A die-cast aluminum alloy and its preparation method, vehicle structural components and vehicles

Abstract

This disclosure relates to a die-cast aluminum alloy, its preparation method, vehicle structural parts, and a vehicle. The die-cast aluminum alloy comprises 0.3–3.5 wt% Mn, 0.4–2.0 wt% Fe, 0.02–0.6 wt% Si, 0.01–0.6 wt% Cr, 0.03–0.45 wt% Ti, 0.01–2.8 wt% Ni, 0.01–0.4 wt% V, 0.01–0.5 wt% Zr, less than 2.5 wt% Zn, 0.01–7.0 wt% RE, less than 0.3 wt% trace elements, less than 0.2 wt% impurities, and the balance aluminum; the Fe to Mn content ratio is 0.14–3.2, and the Ni to Si content ratio is 2–60. This disclosure can meet the requirements for brazing die-cast aluminum alloys and ensure the mechanical properties of the parts.

Description

Technical Field

[0001] This disclosure relates to the field of aluminum alloy technology, specifically to a die-cast aluminum alloy and its preparation method, vehicle structural components, and vehicles. Background Technology

[0002] Battery cooling modules are crucial components of automotive thermal management systems. Traditionally, cooling modules are machined from CNC-machined aluminum alloys (such as 6063 or 3003 aluminum plates) into various shapes, then brazed (at temperatures typically between 595 and 600°C). However, this manufacturing method suffers from drawbacks such as low efficiency, high material waste, long production cycles, and high manufacturing costs. Furthermore, commonly used Al-Si-based heat-treatable aluminum alloys have a solidus temperature below 590°C, causing softening and numerous porosity defects during welding, thus failing to meet brazing requirements.

[0003] Therefore, there is a need to develop a brazable, low thermal conductivity, heat-free die-cast aluminum alloy. Summary of the Invention

[0004] The purpose of this disclosure is to provide a die-cast aluminum alloy and its preparation method, vehicle structural parts, and a vehicle, which can meet the requirements for brazing of die-cast aluminum alloys and ensure the mechanical properties of the parts.

[0005] To achieve the above objectives, the first aspect of this disclosure provides a die-cast aluminum alloy, wherein, based on the total weight of the die-cast aluminum alloy, the die-cast aluminum alloy comprises 0.3-3.5 wt% Mn, 0.4-2.0 wt% Fe, 0.02-0.6 wt% Si, 0.01-0.6 wt% Cr, 0.03-0.45 wt% Ti, 0.01-2.8 wt% Ni, 0.01-0.4 wt% V, 0.01-0.5 wt% Zr, less than 2.5 wt% Zn, 0.01-7.0 wt% RE, less than 0.3 wt% trace elements, less than 0.2 wt% impurities, and the balance aluminum; the trace elements include one or more of Cu, Mg, and Mo; RE includes one or more of La, Ce, and Sm; wherein the content ratio of Fe to Mn is 0.14-3.2, and the content ratio of Ni to Si is 2-60.

[0006] This disclosure provides a die-cast aluminum alloy that not only meets the requirements for brazing and ensures the mechanical properties of the parts, but also reduces the amount of machining required for traditional heat dissipation modules, enabling the production of brazable, low-thermal-conductivity, heat-free die-cast aluminum alloy parts.

[0007] In one embodiment, the die-cast aluminum alloy comprises 1.5–3.2 wt% Mn, 0.7–1.5 wt% Fe, 0.05–0.3 wt% Si, 0.05–0.5 wt% Cr, 0.08–0.40 wt% Ti, 0.01–1.8 wt% Ni, 0.05–0.3 wt% V, 0.05–0.3 wt% Zr, 0.01–2.0 wt% Zn, 0.02–6.0 wt% RE, less than 0.3 wt% trace elements, less than 0.2 wt% impurities, and the balance Al. When the composition of the die-cast aluminum alloy is within the range of this embodiment, the die-cast aluminum alloy can have better brazing performance.

[0008] In one embodiment, the Fe to Mn content ratio in the die-cast aluminum alloy is 0.17 to 2.8; in a preferred embodiment, the Fe to Mn content ratio is 0.25 to 2.5. Controlling the Fe to Mn content ratio within the range of this embodiment, and especially within the preferred range, can improve the performance of the die-cast aluminum alloy.

[0009] In one embodiment, the Ni to Si content ratio in the die-cast aluminum alloy is 2 to 50; in a preferred embodiment, the Ni to Si content ratio is 4 to 50. Controlling the Ni to Si content ratio within the range of this embodiment, and especially within the preferred range, can improve the performance of the die-cast aluminum alloy.

[0010] In one embodiment, the Zr to Ti content ratio in the die-cast aluminum alloy is 0.4 to 17; in a preferred embodiment, the Zr to Ti content ratio is 0.5 to 15. Controlling the Zr to Ti content ratio within the range of this embodiment, and especially within the preferred range, can improve the performance of the die-cast aluminum alloy.

[0011] In one embodiment, the die-cast aluminum alloy has a tensile strength ≥160MPa, a yield strength ≥70MPa, and an elongation at break ≥15% in the as-cast state; in another embodiment, the solidus temperature of the die-cast aluminum alloy is ≥630℃, and the hot cracking tendency is ≤28.

[0012] A second aspect of this disclosure provides a method for preparing die-cast aluminum alloys, comprising the following steps:

[0013] S1. The alloy raw materials are smelted, degassed, refined, and cast to obtain alloy ingots. The alloy raw materials include 0.3-3.5 wt% Mn, 0.4-2.0 wt% Fe, 0.02-0.6 wt% Si, 0.01-0.6 wt% Cr, 0.03-0.45 wt% Ti, 0.01-2.8 wt% Ni, 0.01-0.4 wt% V, 0.01-0.5 wt% Zr, less than 2.5 wt% Zn, 0.01-7.0 wt% RE, less than 0.3 wt% trace elements, less than 0.2 wt% impurities, and the balance aluminum. The trace elements include one or more of Cu, Mg, and Mo; RE includes one or more of La, Ce, and Sm. The Fe to Mn content ratio is 0.14-3.2, and the Ni to Si content ratio is 2-60.

[0014] S2. The alloy ingot is cast.

[0015] This disclosure provides a method for preparing die-cast aluminum alloys that does not require heat treatment, and the resulting die-cast aluminum alloys have the effects of high solidus temperature, brazing capability, and low thermal conductivity.

[0016] In one embodiment, step S1 includes: putting aluminum ingots and intermediate alloys of Mn, Fe, Cr, Ni, Si, V, and Zr into a melting furnace, heating to 750~780°C, and stirring thoroughly after the alloy melts; then adding intermediate alloys of RE and Ti in sequence, cooling to 710~730°C, adding pure Mg and pure Zn, holding at the temperature, and then performing the degassing refining treatment and casting treatment.

[0017] In one embodiment, the degassing and refining time is 10-20 minutes.

[0018] In one embodiment, in step S2, the casting process includes high-pressure die casting and extrusion casting;

[0019] In one embodiment, the conditions for the extrusion casting include: a temperature of 740~760℃, a pressure of 100~120MPa, and a holding time of 12~18s;

[0020] In one embodiment, the conditions for high-pressure die casting include: a temperature of 700~730℃, a mold temperature of 180~230℃, an injection speed of 4.5~6.5m / s, and a vacuum degree of <40mbar.

[0021] The third aspect of this disclosure provides a die-cast aluminum alloy prepared according to the method described in the second aspect of this disclosure.

[0022] This disclosure provides a fourth aspect of a vehicle structural component, comprising the die-cast aluminum alloy described in the first or third aspect of this disclosure.

[0023] This disclosure provides a vehicle including the vehicle structural components described in the fourth aspect of this disclosure.

[0024] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0025] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0026] Figure 1 The DSC curve of the die-cast aluminum alloy obtained in Example 1 of this disclosure;

[0027] Figure 2 This is a schematic diagram illustrating the hot cracking tendency assessment of the die-cast aluminum alloy obtained in Embodiment 1 of this disclosure. Detailed Implementation

[0028] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0029] The first aspect of this disclosure provides a die-cast aluminum alloy, wherein, based on the total weight of the die-cast aluminum alloy, the die-cast aluminum alloy comprises 0.3~3.5 wt% Mn (manganese), 0.4~2.0 wt% Fe (iron), 0.02~0.6 wt% Si (silicon), 0.01~0.6 wt% Cr (chromium), 0.03~0.45 wt% Ti (titanium), 0.01~2.8 wt% Ni (nickel), 0.01~0.4 wt% V (vanadium), and 0.01~0.5 wt% [unclear - possibly referring to a specific component or component]. The composition includes, by weight, Zr (Zr), less than 2.5% Zn (zinc), 0.01 to 7.0% RE, less than 0.3% trace elements, less than 0.2% impurities, and the balance Al (aluminum); the trace elements include one or more of Cu (copper), Mg (magnesium), and Mo (molybdenum); RE includes one or more of La (lanthanum), Ce (cerium), and Sm (samarium); wherein the content ratio of Fe to Mn is 0.14 to 3.2, and the content ratio of Ni to Si is 2 to 60.

[0030] This disclosure provides a die-cast aluminum alloy that not only meets the requirements for brazing and ensures the mechanical properties of the parts, but also reduces the amount of machining required for traditional heat dissipation modules, enabling the production of brazable, low-thermal-conductivity, heat-free die-cast aluminum alloy parts.

[0031] In this disclosure, "0.3~3.5 wt%" includes, but is not limited to, 0.3 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, and any two of these values; "0.4~2.0 wt%" includes, but is not limited to, 0.5 wt%, 0.8 wt%, 1.2 wt%, 1.6 wt%, 2 wt%, and any two of these values; "0.02~0.6 wt%" includes, but is not limited to, 0.02 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, and any two of these values; "0.01~0.6 wt%" includes... The range includes, but is not limited to, 0.01 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, 0.6 wt%, and any two of these values; "0.03~0.45 wt%" includes, but is not limited to, 0.03 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, 0.45 wt%, and any two of these values; "0.01~2.8 wt%" includes, but is not limited to, 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.5 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 2.7 wt%. The range of %, 2.8 wt%, and any two values ​​is included; "0.01~0.4 wt%" includes 0.01 wt%, 0.05 wt%, 0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, 0.3 wt%, 0.35 wt%, 0.4 wt%, and any two values ​​is included; "0.01~0.5 wt%" includes, but is not limited to, 0.01 wt%, 0.07 wt%, 0.1 wt%, 0.2 wt%, 0.3 wt%, 0.4 wt%, 0.5 wt%, and any two values ​​is included; "below 2.5 wt%" includes, but is not limited to, below 2.5 wt%, below 2 wt%, below 1.5 wt%, and below 1 wt%. The following are included: below 0.5 wt%, below 0.1 wt%, below 0.01 wt%, etc.; "0.01~7.0 wt%" includes, but is not limited to, 0.01 wt%, 0.5 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, and any range of two values; "below 0.3 wt%" includes, but is not limited to, below 3 wt%, below 2.5 wt%, below 2 wt%, below 1.5 wt%, below 1 wt%, below 0.5 wt%, below 0.1 wt%, below 0.01 wt%, etc.; "0.2 wt%" includes, but is not limited to, below 2 wt%, below 1.5 wt%, below 1 wt%, below 0.5 wt%, 0.Less than 1% by weight, less than 0.01% by weight, etc.

[0032] In this disclosure, "0.14~3.2" includes, but is not limited to, 0.14, 0.5, 1, 1.5, 2, 2.5, 2.9, 3, 3.2, and any two values; "2~60" includes, but is not limited to, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, and any two values.

[0033] According to this disclosure, a brazable Al-Mn-Fe low thermal conductivity die-cast aluminum alloy, with Mn and Fe as the main alloying elements, can achieve the following effects: 1) The eutectic range temperatures of Al-Mn and Al-Fe are 658℃ and 655℃, respectively, which are beneficial for increasing the solidus temperature of the alloy compared to Al-Si, making it suitable for brazing; 2) A certain content of Mn and Fe elements can ensure that the alloy has good fluidity suitable for die casting and facilitate demolding; 3) This disclosure controls the mass percentage ratio of Fe to Mn in the aluminum alloy to meet the requirements of 0.14~3.2, and the mass percentage ratio of Ni to Si to meet the requirements of 2~60, resulting in good casting performance and low hot cracking index; 4) The addition of Mn and Fe elements can reduce the thermal conductivity of the aluminum alloy and reduce the thermal impact on adjacent parts; 5) The high solidus point alloy avoids the use of expensive Ni element, reducing costs and facilitating recycling.

[0034] According to this disclosure, adding Si to the die-cast aluminum alloy can improve its casting performance. However, the Al-Si eutectic temperature is 577℃, which significantly reduces the solidus temperature of the alloy, failing to meet the requirements for brazing. Furthermore, adding more than 0.6% by weight of Si will form an AlFeSi phase, affecting the alloy's elongation. Adding Ti can increase heterogeneous nucleation sites, refine the grains, increase the alloy's toughness, and improve the material's resistance to hot cracking. Adding Cr forms a second phase, increasing heat dissipation from electron movement, reducing the alloy's thermal conductivity, and decreasing thermal diffusion.

[0035] According to this disclosure, the addition of Ni to the die-cast aluminum alloy forms Al3Ni, which ensures the alloy's high-temperature strength. After brazing, it meets the leak-free requirements of high-pressure and low-pressure static pressure strength tests and increases the maximum destructive force in burst tests. However, Ni increases the tendency for hot cracking. Therefore, V and Ti are added to refine the grains and reduce the lamellar iron-rich phase in the matrix, thereby improving the alloy's toughness.

[0036] According to this disclosure, Zr is added to the die-cast aluminum alloy to form Al3Zr. At high temperatures, the precipitate coarsening rate is low, and the precipitates are uniform and fine, which can pin dislocations, stabilize material deformation, and improve the alloy's mechanical properties. Adding Zn can improve casting performance and reduce bubbling during brazing.

[0037] According to this disclosure, rare earth elements (one or more of La, Ce and Sm) are added to the die-cast aluminum alloy to improve the mechanical properties of the alloy through solid solution strengthening, grain refinement strengthening and second phase strengthening. At the same time, rare earth elements can adsorb impurities and purify the aluminum liquid during the smelting process, effectively reduce the H content in the microstructure, increase the microstructure density, and prevent the parts from bulging and deforming at the brazing temperature.

[0038] According to this disclosure, the addition of Cu, Mg, and Mo as trace elements to the die-cast aluminum alloy can form Mg2Si and Al2Cu reinforcing phases, thereby improving the alloy's strength through solid solution strengthening. Currently, gas shielded welding is the main process. Excessive Mg content not only reduces brazing properties (the melting points of Al-Cu and Al-Mg alloys are both below 600℃), but Mg also readily reacts chemically with the brazing filler metal to form magnesium fluoride (melting point >1000℃), hindering filler metal flow. Therefore, the Mg content in the alloy needs to be controlled. Excessive Cu content can cause hot cracking, leading to a decrease in part production yield. Therefore, this disclosure controls the content of trace elements to avoid excessive Cu content. This disclosure allows for flexible adjustment of the trace element content. Different Mg contents can be selected for different brazing processes (for example, when die-cast aluminum alloys are used in gas shielded welding, Mg is below 0.05% by weight; when die-cast aluminum alloys are used in vacuum welding, Mg can be above 0.05% by weight). The Cu and Mo contents can also be flexibly adjusted to regulate part strength.

[0039] In this disclosure, impurities refer to unavoidably introduced impurities, such as C, N, and O, which are negligible in aluminum alloys.

[0040] In a preferred embodiment, the die-cast aluminum alloy comprises 1.5–3.2 wt% Mn, 0.7–1.5 wt% Fe, 0.05–0.3 wt% Si, 0.05–0.5 wt% Cr, 0.08–0.40 wt% Ti, 0.01–1.8 wt% Ni, 0.05–0.3 wt% V, 0.05–0.3 wt% Zr, 0.01–2.0 wt% Zn, 0.02–6.0 wt% RE, less than 0.3 wt% trace elements, less than 0.2 wt% impurities, and the balance aluminum. When the composition of the die-cast aluminum alloy is within the range of this embodiment, the die-cast aluminum alloy can have better brazing performance.

[0041] In a preferred embodiment, the Fe to Mn content ratio in the die-cast aluminum alloy is 0.17 to 2.8, preferably 0.25 to 2.5. Controlling the Fe to Mn content ratio within the range of this embodiment, and especially within the preferred range, can improve the performance of the die-cast aluminum alloy.

[0042] In a preferred embodiment, the Ni to Si content ratio in the die-cast aluminum alloy is 2 to 50, preferably 4 to 50. Controlling the Ni to Si content ratio within the range of this embodiment, and especially within the preferred range, can improve the performance of the die-cast aluminum alloy.

[0043] In a preferred embodiment, the Zr to Ti content ratio in the die-cast aluminum alloy is 0.4 to 17, including but not limited to 0.4, 1, 2, 4, 6, 8, 10, 12, 14, 16, 17, and any combination of two values; preferably 0.5 to 15. Controlling the Zr to Ti content ratio within the range of this embodiment, especially within the preferred range, can improve the performance of the die-cast aluminum alloy.

[0044] In one specific embodiment, the die-cast aluminum alloy has a tensile strength ≥160MPa, a yield strength ≥70MPa, and an elongation at break ≥15% in the as-cast state; preferably, the die-cast aluminum alloy has a tensile strength ≥165MPa, a yield strength ≥75MPa, and an elongation at break ≥15% in the as-cast state.

[0045] In one specific embodiment, the solidus temperature of the die-cast aluminum alloy is ≥630℃, the hot cracking tendency is ≤28, and the thermal conductivity is <100W / m·K; preferably, the solidus temperature of the die-cast aluminum alloy is ≥635℃, the hot cracking tendency is ≤16, and the thermal conductivity is <95W / m·K. In this disclosure, the "cast state" of the die-cast aluminum alloy refers to the F state, without any brazing or heat treatment.

[0046] In a preferred embodiment, the brazing temperature of the die-cast aluminum alloy is 590~610℃. The brazing process includes gas shielded welding and vacuum brazing. Gas shielded welding does not require vacuuming; nitrogen gas is used directly to protect the parts, and flux needs to be applied to the parts. Vacuum brazing requires vacuuming and heating, does not require flux, and requires cooling after completion. The die-cast aluminum alloy provided in this disclosure has excellent brazing properties.

[0047] A second aspect of this disclosure provides a method for preparing die-cast aluminum alloys, comprising the following steps:

[0048] S1. The alloy raw materials are smelted, degassed, refined, and cast to obtain alloy ingots. The alloy raw materials include 0.3-3.5 wt% Mn, 0.4-2.0 wt% Fe, 0.02-0.6 wt% Si, 0.01-0.6 wt% Cr, 0.03-0.45 wt% Ti, 0.01-2.8 wt% Ni, 0.01-0.4 wt% V, 0.01-0.5 wt% Zr, less than 2.5 wt% Zn, 0.01-7.0 wt% RE, less than 0.3 wt% trace elements, less than 0.2 wt% impurities, and the balance aluminum. The trace elements include one or more of Cu, Mg, and Mo; RE includes one or more of La, Ce, and Sm. The Fe to Mn content ratio is 0.14-3.2, and the Ni to Si content ratio is 2-60.

[0049] S2. The alloy ingot is cast.

[0050] This disclosure provides a method for preparing die-cast aluminum alloys. This process does not require heat treatment, and the resulting die-cast aluminum alloys have the effects of high solidus temperature, brazing capability, and low thermal conductivity.

[0051] In this disclosure, the composition of the alloy raw materials is the same as that of the aforementioned die-cast aluminum alloy, and will not be repeated here.

[0052] In one specific embodiment, step S1 includes:

[0053] Aluminum ingots and intermediate alloys of Mn, Fe, Cr, Ni, Si, V, and Zr are added to a melting furnace and heated to 750-780°C. After the alloys melt, they are stirred thoroughly. Then, intermediate alloys of RE and Ti are added in sequence, the temperature is lowered to 710-730°C, pure Mg and pure Zn are added, and the mixture is kept at this temperature before the degassing refining and casting processes are carried out.

[0054] In one specific embodiment, the degassing and refining time is 10-20 minutes.

[0055] In one specific embodiment, the brazing temperature of the die-cast aluminum alloy is 590~610℃. The die-cast aluminum alloy provided in this disclosure has a relatively high brazing temperature and good brazing stability.

[0056] In one embodiment, step S2 includes high-pressure die casting and squeeze casting.

[0057] In one specific embodiment, the extrusion casting conditions include: a temperature of 740~760℃, a pressure of 100~120MPa, and a holding time of 12~18s; preferably, the temperature is 745~760℃, the pressure is 100~115MPa, and the holding time is 12~16s.

[0058] In one specific embodiment, the conditions for high-pressure die casting include: a temperature of 700~730℃, a mold temperature of 180~230℃, an injection speed of 4.5~6.5m / s, and a vacuum degree of <60mbar. Preferably, the temperature is 700~725℃, the mold temperature is 180~220℃, the injection speed is 4.5~6m / s, and the vacuum degree is <50mbar.

[0059] The third aspect of this disclosure provides a die-cast aluminum alloy prepared according to the method described in the second aspect of this disclosure.

[0060] This disclosure provides a fourth aspect of a vehicle structural component, comprising the die-cast aluminum alloy described in the first or third aspect of this disclosure.

[0061] In one specific embodiment, the vehicle structural component is a battery heat dissipation module. Using the die-cast aluminum alloy provided in this disclosure for the battery heat dissipation module can improve brazing stability and reduce weight.

[0062] This disclosure provides a vehicle including the vehicle structural components described in the fourth aspect of this disclosure.

[0063] The present disclosure is further described in detail below through examples. All raw materials used in the examples are commercially available.

[0064] Example 1

[0065] This embodiment prepares a die-cast aluminum alloy according to the alloy raw material composition listed in Table 1, including the following steps:

[0066] (1) Prepare materials according to the formula ingredients;

[0067] (2) The aluminum ingot and the intermediate alloy of Mn, Fe, Cr, Ni, Si, V, Zr, Cu and Mo elements are put into the melting furnace, heated to 770°C, and stirred thoroughly after the alloy melts; then the intermediate alloy of RE and Ti elements are added in sequence, the temperature is lowered to 730°C, pure Mg and pure Zn are added, and after holding the temperature, the degassing refining treatment and casting treatment are carried out to obtain the alloy ingot; wherein, the degassing refining treatment conditions include adding 0.3~0.5% by weight of refining agent of the total weight of raw materials, degassing for 8~12 min, removing the slag and standing for 10~13 min; then casting into an ingot;

[0068] (2) The alloy ingot is subjected to flat mold casting. The casting process includes: die casting temperature of 700~710℃, vacuum degree of 30mbar, and casting pressure of 500~700bar.

[0069] Examples 2-7

[0070] The preparation method in Example 1 is the same as in Example 1, except that the aluminum alloy material is prepared according to the aluminum alloy raw material composition listed in Table 1, and the rest of the process is the same as in Example 1.

[0071] Comparative Examples 1-7

[0072] The preparation method in Example 1 is the same as in Example 1, except that the aluminum alloy material is prepared according to the aluminum alloy raw material composition listed in Table 1, and the rest of the process is the same as in Example 1.

[0073] Comparative Example 8

[0074] The preparation method described in Example 1 differs from that in that the aluminum alloy material is prepared according to the aluminum alloy raw material composition listed in Table 1 (referring to the alloy composition in Example 1 of CN116334454A, including: Si: 0.06 wt%; Fe: 0.10 wt%; Mn: 1.70 wt%; Ce: 0.13 wt%; Mg: 0.10 wt%; Cs: 0.05 wt%; Sc: 0.08 wt%; Zr: 0.05 wt%; Zn: 0.07 wt%; Ti: 0.041 wt%; B: 0.015 wt%; Sr: 0.005 wt%; other impurities are controlled below 0.3 wt%, with the balance being Al). The remaining processes are the same as in Example 1.

[0075] Table 1

[0076]

[0077] In Table 1, the unit of each element content is "weight %"; " / " indicates that it is not added or does not exist; in Examples 1-8 and Comparative Examples 1-7, "RE" includes one or more of the mixed rare earth elements La, Ce, and Sm; in Example 9, RE only includes La; and the impurity content in each example and comparative example is controlled below 0.2% by weight.

[0078] Test case

[0079] This test example is used to test the performance of the die-cast aluminum alloys obtained in the above embodiments and comparative examples.

[0080] The tensile strength, yield strength, and elongation of the die-cast aluminum alloy were tested according to standard GB / T 228.1 Metallic materials, tensile testing, Part 1: Room temperature test method; the solidus temperature was tested according to standard GB / T 1425 Determination of melting temperature range of precious metals and their alloys by thermal analysis test method; the hot cracking tendency was tested according to the hot cracking bar method, such as... Figure 2As shown, the specific methods include: pouring molten aluminum into a mold after high-temperature melting, observing the location of cracks, and calculating the corresponding values ​​to determine the tendency for hot cracking. The larger the value, the greater the tendency for hot cracking (as disclosed in patent CN117070808A).

[0081] The test results are listed in Table 2 below.

[0082] Table 2

[0083]

[0084] The DSC curve of the die-cast aluminum alloy obtained in Example 1 is as follows: Figure 1 As shown, by Figure 1 It can be seen that the solidus temperature of the die-cast aluminum alloy obtained in Example 1 is 645.2℃, which is higher than the general brazing temperature of 610℃, and can meet the requirements for high-temperature brazing of die-cast aluminum alloys; the schematic diagram of the alloy hot cracking tendency assessment of the die-cast aluminum alloy obtained in Example 1 is shown below. Figure 2 As shown, by Figure 2 It can be seen that the aluminum alloy castings obtained in Example 1 have a very low tendency to hot cracking, which can improve the quality of the castings and ensure the airtightness of the parts.

[0085] The data in Table 2 shows that:

[0086] The die-cast aluminum alloys provided in Comparative Examples 1-8 cannot achieve both high strength and good brazing performance. For example, although the die-cast aluminum alloys of Comparative Examples 3 and 6 have good mechanical properties, their solidus melting points are much lower than 630°C and they have a high tendency to hot crack, which cannot meet the requirements for brazing. Although the die-cast aluminum alloy of Comparative Example 7 meets the brazing requirements for a solidus temperature above 630°C, its strength is low and it does not meet the requirements for use. Therefore, compared with Comparative Examples 1-8, the die-cast aluminum alloys provided in Examples 1-9 of this disclosure can simultaneously meet the mechanical property requirements and brazing requirements, and have a low tendency to hot crack, resulting in better overall performance of the aluminum alloy.

[0087] Comparing Examples 1-3 and 7 with Examples 4-6, it can be seen that the component content of the die-cast aluminum alloy in Examples 1-3 and 7 is within the preferred range provided in this disclosure. The die-cast aluminum alloy in Examples 1-3 and 7 can simultaneously have high strength, elongation, solidus temperature and low hot cracking tendency, and has better overall performance.

[0088] Comparing Example 1 with Examples 4-5, it can be seen that the Fe to Mn and Ni to Si content ratios of the die-cast aluminum alloy in Example 1 are within the preferred range provided in this disclosure, and the overall performance of the die-cast aluminum alloy in Example 1 is better.

[0089] Comparing Example 1 and Example 8, it can be seen that the Zr / Ti content ratio of the die-cast aluminum alloy in Example 1 is within the preferred range provided in this disclosure, and the overall performance of the die-cast aluminum alloy in Example 1 is better.

[0090] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0091] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0092] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A die cast aluminium alloy characterised in that, Based on the total weight of the die-cast aluminum alloy, the die-cast aluminum alloy comprises 1.5~3.2 wt% Mn, 0.7~1.5 wt% Fe, 0.05~0.3 wt% Si, 0.05~0.5 wt% Cr, 0.08~0.40 wt% Ti, 0.01~1.8 wt% Ni, 0.05~0.3 wt% V, 0.05~0.3 wt% Zr, 0.01~2.0 wt% Zn, and 0.02~6.0 wt% RE. The alloy contains less than 0.3% by weight of trace elements, less than 0.2% by weight of impurities, and the balance of Al; the trace elements include one or more of Cu, Mg, and Mo; RE includes one or more of La, Ce, and Sm; wherein the content ratio of Fe to Mn is 0.17~2.8, the content ratio of Ni to Si is 5~50, and the content ratio of Zr to Ti is 1~15; the die-cast aluminum alloy has a tensile strength ≥160MPa, a yield strength ≥70MPa, and an elongation at break ≥15% in the as-cast state.

2. The die-cast aluminum alloy according to claim 1, characterized in that, The solidus temperature of the die-cast aluminum alloy is ≥630℃, and the tendency to hot crack is ≤28%.

3. A method for preparing die-cast aluminum alloys, characterized in that, Includes the following steps: S1. The alloy raw materials are subjected to smelting, degassing, refining, and casting processes to obtain alloy ingots; the alloy raw materials include 1.5~3.2 wt% Mn, 0.7~1.5 wt% Fe, 0.05~0.3 wt% Si, 0.05~0.5 wt% Cr, 0.08~0.40 wt% Ti, 0.01~1.8 wt% Ni, 0.05~0.3 wt% V, and 0.05~0.3 wt% Zr. The mixture contains 0.01 to 2.0 wt% Zn, 0.02 to 6.0 wt% RE, less than 0.3 wt% trace elements, less than 0.2 wt% impurities, and the balance Al; the trace elements include one or more of Cu, Mg, and Mo; RE includes one or more of La, Ce, and Sm; wherein the Fe to Mn content ratio is 0.17 to 2.8, the Ni to Si content ratio is 5 to 50, and the Zr to Ti content ratio is 1 to 15. S2. The alloy ingot is cast.

4. The method according to claim 3, characterized in that, Step S1 includes: Aluminum ingots and intermediate alloys of Mn, Fe, Cr, Ni, Si, V, Zr, Cu and Mo are put into a melting furnace and heated to 750~780℃. After the alloy melts, it is stirred thoroughly. Then, intermediate alloys of RE and Ti are added in sequence, the temperature is lowered to 710~730℃, pure Mg and pure Zn are added, and after holding at the temperature, the degassing refining treatment and casting treatment are carried out. The degassing and refining time is 10-20 minutes.

5. The method according to claim 3, characterized in that, In step S2, the casting process includes high-pressure die casting and squeeze casting; The conditions for extrusion casting include: a temperature of 740~760℃, a pressure of 100~120MPa, and a holding time of 12~18s; The conditions for high-pressure die casting include: temperature of 700~730℃, mold temperature of 180~230℃, injection speed of 4.5~6.5m / s, and vacuum degree of <40mbar.

6. The die-cast aluminum alloy prepared by the method according to any one of claims 3 to 5.

7. A vehicle structural component, characterized in that, Includes the die-cast aluminum alloy described in any one of claims 1 to 2 and 6.

8. The vehicle structural component according to claim 7, characterized in that, The vehicle structural components include a battery cooling module.

9. A vehicle, characterized in that, Includes the vehicle structural component as described in claim 7 or 8.

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