Ce-containing aluminum alloy wheel hub and heat treatment regulation method thereof

Abstract

The application discloses a kind of Ce-containing aluminum alloy wheel hub and its heat treatment regulation method, belong to cast aluminum alloy material technical field.Aluminum alloy wheel hub except containing Ce still include following weight percentage content component: Si 7.30%~8.50%, Mg 0.13%~0.18%, Ti 0.09%~0.14%, Fe≤0.16%, remainder is Al and inevitable impurity.Invention adds suitable content Ce, and at 450 ℃, 480 ℃, 510 ℃, 540 ℃ heat preservation 5 h heat treatment, regulate eutectic Si organization morphology and distribution.SEM and EDS results show that Ce participates in eutectic Si organization evolution.Ce content and heat treatment match, can reduce coarse eutectic Si and interdendritic structure to the fragmentation of alpha-Al matrix.Experiment shows that, 0.265% Ce is treated by 540 ℃ × 5 h, and tensile strength 296.21 MPa, elongation 9.9%;0.534% Ce is treated by 480 ℃ × 5 h, and tensile strength 279.23 MPa, elongation 8.9%.Compared with conventional treatment A356 wheel hub, Ce microalloying synergistic heat treatment improves wheel hub organization and performance consistency, suitable for automobile aluminum alloy wheel hub and aluminum-silicon-magnesium cast load-bearing component.

Description

Technical Field

[0001] This invention belongs to the technical field of cast aluminum alloy materials, specifically relating to an aluminum alloy wheel hub containing Ce and its heat treatment control method. Background Technology

[0002] A356 aluminum alloy is a typical Al-Si-Mg series cast aluminum alloy, characterized by low density, good casting fluidity, good corrosion resistance, heat treatment for strengthening, and strong adaptability to complex component forming. It has been widely used in automotive aluminum alloy wheels, load-bearing housings, and lightweight structural components. As a safety component under the combined action of rotational and impact loads, the material properties of the wheel hub cannot be evaluated solely by tensile strength or hardness. Instead, the strength, plasticity, hardness, and microstructure stability of the rim, flange, and spokes must be considered simultaneously. Han et al., in "Uneven distribution of cooling rate, microstructure and mechanical properties for A356-T6 wheels fabricated by low pressure die casting" (pp. 196-210) of the Journal of Manufacturing Processes, Vol. 127, 2024, pointed out that the cooling rate, microstructure, and mechanical properties of low-pressure cast A356-T6 wheels exhibit uneven distribution in different parts. The eutectic Si morphology, defect state, and mechanical properties of typical locations such as the wheel hub, spokes, flange, and rim show significant differences.

[0003] During solidification, cast A356 aluminum alloys are prone to forming coarse or lamellar eutectic Si phases. Localized Fe phases, inclusions, segregation, and shrinkage defects can also become stress concentration points during tensile testing, making it difficult to simultaneously improve the material's strength and plasticity. For complex castings like wheel hubs, the solidification conditions and thermal histories differ in different parts. The microstructure, interdendritic distribution, and defect sensitivity of the rim, spoke, and flange are not entirely consistent. Therefore, relying solely on conventional A356 composition or a single heat treatment regime is insufficient to consistently achieve both high strength and high elongation in certain areas. Tonetti et al., in their study "Planning Mechanical Behavior of A356 Alloy Wheels by Using Distinct Heat Treatments" published in *Metals*, Vol. 14, No. 4, 2024, investigated the effects of different heat treatment regimes on the strength and microhardness of A356 alloy wheel materials, demonstrating that heat treatment parameters significantly influence the mechanical response of A356 wheel hub materials. Chinese patent CN116145055A (CITIC Dicastal Co., Ltd., "Integrated Manufacturing Method and Production Line Equipment for Casting and Heat Treatment of Aluminum Alloy Wheels", Publication Date: May 23, 2023) discloses an integrated manufacturing method for casting and heat treatment of aluminum alloy wheels. The method improves the mechanical properties of aluminum alloy wheels through processes such as casting, solution treatment, quenching and aging. However, the solution mainly focuses on the casting-heat treatment process and the continuous production line, and does not involve the matching and control of Ce microalloying and heat treatment regime.

[0004] Rare earth element Ce has high chemical activity and interfacial adsorption capacity, and can participate in melt purification, inclusion modification, eutectic Si morphology regulation, and dendrite distribution adjustment in aluminum-silicon alloys. Chinese patent CN112575231A (“A Vacuum Refining and Modification Treatment Method for A356 High-Strength Aluminum Alloy”, publication date: March 30, 2021) discloses a scheme for modifying A356 aluminum alloy melt by adding La and Ce composite rare earth elements, and records that after the mixed rare earth modification, the eutectic silicon size is smaller and the alloy strength and plasticity are improved. Teng et al., in their paper "Mechanical Properties of Refined A356 Alloy in Response to Continuous Rheological Extruded Al-5Ti-0.6C-1.0Ce Alloy Prepared at Different Temperatures" published in *Metals*, Volume 13, Issue 8, 2023, also reported that Ce-containing Al-Ti-C-Ce refining agents affect the microstructure and mechanical properties of A356 alloys. These studies indicate that Ce or Ce-containing refining / modification systems have a basis for controlling the microstructure of A356 aluminum alloys.

[0005] However, existing technologies mostly focus on single heat treatment regimes, casting-heat treatment process optimization, melt refining and modification, or general rare earth treatments. They lack clear definitions of the synergistic relationship between Ce addition and heat treatment regimes, and rarely control the simultaneous improvement of Ce content, heat treatment temperature, and the microstructure and mechanical properties of actual parts such as rims, spokes, etc., as a single technical solution. To address these issues, this invention proposes a Ce-containing aluminum alloy wheel hub and its heat treatment method. By synergistically regulating the microstructure of the wheel hub through Ce microalloying and subsequent heat treatment, its comprehensive mechanical properties are improved. Summary of the Invention

[0006] This invention provides a Ce-containing aluminum alloy wheel hub and its heat treatment control method. By controlling the Ce content and matching the heat treatment temperature, the morphology and distribution of eutectic Si in the aluminum alloy wheel hub are controlled, reducing the cutting effect of semi-continuous dendrite structure and acicular eutectic Si, so as to improve the consistency of structure and performance in different regions of the wheel hub, and synergistically improve the strength and toughness of the rim, flange and spokes.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A Ce-containing aluminum alloy wheel hub, in addition to Ce, also contains the following components by weight percentage: Si 7.30%~8.50%, Mg 0.13%~0.18%, Ti 0.09%~0.14%, Fe≤0.16%, with the balance being Al and unavoidable impurities; the microstructure of the aluminum alloy wheel hub after heat treatment includes an α-Al matrix and a eutectic Si structure, wherein the eutectic Si structure is distributed in the interdendritic region of α-Al.

[0009] Preferably, the weight percentage of Ce is 0.20%~0.30% or 0.50%~0.55%.

[0010] Preferably, the aluminum alloy wheel hub further includes one or more of Zn≤0.03%, Sr≤0.01%, Ca≤0.04%, P≤0.09%, and V≤0.03%.

[0011] Furthermore, in the A356 aluminum alloy wheel hub without Ce, the eutectic Si and interdendritic structure are mainly distributed semi-continuously along the interdendritic region; in the aluminum alloy wheel hub containing Ce, the morphology and distribution of the eutectic Si structure are changed, and Ce element signals are detected in some interdendritic structure test areas.

[0012] Furthermore, Ce element signals were detected in the local test area of ​​the interdendritic structure, and Al, Si, and one or more elements selected from Mg, Ti, and V were also detected. The Ce element participates in the formation or evolution of the interdendritic structure, which changes the distribution state of the eutectic Si structure and helps to improve the consistency of the structure distribution in different areas of the wheel hub.

[0013] Preferably, when the Ce weight percentage is 0.20%~0.30%, the tensile strength of the rim of the Ce-containing aluminum alloy wheel hub is not less than 296 MPa and the elongation is not less than 9.0%; when the Ce weight percentage is 0.50%~0.55%, the tensile strength of the rim of the Ce-containing aluminum alloy wheel hub is not less than 279 MPa and the elongation is not less than 8.0%.

[0014] This invention also provides a method for controlling the heat treatment of Ce-containing aluminum alloy wheels, comprising the following steps: placing the cast Ce-containing aluminum alloy wheel in a heat treatment furnace for heat treatment for 5 hours, and cooling it to room temperature after the heat treatment is completed. The casting process can be completed using the conventional casting process for A356 aluminum alloy wheels, and the casting method itself does not constitute a limitation of this invention.

[0015] Furthermore, the heat treatment is used to regulate the morphology and distribution of the eutectic Si structure, causing the eutectic Si phase to fracture, passivate, round, or granulate, and reducing the cutting effect of the semi-continuous interdendritic structure on the α-Al matrix, thereby reducing the tendency of stress concentration in the local area of ​​the wheel hub.

[0016] Preferably, the heat treatment furnace is a muffle furnace.

[0017] Preferably, the heat treatment temperature is matched according to the Ce content: when the Ce weight percentage is 0.60%~0.65%, the heat treatment temperature is 450 ℃; when the Ce weight percentage is 0.50%~0.55%, the heat treatment temperature is 480 ℃; when the Ce weight percentage is 0.40%~0.45%, the heat treatment temperature is 510 ℃; when the Ce weight percentage is 0.20%~0.30%, the heat treatment temperature is 540 ℃; the holding time for each group is 5 h. The heat treatment is mainly used to control the morphology and distribution of the eutectic Si structure, causing the eutectic Si phase to fracture, passivate, or round out, and significantly reducing the cutting damage of the semi-continuous interdendritic structure, thereby alleviating the tendency of local stress concentration, improving the wheel hub structure, and synergistically improving the strength and toughness of the wheel hub.

[0018] Preferably, the microhardness of the Ce-containing aluminum alloy wheel hub after heat treatment is 89 HV5~99 HV5.

[0019] Preferably, after heat treatment, the average tensile strength of the Ce-containing aluminum alloy wheel hub is not less than 280 MPa, the average yield strength is not less than 219 MPa, and the average elongation is not less than 5.8% in the three parts of the wheel flange, wheel rim, and wheel spoke.

[0020] This invention does not rely solely on Ce addition or a single heat treatment temperature to improve performance, but rather on matching composition and process based on the microstructure characteristics of the Al-Si-Mg system in A356 aluminum alloy. Si, as the main alloying element, helps ensure the casting fluidity of the alloy and forms a eutectic Si structure that influences plasticity and fracture behavior. Mg, as a heat-treatable strengthening element, can participate in the heat treatment strengthening process of the Al-Si-Mg system. Ti is beneficial for refining the casting microstructure, while excessive Fe content easily forms a brittle Fe-containing structure and reduces plasticity; therefore, its content needs to be controlled. Ce, as a rare earth microalloying element, can regulate the morphology and distribution of eutectic Si and interdendritic structures, but its effect does not increase monotonically with increasing content; excessive Ce may cause local microstructure aggregation or coarsening. Based on these characteristics, this invention controls the Ce content within a suitable range and uses an appropriate heat treatment regime for matching, adjusting the eutectic Si and interdendritic structures from a localized needle-like, coarse, or semi-continuous distribution to a passivated, dispersed state, reducing their cutting effect on the α-Al matrix, thereby improving the strength-plasticity matching of different parts of the wheel hub.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] (1) This invention uses A356 aluminum alloy as the matrix and achieves microstructure control through Ce microalloying within a suitable content range without changing the main composition system of A356 aluminum alloy. It has good engineering adaptability and ease of implementation. At the same time, the Ce addition amount and heat treatment temperature are matched as a composition-heat treatment combination process to avoid performance fluctuations caused by simply adding rare earth or simply changing the heat treatment regime.

[0023] (2) This invention clarifies the matching relationship between Ce content and heat treatment temperature, avoiding the simple consideration of Ce addition amount as a single gain factor. Experimental results show that when the Ce content is 0.265% and treated at 540 ℃ for 5 h, the tensile strength of the wheel rim is 296.21 MPa and the elongation is 9.9%; when the Ce content is 0.534% and treated at 480 ℃ for 5 h, the tensile strength of the wheel rim is 279.23 MPa and the elongation is 8.9%, both showing good strength-plasticity matching.

[0024] (3) The present invention exhibits good performance stability in different actual parts of the wheel hub. Under industrial heat treatment conditions, the average tensile strength of the sample with a Ce content of 0.265% is 280.0 MPa, the average yield strength is 227.3 MPa, and the average elongation is 5.98%; the average tensile strength of the sample with a Ce content of 0.534% is 281.3 MPa, the average yield strength is 219.7 MPa, and the average elongation is 5.80%.

[0025] (4) SEM and EDS results show that the untreated sample mainly consists of α-Al matrix, eutectic Si phase, and a small amount of interdendritic structure. The interdendritic structure is mainly distributed semi-continuously along the interdendritic region. After the addition of Ce, the morphology and distribution of the interdendritic structure changed, and Ce signal was detected in some interdendritic structure test areas, indicating that Ce participated in the formation or evolution of the interdendritic structure. The synergistic effect of appropriate Ce and heat treatment can regulate the morphology and distribution of eutectic Si structure, reduce the severing hazard of continuous or coarse interdendritic structure, and play a role in regulating the distribution of interdendritic structure, passivating and strengthening, and homogenizing the structure, thereby improving load transfer and local deformation coordination, and providing a microstructure basis for improving mechanical properties.

[0026] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0027] Figure 1 The tensile properties of wheel rims under different Ce contents and muffle furnace matching heat treatment conditions are shown in the figure. Figure 1 (a) represents tensile strength. Figure 1 (b) represents the elongation rate;

[0028] Figure 2 The graphs show the tensile properties of different parts of aluminum alloy wheel hubs with different Ce contents under industrial heat treatment conditions. Figure 2 (a) represents tensile strength. Figure 2 (b) represents the elongation rate;

[0029] Figure 3 Microhardness diagrams of samples under different Ce contents and muffle furnace matched heat treatment conditions;

[0030] Figure 4 Here are representative SEM images of the aluminum alloy wheel hub specimens, where Figure 4 (a) without Ce addition, heat treated at 450 °C. Figure 4 (b) Add 0.265% Ce and heat treat at 540 °C. Figure 4 (c) Add 0.534% Ce and heat treat at 480 °C;

[0031] Figure 5The images show representative EDS spectra and test area diagrams of the Ce-rich regions in the 0.534% Ce and 0.265% Ce samples. Figure 5 (a) EDS spectrum of Ce signal region detected in 0.534% Ce sample (top right corner of the figure: total line spectrum, representing the total superposition energy spectrum of the line scan). Figure 5 (b) is a SEM image of the EDS test area of ​​the 0.534% Ce sample. Figure 5 (c) EDS spectrum of Ce signal region detected in 0.265% Ce sample (top right corner of the figure: spectrum 114, indicating that this is the 114th single-point energy spectrum). Figure 5 (d) is a SEM image of the EDS test area of ​​the 0.265% Ce sample. Detailed Implementation

[0032] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0033] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. These other embodiments are also covered within the scope of protection of this invention.

[0034] The following embodiments are used to illustrate the present invention, but should not be construed as limiting the scope of protection of the present invention. Any equivalent substitutions or conventional adjustments made based on the disclosure of the present invention regarding Ce content, heat treatment temperature, holding time, and wheel hub sampling location should fall within the scope of protection of the present invention.

[0035] In this embodiment of the invention, the heat treatment control method for a Ce-containing aluminum alloy wheel hub includes the following steps:

[0036] (1) Alloy composition and sample number: Using A356 aluminum alloy wheel hub material as the matrix, a control sample without Ce and samples with different Ce contents were set up. XRF detection showed that the Ce content of sample 1 was 0.607%, sample 2 was 0.534%, sample 3 was 0.432%, and sample 4 was 0.265%. The main chemical composition of different samples is shown in Table 1.

[0037] Table 1. Main chemical composition (wt.%) of A356 aluminum alloy samples with different Ce contents

[0038]

[0039] In Table 1, Al represents the matrix elements. Since Al is displayed in the XRF test results according to the matrix normalization method, it is listed in the form of a balance in this embodiment.

[0040] (2) Heat treatment regime: The cast samples were placed in a muffle furnace for heat treatment. The Ce content and heat treatment regime of different samples are shown in Table 2. The heat treatment time for each group was 5 h, and the samples were cooled to room temperature after the heat treatment was completed. Sample No. 0 was a Ce-free control sample, which was used to compare the performance with the Ce-containing sample.

[0041] It should be noted that the heat treatment regimes listed in Table 2 are not isolated temperature selections, but rather a combination of composition and heat treatment processes set in conjunction with Ce content. Changes in Ce content affect the formation and distribution of eutectic Si microstructure. The detection of Ce signals in the interdendritic microstructure indicates that Ce participates in the formation or evolution of the interdendritic microstructure. Based on this, matching the heat treatment temperature can further regulate the continuity, roundness, and distribution of the eutectic Si microstructure, thereby improving the microstructure and mechanical properties of different regions of the wheel hub.

[0042] Table 2 Sample Number, Ce Content, and Muffle Furnace Heat Treatment Regime

[0043]

[0044] Performance testing:

[0045] 1. Tensile properties of wheel rims after muffle furnace heat treatment

[0046] Tensile properties were tested on the rim samples after muffle furnace heat treatment, and the results are as follows: Figure 1 As shown in Table 3.

[0047] Combination Figure 1 (a) Figure 1 (b) and Table 3 show that the tensile strength of the Ce-free control specimen No. 0 was 265.86 MPa and the elongation was 2.5%; the tensile strength of the 0.607% Ce specimen No. 1 was 247.81 MPa and the elongation was 4.1%; the tensile strength of the 0.534% Ce specimen No. 2 was 279.23 MPa and the elongation was 8.9%; the tensile strength of the 0.432% Ce specimen No. 3 was 258.96 MPa and the elongation was 2.9%; and the tensile strength of the 0.265% Ce specimen No. 4 was 296.21 MPa and the elongation was 9.9%.

[0048] The results show that both the 0.265% Ce and 0.534% Ce samples exhibited good strength-plasticity matching, with the 0.265% Ce sample showing the highest tensile strength and elongation in this group of samples. The 0.607% Ce and 0.432% Ce samples had relatively lower performance, indicating that the Ce content and its corresponding heat treatment temperature have a significant impact on the tensile properties of the rim, and that a higher Ce content is not necessarily more beneficial.

[0049] Compared with the control sample without Ce, the tensile strength of the wheel rim of the 0.265% Ce sample increased from 265.86 MPa to 296.21 MPa, and the elongation increased from 2.5% to 9.9%; the tensile strength of the wheel rim of the 0.534% Ce sample increased to 279.23 MPa, and the elongation increased to 8.9%. This indicates that under appropriate Ce content and matching heat treatment temperature conditions, the material does not only exhibit increased strength, but also shows simultaneous improvement in both strength and plasticity.

[0050] Table 3 Tensile properties of wheel rims after muffle furnace matching heat treatment

[0051]

[0052] 2. Mechanical properties of different parts of the wheel hub after industrial heat treatment

[0053] To further verify the performance stability of Ce-containing aluminum alloy wheels in actual applications, tests were conducted on the rim, spokes, and flange under industrial heat treatment conditions. The results are shown below. Figure 2 See Table 4.

[0054] Analysis of Table 4 shows that the 0.534% Ce sample has an average tensile strength of 281.3 MPa, an average yield strength of 219.7 MPa, an average elongation of 5.80%, and a hardness of 86 HBW. The 0.265% Ce sample has an average tensile strength of 280.0 MPa, an average yield strength of 227.3 MPa, an average elongation of 5.98%, and a hardness of 89 HBW. Compared with the 0.607% Ce and 0.432% Ce samples, the 0.534% Ce and 0.265% Ce samples exhibit better overall performance in the rim, spoke, and flange areas. Figure 2 (a) and Figure 2 (b) shows more intuitively that the 0.534% Ce sample and the 0.265% Ce sample have the best performance.

[0055] Table 4 Mechanical properties of different parts of samples with different Ce contents under industrial heat treatment conditions

[0056]

[0057] In Table 4, UTS represents tensile strength, YS represents yield strength, and EL represents elongation; the unit of strength is MPa, and the unit of elongation is %.

[0058] 3. Microhardness

[0059] The Vickers hardness of the samples after muffle furnace heat treatment was tested under a load of HV5. The test results are as follows: Figure 3 As shown in Table 5.

[0060] analyze Figure 3 As shown in Table 5, the average hardness of each group of samples ranged from 89.7 HV5 to 98.6 HV5. Differences in hardness among different samples indicated that the combination of Ce content and heat treatment regime affected the hardening response of the wheel hub material. Subsequent SEM microstructure observations revealed that the hardening response was closely related to the eutectic Si morphology, interdendritic distribution, and matrix strengthening state. However, material performance cannot be judged solely by microhardness; excessively high hardness often sacrifices material plasticity and toughness. For aluminum alloys used in wheel hubs, a balance must be struck between strength, plasticity, hardness, and microstructure stability to achieve a good strength-plasticity match. Based on previous tensile test results, the 0.265% Ce and 0.534% Ce samples exhibited a good strength-plasticity match.

[0061] Table 5 Microhardness after muffle furnace heat treatment

[0062]

[0063] 4. Microstructure and EDS analysis

[0064] SEM observation was performed on samples with different Ce contents, and the results are as follows: Figure 4 As shown.

[0065] Through observation Figure 4 (a) The sample without Ce addition and heat-treated at 450 °C shows that the eutectic Si and dendritic α-Al outside the α-Al matrix are mainly distributed along the interdendritic region, and locally exhibit a semi-continuous morphology. Figure 4 (b) Figure 4 (c) indicates that the size, morphology, and distribution of the interdendritic structure changed after the addition of Ce and heat treatment, and certain differences were observed between samples with different Ce contents. Among these, observation... Figure 4 (b) It can be observed that no obvious coarse agglomerates were found in the 0.265% Ce sample; Figure 4 In (c), the interdendritic structure in the 0.534% Ce sample is relatively dispersed.

[0066] EDS micro-area energy dispersive spectroscopy point analysis was carried out in a typical interdendritic region. The analysis results are shown in […]. Figure 5 .

[0067] Figure 5 (a) Figure 5 (c) shows that Ce signals were detected in some dendritic microstructure testing areas of the 0.534% Ce and 0.265% Ce samples, accompanied by signals from elements such as Al, Si, Mg, Ti, or V. This indicates that Ce does not exist solely as a solid-solution alloying element, but participates in the formation or evolution of the dendritic microstructure. Observation Figure 5 (b) Figure 5 (d) It was found that the morphology and distribution of eutectic Si changed after the addition of Ce; among them, the appropriate amount of Ce combined with the heat treatment process is beneficial to reduce the cutting effect of local semi-continuous dendrites and improve the deformation coordination between dendrites and matrix.

[0068] The tensile properties show that the 0.265% Ce and 0.534% Ce samples exhibit a good balance of strength and plasticity, indicating that an appropriate amount of Ce combined with the heat treatment process can improve the overall mechanical properties of the wheel hub samples by adjusting the morphology and distribution of the eutectic Si structure and reducing the cutting effect of the continuous interdendritic structure.

[0069] As can be seen from the above embodiments, the present invention achieves better comprehensive mechanical properties in the actual sampling area of ​​A356 aluminum alloy wheel hubs by matching Ce content with heat treatment regime. Among these, 0.265% Ce with a heat treatment regime of 540 ℃ × 5 h and 0.534% Ce with a heat treatment regime of 480 ℃ × 5 h are preferred options. The microstructure regulation mechanism can be attributed to: Ce participating in the evolution of interdendritic microstructure, and heat treatment promoting the improvement of eutectic Si morphology. Both factors jointly reduce the cutting effect of semi-continuous interdendritic microstructure on the matrix, and improve the strength-plasticity matching through interdendritic microstructure morphology regulation, microstructure homogenization, and load transfer.

[0070] Without being limited by specific theories, the performance improvement of this invention can be understood as the result of the combined effect of Ce microalloying and heat treatment microstructure regulation: First, Ce participates in the formation or evolution of interdendritic structures, changing the morphology and distribution of some interdendritic structures, which is beneficial to reducing local stress concentration caused by semi-continuous interdendritic structures; Second, Ce has a regulatory effect on the growth and distribution of eutectic Si structures, which is beneficial to transforming local lamellar, elongated, or semi-continuous interdendritic structures into a more passivated and dispersed state, thereby weakening their weakening effect on the continuity of the matrix; Third, heat treatment can promote the fracture, passivation, or rounding of eutectic Si, thereby improving the load transfer and deformation coordination between the matrix and the eutectic Si phase.

[0071] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention; any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for controlling the heat treatment of a Ce-containing aluminum alloy wheel hub, characterized in that, In addition to Ce, aluminum alloy wheels also contain the following components by weight percentage: Si 7.30%~8.50%, Mg 0.13%~0.18%, Ti 0.09%~0.14%, Fe≤0.16%, with the balance being Al and unavoidable impurities; The heat treatment control method for Ce-containing aluminum alloy wheels includes the following steps: placing the cast Ce-containing aluminum alloy wheel in a heat treatment furnace for heat treatment for 5 hours, and cooling it to room temperature after heat treatment. The heat treatment temperature is matched according to the Ce content: when the Ce weight percentage is 0.60%~0.65%, the heat treatment temperature is 450 ℃; when the Ce weight percentage is 0.50%~0.55%, the heat treatment temperature is 480 ℃; when the Ce weight percentage is 0.40%~0.45%, the heat treatment temperature is 510 ℃; when the Ce weight percentage is 0.20%~0.30%, the heat treatment temperature is 540 ℃.

2. The heat treatment control method for a Ce-containing aluminum alloy wheel hub according to claim 1, characterized in that, The weight percentage of Ce is 0.20%~0.30% or 0.50%~0.55%.

3. A method for controlling the heat treatment of a Ce-containing aluminum alloy wheel hub according to claim 1 or 2, characterized in that, The aluminum alloy wheel hub also includes one or more of the following: Zn≤0.03%, Sr≤0.01%, Ca≤0.04%, P≤0.09%, and V≤0.03%.

4. The heat treatment control method for a Ce-containing aluminum alloy wheel hub according to claim 2, characterized in that, When the Ce weight percentage is 0.20%~0.30%, the tensile strength of the rim of the Ce-containing aluminum alloy wheel hub is not less than 296 MPa and the elongation is not less than 9.0%; when the Ce weight percentage is 0.50%~0.55%, the tensile strength of the rim of the Ce-containing aluminum alloy wheel hub is not less than 279 MPa and the elongation is not less than 8.0%.

5. The heat treatment control method for Ce-containing aluminum alloy wheel hubs according to claim 1, characterized in that, The heat treatment furnace is a muffle furnace.

6. The heat treatment control method for Ce-containing aluminum alloy wheel hubs according to claim 1, characterized in that, The Ce-containing aluminum alloy wheel hub has a microhardness of 89 HV5~99 HV5 after heat treatment.

7. The heat treatment control method for Ce-containing aluminum alloy wheel hubs according to claim 1, characterized in that, After heat treatment, the average tensile strength of the Ce-containing aluminum alloy wheel hub, the rim, and the spokes is not less than 280 MPa, the average yield strength is not less than 219 MPa, and the average elongation is not less than 5.8%.

8. A Ce-containing aluminum alloy wheel hub prepared by the heat treatment control method according to any one of claims 1 to 7.

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