High-strength and high-hardness die-casting aluminum-silicon alloy material and preparation process thereof

Abstract

The invention relates to the technical field of metal materials, and discloses a high-strength and high-hardness die-casting aluminum-silicon alloy material which comprises the following components in percentage by mass: 9-11% of silicon, 0.6-0.9% of iron, 0.1-0.55% of manganese, 0.25-0.5% of magnesium, less than or equal to 0.2% of titanium, less than or equal to 0.15% of nickel, less than or equal to 0.15% of zinc, less than or equal to 0.1% of copper, less than or equal to 0.10% of lead, less than or equal to 0.05% of tin, less than or equal to 0.05% of other single impurities, less than or equal to 0.15% of the total content of other impurities and the balance of aluminum. According to the high-strength and high-hardness die-casting aluminum-silicon alloy material and the preparation process thereof, the content ranges of key elements such as silicon, iron, manganese and magnesium in the alloy are accurately controlled, particularly, the iron content is limited to be 0.6%-0.9%, and the manganese content is limited to be 0.1%-0.55%, so that the strength and hardness of the alloy are remarkably improved, and by forming alpha-Al (Fe, Mn), the high-strength and high-hardness die-casting aluminum-silicon alloy material is prepared. Compared with the prior art, the method has the advantages that generation of harmful beta-AlFeSi phases is effectively inhibited by the (Mn) Si phases, accordingly, the mechanical property and the hot crack tendency of the alloy are improved, generation of MgSi strengthening phases is promoted by optimizing the magnesium content to 0.25%-0.5%, primary aluminum phases and aluminum-silicon eutectic structures of the alloy are refined, and the tensile strength and the yield strength are improved at the same time.

Description

Technical Field

[0001] This invention relates to the field of metal materials technology, specifically to a high-strength, high-hardness die-cast aluminum-silicon alloy material and its preparation process. Background Technology

[0002] Aluminum-silicon alloys, as an important class of lightweight and high-strength alloy materials, have been widely used in aerospace, automobile manufacturing, electronic communications, building decoration and other fields due to their excellent physical and chemical properties. Traditional aluminum-silicon alloys are mainly composed of aluminum and silicon, and may contain small amounts of copper, magnesium, manganese and other elements to adjust their mechanical properties. These alloys have the characteristics of low density, high thermal conductivity, strong corrosion resistance and excellent casting performance. Despite the many advantages of aluminum-silicon alloys, some technical problems and challenges still exist in their practical applications.

[0003] Currently, the machinability of aluminum-silicon alloys needs improvement. The addition of silicon makes the material difficult to cut, resulting in low processing efficiency and easy tool wear. Secondly, aluminum-silicon alloys have relatively low surface hardness, making them susceptible to external environmental erosion, such as scratches and corrosion, which affects their appearance and service life. Furthermore, with the advancement of technology and industrial development, the performance requirements for aluminum-silicon alloys are becoming increasingly stringent, such as higher strength, better wear resistance, and superior corrosion resistance. These have become important directions for current research on aluminum-silicon alloys. Summary of the Invention

[0004] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a high-strength, high-hardness die-cast aluminum-silicon alloy material and its preparation process. It possesses advantages such as high strength, high hardness, excellent comprehensive mechanical properties, stable process, and high production efficiency. It solves the problems of traditional aluminum-silicon alloys, such as processing difficulties due to the presence of silicon, insufficient surface hardness, difficulty in balancing strength and hardness, susceptibility to hot cracking, and the need to improve high-temperature performance and corrosion resistance.

[0005] (II) Technical Solution To achieve the aforementioned objectives of high strength, high hardness, excellent comprehensive mechanical properties, stable process, and high production efficiency, this invention provides the following technical solution: A high-strength, high-hardness die-cast aluminum-silicon alloy material, comprising the following components by mass percentage: silicon 9%~11%, iron 0.6%~0.9%, manganese 0.1%~0.55%, magnesium 0.25%~0.5%, titanium ≤0.2%, nickel ≤0.15%, zinc ≤0.15%, copper ≤0.1%, lead ≤0.10%, tin ≤0.05%, other individual impurities ≤0.05%, total other impurities ≤0.15%, and the balance being aluminum.

[0006] Furthermore, the iron content is 0.6% to 0.9%, which is used to improve the strength and hardness of the die casting and control the generation of hot cracks.

[0007] Furthermore, the manganese content is 0.1%~0.55%, used to transform the needle-like β-Al5FeSi phase into the Chinese character-shaped α-Al. 15 The (Fe,Mn)3Si2 phase mitigates the harmful effects of iron and enhances the mechanical properties of the alloy.

[0008] Furthermore, the magnesium content is 0.25%~0.5%, which forms a Mg2Si strengthening phase with silicon, refines the primary aluminum phase and the aluminum-silicon eutectic phase, and improves the tensile strength and yield strength of the alloy.

[0009] A preparation process for a high-strength, high-hardness die-cast aluminum-silicon alloy material, comprising the above-mentioned high-strength, high-hardness die-cast aluminum-silicon alloy material, and the operation steps are as follows: Step S1: Prepare materials, provide the required raw materials, including aluminum ingots, magnesium ingots, copper plates, aluminum silicon, aluminum manganese, iron powder, nickel blocks, zinc granules, tin granules, titanium powder and lead blocks; Step S2: Melting. After mixing the raw materials, melt them at a temperature of 650℃~680℃. Step S3: Refining. At a temperature of 700℃~740℃, a refining agent is added to the melt, and refining and degassing are carried out in an argon or nitrogen atmosphere for 15~17 minutes. Step S4: Molding, the refined alloy liquid is molded into shape using a die casting method; Step S5: Post-processing: Obtain aluminum-silicon alloy castings with high strength and hardness.

[0010] Furthermore, the refining agent mentioned in step S3 is selected from at least one of hexachloroethane, zinc dichloride, and manganese dichloride.

[0011] Furthermore, the molding process described in step S4 employs a high-vacuum pressure casting method.

[0012] Furthermore, nitrogen is used as a protective gas during the refining process described in step S3.

[0013] (III) Beneficial Effects Compared with the prior art, the present invention provides a high-strength, high-hardness die-cast aluminum-silicon alloy material and its preparation process, which has the following beneficial effects: 1. This high-strength, high-hardness die-cast aluminum-silicon alloy material and its preparation process, through precise control of the content range of key elements such as silicon, iron, manganese, and magnesium in the alloy, especially limiting the iron content to 0.6%~0.9% and the manganese content to 0.1%~0.55%, not only significantly improves the strength and hardness of the alloy, but also forms α-Al 15The (Fe,Mn)3Si2 phase effectively inhibits the formation of the harmful β-Al5FeSi phase, thereby improving the mechanical properties and hot cracking tendency of the alloy.

[0014] 2. This high-strength, high-hardness die-cast aluminum-silicon alloy material and its preparation process, by optimizing the magnesium content to 0.25%~0.5%, promotes the formation of the Mg2Si strengthening phase, refines the primary aluminum phase and aluminum-silicon eutectic structure of the alloy, and maintains good elongation while improving tensile strength and yield strength, thus achieving a synergistic improvement in strength-ductility product (≥593.4MPa·%) and hardness.

[0015] 3. The high-strength, high-hardness die-cast aluminum-silicon alloy material and its preparation process adopt a segmented melting and refining process. Melting is carried out at 650℃~680℃, and refining and degassing are carried out at 700℃~740℃. Combined with nitrogen protection and the use of efficient refining agents, the porosity and inclusion content in the alloy are significantly reduced, and the density and internal quality of the castings are improved.

[0016] 4. This high-strength, high-hardness die-cast aluminum-silicon alloy material and its preparation process, through high-vacuum pressure casting, combined with optimized composition design and process control, achieve excellent comprehensive properties (tensile strength ≥215MPa, Brinell hardness ≥120HBW, elongation ≥2.76%) in the as-cast state. This not only simplifies the subsequent heat treatment process but also improves production efficiency and product consistency. Attached Figure Description

[0017] Figure 1 This is a schematic representation of the aluminum-silicon alloy raw material of the present invention; Figure 2 This is a process flow diagram for preparing the aluminum-silicon alloy of the present invention; Figure 3 The image shows the metallographic structure of the aluminum-silicon alloy prepared in Example 1 of this invention. Figure 4 The image shows the metallographic structure of the aluminum-silicon alloy prepared in Example 2 of this invention. Figure 5 This is a metallographic image of the aluminum-silicon alloy prepared in Comparative Example 1 of the present invention. Figure 6 The tensile stress-strain curve of the aluminum-silicon alloy prepared in Example 1 of the present invention is shown. Figure 7 The tensile stress-strain curve of the aluminum-silicon alloy prepared in Example 2 of this invention is shown. Figure 8 The tensile stress-strain curve of the aluminum-silicon alloy prepared in Comparative Example 1 of this invention is shown. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1-8 A high-strength, high-hardness die-cast aluminum-silicon alloy material, comprising the following components by mass percentage: silicon 9%~11%, iron 0.6%~0.9%, manganese 0.1%~0.55%, magnesium 0.25%~0.5%, titanium ≤0.2%, nickel ≤0.15%, zinc ≤0.15%, copper ≤0.1%, lead ≤0.10%, tin ≤0.05%, other individual impurities ≤0.05%, total other impurities ≤0.15%, and the balance being aluminum.

[0020] In the case study, the iron content was 0.6%–0.9% to improve the strength and hardness of the die-cast parts and control the formation of hot cracks, while the manganese content was 0.1%–0.55% to transform the acicular β-Al5FeSi phase into the Chinese character-shaped α-Al. 15 The (Fe,Mn)3Si2 phase mitigates the harmful effects of iron and enhances the mechanical properties of the alloy. The magnesium content is 0.25%~0.5%, which forms the Mg2Si strengthening phase with silicon, refines the primary aluminum phase and the aluminum-silicon eutectic phase, and improves the tensile strength and yield strength of the alloy. In the aluminum-silicon alloy, by mass percentage, silicon includes, but is not limited to, 9%, 9.2%, 9.5%, 9.8%, 10%, 10.2%, 10.5%, 10.65%, 10.7%, and 11%; iron includes, but is not limited to, 0.6%, 0.65%, 0.7%, 0.75%, 0.85%, and 0.9%; manganese includes, but is not limited to, 0.1%, 0.12%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.43%, 0.45%, 0.5%, and 0.55%; magnesium includes, but is not limited to, 0.25%, 0.3%, 0.35%, 0.37%, 0.38%, 0.4%, 0.43%, 0.45%, and 0.5%; and titanium includes, but is not limited to, 0.01%, 0.03%, 0.05%, 0.07%, and 0.1%. 0.15%, 0.17%, 0.2%; Nickel includes but is not limited to 0.01%, 0.03%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15%; Zinc includes but is not limited to 0.02%, 0.05%, 0.08%, 0.1%, 0.12%, 0.14%, 0.15%; Copper includes but is not limited to 0.01%, 0.02%, 0.03%, 0.05%, 0.07%, 0.09%, 0.1%; Lead includes but is not limited to 0.02%, 0.03%, 0.05%, 0.06%, 0.08%, 0.09%, 0.1%; Tin includes but is not limited to 0.01%, 0.02%, 0.03%, 0.04%, 0.05%; In some examples, any two of these point values ​​can be used as endpoints within a range, the same applies below; A small amount of Fe in aluminum-silicon alloys can improve the strength and hardness of die castings. By controlling the Fe content, the thermal strength of the castings can be increased, thereby reducing the occurrence of hot cracks. The main role of adding Mn is to mitigate the harmful effects of Fe on the alloy, changing the needle-like β-Al5FeSi phase in the microstructure into the Chinese character-shaped α-Al15(Fe,Mn)3Si2 phase or other AlFeMnSi intermetallic compounds, thus improving the mechanical properties of the alloy material. Magnesium and silicon form the Mg2Si strengthening phase, which has a significant refining effect on the primary aluminum phase and the aluminum-silicon eutectic phase. A small amount of Mg can improve the tensile strength and yield strength of the alloy, resulting in good mechanical properties. The good tensile strength, yield strength, and plasticity of aluminum-silicon alloys are achieved through the mutual cooperation and restraint among the components, and are not caused by the individual components.

[0021] A preparation process for a high-strength, high-hardness die-cast aluminum-silicon alloy material, comprising the above-mentioned high-strength, high-hardness die-cast aluminum-silicon alloy material, and the operation steps are as follows: Step S1: Prepare materials, provide the required raw materials, including aluminum ingots, magnesium ingots, copper plates, aluminum silicon, aluminum manganese, iron powder, nickel blocks, zinc granules, tin granules, titanium powder and lead blocks; Step S2: Melting. After mixing the raw materials, melt them at a temperature of 650℃~680℃. Step S3: Refining. At a temperature of 700℃~740℃, a refining agent is added to the melt, and refining and degassing are carried out in an argon or nitrogen atmosphere for 15~17 minutes. Step S4: Molding, the refined alloy liquid is molded into shape using a die casting method; Step S5: Post-processing: Obtain aluminum-silicon alloy castings with high strength and hardness.

[0022] In some of these examples, the raw materials used in the preparation methods of aluminum-silicon alloys include, but are not limited to, aluminum ingots, magnesium ingots, copper plates, aluminum-silicon, aluminum-manganese, iron powder, nickel blocks, zinc granules, tin granules, titanium powder, and lead blocks.

[0023] In some examples, the melting temperature in the preparation method of aluminum-silicon alloy is 650℃~680℃. It can be understood that the melting temperature includes, but is not limited to, 650℃, 660℃, 670℃, and 680℃. In some examples, the refining temperature in the preparation method of aluminum-silicon alloy is 700℃~740℃. It can be understood that the refining temperature includes, but is not limited to, 700℃, 710℃, 720℃, 730℃, and 740℃.

[0024] In some of these examples, the refining atmosphere used in the preparation of aluminum-silicon alloys includes at least one of argon and nitrogen, with nitrogen being the gas used in this method.

[0025] In some of these examples, the refining agents used in the refining step of the aluminum-silicon alloy preparation method include, but are not limited to, at least one of hexachloroethane, zinc dichloride, and manganese dichloride.

[0026] In some of these examples, the refining time in the preparation method of aluminum-silicon alloy is 15-17 minutes.

[0027] In some of these examples, the aluminum-silicon alloy is formed using die casting.

[0028] In the implementation of this case, the method of implementation is not limited to this, as follows: Example 1 By mass percentage, it includes the following components: silicon 9%; iron 0.6%; manganese 0.1%; magnesium 0.25%; titanium 0.2%; nickel 0.15%; zinc 0.15%; copper 0.1%; lead 0.1%; tin 0.05%; other individual impurities ≤0.05%; total other impurities ≤0.15%; balance aluminum.

[0029] According to the above-mentioned components, each raw material is placed into the furnace in sequence for melting at a melting temperature of 650℃~680℃. Then, a refining agent is added, and nitrogen is used to refine and degas the aluminum liquid at 700℃~740℃ for 715s~730s. Subsequently, the refined and degassed aluminum-silicon alloy liquid is used to prepare aluminum-silicon alloy test bars by high vacuum pressure casting.

[0030] Example 2 It is basically the same as Example 1, except that: By mass percentage, it includes the following components: Silicon 9.5%; Iron 0.7%; Manganese 0.3%; Magnesium 0.35%; Titanium 0.2%; Nickel 0.15%; Zinc 0.15%; Copper 0.1%; Lead 0.1%; Tin 0.05%; Other individual impurities ≤0.05%; Total other impurities ≤0.15%; Balance: Aluminum.

[0031] Example 3 It is basically the same as Example 1, except that: By mass percentage, it includes the following components: Silicon 10.5%; Iron 0.8%; Manganese 0.4%; Magnesium 0.45%; Titanium 0.2%; Nickel 0.15%; Zinc 0.15%; Copper 0.1%; Lead 0.1%; Tin 0.05%; Other individual impurities ≤0.05%; Total other impurities ≤0.15%; Balance: Aluminum.

[0032] The alloy composition of this invention is an improvement on the grade AlSi1OMg(Fe), and by mass percentage includes the following components: silicon 9%~11%, iron ≤1%, manganese ≤0.55%, magnesium 0.20%~0.5%, titanium ≤0.2%, nickel ≤0.15%, zinc ≤0.15%, copper ≤0.1%, lead ≤0.15%, tin ≤0.05%, other individual impurities ≤0.05%, total other impurities ≤0.15%, and the balance being aluminum.

[0033] Comparative Example 1 It is basically the same as Example 1, except for the content of iron and lead; By mass percentage, it includes the following components: Silicon 9%; Iron 1%; Manganese 0.1%; Magnesium 0.20%; Titanium 0.2%; Nickel 0.15%; Zinc 0.15%; Copper 0.1%; Lead 0.15%; Tin 0.05%; Other individual impurities ≤0.05%; Total other impurities ≤0.15%; Balance: Aluminum.

[0034] The composition and proportions of the aluminum-silicon alloys in each embodiment and comparative example are shown in Table 1, in wt%; Table 1 The aluminum-silicon alloy materials prepared in the above embodiments and comparative examples were tested for tensile strength, yield strength, elongation, and Brinell hardness in the as-cast state, and the metallographic structure was observed. The test conditions and standards for tensile strength, yield strength, and elongation were in accordance with GB / T228.1; the strength-ductility product, calculated as the product of tensile strength and elongation, was used to evaluate the comprehensive performance of the aluminum-silicon alloy; the test conditions and standards for Brinell hardness were in accordance with GB / T231.1 and GB / T231.3, and the results are as follows: Figures 6-8 and Table 2; Table 2 From Table 2 and Figures 6-8 It can be seen that the aluminum-silicon alloy material of the embodiment, while ensuring a tensile strength of ≥200MPa, also has excellent comprehensive mechanical properties such as elongation of ≥2.76% and strength-ductility product of ≥593.4MPa·%, and a Brinell hardness of ≥120HBW; the strength-ductility product and elongation of the embodiment 2 are further superior to those of the other embodiments.

[0035] In summary, this high-strength, high-hardness die-cast aluminum-silicon alloy material and its preparation process, by precisely controlling the content range of key elements such as silicon, iron, manganese, and magnesium in the alloy, especially limiting the iron content to 0.6%~0.9% and the manganese content to 0.1%~0.55%, not only significantly improves the strength and hardness of the alloy, but also forms α-Al 15 The (Fe,Mn)3Si2 phase effectively inhibits the formation of harmful β-Al5FeSi phase, thereby improving the mechanical properties and hot cracking tendency of the alloy. By optimizing the magnesium content to 0.25%~0.5%, the formation of Mg2Si strengthening phase is promoted, and the primary aluminum phase and aluminum-silicon eutectic structure of the alloy are refined. While improving tensile strength and yield strength, good elongation is maintained, and the synergistic improvement of strength-ductility product (≥593.4MPa·%) and hardness is achieved.

[0036] Furthermore, by employing a segmented melting and refining process, melting is carried out at 650℃~680℃, and refining and degassing are performed at 700℃~740℃. Combined with nitrogen protection and the use of highly efficient refining agents, the porosity and inclusion content in the alloy are significantly reduced, improving the density and internal quality of the castings. By using a high-vacuum pressure casting method, coupled with optimized composition design and process control, the alloy achieves excellent comprehensive properties in the as-cast state (tensile strength ≥215MPa, Brinell hardness ≥120HBW, elongation ≥2.76%), which not only simplifies the subsequent heat treatment process but also improves production efficiency and product consistency.

[0037] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0038] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-strength high-hardness die-cast aluminum-silicon alloy material, characterized by: By mass percent, the following components are included: silicon 9%~11%, iron 0.6%~0.9%, manganese 0.1%~0.55%, magnesium 0.25%~0.5%, titanium ≤0.2%, nickel ≤0.15%, zinc ≤0.15%, copper ≤0.1%, lead ≤0.10%, tin ≤0.05%, other single impurity content ≤0.05%, other impurities total content ≤0.15%, and the balance of aluminum.

2. The high-strength high-hardness die-casting aluminum-silicon alloy material according to claim 1, characterized in that: The iron content is 0.6%~0.9%, which is used to improve the strength and hardness of the die casting and control the generation of hot cracks.

3. The high-strength high-hardness die-casting aluminum-silicon alloy material according to claim 1, characterized in that: The manganese content is 0.1% to 0.55%, which is used to convert the needle-like β-Al5FeSi phase into Chinese character-like α-Al 15 (Fe,Mn)3Si2 phase, improve the harmful effect of iron, and improve the mechanical properties of the alloy.

4. The high-strength high-hardness die-casting aluminum-silicon alloy material according to claim 1, characterized in that: The magnesium content is 0.25%~0.5%, which forms Mg2Si strengthening phase with silicon, refines primary aluminum phase and aluminum-silicon eutectic phase, and improves the tensile strength and yield strength of the alloy.

5. A high-strength and high-hardness die-casting aluminum-silicon alloy material and a preparation process thereof, comprising the high-strength and high-hardness die-casting aluminum-silicon alloy material according to claims 1-4, characterized in that: The operation steps are as follows: Step S1: preparing materials, providing the required raw materials, including aluminum ingot, magnesium ingot, copper plate, aluminum silicon, aluminum manganese, iron powder, nickel block, zinc grain, tin grain, titanium powder and lead block; Step S2: smelting, after mixing the raw materials, smelting at a temperature of 650℃~680℃; Step S3: refining, at a temperature of 700℃~740℃, adding a refining agent to the melt and refining degassing in an argon or nitrogen atmosphere, the refining time being 15~17 minutes; Step S4: forming, using die casting method to form the refined alloy liquid; Step S5: post-processing: obtaining aluminum-silicon alloy castings with high strength and hardness.

6. The high-strength high-hardness die-casting aluminum-silicon alloy material and its preparation process according to claim 1, characterized in that: The refining agent in step S3 is selected from at least one of hexachloroethane, zinc dichloride and manganese dichloride.

7. The high-strength high-hardness die-casting aluminum-silicon alloy material and the preparation process thereof according to claim 1, characterized in that: The forming in step S4 uses high vacuum pressure casting method.

8. The high-strength high-hardness die-casting aluminum-silicon alloy material and the preparation process thereof according to claim 1, characterized in that: Nitrogen is used as the protective gas in the refining process in step S3.

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