High-strength ZLGQ104 aluminum alloy, and preparation method and application thereof

Abstract

This invention relates to a high-strength ZLGQ104 aluminum alloy, its preparation method, and its applications. The high-strength ZLGQ104 aluminum alloy has the following composition by mass percentage: Si: 7.0%~10%, Cu: 2.0%~4.0%, Mg: 0.1%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance. The high-strength ZLGQ104 aluminum alloy prepared by this invention has a tensile strength ≥195MPa, elongation ≥2.0%, and hardness ≥70HB, exhibiting excellent performance. It is particularly suitable for manufacturing key automotive components requiring higher strength, heat resistance, wear resistance, and surface quality, such as automotive engine cylinder heads and intake manifolds, thus contributing to the lightweighting and performance upgrades of automotive parts.

Description

Technical Field

[0001] This invention relates to an aluminum alloy, its preparation method, and its applications. Background Technology

[0002] Cast aluminum alloys are widely used in the manufacture of complex parts in the automotive, aerospace and other fields due to their excellent casting and mechanical properties.

[0003] Currently, ZL104 and ZL101 are widely used conventional cast aluminum alloys. Their chemical composition and mechanical properties are shown in Table 1 and Table 2.

[0004] Table 1 Chemical composition and mechanical properties of ZL104

[0005]

[0006] Table 2 Chemical composition and mechanical properties of ZL101

[0007]

[0008] Although the existing ZL104 and ZL101 aluminum alloys can meet the needs of general industrial applications, as the automotive industry develops towards lightweighting and high performance, the service conditions of core engine components are becoming increasingly stringent, placing higher demands on the comprehensive mechanical properties of materials.

[0009] The existing ZL104 and ZL101 cast aluminum alloys have a tensile strength of only ≥150MPa and a hardness of only ≥50HBW, which are relatively low and cannot meet the requirements of high load-bearing capacity and high wear resistance for key components such as cylinder heads and intake manifolds of modern automobile engines. In addition, while pursuing higher strength, how to maintain good corrosion resistance, machinability and casting surface quality is also a challenge that those skilled in the art have been facing. Summary of the Invention

[0010] The purpose of this invention is to address the shortcomings of existing ZL104 and ZL101 cast aluminum alloys in terms of strength and hardness, which make it difficult to meet the requirements of high load-bearing capacity and high wear resistance for key automotive components, as well as the problems of low corrosion resistance, machinability, and casting surface quality of cast aluminum alloys. The invention provides a high-strength ZLGQ104 aluminum alloy, its preparation method, and its applications.

[0011] A high-strength ZLGQ104 aluminum alloy, with the following composition by mass percentage: Si: 7.0%~10%, Cu: 2.0%~4.0%, Mg: 0.1%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

[0012] A method for preparing a high-strength ZLGQ104 aluminum alloy, specifically comprising the following steps:

[0013] I. Weighing the raw materials:

[0014] Weigh out aluminum ingots, metallic silicon, electrolytic copper, and magnesium ingots for remelting;

[0015] II. Smelting:

[0016] ① Add aluminum ingots and metallic silicon for remelting to the melting furnace and heat them until they are completely melted;

[0017] ② Add electrolytic copper, keep it at 730~750℃ until it is completely melted, and stir.

[0018] ③ Add magnesium ingots and press them into the bottom of the molten aluminum using a bell jar, stirring until completely melted;

[0019] ④ Use an aluminum liquid refining machine with nitrogen as the medium to evenly spray the refining agent into the aluminum alloy liquid. The refining time is not less than 20 minutes to effectively remove the slag in the aluminum alloy liquid and obtain the smelted aluminum liquid.

[0020] III. Casting:

[0021] The high-pressure die casting process involves pouring molten aluminum into the mold of a die casting machine to obtain the die casting.

[0022] IV. Post-processing:

[0023] The die-cast parts were subjected to solution treatment and artificial aging in sequence to obtain high-strength ZLGQ104 aluminum alloy.

[0024] The composition of the high-strength ZLGQ104 aluminum alloy mentioned in step four is as follows (by mass percentage): Si: 7.0%~10%, Cu: 2.0%~4.0%, Mg: 0.1%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

[0025] A high-strength ZLGQ104 aluminum alloy is used in key automotive components.

[0026] This invention solves the problem of insufficient strength in existing cast aluminum alloys while maintaining good overall performance.

[0027] The principle of this invention:

[0028] Compared with existing technologies (such as ZL104), the key technical point of this invention lies in the optimization and adjustment of the alloy composition, particularly the significant increase in the Cu content range (from ≤0.1% to 2.0~4.0%), and the corresponding adjustment of the Si content range (from 8.0~10.5% to 7.0~10.0%). The addition of Cu forms a reinforcing phase in the alloy, which is crucial for improving the material's strength and hardness. Simultaneously, through the rational control of Si and other impurity elements (Fe, Mn, Zn, Ti, Ni), the alloy achieves high strength without sacrificing its excellent casting properties, corrosion resistance, and machinability.

[0029] Effects of the invention:

[0030] Compared with existing technologies (especially the ZL104 aluminum alloy mentioned in the background section), the high-strength ZLGQ104 aluminum alloy provided by this invention has the following significant advantages and beneficial effects:

[0031] I. Significantly Improved Mechanical Properties: Through a unique composition design, especially the addition of Cu, this invention significantly improves the strength and hardness of the alloy; its tensile strength increases from ≥150MPa of the original ZL104 to ≥195MPa; its hardness increases from ≥50HBW of the original ZL104 to ≥70HB, which can better meet the requirements of high-load components.

[0032] II. Excellent comprehensive performance: While achieving high strength, the new material still maintains excellent corrosion resistance. Furthermore, its machinability, weldability, and the surface finish and brightness of castings are superior to or equivalent to existing materials, demonstrating good industrial applicability.

[0033] III. Clear Application Prospects: In view of the above-mentioned excellent properties, the material of the present invention is particularly suitable for manufacturing key automotive components that have higher requirements for strength, heat resistance, wear resistance and surface quality, such as automotive engine cylinder heads and intake manifolds, which will help promote the lightweighting and performance upgrading of automotive components. Attached Figure Description

[0034] Figure 1 Metallographic structure of the high-strength ZLGQ104 aluminum alloy automotive engine cylinder head prepared in Example 1, magnified 400 times;

[0035] Figure 2 A surface view of the high-strength ZLGQ104 aluminum alloy automotive engine cylinder head prepared in Example 1. Detailed Implementation

[0036] Specific implementation method one: This implementation method is a high-strength ZLGQ104 aluminum alloy, which is composed of the following by mass percentage: Si: 7.0%~10%, Cu: 2.0%~4.0%, Mg: 0.1%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

[0037] Specific Implementation Method Two: This implementation method differs from Specific Implementation Method One in that the high-strength ZLGQ104 aluminum alloy is composed of the following by mass percentage: Si: 8.0%~10%, Cu: 3.0%~4.0%, Mg: 0.2%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance. Other steps are the same as in Specific Implementation Method One.

[0038] Specific Implementation Method Three: This implementation method differs from Specific Implementation Method One or Two in that the high-strength ZLGQ104 aluminum alloy is composed of the following by mass percentage: Si: 8.0%~9.0%, Cu: 3.0%~3.5%, Mg: 0.2%~0.3%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance. Other steps are the same as in Specific Implementation Method One or Two.

[0039] Specific Implementation Method Four: This implementation method differs from Specific Implementation Methods One to Three in that the high-strength ZLGQ104 aluminum alloy is composed of the following by mass percentage: Si: 8.5%, Cu: 3.0%, Mg: 0.25%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance. Other steps are the same as in Specific Implementation Methods One to Three.

[0040] Specific Implementation Method Five: This implementation method differs from Specific Implementation Methods One to Four in that the high-strength ZLGQ104 aluminum alloy has a tensile strength ≥195MPa, an elongation ≥2.0%, and a hardness ≥70HB. The other steps are the same as in Specific Implementation Methods One to Four.

[0041] Specific Implementation Method Six: This implementation method is a preparation method for high-strength ZLGQ104 aluminum alloy, specifically completed according to the following steps:

[0042] I. Weighing the raw materials:

[0043] Weigh out aluminum ingots, metallic silicon, electrolytic copper, and magnesium ingots for remelting;

[0044] II. Smelting:

[0045] ① Add aluminum ingots and metallic silicon for remelting to the melting furnace and heat them until they are completely melted;

[0046] ② Add electrolytic copper, keep it at 730~750℃ until it is completely melted, and stir.

[0047] ③ Add magnesium ingots and press them into the bottom of the molten aluminum using a bell jar, stirring until completely melted;

[0048] ④ Use an aluminum liquid refining machine with nitrogen as the medium to evenly spray the refining agent into the aluminum alloy liquid. The refining time is not less than 20 minutes to effectively remove the slag in the aluminum alloy liquid and obtain the smelted aluminum liquid.

[0049] III. Casting:

[0050] The high-pressure die casting process involves pouring molten aluminum into the mold of a die casting machine to obtain the die casting.

[0051] IV. Post-processing:

[0052] The die-cast parts were subjected to solution treatment and artificial aging in sequence to obtain high-strength ZLGQ104 aluminum alloy.

[0053] The composition of the high-strength ZLGQ104 aluminum alloy mentioned in step four is as follows (by mass percentage): Si: 7.0%~10%, Cu: 2.0%~4.0%, Mg: 0.1%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

[0054] Specific Implementation Method Seven: This implementation method differs from Specific Implementation Methods One through Six in that the die-casting process parameters described in step three are: pouring temperature 660℃~700℃, mold temperature 180℃~250℃, injection pressure 80MPa~120MPa, injection speed 2m / s~5m / s, and holding time 2 seconds~5 seconds. Other steps are the same as in Specific Implementation Methods One through Six.

[0055] Specific Implementation Method Eight: This implementation method differs from Specific Implementation Methods One to Seven in the following ways: The solution treatment method described in step four involves holding the solution at 500℃~540℃ for 4h~8h, then quickly transferring it to hot water at 60℃~80℃ for quenching; the artificial aging method described in step four involves holding the solution at 160℃~200℃ for 4h~10h, then removing it and air cooling to obtain high-strength ZLGQ104 aluminum alloy. Other steps are the same as in Specific Implementation Methods One to Seven.

[0056] Specific implementation method nine: This implementation method is a high-strength ZLGQ104 aluminum alloy used in key automotive components.

[0057] Specific Implementation Method Ten: This implementation method differs from Specific Implementation Methods One to Nine in that the key automotive component mentioned is the automotive engine cylinder head or the automotive intake manifold. The other steps are the same as in Specific Implementation Methods One to Nine.

[0058] The beneficial effects of the present invention are verified using the following embodiments:

[0059] Example 1: A method for preparing a high-strength ZLGQ104 aluminum alloy, specifically completed according to the following steps:

[0060] I. Weighing the raw materials:

[0061] Weigh out aluminum ingots, metallic silicon, electrolytic copper, and magnesium ingots for remelting;

[0062] II. Smelting:

[0063] ① Add aluminum ingots and metallic silicon for remelting to the melting furnace and heat them until they are completely melted;

[0064] ② Add electrolytic copper, keep it at 750℃ until it is completely melted, and stir.

[0065] ③ Add magnesium ingots and press them into the bottom of the molten aluminum using a bell jar, stirring until completely melted;

[0066] ④ Using an aluminum liquid refining machine, with nitrogen (purity 99.999%) as the medium, the refining agent (slag remover) is evenly sprayed into the aluminum alloy liquid. The refining time is 40 minutes, which effectively removes the slag inclusions in the aluminum alloy liquid and obtains the smelted aluminum liquid.

[0067] III. Casting:

[0068] The high-pressure die casting process involves pouring molten aluminum into a mold (the mold is a car engine cylinder head) in a die casting machine to obtain the die casting.

[0069] The die-casting process parameters mentioned in step three are: pouring temperature 680℃, mold temperature 220℃, injection pressure 100MPa, injection speed 4m / s, and holding time 4 seconds.

[0070] IV. Post-processing:

[0071] The die-cast parts were subjected to solution treatment and artificial aging in sequence to obtain high-strength ZLGQ104 aluminum alloy automotive engine cylinder heads.

[0072] The solution treatment method described in step four is as follows: keep at 520℃ for 6 hours, and then quickly transfer to hot water at 70℃ for quenching;

[0073] The artificial aging method described in step four is as follows: heat at 180℃ for 7 hours, then remove and air cool to obtain high-strength ZLGQ104 aluminum alloy;

[0074] The composition of the high-strength ZLGQ104 aluminum alloy automotive engine cylinder head mentioned in step four is as follows, by mass percentage: Si: 8.5%, Cu: 3.0%, Mg: 0.25%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance; wherein Mn, Ni, Fe, Zn, and Ni are impurity elements introduced from the raw materials.

[0075] The high-strength ZLGQ104 aluminum alloy automotive engine cylinder head prepared in Example 1 has a tensile strength ≥195MPa, an elongation ≥2.0%, and a hardness ≥70HB.

[0076] Figure 1 Metallographic structure of the high-strength ZLGQ104 aluminum alloy automotive engine cylinder head prepared in Example 1, magnified 400 times;

[0077] 1. Phase composition and morphological identification:

[0078] from Figure 1 It can be seen that the light-colored matrix phase is α-Al solid solution, which is the main phase of the alloy. It has an irregular dendritic / equiaxed grain morphology and is the aluminum-based solid solution that precipitates first during the crystallization process, forming the "skeleton" of the structure.

[0079] Dark network / skeleton-like phase: (α+Si) eutectic + intermetallic compound; the eutectic structure is distributed between α-Al grain boundaries and is a mixture formed by the co-crystallization of Si and Al at the eutectic temperature. Fine short rod-shaped / granular eutectic silicon (dark dots / short rods) are visible inside. It also contains skeletal / acicular Fe-rich phases (such as β-Al9Fe2Si2) and Al-Cu phases (such as Al2Cu), which are impurities or strengthening phases in the alloy. Tiny black dot / acicular phase:

[0080] It could be porosity / inclusions (gas or oxides introduced during casting) or fine strengthening phases precipitated during aging (such as Al2Cu, Mg2Si).

[0081] 2. Relationship between organizational characteristics and process / performance:

[0082] As-cast characteristics: α-Al is dendritic, with eutectic distributed along grain boundaries. This is a typical as-cast / die-cast microstructure. With faster cooling, the eutectic silicon becomes finer (the Si phase in the image does not appear as large plates, indicating that cooling or modification treatment is reasonable). Influence of the Fe phase: The skeletal Fe-rich phase visible in the image is an impurity phase that reduces alloy plasticity but improves high-temperature strength, confirming its "excellent high-temperature strength" characteristic. Role of the Cu phase: The Al₂Cu phase is the main strengthening phase. Aging heat treatment can further refine its precipitation, improving alloy strength, which explains its combination of strength and corrosion resistance.

[0083] 3. Overall Evaluation:

[0084] This microstructure diagram conforms to the typical characteristics of hypoeutectic cast aluminum alloys: α-Al dendrites + intergranular eutectic structure + Fe-rich / Cu-rich intermetallic compounds. The microstructure is uniformly distributed, and there are no obvious coarse primary silicon crystals or severe porosity, indicating that the casting process is well controlled and can meet the performance requirements of conventional structural parts.

[0085] Figure 2 A surface view of the high-strength ZLGQ104 aluminum alloy automotive engine cylinder head prepared in Example 1.

[0086] from Figure 2 It can be seen that the surface finish of the casting is good.

Claims

1. A high-strength ZLGQ104 aluminum alloy, characterized in that... The high-strength ZLGQ104 aluminum alloy is composed of the following components by mass percentage: Si: 7.0%~10%, Cu: 2.0%~4.0%, Mg: 0.1%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

2. The high-strength ZLGQ104 aluminum alloy according to claim 1, characterized in that... The high-strength ZLGQ104 aluminum alloy is composed of the following components by mass percentage: Si: 8.0%~10%, Cu: 3.0%~4.0%, Mg: 0.2%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

3. The high-strength ZLGQ104 aluminum alloy according to claim 1, characterized in that... The high-strength ZLGQ104 aluminum alloy is composed of the following components by mass percentage: Si: 8.0%~9.0%, Cu: 3.0%~3.5%, Mg: 0.2%~0.3%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

4. The high-strength ZLGQ104 aluminum alloy according to claim 1, characterized in that... The high-strength ZLGQ104 aluminum alloy is composed of the following components by mass percentage: Si: 8.5%, Cu: 3.0%, Mg: 0.25%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

5. A high-strength ZLGQ104 aluminum alloy according to claim 1, characterized in that... The high-strength ZLGQ104 aluminum alloy has a tensile strength ≥195MPa, an elongation ≥2.0%, and a hardness ≥70HB.

6. The method for preparing a high-strength ZLGQ104 aluminum alloy according to claim 1, characterized in that... The preparation method is specifically carried out according to the following steps: I. Weighing the raw materials: Weigh out aluminum ingots, metallic silicon, electrolytic copper, and magnesium ingots for remelting; II. Smelting: ① Add aluminum ingots and metallic silicon for remelting to the melting furnace and heat them until they are completely melted; ② Add electrolytic copper, keep it at 730~750℃ until it is completely melted, and stir. ③ Add magnesium ingots and press them into the bottom of the molten aluminum using a bell jar, stirring until completely melted; ④ Use an aluminum liquid refining machine with nitrogen as the medium to evenly spray the refining agent into the aluminum alloy liquid. The refining time is not less than 20 minutes to effectively remove the slag in the aluminum alloy liquid and obtain the smelted aluminum liquid. III. Casting: The high-pressure die casting process involves pouring molten aluminum into the mold of a die casting machine to obtain the die casting. IV. Post-processing: The die-cast parts were subjected to solution treatment and artificial aging in sequence to obtain high-strength ZLGQ104 aluminum alloy. The composition of the high-strength ZLGQ104 aluminum alloy mentioned in step four is as follows (by mass percentage): Si: 7.0%~10%, Cu: 2.0%~4.0%, Mg: 0.1%~0.4%, Fe≤0.9%, Mn≤0.5%, Zn≤1.0%, Ti≤0.2%, Ni≤0.3%, Al: balance.

7. The method for preparing a high-strength ZLGQ104 aluminum alloy according to claim 6, characterized in that... The die-casting process parameters described in step three are: pouring temperature 660℃~700℃, mold temperature 180℃~250℃, injection pressure 80MPa~120MPa, injection speed 2m / s~5m / s, and holding time 2 seconds~5 seconds.

8. The method for preparing a high-strength ZLGQ104 aluminum alloy according to claim 6, characterized in that... The solution treatment method described in step four is as follows: hold at 500℃~540℃ for 4h~8h, and then quickly transfer to hot water at 60℃~80℃ for quenching; the artificial aging method described in step four is as follows: hold at 160℃~200℃ for 4h~10h, and then remove and air cool to obtain high-strength ZLGQ104 aluminum alloy.

9. The application of a high-strength ZLGQ104 aluminum alloy as described in claim 1, characterized in that... A high-strength ZLGQ104 aluminum alloy is used in key automotive components.

10. The application of a high-strength ZLGQ104 aluminum alloy according to claim 9, characterized in that... The key automotive components mentioned are the engine cylinder head or the intake manifold.

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