Non-heat-treated high-toughness Al-Si alloy die-casting material and its manufacturing method

Abstract

The present invention discloses a non-heat-treated high-toughness Al-Si alloy die-casting material and its manufacturing process. The alloy can effectively suppress the adverse effect of Fe element by controlling the Mn / Fe ratio within a certain range. In addition, rare earth is introduced at a certain ratio to effectively refine the Si in the material and form a high-temperature phase together with elements such as Al·Cu, so that the material can improve the deformation resistance when applied to large structural parts integrally molded by die-casting. After sampling and testing the main body of a large die-casting product, the F material of the alloy can reach a tensile strength of 290 MPa, a yield strength of 140 MPa, and an elongation of 13%, which not only has excellent die-castability, but also meets the standard of low carbon emissions due to the use of clean energy.

Description

[Technical field]

[0001] <CROSS REFERENCE TO RELATED APPLICATIONS>

[0002] This application claims priority to Chinese Patent Application No. 202111507879.5 filed on December 10, 2021 (titled "Non-heat-treatable high-toughness Al-Si alloy die-casting material and its manufacturing method"), the entirety of which is incorporated herein by reference.

[0003] The present invention relates to the technical field of metallic materials, and more particularly to a non-heat-treatable high-toughness Al-Si alloy die-cast material and a method for producing the same. [Background technology]

[0004] With the further promotion of the "peaking CO2 emissions and becoming carbon neutral" policy, the carbon emission target value is gradually lowered. Recycled aluminum has the obvious advantage of low energy consumption, and can break away from the aluminum industry's dependence on electricity, which causes prices to rise with the increase in electricity prices. Therefore, making the recycled aluminum industry the leading industry will contribute to the healthy, stable, and long-term development of the aluminum industry. The carbon emissions of recycled aluminum are significantly lower than those of new aluminum ingot production using electrolysis with thermal power generation. The carbon dioxide emissions of one ton of new aluminum ingot produced using electrolysis with thermal power generation are about 12 tons, while the carbon dioxide emissions of one ton of recycled aluminum are only about 300 kg. In addition, its production can save 3.4 tons of standard coal and 14 cubic meters of water, and reduce the amount of solid waste discharged by 20 tons. Based on the calculation that one ton of standard coal emits 3 tons of carbon dioxide, one ton of recycled aluminum, together with the carbon dioxide emissions from other auxiliary materials, can reduce a total of about 11.5 tons of carbon dioxide emissions. At the same time, recycled aluminum also has great economic benefits. The production of virgin aluminum requires the mining of bauxite and long-distance transportation, and the extraction of alumina and the production of virgin aluminum through electrolysis using thermal power generation consume huge amounts of energy, so the production cost of recycled aluminum is lower than that of virgin aluminum. With the rapid growth of China's aluminum scrap reserves and the continuous improvement of the waste resource recycling system, the price of aluminum scrap is expected to further decline, and the cost advantage of recycled aluminum production over the production of virgin aluminum through electrolysis using thermal power generation is expected to become more prominent. In addition, it is also possible to consider replacing electrolysis in the production of virgin aluminum with clean energy that does not emit carbon dioxide, such as hydroelectric, wind, and solar power.

[0005] In recent years, new energy vehicles have been appearing and developing one after another. However, due to the constraints of the weight and driving range of the drive battery, as well as strict automobile energy conservation and carbon emission reduction policies, the demand for lighter body weight in the vehicle design and material selection of battery-powered new energy vehicles is higher than that of traditional automobiles. Aluminum alloy is one of the lightweight materials, and has comparative advantages in terms of technology, operational safety and recycling. Therefore, it has gradually replaced steel in the automobile industry, and has been widely used in the manufacture of automobile parts through the application of die casting molding process.

[0006] The automotive and aerospace industries place strict requirements on parts, especially for excellent impact toughness and high elongation during deformation. Based on these requirements, the automotive industry requires aluminum alloy die-casting products with tensile strength exceeding 180 MPa, yield strength exceeding 120 MPa, and elongation exceeding 10% for large integrated body structural parts. Conventional Al-Si alloys have high strength and good castability. However, due to their poor plasticity and low elongation, they cannot meet the standards for large integrated die-casting products for automobiles. In recent years, the development of high-toughness aluminum alloys has attracted more and more attention to meet the demands of the automotive industry market. For example, the Silafont-36 alloy (Patent Publication No.: US 6364970B1) developed by Rheinland of Germany has an elongation of less than 6% at room temperature, but after long-term T7 heat treatment, it has a tensile strength of about 210 MPa, a yield strength of 140 MPa, and an elongation of 15%, which can meet the requirements of automotive structural parts. However, the production efficiency of this process is low, the heat treatment process is complicated, and it is difficult to properly control the heat treatment process, so the heat treatment cost is very high. As another example, the non-heat-treated reinforced high-strength and high-toughness Al-Mg-Si alloy die-casting material (patent disclosure number: CN 108754256A) developed by Shanghai Jiao Tong University has better mechanical properties, but because it is an Al-Mg-Si alloy, it has poor castability and is prone to oxidation and burning due to its high magnesium content. In addition to the above, the aluminum liquid of this alloy has high viscosity and shrinkage rate, which causes strong erosion of the die-casting mold and shortens the life of the mold, making it unsuitable for large body structural parts. In addition, Fengyang Aersi and Shanghai Jiao Tong University have developed a non-heat-treated self-reinforced Al-Si alloy (patent disclosure number: CN 104831129A). However, this alloy has high requirements for impurity elements, and it is impossible to use aluminum scrap in its production, which means it cannot meet the various targets based on the future "peaking out of CO2 emissions and becoming carbon neutral." In addition, the elongation of the castings of this alloy after precision die casting is about 7.5%, which cannot meet the high toughness requirements of large vehicle body structural parts at present.In addition, the high-strength and tough aluminum alloy die-casting material (patent publication number: CN 109881056A) developed by Shanghai Yongmaotai Automotive Parts and Shanghai Jiao Tong University has good castability, but the elongation of the die-casting product in a non-heat-treated state is only 7%, making it unsuitable for automotive structural parts that require high toughness. The high-toughness aluminum alloy die-casting material (patent publication number: CN 106636787A) developed by Suzhou Huichi Light Alloy has good castability and strength, but requires an impurity element content of less than 0.005%, which places extremely high requirements on the impurity content and makes it impossible to use aluminum scrap in its production, while the elongation of the die-casting product in a non-heat-treated state is only 9.7%, making it unsuitable for automotive structural parts that require high toughness. Summary of the Invention

[0007] This Summary introduces in a simplified form the concepts that are subsequently described in detail in the Examples. This Summary is not intended to identify key / essential features of the claimed technical solution, nor to limit the scope of the claimed technical solution.

[0008] The present invention provides a non-heat-treatable high-toughness Al-Si alloy die-cast material that reduces carbon emissions and achieves an elongation of 11% to 16% without heat treatment, and a manufacturing method thereof.

[0009] In the first aspect of the present invention, the mass percentage of each component of the non-heat-treated high-toughness Al-Si alloy die casting material provided in the examples of the present invention is as follows, based on the total weight of the alloy.

[0010] It is preferable that the total amount of Si is 6.3 to 8.3%, Fe: 0.07 to 0.45%, Cu: 0.05 to 0.5%, Mn: 0.5 to 0.8%, Mg: 0.15 to 0.35%, Ti: 0.01 to 0.2%, Sr: 0.015 to 0.035%, the total amount of rare earths consisting of one or more of La / Ce / Sc: 0.04% to 0.2%, Ni: 0.001 to 0.1%, Zn: 0.005 to 0.1%, Ga: 0.01 to 0.03%, the total amount of other impurities is 0.2% or less, and the balance is Al.

[0011] The mass percent of each component of the Al-Si alloy die casting material may be as follows:

[0012] It is preferable that the total amount of Si is 6.3-7.0%, Fe: 0.2-0.4%, Cu: 0.35-0.45%, Mn: 0.5-0.8%, Mg: 0.25-0.35%, Ti: 0.1-0.2%, Sr: 0.015-0.035%, the total amount of rare earths consisting of one or more of La / Ce / Sc: 0.04%-0.2%, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, the total amount of other impurities is 0.2% or less, and the balance is Al.

[0013] The mass percent of each component of the Al-Si alloy die casting material may be as follows:

[0014] It is preferable that the total amount of Si is 6.4-7.1%, Fe: 0.10-0.25%, Cu: 0.05-0.28%, Mn: 0.5-0.8%, Mg: 0.25-0.35%, Ti: 0.03-0.16%, Sr: 0.025-0.035%, the total amount of rare earths consisting of one or more of La / Ce / Sc: 0.04%-0.15%, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, the total amount of other impurities is 0.2% or less, and the balance is Al.

[0015] The mass percent of each component of the Al-Si alloy die casting material may be as follows:

[0016] It is preferable that the total amount of Si is 7.0-7.7%, Fe: 0.15-0.3%, Cu: 0.2-0.35%, Mn: 0.6-0.8%, Mg: 0.2-0.3%, Ti: 0.05-0.2%, Sr: 0.015-0.035%, the total amount of rare earths consisting of one or more of La / Ce / Sc: 0.04%-0.2%, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, the total amount of other impurities is 0.2% or less, and the balance is Al.

[0017] The mass percent of each component of the Al-Si alloy die casting material may be as follows:

[0018] It is preferable that the total amount of rare earths consisting of one or more of La, Ce, and Sc is 0.04% to 0.2%, Si: 7.7 to 8.3%, Fe: 0.07 to 0.2%, Cu: 0.05 to 0.2%, Mn: 0.6 to 0.8%, Mg: 0.15 to 0.3%, Ti: 0.01 to 0.15%, Sr: 0.015 to 0.035%, La / Ce / Sc: 0.04% to 0.2%, Ni: 0.001 to 0.1%, Zn: 0.005 to 0.1%, Ga: 0.01 to 0.03%, the total amount of other impurities is 0.2% or less, and the balance is Al.

[0019] The Al-Si alloy die casting material can exhibit a tensile strength of 270 MPa or more, a yield strength of 130 MPa or more, and an elongation of 11% or more.

[0020] As the second aspect of the present invention, the manufacturing process of the Al-Si alloy die casting material provided in the embodiment of the present invention is as follows:

[0021] First, the raw materials which are unlikely to burn are heated and melted to prepare the Al-Si alloy die-casting material to obtain an aluminum alloy liquid. Next, the raw materials which are likely to burn are added to the aluminum alloy liquid after slag removal and refining, and after the components reach the specified values, a casting process is performed to obtain the Al-Si alloy die-casting material.

[0022] The present invention can be used to die-cast the Al-Si alloy die-cast material, which is characterized in that the forming temperature is 680-720°C, the die-casting speed is 2.5-5 m / s, and the heat-retention time is 2-10 seconds, resulting in a die-cast product in a non-heat-treated state.

[0023] In the present invention, after each raw material is completely melted, the aluminum alloy liquid is uniformly stirred and allowed to stand, and then sampling and analysis are performed, so that the content of necessary elements can be adjusted to fall within the required range of component ratio.

[0024] The present invention allows the refining flux used to be free of sodium ions.

[0025] The present invention provides a non-heat-treated high-toughness Al-Si alloy die-casting material and its manufacturing method. The aluminum alloy prepared by the present invention breaks through the limitations of conventional aluminum alloy die-casting materials that require T7 heat treatment to meet the requirements of structural parts of automobile bodies, and can be manufactured from aluminum scrap, reducing the carbon emissions generated during the manufacturing process, and the elongation can reach 11-16% without heat treatment.

[0026] It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide further explanation of the invention which is claimed. [Brief description of the drawings]

[0027] The above and other features, advantages, and aspects of the embodiments of the present disclosure will become more apparent with reference to the accompanying drawings and the following embodiments. Throughout the accompanying drawings, the same or similar affixed reference numerals refer to the same or similar elements. It should be understood that the accompanying drawings are schematic, and that the drawings and elements are not necessarily drawn to scale. [Figure 1] 1A and 1B are metallographic diagrams of the microstructure of an aluminum die casting obtained in Example 2 of the present invention, where FIG. 1A is a metallographic diagram of the microstructure at 100 times magnification, and FIG. 1B is a metallographic diagram of the microstructure at 500 times magnification. [Diagram 2] 1 is a fluidity test mold for aluminum die casting obtained in Example 2. [Diagram 3] 1 shows tensile stress-strain curves of the aluminum die castings obtained in Example 2, Comparative Example 1, and Comparative Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, the embodiments of the present disclosure will be described in more detail with reference to the attached drawings. Although some embodiments are shown in the attached drawings, it should be understood that the present disclosure is not limited thereto and can be implemented in various forms beyond the scope of the embodiments described below. The provision of these embodiments is for the purpose of a more complete and thorough understanding of the present disclosure. It should also be understood that the attached drawings and embodiments of the present disclosure are merely illustrative and are not intended to limit the scope of protection of the present disclosure.

[0029] It should be understood that the steps described in the embodiments of the disclosed method may be performed in different orders and / or in parallel. Furthermore, the embodiments of the disclosed method may include additional steps and / or omit the performance of steps shown. Thus, the scope of the disclosure is not limited in any way.

[0030] The present disclosure provides a non-heat-treated high-toughness Al-Si alloy die-casting material and a manufacturing method thereof. Hereinafter, examples of the present disclosure will be described in detail with reference to the accompanying drawings.

[0031] Example 1 The non-heat-treated, highly tough Al-Si alloy die-cast material with low carbon emissions and renewable properties of this example contains, by mass, the following components: Mg: 0.2%, Si: 6.5%, Fe: 0.15%, Cu: 0.1%, Mn: 0.5%, Ti: 0.03%, Sr: 0.025%, total amount of La·Ce: 0.05%, Ni: 0.005%, Zn: 0.006%, Ga: 0.015%, with the remainder being aluminum and 0.2% or less of remaining impurities.

[0032] The manufacturing method of the present embodiment for producing a non-heat-treated high-toughness Al-Si alloy die casting that is renewable and has low carbon emissions includes the following steps.

[0033] (1) Preparation before putting the materials into the furnace: Clean the bottom of the furnace and preheat it until the furnace walls turn red. At the same time, coat all the tools with graphite powder, dry them, and preheat them.

[0034] (2) Materials: The raw materials of each element that constitutes the aluminum alloy, such as metallic Al ingot, metallic Mg ingot, industrial silicon, Al-Mn intermediate alloy or metallic Mn, metallic Fe, Al-Ti intermediate alloy, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn and metallic Ga, Al-Sr intermediate alloy, rare earth aluminum intermediate alloy, etc., are prepared in advance and added according to the alloy component ratio described above, taking into consideration the amount of burnt damage as appropriate.

[0035] (3) Melting in furnace: First, an ingot of metallic Al is put into a furnace and melted while maintaining the melting temperature at 760-790° C. After the Al ingot is completely melted, the temperature is increased and the furnace temperature is maintained at 760-780° C., and industrial silicon, metallic Fe, an Al-Mn intermediate alloy or metallic Mn, metallic Cu or an Al-Cu intermediate alloy, metallic Ni, metallic Zn, and metallic Ga are added for smelting.

[0036] (4) Refining and slag treatment: The aluminum alloy melt is stirred uniformly while maintaining the temperature at 740-760°C, and a special refining flux for aluminum alloys is added to carry out primary and secondary refining by powder injection. The time interval between the two refining processes is controlled to 50-60 minutes, and slag treatment is carried out after each refining process to remove the flux and floating dross on the liquid surface.

[0037] (5) Addition of other metal elements: While maintaining the molten metal temperature at 740-760°C, ingots of Al-Ti intermediate alloy, rare earth aluminum intermediate alloy, metallic Mg, and Al-Sr intermediate alloy are added to the furnace and smelted, refined, and inoculated to obtain an aluminum alloy melt, which is then sampled and analyzed.

[0038] (6) Furnace degassing: While maintaining the smelting temperature at 740 to 760°C, the furnace is degassed for about 30 to 50 minutes using gas, and then allowed to stand for 15 to 30 minutes.

[0039] (7) Casting or die casting: After the component analysis results before putting into the furnace are found to be acceptable, casting is carried out at an appropriate casting temperature to produce an ingot, or high-pressure casting is carried out in a die casting process to produce a die-cast product in a non-heat-treated state.

[0040] Example 2 The non-heat treated, high toughness Al-Si alloy die casting material with low carbon emissions and renewable properties of this embodiment contains, by mass, the following components: Mg: 0.3%, Si: 6.9%, Fe: 0.2%, Cu: 0.2%, Mn: 0.6%, Ti: 0.07%, Sr: 0.02%, La: 0.1%, Ni: 0.003%, Zn: 0.07%, Ga: 0.02%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0041] The manufacturing method of the present embodiment for producing a non-heat-treated high-toughness Al-Si alloy die casting that is renewable and has low carbon emissions includes the following steps.

[0042] (1) Preparation before putting the materials into the furnace: Clean the bottom of the furnace and preheat it until the furnace walls turn red. At the same time, coat all the tools with graphite powder, dry them, and preheat them.

[0043] (2) Materials: The raw materials for each element that constitutes the aluminum alloy, such as metallic Al ingot or aluminum scrap, metallic Mg ingot, industrial silicon, Al-Mn intermediate alloy or metallic Mn, metallic Fe, Al-Ti intermediate alloy, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn and metallic Ga, Al-Sr intermediate alloy, rare earth aluminum intermediate alloy, etc., are prepared in advance and added according to the alloy component ratio described above, taking into consideration the amount of burnt damage as appropriate.

[0044] (3) Melting in furnace: First, aluminum metal ingots or aluminum scrap are put into a furnace and melted while maintaining the melting temperature at 760 to 790° C. After the aluminum ingots or aluminum scrap are all melted, the temperature is increased and the furnace temperature is maintained at 760 to 780° C., and industrial silicon, metallic Fe, Al-Mn intermediate alloy or metallic Mn, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn, and metallic Ga are added for smelting.

[0045] (4) Refining and slag treatment: The aluminum alloy melt is stirred uniformly while maintaining the temperature at 740-760°C, and a special refining flux for aluminum alloys is added to carry out primary and secondary refining by powder injection. The time interval between the two refining processes is controlled to 50-60 minutes, and slag treatment is carried out after each refining process to remove the flux and floating dross on the liquid surface.

[0046] (5) Addition of other metal elements: While maintaining the molten metal temperature at 740-760°C, ingots of Al-Ti intermediate alloy, rare earth aluminum intermediate alloy, metallic Mg, and Al-Sr intermediate alloy are added to the furnace and smelted, refined, and inoculated to obtain an aluminum alloy melt, which is then sampled and analyzed.

[0047] (6) Furnace degassing: While maintaining the smelting temperature at 740 to 760°C, the furnace is degassed for about 30 to 50 minutes with nitrogen gas, and then allowed to stand for 15 to 30 minutes.

[0048] (7) Casting or die casting: After the component analysis results before putting into the furnace are found to be acceptable, casting is carried out at an appropriate casting temperature to produce an ingot, or high-pressure casting is carried out in a die casting process to produce a die-cast product in a non-heat-treated state.

[0049] Example 3 The non-heat treated, high toughness Al-Si alloy die casting material with low carbon emissions and renewable properties of this embodiment contains, by mass, the following components: Mg: 0.35%, Si: 7.5%, Fe: 0.25%, Cu: 0.3%, Mn: 0.7%, Ti: 0.15%, Sr: 0.03%, Ce: 0.08%, Ni: 0.08%, Zn: 0.09%, Ga: 0.025%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0050] The manufacturing method of the present embodiment for producing a non-heat-treated high-toughness Al-Si alloy die casting that is renewable and has low carbon emissions includes the following steps.

[0051] (1) Preparation before putting the materials into the furnace: Clean the bottom of the furnace and preheat it until the furnace walls turn red. At the same time, coat all the tools with graphite powder, dry them, and preheat them.

[0052] (2) Materials: The raw materials for each element that constitutes the aluminum alloy, such as metallic Al ingot or aluminum scrap, metallic Mg ingot, industrial silicon, Al-Mn intermediate alloy or metallic Mn, metallic Fe, Al-Ti intermediate alloy, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn and metallic Ga, Al-Sr intermediate alloy, rare earth aluminum intermediate alloy, etc., are prepared in advance and added according to the alloy component ratio described above, taking into consideration the amount of burnt damage as appropriate.

[0053] (3) Melting in furnace: First, aluminum metal ingots or aluminum scrap are put into a furnace and melted while maintaining the melting temperature at 760 to 790° C. After the aluminum ingots or aluminum scrap are all melted, the temperature is increased and the furnace temperature is maintained at 760 to 780° C., and industrial silicon, metallic Fe, Al-Mn intermediate alloy or metallic Mn, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn, and metallic Ga are added for smelting.

[0054] (4) Refining and slag treatment: The aluminum alloy melt is stirred uniformly while maintaining the temperature at 740-760°C, and a special refining flux for aluminum alloys is added to carry out primary and secondary refining by powder injection. The time interval between the two refining processes is controlled to 50-60 minutes, and slag treatment is carried out after each refining process to remove the flux and floating dross on the liquid surface.

[0055] (5) Addition of other metal elements: While maintaining the molten metal temperature at 740-760°C, ingots of Al-Ti intermediate alloy, rare earth aluminum intermediate alloy, metallic Mg, and Al-Sr intermediate alloy are added to the furnace and smelted, refined, and inoculated to obtain an aluminum alloy melt, which is then sampled and analyzed.

[0056] (6) Furnace degassing: While maintaining the smelting temperature at 740 to 760°C, the furnace is degassed for about 30 to 50 minutes with nitrogen gas, and then allowed to stand for 15 to 30 minutes.

[0057] (7) Casting or die casting: After the component analysis results before putting into the furnace are found to be acceptable, casting is carried out at an appropriate casting temperature to produce an ingot, or high-pressure casting is carried out in a die casting process to produce a die-cast product in a non-heat-treated state.

[0058] Example 4 The non-heat treated, high toughness Al-Si alloy die casting material with low carbon emissions and renewable properties of this embodiment contains, by mass, the following components: Mg: 0.25%, Si: 7.8%, Fe: 0.35%, Cu: 0.4%, Mn: 0.8%, Ti: 0.2%, Sr: 0.035%, Sc: 0.15%, Ni: 0.02%, Zn: 0.08%, Ga: 0.012%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0059] The manufacturing method of the present embodiment for producing a non-heat-treated high-toughness Al-Si alloy die casting that is renewable and has low carbon emissions includes the following steps.

[0060] (1) Preparation before putting the materials into the furnace: Clean the bottom of the furnace and preheat it until the furnace walls turn red. At the same time, coat all the tools with graphite powder, dry them, and preheat them.

[0061] (2) Materials: The raw materials for each element that constitutes the aluminum alloy, such as metallic Al ingot or aluminum scrap, metallic Mg ingot, industrial silicon, Al-Mn intermediate alloy or metallic Mn, metallic Fe, Al-Ti intermediate alloy, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn and metallic Ga, Al-Sr intermediate alloy, rare earth aluminum intermediate alloy, etc., are prepared in advance and added according to the alloy component ratio described above, taking into consideration the amount of burnt damage as appropriate.

[0062] (3) Melting in furnace: First, aluminum metal ingots or aluminum scrap are put into a furnace and melted while maintaining the melting temperature at 760 to 790° C. After the aluminum ingots or aluminum scrap are all melted, the temperature is increased and the furnace temperature is maintained at 760 to 780° C., and industrial silicon, metallic Fe, Al-Mn intermediate alloy or metallic Mn, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn, and metallic Ga are added for smelting.

[0063] (4) Refining and slag treatment: The aluminum alloy melt is stirred uniformly while maintaining the temperature at 740-760°C, and a special refining flux for aluminum alloys is added to carry out primary and secondary refining by powder injection. The time interval between the two refining processes is controlled to 50-60 minutes, and slag treatment is carried out after each refining process to remove the flux and floating dross on the liquid surface.

[0064] (5) Addition of other metal elements: While maintaining the molten metal temperature at 740-760°C, ingots of Al-Ti intermediate alloy, rare earth aluminum intermediate alloy, metallic Mg, and Al-Sr intermediate alloy are added to the furnace and smelted, refined, and inoculated to obtain an aluminum alloy melt, which is then sampled and analyzed.

[0065] (6) Furnace degassing: While maintaining the smelting temperature at 740 to 760°C, the furnace is degassed for about 30 to 50 minutes with nitrogen gas, and then allowed to stand for 15 to 30 minutes.

[0066] (7) Casting or die casting: After the component analysis results before putting into the furnace are found to be acceptable, casting is carried out at an appropriate casting temperature to produce an ingot, or high-pressure casting is carried out in a die casting process to produce a die-cast product in a non-heat-treated state.

[0067] Example 5 The non-heat-treated, highly tough Al-Si alloy die-cast material with low carbon emissions and renewable properties of this embodiment contains, by mass, the following components: Mg: 0.15%, Si: 8.3%, Fe: 0.45%, Cu: 0.5%, Mn: 0.65%, Ti: 0.15%, Sr: 0.03%, total amount of La·Sc: 0.2%, Ni: 0.08%, Zn: 0.01%, Ga: 0.018%, with the remainder being aluminum and 0.2% or less of remaining impurities.

[0068] The manufacturing method of the present embodiment for producing a non-heat-treated high-toughness Al-Si alloy die casting that is renewable and has low carbon emissions includes the following steps.

[0069] (1) Preparation before putting the materials into the furnace: Clean the bottom of the furnace and preheat it until the furnace walls turn red. At the same time, coat all the tools with graphite powder, dry them, and preheat them.

[0070] (2) Materials: The raw materials for each element that constitutes the aluminum alloy, such as metallic Al ingot or aluminum scrap, metallic Mg ingot, industrial silicon, Al-Mn intermediate alloy or metallic Mn, metallic Fe, Al-Ti intermediate alloy, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn and metallic Ga, Al-Sr intermediate alloy, rare earth aluminum intermediate alloy, etc., are prepared in advance and added according to the alloy component ratio described above, taking into consideration the amount of burnt damage as appropriate.

[0071] (3) Melting in furnace: First, aluminum metal ingots or aluminum scrap are put into a furnace and melted while maintaining the melting temperature at 760 to 790° C. After the aluminum ingots or aluminum scrap are all melted, the temperature is increased and the furnace temperature is maintained at 760 to 780° C., and industrial silicon, metallic Fe, Al-Mn intermediate alloy or metallic Mn, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn, and metallic Ga are added for smelting.

[0072] (4) Refining and slag treatment: The aluminum alloy melt is stirred uniformly while maintaining the temperature at 740-760°C, and a special refining flux for aluminum alloys is added to carry out primary and secondary refining by powder injection. The time interval between the two refining processes is controlled to 50-60 minutes, and slag treatment is carried out after each refining process to remove the flux and floating dross on the liquid surface.

[0073] (5) Addition of other metal elements: While maintaining the molten metal temperature at 740-760°C, ingots of Al-Ti intermediate alloy, rare earth aluminum intermediate alloy, metallic Mg, and Al-Sr intermediate alloy are added to the furnace and smelted, refined, and inoculated to obtain an aluminum alloy melt, which is then sampled and analyzed.

[0074] (6) Furnace degassing: While maintaining the smelting temperature at 740 to 760°C, the furnace is degassed for about 30 to 50 minutes with nitrogen gas, and then allowed to stand for 15 to 30 minutes.

[0075] (7) Casting or die casting: After the component analysis results before putting into the furnace are found to be acceptable, casting is carried out at an appropriate casting temperature to produce an ingot, or high-pressure casting is carried out in a die casting process to produce a die-cast product in a non-heat-treated state.

[0076] Example 6 The low carbon emission, renewable, non-heat-treated, high-toughness Al-Si alloy die-cast material of this embodiment is manufactured using recycled aluminum scrap as raw material through the following process.

[0077] (1) Preparation before putting the materials into the furnace: Clean the bottom of the furnace and preheat it until the furnace walls turn red. At the same time, coat all the tools with graphite powder, dry them, and preheat them.

[0078] (2) Materials: First, recycled aluminum scrap is selected and processed. Next, based on the alloy component ratio, raw materials for each element that constitutes the aluminum alloy, such as metallic Al ingot, metallic Mg ingot, industrial silicon, Al-Mn intermediate alloy or metallic Mn, metallic Fe, Al-Ti intermediate alloy, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn and metallic Ga, Al-Sr intermediate alloy, rare earth aluminum intermediate alloy, etc., are prepared and added according to the above alloy component ratio, taking into account the amount of burnt loss.

[0079] (3) Melting in furnace: First, aluminum metal ingots and aluminum scrap are put into the furnace in the following order in a mass ratio of 40% to 60%, and smelted while maintaining the furnace temperature at 760-790°C. After everything is melted, sampling and analysis are performed, and other elements are added according to their respective ratios. Next, the temperature is increased, and the furnace temperature is maintained at 760-780°C, and industrial silicon, metal Fe, Al-Mn intermediate alloy or metal Mn, metal Cu or Al-Cu intermediate alloy, metal Ni, metal Zn, and metal Ga are added and smelted.

[0080] (4) Refining and slag treatment: The aluminum alloy melt that passed the component analysis is stirred uniformly while maintaining the temperature at 740-760℃, and a special refining flux for aluminum alloys is added to carry out primary and secondary refining by powder injection. The time interval between the two refining processes is controlled to 50-60 minutes, and slag treatment is carried out after each refining to remove the flux and floating dross on the liquid surface.

[0081] (5) Addition of other metal elements: While maintaining the molten metal temperature at 740-760°C, ingots of Al-Ti intermediate alloy, rare earth aluminum intermediate alloy, metallic Mg, and Al-Sr intermediate alloy are added to the furnace and smelted, refined, and inoculated to obtain an aluminum alloy melt, which is then sampled and analyzed.

[0082] (6) Furnace degassing: While maintaining the smelting temperature at 740 to 760°C, the furnace is degassed for about 30 to 50 minutes with nitrogen gas, and then allowed to stand for 15 to 30 minutes.

[0083] (7) Casting or die casting: The final mass percent content of each component is: Mg: 0.25%, Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Ti: 0.12%, Sr: 0.028%, La·Ce·Sc total: 0.2%, Ni: 0.005%, Zn: 0.06%, Ga: 0.02%, and the remainder is aluminum and impurities of less than 0.2%. After the component analysis results before putting into the furnace are found to be acceptable, casting is performed under an appropriate casting temperature to create an ingot, and high-pressure casting is performed in a die casting process to create a die-cast product in a non-heat-treated state.

[0084] Example 7 The low carbon emission, renewable, non-heat-treated, high-toughness Al-Si alloy die-cast material of this embodiment is manufactured using recycled aluminum scrap as raw material through the following process.

[0085] (1) Preparation before putting the materials into the furnace: Clean the bottom of the furnace and preheat it until the furnace walls turn red. At the same time, coat all the tools with graphite powder, dry them, and preheat them.

[0086] (2) Materials: First, recycled aluminum scrap is selected. Next, based on the alloy component ratio, raw materials for each element that constitutes the aluminum alloy, such as metallic Mg ingot, industrial silicon, Al-Mn intermediate alloy or metallic Mn, metallic Fe, Al-Ti intermediate alloy, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn and metallic Ga, Al-Sr intermediate alloy, rare earth aluminum intermediate alloy, etc., are prepared and added according to the above alloy component ratio, taking into account the amount of burnt loss.

[0087] (3) Melting in furnace: First, aluminum scrap is put into the furnace at a mass ratio of 100%, and smelted while maintaining the furnace temperature at 760-790°C. After it is all melted, sampling and analysis are performed, and other elements are added according to their respective ratios. Next, the temperature is increased, and the furnace temperature is maintained at 760-780°C, and industrial silicon, metallic Fe, Al-Mn intermediate alloy or metallic Mn, metallic Cu or Al-Cu intermediate alloy, metallic Ni, metallic Zn, and metallic Ga are added for smelting.

[0088] (4) Refining and slag treatment: The aluminum alloy melt that passed the component analysis is stirred uniformly while maintaining the temperature at 740-760℃, and a special refining flux for aluminum alloys is added to carry out primary and secondary refining by powder injection. The time interval between the two refining processes is controlled to 50-60 minutes, and slag treatment is carried out after each refining to remove the flux and floating dross on the liquid surface.

[0089] (5) Addition of other metal elements: While maintaining the molten metal temperature at 740-760°C, ingots of Al-Ti intermediate alloy, rare earth aluminum intermediate alloy, metallic Mg, and Al-Sr intermediate alloy are added to the furnace and smelted, refined, and inoculated to obtain an aluminum alloy melt, which is then sampled and analyzed.

[0090] (6) Furnace degassing: While maintaining the smelting temperature at 740 to 760°C, the furnace is degassed for about 30 to 50 minutes with nitrogen gas, and then allowed to stand for 15 to 30 minutes.

[0091] (7) Casting or die casting: The final mass percent content of each component is: Mg: 0.3%, Si: 7.7%, Fe: 0.15%, Cu: 0.3%, Mn: 0.7%, Ti: 0.15%, Sr: 0.035%, Ce: 0.08%, Ni: 0.1%, Zn: 0.1%, Ga: 0.03%, and the remainder is aluminum and impurities of less than 0.2%. After the component analysis results before putting into the furnace are found to be acceptable, casting is performed under an appropriate casting temperature to create an ingot, and high-pressure casting is performed using a die casting process to create a die-cast product in a non-heat-treated state.

[0092] Comparative Example 1 This comparative example is based on Example 2, but the amount of Sr element has been reduced and the La element has been removed, and the content of each component in mass% is: Si: 6.9%, Fe: 0.2%, Cu: 0.2%, Mn: 0.6%, Mg: 0.3%, Ti: 0.07%, Sr: 0.008%, Ni: 0.003%, Zn: 0.07%, Ga: 0.02%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0093] The manufacturing method of the aluminum alloy die-cast material in this comparative example includes the following steps.

[0094] (1) Preparation before putting the materials into the furnace: Clean the bottom of the furnace and preheat it until the furnace walls turn red. At the same time, coat all the tools with graphite powder, dry them, and preheat them.

[0095] (2) Materials: Prepare the raw materials for each element that constitutes the aluminum alloy, such as metallic Al ingot, metallic Mg ingot, industrial silicon, metallic Cu, Al-Mn intermediate alloy or metallic Mn, metallic Fe, Al-Ti intermediate alloy, Al-Sr intermediate alloy, etc., in advance and add them according to the alloy component ratio described above, taking into account the amount of burnt damage as appropriate.

[0096] (3) Melting in furnace: First, an ingot of metallic Al is put into the furnace and smelting is performed while maintaining the smelting temperature at 670-690°C. After the Al ingot is completely melted, the temperature is increased and the furnace temperature is maintained at 760-780°C, and industrial silicon, metallic Fe, metallic Cu, an Al-Mn intermediate alloy, or metallic Mn is added for smelting.

[0097] (4) Refining and slag treatment: The aluminum alloy melt that passed the component analysis is stirred uniformly while maintaining the temperature at 740-760℃, and a special refining flux for aluminum alloys is added to carry out primary and secondary refining by powder injection. The time interval between the two refining processes is controlled to 50-60 minutes, and slag treatment is carried out after each refining to remove the flux and floating dross on the liquid surface.

[0098] (5) Addition of other metal elements: While maintaining the temperature of the molten metal at 740-760°C, ingots of Al-Ti intermediate alloy, metallic Mg, and Al-Sr intermediate alloy are added to the furnace and smelted to obtain an aluminum alloy melt, which is then sampled and analyzed.

[0099] (6) Furnace degassing: While maintaining the smelting temperature at 740 to 760°C, the furnace is degassed for about 30 to 50 minutes with nitrogen gas, and then allowed to stand for 15 to 30 minutes.

[0100] (7) Casting or die casting: After the component analysis results before putting into the furnace are found to be acceptable, casting is carried out at an appropriate casting temperature to produce an ingot, or high-pressure casting is carried out in a die casting process to produce a die-cast product in a non-heat-treated state.

[0101] Comparative Example 2 This comparative example is based on Example 2, but the Sr element has been increased and the La element has been removed. The contents of each component in mass% are: Si: 6.9%, Fe: 0.2%, Cu: 0.2%, Mn: 0.6%, Mg: 0.3%, Ti: 0.07%, Sr: 0.05%, Ni: 0.003%, Zn: 0.07%, Ga: 0.02%, and the remainder is aluminum and 0.2% or less of remaining impurities.

[0102] The manufacturing method of this comparative example is the same as that of the comparative example 1.

[0103] Comparative Example 3 This comparative example is based on Example 6, but with the exception of the elements La, Ce, Sc, Zn, Ni, and Ga, and the contents of each component in mass% are: Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0104] The manufacturing method of this comparative example is the same as that of the comparative example 1.

[0105] Comparative Example 4

[0106] This comparative example is based on Example 6, but with the exception of the La, Ce, and Sc elements, and the contents of each component in mass% are: Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0107] The manufacturing method of this comparative example is the same as that of the comparative example 1.

[0108] Comparative Example 5 This comparative example is based on Example 6, but with high additions of La, Ce, and Sc elements, and the content of each component in mass% is: Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, La: 0.2%, Ce: 0.2%, Sc: 0.2%, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0109] The manufacturing method of this comparative example is the same as that of the comparative example 1.

[0110] Comparative Example 6 This comparative example is based on Example 6, but with a high La element added, and the content of each component in mass% is: Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, La: 1.0%, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0111] The manufacturing method of this comparative example is the same as that of the comparative example 1.

[0112] Comparative Example 7 This comparative example is based on Example 6, but with a high addition of Sc element, and the content of each component in mass% is: Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, Sc: 0.5%, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0113] The manufacturing method of this comparative example is the same as that of the comparative example 1.

[0114] Comparative Example 8 This comparative example is based on Example 6, but with a high addition of Sc element, and the content of each component in mass% is: Si: 7.0%, Fe: 0.35%, Cu: 0.25%, Mn: 0.6%, Mg: 0.25%, Ti: 0.12%, Sr: 0.028%, La: 0.01%, Sc: 0.01%, Ni: 0.06%, Zn: 0.005%, Ga: 0.02%, with the remainder being aluminum and less than 0.2% remaining impurities.

[0115] The manufacturing method of this comparative example is the same as that of the comparative example 1.

[0116] Table 1 shows the compositions of the aluminum alloys produced in Examples 1-7 and Comparative Examples 1-8.

[0117] [Table 1]

[0118] Table 2 shows the mechanical properties and fluidity measured at room temperature for the F materials sampled from the aluminum alloy ingot bodies produced in Examples 1 to 7 and Comparative Examples 1 to 8, and for the same materials heated at 180°C for 30 minutes. [Table 2]

[0119] According to Tables 1 and 2, in Comparative Example 1, in which the Sr element content was significantly reduced and no rare earth was added, the yield strength was 26 MPa and the elongation was 4.2% lower than in Example 2. In Comparative Example 2, in which the Sr element content was significantly increased and no rare earth was added, the yield strength was 17 MPa and the elongation was 4.9% lower than in Example 2. In Comparative Example 3, in which no rare earth, Zn, Ni, or Ga elements were added, the yield strength was 25 MPa and the elongation was 3.3% lower than in Example 6. In Comparative Example 4, in which no rare earth was added, the yield strength was 23 MPa and the elongation was 3.6% lower than in Example 6. In Comparative Example 5, in which the total amount of rare earth La·Ce·Sc added was adjusted to 0.6%, the yield strength was 18 MPa and the elongation was 4.8% lower than in Example 6. In Comparative Example 6, in which the amount of rare earth La added was adjusted to 1.0%, the yield strength was 16 MPa and the elongation was 5.1% lower than in Example 6. In comparison with Example 6, Comparative Example 7, in which the amount of rare earth Sc added was adjusted to 0.5%, had a yield strength that was reduced by 20 MPa and an elongation that was reduced by 4.1%. In comparison with Example 6, Comparative Example 8, in which the total amount of rare earth La·Sc added was adjusted to 0.02%, had a yield strength that was reduced by 16 MPa and an elongation that was reduced by 4.2%. Therefore, only when the contents of Sr and rare earth La·Ce·Sc elements are within the range of the present invention can excellent mechanical properties be exhibited. If the contents of Sr or rare earth La·Ce·Sc elements are too low or too high, the overall mechanical properties are reduced.

[0120] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited thereto. Various simple modifications can be made to the technical means of the present invention within the scope of the technical idea of ​​the present invention, such as arbitrarily combining each technical feature in other suitable ways. All such simple modifications and combinations are considered to be the disclosure of the present invention and fall within the protection scope of the present invention.

Claims

1. A non-heat treated high-toughness Al-Si alloy die casting material characterized in that the content of each component, by mass%, is as follows: Si: 6.3-8.3%, Fe: 0.07-0.45%, Cu: 0.05-0.5%, Mn: 0.5-0.8%, Mg: 0.15-0.35%, Ti: 0.01-0.2%, Sr: 0.015-0.035%, total amount of rare earths including one or more of La / Ce / Sc: 0.04-0.2%, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, and the balance is Al and 0.2% or less of remaining impurities.

2. 2. The Al-Si alloy die casting material according to claim 1, characterized in that the contents of each component, in mass%, are: Si: 6.3-7.0%, Fe: 0.2-0.4%, Cu: 0.35-0.45%, Mn: 0.5-0.8%, Mg: 0.25-0.35%, Ti: 0.1-0.2%, Sr: 0.015-0.035%, total amount of rare earths including one or more of La / Ce / Sc: 0.04-0.2%, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, and the balance is Al and remaining impurities of 0.2% or less.

3. 2. The non-heat-treated high-toughness Al-Si alloy die casting material according to claim 1, characterized in that the contents of each component, in mass%, are: Si: 6.4-7.1%, Fe: 0.10-0.25%, Cu: 0.05-0.28%, Mn: 0.5-0.8%, Mg: 0.25-0.35%, Ti: 0.03-0.16%, Sr: 0.025-0.035%, total amount of rare earths including one of La / Ce / Sc: 0.04-0.15%, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, and the balance being Al and remaining impurities of 0.2% or less.

4. 2. The Al-Si alloy die casting material according to claim 1, characterized in that the contents of each component, in mass%, are: Si: 7.0-7.7%, Fe: 0.15-0.3%, Cu: 0.2-0.35%, Mn: 0.6-0.8%, Mg: 0.2-0.3%, Ti: 0.05-0.2%, Sr: 0.015-0.035%, total amount of rare earths including one or more of La / Ce / Sc: 0.04-0.2%, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, and the balance is Al and remaining impurities of 0.2% or less.

5. 2. The Al-Si alloy die casting material according to claim 1, characterized in that the contents of each component, in mass%, are: Si: 7.7-8.3%, Fe: 0.07-0.2%, Cu: 0.05-0.2%, Mn: 0.6-0.8%, Mg: 0.15-0.3%, Ti: 0.01-0.15%, Sr: 0.015-0.035%, total amount of rare earths including one or more of La / Ce / Sc: 0.04-0.2%, Ni: 0.001-0.1%, Zn: 0.005-0.1%, Ga: 0.01-0.03%, and the balance is Al and remaining impurities of 0.2% or less.

6. 6. The Al-Si alloy die casting material according to any one of claims 1 to 5, characterized in that it has a tensile strength of 270 MPa or more, a yield strength of 130 MPa or more, and an elongation of 11% or more.

7. 7. The process for producing an Al-Si alloy die-casting material according to any one of claims 1 to 6, characterized in that the raw material which is unlikely to be burned is heated and melted to prepare the Al-Si alloy die-casting material, an aluminum alloy liquid is obtained, the aluminum alloy liquid is subjected to slag removal and refining, and then the raw material which is likely to be burned is added, and after the components reach specified values, a casting process is performed to obtain the Al-Si alloy die-casting material.

8. The manufacturing process according to claim 7, characterized in that the Al-Si alloy die-casting material is die-cast at a forming temperature of 680-720°C, a die-casting speed of 2.5-5m / s, and a heat-retention time of 2-10 seconds to obtain a non-heat-treated die-cast product.

9. The manufacturing process according to claim 7, characterized in that after each raw material is completely melted, the aluminum alloy liquid is uniformly stirred, and then allowed to stand, after which sampling and analysis are performed to adjust the contents of required elements within the required ranges of component ratios.

10. 8. The process according to claim 7, characterized in that the refining flux used does not contain sodium ions.

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