CN115125420A - A kind of cast aluminum alloy for high-performance structural parts without heat treatment and preparation method thereof - Google Patents

Abstract

The invention relates to the technical field of alloy materials, and particularly discloses a heat-treatment-free high-performance structural member cast aluminum alloy and a preparation method thereof. The aluminum alloy comprises the following components in percentage by mass: si: 6.0-8.5%, Mg: 0.05-0.40%, Cu: 0.50-0.85%, Cr: 0.20-0.60%, Er: 0.01-0.10%, Mn: 0.45-0.75%, Zn: 0.1% -3.0%, V: 0.04-0.14%, Ni: 0.01 to 0.1 percent of Ba, less than or equal to 0.1 percent of Y, less than or equal to 0.16 percent of Fe, and the balance of Al. The preparation method provided by the invention can enable the aluminum alloy to have excellent mechanical properties under the condition of no solid solution heat treatment, meet the use requirements, and can also avoid the problem that large parts are easy to deform in the high-temperature solid solution treatment process.

Description

A kind of cast aluminum alloy for high-performance structural parts without heat treatment and preparation method thereof

technical field

The invention relates to the field of aluminum alloy material technology, in particular to a heat-treatment-free high-performance structural component cast aluminum alloy and a preparation method thereof.

Background technique

At present, the lightweight of automobiles is an urgent need for the development of the new energy automobile industry, and the die-casting process of structural parts and the manufacturing technology of materials for structural parts are the key to the development of lightweight automobiles. Therefore, the demand for integrated die-casting technology in the automobile industry is also increasing. Integrated die casting can greatly reduce the weight of structural parts, reduce production costs, and further improve the safety performance of automobiles. In order to meet the requirements of mechanical properties, the structural stress-bearing parts of traditional aluminum alloy vehicles often need to be strengthened by solution heat treatment and aging heat treatment to improve their mechanical properties.

However, the temperature in the solution heat treatment stage is relatively high, the temperature is at least greater than 500 °C, and the time is generally greater than 2 hours, which leads to the deformation of the structural parts during the long-term high-temperature heating and quenching process, and the deformation of large parts is especially serious. frame and subframe, etc. With the further expansion of the integrated application field, the integrated structural parts are larger in size and more complex in shape, and are not suitable for further strengthening by solution heat treatment. However, the mechanical properties of traditional aluminum alloy materials without solution heat treatment basically do not meet the standard requirements. In addition, solution heat treatment requires additional consumption of a lot of energy, energy and time, which virtually increases production costs. Therefore, , the research on aluminum alloy materials without solution heat treatment or low temperature solution heat treatment has become an inevitable demand for the development of the industry.

SUMMARY OF THE INVENTION

Aiming at the problems that the existing large parts are easily deformed during the high-temperature solution treatment, the present invention provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment.

And, the present invention also provides a preparation method of cast aluminum alloy for high-performance structural parts without heat treatment.

In order to achieve the above-mentioned purpose of the invention, the embodiment of the present invention adopts the following technical scheme:

A heat treatment-free high-performance structural casting aluminum alloy, comprising the following components by mass percentage: Si: 6.0%-8.5%, Mg: 0.05%-0.40%, Cu: 0.50%-0.85%, Cr: 0.20% ～0.60%, Er: 0.01%～0.10%, Mn: 0.45%～0.75%, Zn: 0.1%～3.0%, V: 0.04%～0.14%, Ni: 0.01%～0.1%, Ba≤0.1%, Y ≤0.1%, Fe≤0.16%, the total content of other impurity elements is ≤0.25%, and the balance is Al.

Compared with the prior art, the cast aluminum alloy for heat treatment-free high-performance structural parts provided by the present application has the following advantages:

In the present application, by adding specific content of Cu, Mg, Si elements, during the solidification process of the molten aluminum, it can generate Al ₂ Cu, Mg ₂ Si, Al-Si-Cu-Mg and other strengthening phases between the dendrites. The interaction between the strengthening phase and dislocations hinders the movement of dislocations and significantly improves the deformation resistance and mechanical strength of the alloy; in addition, the elements of Cu, Mg, and Si in the alloy matrix, during the rapid cooling process, more Retained in the matrix, this part of the strengthening elements will form a strengthening phase in the matrix during the later aging heat treatment process, thereby improving the strength of the matrix, and achieving an aluminum alloy material with excellent comprehensive properties without additional solution heat treatment. In the present invention, the casting performance of the molten aluminum can be improved by adding Si element with a relatively high content, and the adverse effects caused by the faster cooling rate can be offset.

During the solidification process of Fe element, together with Al, Si and other elements, a needle-like β-Fe phase is formed, and stress concentration is easily generated during the stress process, thereby splitting the matrix and reducing the performance of the alloy material. The content of Mn, Cr, V, and Ni elements can make the needle-like Fe-containing phase in the alloy into particles, which not only reduces its splitting effect, but also acts as a strengthening phase to hinder the movement of dislocations, so that the alloy does not need heat treatment. In addition, if the ratio between Mn, Cr, V, and Ni is arbitrarily changed, the size of the Fe-containing phase will increase sharply, which is extremely unfavorable to the performance of the cast aluminum alloy material.

Er and Y added in this application have the effect of refining grains. Ba element can convert eutectic silicon from lamellar to coral or granular shape, reducing stress concentration. Y can reduce the size of eutectic silicon, which can make eutectic silicon smaller. The strength and plasticity of the alloy material can be significantly improved without heat treatment to meet the application requirements.

The Zn element added in this application can be enriched on the surface of the Al-Si-Cu-Mg phase and the Fe-containing phase during the solidification process, inhibiting their growth and reducing the size of the Al-Si-Cu-Mg phase and the Fe-containing phase , can also significantly improve the as-cast properties of aluminum alloy materials, and due to the increase in the solid solubility of Zn in the α-Al phase during the aging process, the Zn element is dissolved into α-Al, which has a solid solution strengthening effect, and then Increase the strength of aluminum alloy materials.

Further, the present invention also provides a preparation method of cast aluminum alloy for high-performance structural parts without heat treatment, comprising the following steps:

Step 1. Combine the master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al-Y and pure Al and pure Al Mg is pretreated respectively, then each component is weighed according to the raw material proportioning as claimed in claim 1;

Step 2: The pretreated master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al- Y, pure Al and pure Mg are completely melted to obtain molten aluminum;

Step 3, under the condition of 700℃～720℃, pass argon gas into the molten aluminum to obtain the molten aluminum;

Step 4. When the temperature of the refined aluminum liquid is 650°C to 690°C, the refined aluminum liquid is cast into a mold with a temperature of 130°C to 170°C to obtain a test bar;

Step 5, subjecting the test bar to aging heat treatment, so that the high-performance structural parts can be cast aluminum alloy without heat treatment.

Compared with the prior art, the preparation method of the cast aluminum alloy for heat treatment-free high-performance structural parts provided by the present application has the following advantages:

In the casting process of the present application, the mold temperature is relatively low, so that the cooling rate of the aluminum liquid is faster, and the strengthening phase can be refined, thereby further improving the strength of the alloy, so that the alloy does not need to undergo solution heat treatment, and also has excellent mechanical properties. At the same time, the preheating temperature of the mold is controlled to be 130 ° C ~ 170 ° C, and the cooling speed can be reduced to prevent the cooling speed from being fast and the occurrence of cracks and other defects.

The preparation method provided by the present application can make the aluminum alloy material have excellent mechanical properties without solid solution heat treatment, meet the requirements of use, and can avoid the problem that large parts are easily deformed during the high temperature solution treatment process, and improve the yield.

Optionally, the conditions of the aging heat treatment are as follows: the temperature is 150°C to 230°C, and the time is 1 hour to 3 hours.

The preferred aging heat treatment conditions can make Cu, Mg, Si elements form strengthening phases in the matrix, and improve the strength of the aluminum alloy matrix; and can increase the solid solubility of Zn element in α-Al, and solid solution of Zn element into α-Al Al, thereby increasing the strength of the aluminum alloy material.

Optionally, the flow rate of the argon is 3-5L/min.

Optionally, the introduction time of the argon gas is 8 min to 12 min.

Optionally, the vent of the argon gas is located at the bottom of the molten aluminum.

The preferred argon inflow conditions make the molten aluminum in an argon atmosphere to avoid the generation of oxides during the solidification process of the molten aluminum and reduce the mechanical properties of the aluminum alloy material; it can also float the impurities in the molten aluminum through nitrogen to remove the aluminum The harmful elements and impurities in the liquid are separated cleanly.

Optionally, in step 2, under the condition of 730 ℃ ~ 755 ℃, first place the master alloy Al-Si, Al-Cu and pure Al in a furnace for melting, and after complete melting, add the master alloy Al-Cr, Al-Mn, Al-Zn, Al-V, Al-Ni and pure Mg were completely melted, and then allowed to stand for 10min-20min, and the master alloys Al-Er, Al-Ba, Al- Y, when all components are completely melted, the molten aluminum is obtained.

The preferred order of addition enables each element to generate specific strengthening phases such as Al ₂ Cu, Mg ₂ Si, Al-Si-Cu-Mg, etc. during the smelting process, thereby improving the mechanical properties of the aluminum alloy material.

Optionally, the casting cycle of the casting is 35s˜55s.

Optionally, the pretreatment process is as follows: grinding, polishing, cleaning and drying the master alloy, pure Al, pure Mg and pure Zn, respectively.

In the present application, the oxide scale on the surface of the master alloy, pure Al, pure Mg and pure Zn is removed by grinding and polishing, and then it can be weighed after cleaning and drying. This pretreatment method can try to avoid the introduction of impurity elements.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

Fig. 1 is the microstructure diagram provided in Example 1 of the present invention;

2 is a partially enlarged microstructure diagram provided in Example 1 of the present invention;

Fig. 3 is the microstructure diagram provided by comparative example 1 of the present invention;

FIG. 4 is a partial enlarged microstructure diagram provided by Comparative Example 1 of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

Example 1

Embodiment 1 of the present invention provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment, including the following components by mass percentage: Si: 7.0%, Mg: 0.4%, Cu: 0.70%, Cr: 0.20%, Er: 0.08%, Mn: 0.60%, Zn: 2.0%, V: 0.04%, Ni: 0.1%, Ba: 0.06%, Y: 0.02%, and the balance is Al.

The above-mentioned preparation method of cast aluminum alloy for heat-free high-performance structural parts comprises the following steps:

Step 1. Combine the master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al-Y and pure Al and pure Al Mg is polished and polished to remove the oxide scale on the surface, then cleaned and dried, and then each component is weighed according to the above-mentioned raw material ratio;

Step 2: Under the condition of 740°C, first place the master alloys Al-Si, Al-Cu and pure Al in a melting furnace for melting, and then add master alloys Al-Cr, Al-Mn, Al-Zn, Al-V, Al-Ni and pure Mg were completely melted, and then allowed to stand for 10 minutes. The master alloys Al-Er, Al-Ba, and Al-Y were added at 710 °C. When all components were completely melted, aluminum was obtained. liquid;

Step 3. Under the condition of 710°C, pass argon gas into the molten aluminum to obtain the molten aluminum, the flow rate of argon gas is 4L/min, the feeding time is 10min, and the vent pipe opening of the argon gas is located at the bottom of the molten aluminum;

Step 4. When the temperature of the refined aluminum liquid is 670°C, the refined aluminum liquid is cast into a mold with a temperature of 150°C to obtain a test rod, and the casting cycle is 50s;

Step 5. The test rod is subjected to an aging heat treatment at 190° C. for 3 hours, so that the high-performance structural parts can be cast aluminum alloy without heat treatment.

Example 2

Embodiment 1 of the present invention provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment, including the following components by mass percentage: Si: 8.5%, Mg: 0.3%, Cu: 0.5%, Cr: 0.2%, Er: 0.01%, Mn: 0.75%, Zn: 0.1%, V: 0.1%, Ni: 0.08%, Ba: 0.1%, Y: 0.1%, and the balance is Al.

The above-mentioned preparation method of cast aluminum alloy for heat-free high-performance structural parts comprises the following steps:

Step 1. Combine the master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al-Y and pure Al and pure Al Mg is polished and polished to remove the oxide scale on the surface, then cleaned and dried, and then each component is weighed according to the above-mentioned raw material ratio;

Step 2: Under the condition of 730°C, first place the master alloy Al-Si, Al-Cu and pure Al in a furnace for smelting, and after complete melting, add the master alloy Al-Cr, Al-Mn, Al-Zn, Al-V, Al-Ni and pure Mg were completely melted, and then allowed to stand for 15 minutes. The master alloys Al-Er, Al-Ba, and Al-Y were added at 720 °C. When all components were completely melted, aluminum was obtained. liquid;

Step 3. Under the condition of 720°C, argon gas is introduced into the aluminum liquid to obtain the refined aluminum liquid. The flow rate of argon gas is 3L/min, the introduction time is 10min, and the vent pipe opening of the argon gas is located at the bottom of the molten aluminum;

Step 4. When the temperature of the refined aluminum liquid is 650°C, the refined aluminum liquid is cast into a mold with a temperature of 130°C to obtain a test rod, and the casting cycle is 35s;

Step 5. The test rod is subjected to an aging heat treatment at 200° C. for 1.5 hours, so that the high-performance structural parts can be cast aluminum alloy without heat treatment.

Example 3

Embodiment 1 of the present invention provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment, including the following components by mass percentage: Si: 7.5%, Mg: 0.2%, Cu: 0.6%, Cr: 0.6%, Er: 0.1%, Mn: 0.5%, Zn: 1.0%, V: 0.08%, Ni: 0.01%, Ba: 0.08%, Y: 0.02%, and the balance is Al.

The above-mentioned preparation method of cast aluminum alloy for heat-free high-performance structural parts comprises the following steps:

Step 1. Combine the master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al-Y and pure Al and pure Al Mg is polished and polished to remove the oxide scale on the surface, then cleaned and dried, and then each component is weighed according to the above-mentioned raw material ratio;

Step 2: Under the condition of 755°C, first place the master alloys Al-Si, Al-Cu and pure Al in a furnace for smelting, and after complete melting, add master alloys Al-Cr, Al-Mn, Al-Zn, Al-V, Al-Ni and pure Mg were completely melted, and then allowed to stand for 20 minutes. The master alloys Al-Er, Al-Ba, and Al-Y were added at 700 °C. When all components were completely melted, aluminum was obtained. liquid;

Step 3. Under the condition of 700 ℃, pass argon gas into the aluminum liquid to obtain the refined aluminum liquid, the flow rate of the argon gas is 5L/min, the feeding time is 8min, and the vent pipe port of the argon gas is located at the bottom of the molten aluminum;

Step 4. When the temperature of the refined aluminum liquid is 690°C, the refined aluminum liquid is cast into a mold with a temperature of 170°C to obtain a test rod, and the casting cycle is 55s;

Step 5. The test bar is subjected to an aging heat treatment at 150° C. for 3 hours, so that the high-performance structural parts can be cast aluminum alloy without heat treatment.

Example 4

Embodiment 1 of the present invention provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment, including the following components by mass percentage: Si: 6.0%, Mg: 0.05%, Cu: 0.85%, Cr: 0.6%, Er: 0.08%, Mn: 0.45%, Zn: 0.1%, V: 0.14%, Ni: 0.08%, Ba: 0.02%, Y: 0.04%, and the balance is Al.

The above-mentioned preparation method of cast aluminum alloy for heat-free high-performance structural parts comprises the following steps:

Step 1. Combine the master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al-Y and pure Al and pure Al Mg is polished and polished to remove the oxide scale on the surface, then cleaned and dried, and then each component is weighed according to the above-mentioned raw material ratio;

Step 2: Under the condition of 745°C, first place the master alloy Al-Si, Al-Cu and pure Al in a furnace for smelting, and after complete melting, add the master alloy Al-Cr, Al-Mn, Al-Zn, Al-V, Al-Ni and pure Mg were completely melted, and then allowed to stand for 12 minutes. The master alloys Al-Er, Al-Ba, and Al-Y were added at 715 °C. When all components were completely melted, aluminum was obtained. liquid;

Step 3. Under the condition of 715°C, argon gas is introduced into the aluminum liquid to obtain the refined aluminum liquid. The flow rate of the argon gas is 4.5L/min, the introduction time is 12min, and the argon gas vent pipe mouth at the bottom of the molten aluminum;

Step 4. When the temperature of the refined aluminum liquid is 680°C, the refined aluminum liquid is cast into a mold with a temperature of 160°C to obtain a test rod, and the casting cycle is 40s;

Step 5. The test bar is subjected to an aging heat treatment at 230° C. for 1 hour, so that the high-performance structural parts can be cast aluminum alloy without heat treatment.

Example 5

Embodiment 1 of the present invention provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment, including the following components by mass percentage: Si: 6.5%, Mg: 0.1%, Cu: 0.8%, Cr: 0.4%, Er: 0.08%, Mn: 0.5%, Zn: 3%, V: 0.08%, Ni: 0.08%, Ba: 0.04%, Y: 0.04%, and the balance is Al.

The above-mentioned preparation method of cast aluminum alloy for heat-free high-performance structural parts comprises the following steps:

Step 1. Combine the master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al-Y and pure Al and pure Al Mg is polished and polished to remove the oxide scale on the surface, then cleaned and dried, and then each component is weighed according to the above-mentioned raw material ratio;

Step 2: Under the condition of 735°C, first place the master alloy Al-Si, Al-Cu and pure Al in a furnace for smelting, and after complete melting, add the master alloy Al-Cr, Al-Mn, Al-Zn, Al-V, Al-Ni and pure Mg were completely melted, and then allowed to stand for 16 minutes. The master alloys Al-Er, Al-Ba, and Al-Y were added at 720 °C. When all components were completely melted, aluminum was obtained. liquid;

Step 3. Under the condition of 720°C, argon gas is introduced into the molten aluminum to obtain the molten aluminum. The flow rate of the argon gas is 3.5L/min, the introduction time is 11min, and the vent pipe of the argon gas is at the bottom of the molten aluminum;

Step 4. When the temperature of the refined aluminum liquid is 660°C, the refined aluminum liquid is cast into a mold with a temperature of 140°C to obtain a test rod, and the casting cycle is 45s;

Step 5. The test rod is subjected to an aging heat treatment at 210° C. for 2 hours, so that the high-performance structural parts can be cast aluminum alloy without heat treatment.

In order to better illustrate the technical solutions of the present invention, further comparisons are made below with the examples of the present invention through comparative examples.

Comparative Example 1

This comparative example provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment, including the following components by mass percentage: Si: 7.0%, Mg: 0.4%, Cu: 0.70%, Cr: 0.02%, Er: 0.08% , Mn: 0.8%, Zn: 2.0%, V: 0.04%, Ni: 0.1%, Ba: 0.06%, Y: 0.02%, and the balance is Al.

The above-mentioned preparation process of the cast aluminum alloy for the heat treatment-free high-performance structural parts is as described in Example 1, and will not be repeated here.

Comparative Example 2

This comparative example provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment.

The above-mentioned preparation method of cast aluminum alloy for heat-free high-performance structural parts comprises the following steps:

The temperature of the molten aluminum refining described in step 4 was replaced with 720° C., and the remaining preparation process steps were the same as those in Example 1, and will not be repeated here.

Comparative Example 3

This comparative example provides a cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment.

The above-mentioned preparation method of cast aluminum alloy for heat-free high-performance structural parts comprises the following steps:

The temperature of the mold in step 5 was replaced with 200° C., and the rest of the preparation process steps were the same as those in Example 1, and will not be repeated here.

In order to better illustrate the characteristics of the cast aluminum alloy for heat-treatment-free high-performance structural parts provided by the embodiments of the present invention, the aluminum alloy materials prepared in Example 1 and Comparative Example 1 are analyzed below.

Test Example 1 Microstructure

The microstructure of the aluminum alloy material prepared in Example 1 is shown in FIG. 1 , and then partially enlarged as shown in FIG. 2 .

The microstructure of the aluminum alloy material prepared in Comparative Example 1 is shown in FIG. 3 , and then partially enlarged as shown in FIG. 4 .

It can be seen from Figures 1 and 3 that the secondary dendrite spacing of the aluminum alloy material prepared in Example 1 is smaller than that of Comparative Example 1, and the overall size of the grains is also smaller; it can be more obvious from Figures 2 and 4 It can be seen that the interdendritic particle size of the aluminum alloy material prepared in Example 1 is smaller and the distribution is more uniform, which can promote the increase of the strength and toughness of the alloy, while the overall size of the phase generated in the aluminum alloy material prepared in Comparative Example 1 is larger. , and most of them are needle-shaped, which will cause stress concentration in the alloy during the stress process, thereby greatly reducing the performance of the alloy.

Test Example 2 Energy Spectrum Analysis

The positions 1, 2, 3, 4, and 5 marked in Figure 2 were analyzed by energy spectrum, and the results were shown in Tables 1 to 5 below. It can be seen from Tables 1 to 5 that there are Al ₂ Cu and Al between dendrites. -Si-Cu-Mg, Mg ₂ Si strengthening phase, and the marks 1 and 3 in Figure 2 also prove that the morphology of the Fe-containing phase can be significantly improved due to the combined action of the alloying elements in the present application.

Table 1

Table 2

table 3

Table 4

table 5

Test Example 3 Mechanical Properties

The room temperature tensile mechanical properties of the cast aluminum alloys prepared in Examples 1 to 5 and Comparative Examples 1 to 3 for high-performance structural parts that can be exempted from heat treatment were tested, and the test results are shown in Table 6.

Table 6 Test results

It can be seen from Table 6 that the cast aluminum alloy for high-performance structural parts that can be free from heat treatment provided by the embodiment of the present invention also has excellent mechanical properties without solid solution heat treatment, and meets the requirements for use.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements or improvements made within the spirit and principles of the present invention shall be included in the protection of the present invention. within the range.

Claims (9)

1. A cast aluminum alloy for high-performance structural parts that can be exempted from heat treatment, characterized in that: each component comprises the following mass percentages: Si: 6.0% to 8.5%, Mg: 0.05% to 0.40%, Cu: 0.50% to 0.85% %, Cr: 0.20% to 0.60%, Er: 0.01% to 0.10%, Mn: 0.45% to 0.75%, Zn: 0.1% to 3.0%, V: 0.04% to 0.14%, Ni: 0.01% to 0.1%, Ba≤0.1%, Y≤0.1%, Fe≤0.16%, the total content of other impurity elements is ≤0.25%, and the balance is Al. 2. a preparation method of cast aluminum alloy for heat-free high-performance structural parts is characterized in that: comprise the following steps: Step 1. Combine the master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al-Y and pure Al and pure Al Mg is pretreated respectively, then each component is weighed according to the raw material proportioning as claimed in claim 1; Step 2: The pretreated master alloys Al-Si, Al-Cu, Al-Cr, Al-Er, Al-Mn, Al-Zn, Al-V, Al-Ni, Al-Ba, Al- Y, pure Al and pure Mg are completely melted to obtain molten aluminum; Step 3, under the condition of 700℃～720℃, pass argon gas into the molten aluminum to obtain the molten aluminum; Step 4. When the temperature of the refined aluminum liquid is 650°C to 690°C, the refined aluminum liquid is cast into a mold with a temperature of 130°C to 170°C to obtain a test bar; Step 5, subjecting the test bar to aging heat treatment, so that the high-performance structural parts can be cast aluminum alloy without heat treatment. 3 . The method for preparing a heat-treated high-performance cast aluminum alloy for high-performance structural parts as claimed in claim 2 , wherein the conditions of the aging heat treatment are as follows: the temperature is 150° C. to 230° C. and the time is 1 hour to 3 hours. 4 . 4 . The method for preparing a cast aluminum alloy for heat-free high-performance structural parts according to claim 2 , wherein the flow rate of the argon gas is 3-5 L/min. 5 . 5 . The method for preparing cast aluminum alloy for heat-treated high-performance structural parts as claimed in claim 2 , wherein the argon gas is introduced for a time of 8 min to 12 min. 6 . 6 . The method for preparing cast aluminum alloy for heat-free high-performance structural parts according to claim 2 , wherein the argon gas vent pipe is located at the bottom of the molten aluminum. 7 . 7 . The method for preparing a cast aluminum alloy for a heat-treated high-performance structural part as claimed in claim 2 , wherein in the second step, under the condition of 730° C. to 755° C., the intermediate alloy Al-Si, Al-Cu and pure Al are placed in a furnace for smelting. After complete melting, the intermediate alloys Al-Cr, Al-Mn, Al-Zn, Al-V, Al-Ni and pure Mg are added. After complete melting, let stand for 10 min~ 20min, add the master alloy Al-Er, Al-Ba, Al-Y at 700 ℃～720 ℃, when all the components are completely melted, the aluminum liquid is obtained. 8 . The method for preparing an aluminum alloy cast for a heat-treatment-free high-performance structural part according to claim 2 , wherein the casting cycle of the casting is 35s˜55s. 9 . 9 . The method for preparing a cast aluminum alloy for a heat-treated high-performance structural part as claimed in claim 2 , wherein the process of the pretreatment is: separate the master alloy, pure Al, pure Mg and pure Zn respectively. 10 . Sand, polish, wash and dry.

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