature is 720-740°C, sampling and analyzing the chemical composition of the aluminum liquid, adding the required pure Mg ingot, and performing the third refining and slag removal operation after they are completely melted.

[0012] As a further improvement of the present invention, in step S3, before hot top casting, a super grain refiner is added into the launder, and the added amount is 0.5-1.2 kg / ton.

[0013] As a further improvement of the present invention, the hot top casting process in step S3 is: controlling the aluminum liquid temperature to 720-730°C, filtering through a ceramic filter plate, casting when the table aluminum liquid temperature is 690-720°C, the cooling water flow rate is 180-210 cubic meters / hour, and the billet drawing speed is 73-79 mm / minute.

[0014] As a further improvement of the present invention, the homogenization process in step S4 is single-stage, double-stage or three-stage, wherein the single-stage homogenization process is: (565~580)℃-(2~10)h, the double-stage homogenization process is: (520~550)℃-(1~2)h+(565~580)℃-(2~10)h, and the three-stage homogenization process is: (350~450)℃-(1~2)h+(520~550)℃-(1~2)h+(565~580)℃-(2~10)h.

[0015] As a further improvement of the present invention, the hot extrusion forming process in step S5 is: aluminum rod preheating temperature 450-500°C, mold temperature 400-450°C, extrusion barrel temperature 380-450°C, extrusion speed 4-10 mm / s, extrusion ratio 10-180, and outlet temperature 500-560°C.

[0016] As a further improvement of the present invention, the aging treatment in step S7 is to store at room temperature for no more than 12 h after online quenching, artificial aging at 170-210°C, holding time of 1-20 h, and then air cooling after taking out of the furnace.

[0017] As a further improvement of the present invention, the aging treatment in step S7 may be selected as T6 heat treatment, and the T6 heat treatment process is solution temperature 530-560 ° C insulation 10-120 min, water quenching, artificial aging temperature 170-210 ° C, insulation time 1-20 h, followed by air cooling.

[0018] Compared with the prior art, the present invention has the following beneficial effects: The aluminum alloy material of the present invention does not contain precious metals such as Zr, Sc, and rare earths. The designed Mg / Si ratio is used to regulate the strengthening precipitation phase, so that the alloy has better precipitation strengthening effect and stability, while taking into account the consumption of Si element by the Fe-rich phase; the designed (Mn+Cr) / Fe regulates the Fe-rich phase, so that the needle-like Fe-rich phase is transformed into a skeleton-like or mesh-like Fe-rich phase (such as -Al(Fe,Mn / Cr)Si phase), reducing its adverse effects on the extrudability of the aluminum rod and the mechanical properties of the final aluminum profile; a super grain refiner is added and a small amount of V element is added as an auxiliary to enhance the grain refinement effect or effectively control the grain structure in the cast rod, thereby greatly reducing the addition amount of the ordinary grain refiner (usually 2.0-3.5 kg / ton) and the introduction of non-nucleating TiB2 particles are beneficial to improving the extrudability of aluminum rods and the surface quality of aluminum profiles; at the same time, V may also combine with Al, Fe, Si, Cr, Mn, etc. to form V-containing dispersed particles, which, combined with a multi-stage homogenization process, can improve the number density and distribution uniformity of dispersed particles in the aluminum matrix, which is beneficial to improving the uniformity of extrusion deformation and the mechanical properties of profiles; adding a small amount of Ni to form AlFeNi phase with Fe and Al, consuming a certain amount of Fe element to reduce the Si-containing Fe-rich phase or reduce the consumption of Si element by the Fe-rich phase, so as to increase the effective Si content of precipitation strengthening and promote the formation of more Mg2Si metastable precipitation phases, thereby reducing the harm of Fe-rich phases and improving the mechanical properties after artificial aging; adding the required Mg ingots or blocks after the second refining, melting them and then refining them for the third time can avoid the oxidation of Mg during the refining process due to the premature addition of Mg ingots, which increases its burnout, resulting in inaccurate control of Mg content and excessive cost of adding Mg ingots.

[0019] Utilizing the above beneficial effects, the aluminum alloy material of the present invention has a tensile strength of ≥270MPa, a yield strength of ≥240MPa, and an elongation of ≥10% after extrusion molding and artificial aging treatment, especially a tensile strength of ≥310MPa, a yield strength of ≥300MPa, and an elongation of ≥10% after T6 heat treatment. The material can be applied to architectural aluminum formwork, aluminum rods, and lightweight and low-carbon aluminum alloy components for automobiles such as wheel hubs, control arms, and anti-collision parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : Microstructure diagram of aluminum rod with 70% scrap aluminum template content before homogenization.

[0021] Figure 2 : Microstructure diagram of aluminum rod with 70% scrap aluminum template content after homogenization.

[0022] Figure 3 : Typical tensile stress-strain curves of samples in Examples 1 and 2.

[0023] Figure 4 : Microstructure diagram of aluminum rod with 100% scrap aluminum template content before homogenization.

[0024] Figure 5 : Microstructure diagram of aluminum rod with 100% scrap aluminum template content before homogenization.

[0025] Figure 6 : Typical tensile stress-strain curves of samples in Examples 3, 4 and 5.

[0026] Figure 7 : Typical tensile stress-strain curve of the sample in Example 6.

[0027] Figure 8 : Typical tensile stress-strain curves of samples in Examples 7 and 8.

[0028] Fig. 9 : Typical tensile stress-strain curve of the sample in Example 9. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with specific embodiments.

[0030] Example 1 The scrap aluminum templates accounting for 70% of the total melting capacity of the industrial furnace are added into the furnace in stages. After it is completely melted, the aluminum liquid is magnetically attracted and refined once respectively, and the slag on the surface of the aluminum liquid is scraped to the furnace door. Then, the leftover materials such as casting and extrusion are added, which account for 30% of the total melting capacity of the industrial furnace. After it is completely melted, the temperature of the aluminum liquid is controlled at about 720 ℃ and stirred. Then, samples are taken to detect the chemical composition and according to the internal control composition range of the enterprise, the required pure metals or intermediate alloys such as Mg, Si, Cu, Cr, V are added in turn. After it is fully dissolved, the aluminum liquid is heated to 730 ℃ for two refining, degassing and slag removal operations. The aluminum liquid was cast after standing for 20-30 min. A super grain refiner was added to the flow trough at an addition amount of 1 kg / ton. The aluminum rod was cast into a 320 mm diameter aluminum rod with the chemical composition of Al-0.6Si-0.29Fe-0.23Cu-0.04Mn-0.85Mg-0.14Cr-0.02Zn-0.02Ti-0.01V (mass percentage, %), wherein the Mg / Si mass fraction ratio was 1.42, and the (Mn+Cr) / Fe mass fraction ratio was 0.62.

[0031] The aluminum rod was then homogenized. The single-stage homogenization process was as follows: the industrial homogenization furnace was heated to 580°C at 100-150°C / h and kept at this temperature for 5 hours, and then cooled by wind and mist after being taken out of the furnace; the double-stage homogenization process was as follows: the aluminum rod was heated to 550°C at 50-100°C / h and kept at this temperature for 1 hour, and then heated to 580°C at 10-50°C / h and kept at this temperature for 5 hours, and then cooled by wind and mist after being taken out of the furnace. The microstructures before and after homogenization are shown in the attached figure. Figure 1-2 As shown in the figure, it can be seen that there are many needle-like and skeleton-like Fe-rich phases and irregular black Mg2Si phases at the grain boundaries before homogenization treatment, and there is almost no second phase in the crystal. After homogenization treatment, some needle-like Fe-rich phases at the grain boundaries are broken and spheroidized, and the morphology of the skeleton-like Fe-rich phase is almost unchanged. No black Mg2Si phase is found to remain at the grain boundaries. There are a large number of dispersed fine granular and short rod-like second phases in the crystal, which are analyzed to be -Al(Fe,Mn / Cr)Si dispersed particles and Mg2Si phase precipitated by cooling.

[0032] Hot extrusion process parameters: 320 mm diameter aluminum rod heated to 460-470 ℃, mold temperature 450 ℃, extrusion ratio ~123, extrusion speed 6.0-6.5 mm / s, outlet temperature 540-560 ℃, extruded into a 400 mm wide, 4 mm thick slot aluminum template, forced air cooling + mist cooling at the outlet, pre-straightening amount 1.0%, natural aging 6 h, artificial aging 200 ℃ -5 h, the tested mechanical properties are: tensile strength 286 MPa, yield strength 255 MPa, elongation after fracture 11.5%, such as Figure 3 As shown in the curve.

[0033] Example 2 The alloy composition and preparation process are the same as those in Example 1, except that the extruded aluminum template is subjected to T6 heat treatment: 540 ° C -1 h solid solution followed by water quenching, T6 artificial aging 200 ° C -5 h, and the tested mechanical properties are: tensile strength 324 MPa, yield strength 301 MPa, elongation after fracture 10.5%, as shown in FIG. Figure 3 As shown in the curve.

[0034] Example 3 Add waste aluminum templates accounting for 50% of the total melting capacity of the industrial furnace into the furnace in stages. After it is completely melted, perform a magnetic iron absorption operation on the aluminum liquid; then continue to add waste aluminum template materials to account for 70% of the total melting capacity of the industrial furnace. After it is completely melted, perform magnetic iron absorption and slag removal on the aluminum liquid once; then continue to add waste aluminum template materials to account for 90% of the total melting capacity of the industrial furnace. After it is completely melted, perform magnetic iron absorption, refining and slag removal on the aluminum liquid once; then continue to add waste aluminum template materials to account for 100% of the total melting capacity of the industrial furnace. After it is completely melted, stir it, wait for the aluminum liquid to heat up to 730 ℃, perform magnetic iron absorption, refining and slag removal once, then take samples to test the chemical composition and add the required pure metals or intermediate alloys such as Mg, Si, Cu, Cr, Ni, V in turn according to the internal control alloy composition range of the enterprise, wait for it to be fully dissolved, and ensure that the aluminum liquid temperature is 730 ℃ and above, and perform refining and slag removal on the aluminum liquid once. The aluminum liquid was cast after standing for 20-30 min. A super grain refiner was added to the flow trough at an addition amount of 1 kg / ton. The aluminum rod with a diameter of 320 mm was cast. Its chemical composition was: Al-0.67Si-0.42Fe-0.2Cu-0.05Mn-0.87Mg-0.11Cr-0.02Zn-0.02Ti-0.04Ni-0.01V (mass percentage, %), wherein the mass fraction ratio of Mg / Si was 1.30, and the mass fraction ratio of (Mn+Cr) / Fe was 0.38.

[0035] The aluminum rod was then homogenized. The traditional process was as follows: heating to 580°C at 100-150°C / h in an industrial homogenization furnace and keeping it warm for 5 hours, followed by air-fog cooling after leaving the furnace; the two-stage homogenization process was heating to 550°C at 50-100°C / h and keeping it warm for 1 hour, then heating to 580°C at 10-50°C / h and keeping it warm for 5 hours, followed by air-fog cooling after leaving the furnace. The microstructures before and after homogenization are shown in the attached figure. Figure 4-5As shown in the figure, it can be seen that there are more needle-like and skeleton-like Fe-rich phases and a small amount of irregular black Mg2Si phases at the grain boundaries before homogenization treatment, and there are a large number of dense fine second phases near the inner side of the grain boundary. After homogenization treatment, some needle-like Fe-rich phases at the grain boundaries are broken and spheroidized, and the morphology of the skeleton-like Fe-rich phase is almost unchanged. No black Mg2Si phase is found to remain at the grain boundaries. There are a large number of dispersed fine granular and short rod-like second phases in the crystal, which are analyzed to be -Al(Fe,Mn / Cr)Si dispersed particles and Mg2Si phases precipitated by cooling.

[0036] Hot extrusion process parameters: 320mm diameter aluminum rod heated to 450-460℃, mold temperature 440℃, extrusion ratio ~123, extrusion speed 6.0-7.5 mm / s, outlet temperature 530-550℃, extruded into a 400mm wide, 4mm thick slot aluminum template, forced air cooling + mist cooling at the outlet, pre-straightening amount 1.0%, natural aging 6h, artificial aging 200℃-5h, tested mechanical properties: tensile strength 302MPa, yield strength 270MPa, elongation after fracture 11.5%, such as Figure 6 As shown in the curve.

[0037] Example 4 The alloy composition and preparation process are the same as those in Example 3, except that the extruded aluminum template is subjected to T6 heat treatment: 540 ° C -1 h solid solution followed by water quenching, T6 artificial aging 200 ° C -5 h, and the tested mechanical properties are: tensile strength 326 MPa, yield strength 312 MPa, elongation after fracture 12.0%, as shown in FIG. Figure 6 As shown in the curve.

[0038] Example 5 The alloy composition and preparation process are the same as those in Example 3, except that the extrusion ratio is 158, the outlet temperature of the extruded aluminum template is lower than 520 °C, and the mechanical properties of the final tested profile are: tensile strength 260 MPa, yield strength 227 MPa, elongation after fracture 12.0%, as shown in FIG. Figure 6 As shown in the curve.

[0039] Example 6 The scrap aluminum templates accounting for 80% of the total melting capacity of the industrial furnace are added into the furnace in stages. After it is completely melted, the aluminum liquid is magnetically attracted, and the slag on the surface of the aluminum liquid is scraped to the furnace door. Then, the scrap aluminum templates are added to 100% of the total melting capacity of the industrial furnace. After it is completely melted, it is stirred. The aluminum liquid is heated to 730 ℃ and magnetically attracted and slag is removed once. Then, samples are taken to detect the chemical composition and according to the internal control alloy composition range of the enterprise, the required Si, Cu, Cr, Ni, V and other pure metals or intermediate alloys are added in turn. After it is fully dissolved and the aluminum liquid temperature is ensured to reach 730 ℃ or above, the aluminum liquid is refined and slag removed once, and then the required pure Mg is added. After it is melted and the aluminum liquid temperature reaches 730 ℃, it is refined and slag removed once. After that, the aluminum liquid is cast after standing for 20-30 minutes. Super grain refiner is added to the flow trough, and the addition amount is 0.8 kg / ton. It is cast into a diameter of 320 mm aluminum rod, whose chemical composition is: Al-0.64Si-0.35Fe-0.18Cu-0.05Mn-0.86Mg-0.11Cr-0.02Zn-0.01Ni-0.01V-0.02Ti (mass percentage, %), among which the mass fraction ratio of Mg / Si is 1.34, and the mass fraction ratio of (Mn+Cr) / Fe is 0.46.

[0040] The aluminum rod is then subjected to a three-stage homogenization treatment: in an industrial homogenization furnace, the aluminum rod is heated to 400°C at 70-120°C / h and kept warm for 1 hour, then heated to 550°C at 40-80°C / h and kept warm for 1 hour, then heated to 575°C at 10-50°C / h and kept warm for 5 hours, and then cooled by wind and mist after being taken out of the furnace.

[0041] Hot extrusion process parameters: 320 mm diameter aluminum rod heated to 470-480 ℃, mold temperature 440 ℃, extrusion ratio ~126, extrusion speed 4.5-5.5 mm / s, outlet temperature 530-550 ℃, extruded into a C-groove aluminum template with a width of 150 mm and a wall thickness of 7 mm, forced air cooling + mist cooling at the outlet, pre-straightening amount 1.2%, natural aging 6 h, artificial aging 200 ℃ -5 h, the tested mechanical properties are: tensile strength 288 MPa, yield strength 260 MPa, elongation after fracture 11.0%, such as Figure 7 As shown in the curve.

[0042] Example 7 The scrap aluminum templates accounting for 80% of the total melting capacity of the industrial furnace are added into the furnace in stages. After it is completely melted, the aluminum liquid is magnetically attracted, and the slag on the surface of the aluminum liquid is scraped to the furnace door. Then, the scrap aluminum templates are added to 100% of the total melting capacity of the industrial furnace. After it is completely melted, it is stirred. The aluminum liquid is heated to 730 ℃ and magnetically attracted and slag is removed once. Then, samples are taken to detect the chemical composition and according to the internal control alloy composition range of the enterprise, the required Si, Cu, Cr, Ni, V and other pure metals or intermediate alloys are added in turn. After it is fully dissolved and the aluminum liquid temperature is ensured to reach 730 ℃ or above, the aluminum liquid is refined and slag removed once, and then the required pure Mg is added. After it is melted and the aluminum liquid temperature reaches 730 ℃, it is refined and slag removed once. After that, the aluminum liquid is cast after standing for 20-30 min. Super grain refiner is added to the flow trough, and the addition amount is 0.8 kg / ton. It is cast into a diameter of 320 mm aluminum rod, whose chemical composition is: Al-0.65Si-0.35Fe-0.17Cu-0.04Mn-0.85Mg-0.1Cr-0.02Zn-0.01Ni-0.01V-0.03Ti (mass percentage, %), among which the Mg / Si mass fraction ratio is 1.31, and the (Mn+Cr) / Fe mass fraction ratio is 0.4.

[0043] The aluminum rod is then subjected to a three-stage homogenization treatment: in an industrial homogenization furnace, the aluminum rod is heated to 400 ℃ at 70-120 ℃ / h and kept warm for 1 hour, then heated to 550 ℃ at 40-80 ℃ / h and kept warm for 2 hours, then heated to 570 ℃ at 10-50 ℃ / h and kept warm for 6 hours, and then cooled by wind and mist after being taken out of the furnace.

[0044] Hot extrusion process parameters: 320 mm diameter aluminum rod heated to 460-470 ℃, mold temperature 440 ℃, extrusion ratio ~135, extrusion speed 6.0-6.5 mm / s, outlet temperature 540-550 ℃, extruded into 350 mm wide, 4 mm wall thickness slot-shaped aluminum template, forced air cooling + mist cooling at the outlet, pre-straightening amount 1.5%, natural aging 6 h, artificial aging 200 ℃-5 h, the tested mechanical properties are: tensile strength 279 MPa, yield strength 251 MPa, elongation after break 10.0%.

[0045] Example 8 The alloy composition and preparation process are the same as those in Example 7, except that the aluminum groove template with a width of 300 mm and a wall thickness of 4 mm is extruded, the extrusion ratio is 159, the outlet temperature is lower than 520 ° C, and the mechanical properties of the final tested profile are as follows: tensile strength 237 MPa, yield strength 193 MPa, elongation after fracture 10.0%, as shown in FIG. Figure 8 As shown in the curve.

[0046] Example 9 Add the scrap aluminum templates accounting for 80% of the total melting capacity of the industrial furnace into the furnace in stages. After it is completely melted, the aluminum liquid is magnetically attracted, and the slag on the surface of the aluminum liquid is scraped to the furnace door. Then continue to add scrap aluminum templates to 100% of the total melting capacity of the industrial furnace. After it is completely melted, stir it. The aluminum liquid is heated to 730℃ and magnetically attracted and slag is scraped once. Then take samples to test the chemical composition and add the required Si, Cu, Cr, Ni, V and other pure metals or intermediate alloys in turn according to the aluminum alloy composition range controlled by the enterprise. After it is fully dissolved and the aluminum liquid temperature is ensured to reach 730℃ or above, the aluminum liquid is refined and slag is scraped. Then add the required pure Mg. After it is melted and the aluminum liquid temperature reaches 730℃, it is refined and slag is scraped. After that, the aluminum liquid is left to stand for 20-30 minutes. min later, casting was carried out, and super grain refiner was added into the flow trough in an amount of 0.8 kg / ton, and the aluminum rod with a diameter of 178 mm was cast. Its chemical composition was: Al-0.63Si-0.36Fe-0.17Cu-0.06Mn-0.82Mg-0.07Cr-0.03Zn-0.01Ni-0.01V-0.02Ti (mass percentage, %), among which the mass fraction ratio of Mg / Si was 1.30, and the mass fraction ratio of (Mn+Cr) / Fe was 0.36.

[0047] The aluminum rod is then subjected to a three-stage homogenization treatment: in an industrial homogenization furnace, the aluminum rod is heated to 400 ℃ at 120-170 ℃ / h and kept warm for 1 hour, then heated to 550 ℃ at 80-100 ℃ / h and kept warm for 1 hour, then heated to 570 ℃ at 10-50 ℃ / h and kept warm for 5 hours, and then cooled by wind and mist after being taken out of the furnace.

[0048] Hot extrusion process parameters: 178 mm diameter aluminum bar heated to 450-460 ℃, die temperature 455 ℃, extrusion ratio about 133, extrusion speed 6.0-8.0 mm / s, outlet temperature 530-550 ℃, extruded into 125 mm wide, 6 mm thick flat profiles, forced wind mist + water mist cooling at the outlet, pre-straightening amount 1.3%, natural aging 6 h, artificial aging 200 ℃-5 h, tested mechanical properties: tensile strength 306 MPa, yield strength 277 MPa, elongation after fracture 11.0%, such as Fig. 9 As shown in the curve.

[0049] Example 10 The alloy composition and preparation process are the same as those in Example 9, except that the mold temperature is 448 ° C, the U-shaped aluminum profile with a width of 50 mm and a wall thickness of 3 mm is extruded, the extrusion ratio is ~99, the outlet temperature is lower than 530-550 ° C, and the mechanical properties of the final tested profile are: tensile strength 287 MPa, yield strength 260 MPa, and elongation after fracture 10.5%.

[0050] It can be seen from the above embodiments that the aluminum alloy material and profile preparation method of the present invention are used, the prepared aluminum alloy profile has a tensile strength of >= 270 MPa, a yield strength of >= 240 MPa, and a fracture elongation of >= 10%, and the extruded aluminum profile has a tensile strength of >= 310 MPa, a yield strength of >= 300 MPa, and a fracture elongation of >= 10% after solid solution + T6 artificial aging treatment, which can meet the performance requirements of lightweight aluminum parts such as architectural aluminum formwork and new energy vehicle hubs, structural parts, and forgings.

[0051] The above are preferred embodiments of the present invention. It should be noted that a person skilled in the art may make various changes, modifications, substitutions and variations to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for recycling aluminum alloy materials from waste aluminum templates, characterized in that: The mass percentage of the chemical composition of aluminum alloy is: Cu 0.05-0.20, Si 0.50-0.70, Zn<0.10, Mn 0.04-0.17, Mg 0.70-0.90, Fe 0.15-0.50, Cr0.05-0.20, Ni 0.01-0.07, V 0.01-0.07, Ti<=0.05, the balance is aluminum and impurity elements, where each impurity element is ≤0.05 and the total content is ≤0.20; The mass percentage of Mg+Si+Cu is 1.6-1.8, the mass percentage ratio of Mg / Si is 1.2~1.5, the mass percentage of Fe+Mn+Cr is 0.35~0.65, and the mass percentage ratio of (Mn+Cr) / Fe is 0.35~0.

65.

2. The aluminum alloy material recycled from waste aluminum template according to claim 1 is characterized by: The aluminum alloy material component has a tensile strength of ≥270MPa, a yield strength of ≥240MPa, and an elongation after fracture of ≥10%.

3. The aluminum alloy material recycled from waste aluminum template according to claim 1 is characterized by: The aluminum alloy material component has a tensile strength of ≥310MPa, a yield strength of ≥300MPa, and an elongation after fracture of ≥10%.

4. A method for preparing aluminum alloy materials recycled from waste aluminum templates according to claim 1, characterized in that: The preparation method comprises the following steps: S1. Collect and pre-treat waste aluminum formwork materials to ensure that there is no iron products, concrete, etc. residue on the surface, and dry the waste aluminum formwork; S2, the dried waste aluminum template is melted in an industrial furnace to obtain an aluminum alloy solution, which is then refined. After degassing and slagging, the aluminum liquid is filtered to remove oxide inclusions; S3, casting the filtered aluminum liquid into aluminum rods by hot top casting; S4, aluminum rod homogenization treatment; S5, the homogenized aluminum rod is preheated and then extruded; S6, extruded aluminum profiles are quenched and pre-straightened online; S7. After aging treatment of the aluminum profile, an aluminum alloy material component is obtained.

5. The preparation method according to claim 4, characterized in that: The pretreatment of the waste aluminum template raw material in step S1 can be performed manually or by shot blasting.

6. The preparation method according to claim 4, characterized in that: The amount of pretreated and dried waste aluminum template added in step S2 is 70% to 100%.

7. The preparation method according to claim 4, characterized in that: The specific steps of the refining treatment in step S2 are as follows: when the temperature of the aluminum liquid is about 730°C, a high-precision refining agent is introduced into the aluminum alloy liquid by using an inert gas, the amount of the refining agent added is 90 kg, and it is added three times. The inert gas is nitrogen or argon, and the gas introduction amount is 40-50 kg / furnace, calculated by the weight of the liquid gas, and the refining is performed three times, and each refining time is 10-20 minutes.

8. The preparation method according to claim 4, characterized in that: The filtration in step S2 can be carried out by using one of a single-stage ceramic filter plate, a double-stage ceramic filter plate, and a deep bed filter, wherein the pore size of the ceramic filter plate is 20-60 ppi.

9. The preparation method according to claim 4, characterized in that: The specific steps of melting in step S2 are as follows: adding the pretreated and dried waste aluminum template into an industrial melting furnace in stages for melting, and after it is completely melted and refined once, sampling and analyzing the chemical composition of the aluminum liquid, adding the required dried pure metals or intermediate alloys of Cu, Mn, Cr, Si, Ni, and V in sequence, and refining for the second time after it is completely dissolved, sampling and analyzing the chemical composition of the aluminum liquid, adding the required pure Mg ingot, and performing a third refining and slag removal operation after it is completely melted.

10. The waste preparation method according to claim 4, characterized in that: The hot top casting process in step S3 is as follows: the aluminum liquid temperature is controlled at 720-730°C, after filtering through a ceramic filter plate, the table aluminum liquid temperature is cast at 690-720°C, the cooling water flow rate is 180-210 cubic meters per hour, and the billet drawing speed is 73-79 mm per minute.

11. The preparation method according to claim 4, characterized in that: In the step S3, a super grain refiner is added into the chute before hot top casting, and the added amount is 0.5-1.2 kg / ton.

12. The preparation method according to claim 4, characterized in that: The homogenization process in step S4 is single-stage, double-stage or three-stage, wherein the single-stage homogenization process is: (565-580)°C-(2-10)h, the double-stage homogenization process is: (520-550)°C-(1-2)h+(565-580)°C-(2-10)h, and the three-stage homogenization process is: (350-450)°C-(1-2)h+(520-550)°C-(1-2)h+(565-580)°C-(2-10)h.

13. The preparation method according to claim 4, characterized in that: The hot extrusion forming process in step S5 is as follows: the aluminum rod preheating temperature is 440-490°C, the mold temperature is 400-450°C, the extrusion barrel temperature is 380-450°C, the extrusion speed is 4-10 mm / s, the extrusion ratio is 10-180, and the outlet temperature is 500-560°C.

14. The preparation method according to claim 4, characterized in that: In step S6, the online quenching is performed by first air cooling and then water cooling, or first air cooling and then air mist cooling.

15. The preparation method according to claim 4, characterized in that: The pre-straightening amount in step S6 is 0.5-3.0%.

16. The preparation method according to claim 4, characterized in that: The aging treatment in step S7 is to store at room temperature for no more than 12 hours after online cooling, artificial aging at 170-210° C., and a holding time of 1-20 hours, followed by air cooling after being taken out of the furnace.

17. The preparation method according to claim 4, characterized in that: The aging treatment in step S7 may be T6 heat treatment, wherein the T6 heat treatment process comprises a solution temperature of 530-560° C., holding for 10-120 min, water quenching, an artificial aging temperature of 170-210° C., a holding time of 1-20 h, and then air cooling after being taken out of the furnace.

18. The preparation method according to claim 4, characterized in that: The drying treatment in step S1 is to keep the temperature at 50-250° C. for 1-30 hours or expose the mixture to sunlight for 0.5 days to 1 week.

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