Non-heat treated aluminum alloy and method of processing, vehicle die cast and vehicle end

Abstract

The present disclosure relates to a non-heat treated aluminum alloy and a processing method, a vehicle die casting and a vehicle terminal. The non-heat treated aluminum alloy includes aluminum, iron, silicon, copper, magnesium, manganese, titanium, carbon and boron, wherein the titanium, the carbon and the boron are used to refine coarse pre-crystalline alpha-Al organization generated when the non-heat treated aluminum alloy is cast, improve the organization morphology of the processed non-heat treated aluminum alloy, and improve the mechanical properties.

Description

Technical Field

[0001] This disclosure relates to the field of terminal technology, and in particular to a non-heat-treated aluminum alloy and its processing method, automotive die castings, and vehicle terminals. Background Technology

[0002] Die-cast automotive parts made from non-heat-treated aluminum alloys do not require heat treatment and can be directly formed and put into use based on the shape and volume requirements of the vehicle end. This effectively reduces production costs, making non-heat-treated aluminum alloy technology highly sought after by major vehicle manufacturers and one of the most popular technologies in the industry. Summary of the Invention

[0003] This disclosure provides a non-heat-treatable aluminum alloy and its processing method, automotive die castings, and vehicle terminals to address the shortcomings of related technologies.

[0004] According to a first aspect of the present disclosure, a non-heat-treatable aluminum alloy is provided. The composition of the non-heat-treatable aluminum alloy includes aluminum, iron, silicon, copper, magnesium, manganese, titanium, carbon, and boron. The titanium, carbon, and boron are used to refine the coarse pre-crystallized α-Al structure generated during the casting of the non-heat-treatable aluminum alloy, improve the microstructure of the processed non-heat-treatable aluminum alloy, and enhance its mechanical properties.

[0005] Optional,

[0006] The weight percentage of silicon is greater than or equal to 6.5% and less than or equal to 9%;

[0007] The iron element has a weight percentage greater than or equal to 0.1% and less than or equal to 0.3%;

[0008] The weight percentage of copper is greater than or equal to 0.1% and less than or equal to 0.5%;

[0009] The magnesium element has a weight percentage greater than or equal to 0.1% and less than or equal to 0.45%;

[0010] The manganese element has a weight percentage greater than or equal to 0.4% and less than or equal to 0.8%.

[0011] Optionally, the sum of the weight percentages of the copper and magnesium elements is less than or equal to 0.8%.

[0012] Optional,

[0013] The titanium element has a weight percentage greater than or equal to 0.01% and less than or equal to 0.3%;

[0014] The carbon element has a weight percentage greater than or equal to 0.001% and less than or equal to 0.05%;

[0015] The weight percentage of boron is greater than or equal to 0.001% and less than or equal to 0.05%.

[0016] Optionally, the ratio of the mass of silicon to the sum of the masses of titanium, carbon, and boron is less than or equal to 200.

[0017] Optionally, the ratio of the mass of silicon to the sum of the masses of titanium, carbon, and boron is equal to 150.

[0018] Optionally, the weight percentages of the titanium, carbon, and boron elements are in the range of 5-120:1:0.5-3.0.

[0019] Optionally, the composition of the non-heat-treated aluminum alloy may also include vanadium, wherein the weight percentage of vanadium is greater than or equal to 0.05% and less than or equal to 0.1%.

[0020] Optionally, the composition of the non-heat-treated aluminum alloy may also include strontium, wherein the weight percentage of strontium is greater than or equal to 0.01% and less than or equal to 0.03%.

[0021] According to a second aspect of the present disclosure, a method for processing non-heat-treatable aluminum alloys is provided, comprising:

[0022] Melting an intermediate aluminum alloy yields a first aluminum alloy melt, wherein the intermediate aluminum alloy comprises silicon-aluminum alloy, iron-aluminum alloy, copper-aluminum alloy, magnesium-aluminum alloy, and manganese-aluminum alloy;

[0023] An aluminum-titanium-carbon-boron alloy refining agent is added to the first aluminum alloy melt for refining treatment to obtain a second aluminum alloy melt. The aluminum-titanium-carbon-boron alloy refining agent is used to refine the coarse pre-crystallized α-AL structure generated during the casting of the non-heat-treated aluminum alloy.

[0024] Strontium alloy was added to the second aluminum alloy melt for modification treatment to obtain a third aluminum alloy melt;

[0025] The non-heat-treated aluminum alloy is obtained by casting based on the third aluminum alloy melt.

[0026] Optional, also includes:

[0027] The first aluminum alloy melt is subjected to degassing treatment;

[0028] The first aluminum alloy melt is subjected to slag removal treatment.

[0029] Optionally, the amount of the aluminum-titanium-carbon-boron alloy refining agent added is 0.2%-0.5% of the mass of the first aluminum alloy melt.

[0030] Optionally, the intermediate aluminum alloy may also include a manganese-aluminum alloy and / or a vanadium-aluminum alloy.

[0031] Optionally, the ratio of the mass of silicon to the sum of the masses of titanium, carbon, and boron in the non-heat-treated aluminum alloy is less than or equal to 200.

[0032] Optionally, the ratio of the mass of silicon to the sum of the masses of titanium, carbon, and boron in the non-heat-treated aluminum alloy is equal to 150.

[0033] Optionally, the weight percentages of titanium, carbon, and boron are in the range of 5-120:1:0.5-3.0.

[0034] Optional,

[0035] In the non-heat-treated aluminum alloy, the weight percentage of silicon is greater than or equal to 6.5% and less than or equal to 9%.

[0036] The weight percentage of iron is greater than or equal to 0.1% and less than or equal to 0.3%;

[0037] The weight percentage of copper is greater than or equal to 0.1% and less than or equal to 0.5%;

[0038] The magnesium content is greater than or equal to 0.1% and less than or equal to 0.45% by weight.

[0039] The weight percentage of strontium is greater than or equal to 0.01% and less than or equal to 0.03%;

[0040] The manganese element has a weight percentage greater than or equal to 0.4% and less than or equal to 0.8%.

[0041] Optionally, the sum of the weight percentages of copper and magnesium is less than or equal to 0.8%.

[0042] Optionally, in the non-heat-treated aluminum alloy,

[0043] The weight percentage of titanium is greater than or equal to 0.01% and less than or equal to 0.3%;

[0044] The weight percentage of carbon is greater than or equal to 0.001% and less than or equal to 0.05%;

[0045] The weight percentage of boron is greater than or equal to 0.001% and less than or equal to 0.05%.

[0046] Optionally, the sum of the weight percentages of copper and magnesium is less than or equal to 0.8%.

[0047] According to a third aspect of the present disclosure, a method for processing automotive die-cast parts is provided, comprising:

[0048] Melting the non-heat-treated aluminum alloy described in any of the embodiments;

[0049] The automotive die-casting part is obtained by die-casting the molten material.

[0050] Optionally, the die-casting process based on the molten melt to obtain the automotive die-casting part includes:

[0051] The die casting process is based on the molten melt, with casting pressure ranging from 20MPa to 70MPa, mold temperature ranging from 60℃ to 160℃, and filling time ranging from 60ms to 150ms.

[0052] According to a fourth aspect of the present disclosure, an automotive die casting is provided, wherein the automotive die casting is obtained by the processing method described in any of the above embodiments, and wherein the automotive die casting has a tensile strength ≥250MPa, a yield strength ≥120MPa, and an elongation ≥7% at a distance of 1.5m from the gate.

[0053] According to a fifth aspect of the present disclosure, a vehicle terminal is provided, including a rear floor die casting, the rear floor die casting including an automotive die casting as described in any of the above embodiments.

[0054] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects:

[0055] As can be seen from the above embodiments, the dispersed B, carbon, and titanium elements in the non-heat-treated aluminum alloy provided by this disclosure, by forming B-doped TiC and TiCB particles, adhere to the abundant AlTi3 nucleation particles, effectively improving the heterogeneous nucleation stability of AlTi3, becoming stable α-Al nucleation particles, refining the coarse dendritic α-Al structure, reducing the decrease in elongation caused by the enrichment of shrinkage porosity or shrinkage cavities around α-Al, and at the same time improving the flow properties of the non-heat-treated aluminum alloy after melting under limited process conditions, maintaining relatively stable mechanical properties of the melt after melting of the non-heat-treated aluminum alloy as the flow distance increases, especially having a good effect on maintaining elongation, which is beneficial for the processing of large die castings based on the melt of non-heat-treated aluminum alloy.

[0056] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0057] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0058] Figure 1 This is a schematic diagram of the composition of a non-heat-treatable aluminum alloy according to an exemplary embodiment.

[0059] Figure 2 This is a flowchart illustrating a non-heat-treated aluminum alloy processing method according to an exemplary embodiment.

[0060] Figure 3 This is the metallographic image of the alloy disclosed herein at a flow distance of 1500 mm.

[0061] Figure 4 It is the metallographic structure of alloy 1 at a position with a flow distance of 1500 mm.

[0062] Figure 5 This is a flowchart illustrating a method for processing a die-cast automotive part according to an exemplary embodiment. Detailed Implementation

[0063] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this disclosure as detailed in the appended claims.

[0064] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0065] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0066] For some one-piece die-cast parts used in automobiles or other large equipment, heat treatment is usually required to modify the parts and obtain good mechanical properties. However, the heat treatment process for one-piece die-cast parts increases the number of processes and may also cause local deformation of the parts, leading to subsequent straightening, which undoubtedly increases production costs.

[0067] To address the aforementioned issues, a non-heat-treated aluminum alloy for die casting has been developed in this field. One-piece die-cast parts formed from this aluminum alloy do not require heat treatment after forming and can be used directly. However, when this non-heat-treated aluminum alloy is used to die-cast some large or ultra-large parts, two problems arise. First, the die-casting machines designed for large or ultra-large parts have limited die-casting process conditions, such as limited filling time, die-casting speed, die-casting pressure, and mold temperature, leading to unstable mechanical properties of the aluminum alloy under these conditions. Second, as the flow distance increases, the mechanical properties of the aluminum alloy also become unstable, easily exhibiting a decline in mechanical properties, especially in terms of ductility.

[0068] To address the aforementioned problems, this disclosure provides a processing method for non-heat-treated aluminum alloys. The non-heat-treated aluminum alloys obtained through this method exhibit good mechanical property stability under the die-casting process conditions provided by die-casting machines for large or ultra-large die-casting parts. Furthermore, it appropriately slows down the rate of decrease in elongation of the non-heat-treated aluminum alloy as the flow distance increases, ensuring that the elongation of the non-heat-treated aluminum alloy still meets process requirements at a given flow distance. Specifically, Figure 1 This is a schematic diagram illustrating the composition of a non-heat-treatable aluminum alloy according to an exemplary embodiment, such as... Figure 1 As shown, the composition of this non-heat-treated aluminum alloy may include aluminum, iron, silicon, copper, magnesium, manganese, titanium, carbon, and boron. The addition of aluminum, iron, silicon, copper, magnesium, and manganese can give the die-cast parts formed by die casting of this non-heat-treated aluminum alloy better comprehensive mechanical properties. For example, the mechanical properties are stable when forming medium-sized die-cast parts. The addition of titanium, carbon, and boron can refine the coarse pre-crystallized α-Al structure generated during the casting of the non-heat-treated aluminum alloy, improve the microstructure of the processed non-heat-treated aluminum alloy, reduce the decrease in elongation caused by the enrichment of shrinkage porosity or shrinkage cavities around α-Al, and improve the mechanical properties of large die-cast parts at the end away from the gate, thus improving the mechanical stability of large die-cast parts.

[0069] Figure 2 This is a flowchart illustrating a non-heat-treated aluminum alloy processing method according to an exemplary embodiment, such as... Figure 2As shown, the processing method may include the following steps:

[0070] In step 201, the intermediate aluminum alloy is melted to obtain a first aluminum alloy melt, wherein the intermediate aluminum alloy includes silicon-aluminum alloy, iron-aluminum alloy, copper-aluminum alloy, magnesium-aluminum alloy, and manganese-aluminum alloy.

[0071] In this embodiment, the intermediate aluminum alloy can include various types, such as a silicon-aluminum alloy. The non-heat-treated aluminum alloy formed by this processing method can contain silicon. The silicon-aluminum alloy can be a hypoeutectic alloy, and the resulting first aluminum alloy melt can contain silicon. As the weight percentage of silicon increases, the proportion of eutectic silicon in the formed non-heat-treated aluminum alloy increases, which can significantly improve the strength of the non-heat-treated aluminum alloy. However, it can also lead to a significant decrease in the elongation of the non-heat-treated aluminum alloy. If the weight percentage of silicon is too low, the non-heat-treated die-cast aluminum alloy will have insufficient fluidity, making it unsuitable for filling large or ultra-large complex die-cast parts. Therefore, the weight percentage of silicon in the non-heat-treated aluminum alloy can be controlled within the range of greater than or equal to 6.5% and less than or equal to 9%.

[0072] Of course, in addition to silicon-aluminum alloys, the intermediate aluminum alloy may also include iron-aluminum alloys, copper-aluminum alloys, and magnesium-aluminum alloys. The composition of the non-heat-treated aluminum alloy formed by this processing method may include copper, iron, and magnesium.

[0073] Since iron readily forms needle-like coarse aluminum-iron-silicon phases with silicon and aluminum, which can cleave the aluminum matrix and reduce elongation, the weight percentage of iron can be controlled to be greater than or equal to 0.1% and less than or equal to 0.3%.

[0074] Copper has a solid solution strengthening effect, and CuAl2 strengthening phase will also precipitate during the natural aging process, which improves the strength of non-heat-treated aluminum alloys. Therefore, the presence of a small amount of copper helps to improve the strength of non-heat-treated aluminum alloys, especially the tensile strength. However, excessive copper will lead to a significant decrease in the elongation of non-heat-treated aluminum alloys. Therefore, the weight percentage of copper can be controlled within the range of greater than or equal to 0.1% and less than or equal to 0.5%.

[0075] Magnesium integrates into the aluminum matrix, acting as a solid solution strengthener. During the subsequent settling process, magnesium and silicon form precipitates similar to Mg₂Si, resulting in natural aging. The presence of small amounts of magnesium significantly improves the strength, especially the yield strength, of non-heat-treated die-cast alloys. However, excessive magnesium content significantly reduces the alloy's elongation. Therefore, the weight percentage of magnesium should be controlled within the range of greater than or equal to 0.1% and less than or equal to 0.45%. Furthermore, magnesium and copper have a strengthening effect on non-heat-treated aluminum alloys and exhibit a certain coupling effect. A low total content of magnesium and copper significantly improves the strength of non-heat-treated aluminum alloys, while a total content exceeding 0.8% diminishes the strength-enhancing effect and even significantly worsens the elongation. Therefore, the combined weight percentage of copper and magnesium should be controlled within the range of less than or equal to 0.8%.

[0076] Manganese can form short rod-shaped AlFeMnSi phases with aluminum, iron, and silicon, improving the morphology of the AlFeMnSi phase. In appropriate amounts, manganese can also act as a substitute for iron, improving the demolding effect of non-heat-treated aluminum alloys and facilitating their mass production. However, excessive manganese content results in coarse AlFeMnSi phases, which are detrimental to the mechanical properties of non-heat-treated die-cast alloys. Therefore, the weight percentage of manganese should be controlled within the range of greater than or equal to 0.4% and less than or equal to 0.8%.

[0077] In addition to the aforementioned intermediate aluminum alloy, the intermediate aluminum alloy may also include a vanadium-aluminum alloy. The non-heat-treated aluminum alloy formed by this processing method may also include vanadium. Vanadium can form intermetallic compounds such as AlFeV and AlFeMnV in the aluminum alloy melt, which can improve the morphology of coarse needle-like iron-containing phases. The weight percentage of vanadium can be controlled to be greater than or equal to 0.05% and less than or equal to 0.1%.

[0078] In step 202, an aluminum-titanium-carbon-boron alloy refining agent is added to the first aluminum alloy melt for refining treatment to obtain a second aluminum alloy melt.

[0079] In some related technologies, Al-Ti-C or Al-Ti-B has been proposed as a refining agent to improve the elongation of non-heat-treated aluminum alloys, thereby achieving a good refining effect and increasing elongation. However, for silicon-aluminum alloys, especially when the silicon content exceeds 5%, the refining effect is not significant due to the easy coating effect of silicon with TiB2 or TiC in the refining agent, resulting in "silicon poisoning".

[0080] Therefore, the inventors propose adding an aluminum-titanium-carbon-boron alloy refining agent to the first aluminum alloy melt for refining treatment to obtain a second aluminum alloy melt. This aluminum-titanium-carbon-boron refining agent can refine the coarse pre-crystallized α-Al structure generated during the casting of the non-heat-treated aluminum alloy, improving the morphology and structure of the subsequent non-heat-treated aluminum alloy. The composition of the subsequently obtained non-heat-treated aluminum alloy can include titanium, boron, and carbon. By forming boron-doped TiC and TiCB particles, which adhere to the abundant AlTi3 nucleation sites, the heterogeneous nucleation stability of AlTi3 is effectively improved, becoming stable α-Al nucleation sites. This refines the coarse dendritic α-Al, reducing the decrease in elongation caused by the enrichment of shrinkage porosity or shrinkage cavities around α-Al. Simultaneously, it can improve the flow properties of the non-heat-treated aluminum alloy when manufacturing target parts after melting, maintaining relatively stable mechanical properties even over long flow distances, making it particularly suitable for the die-casting of large, integrated die-cast parts.

[0081] Furthermore, to obtain good mechanical properties, the proportion of titanium, carbon, and boron in the formed non-heat-treated aluminum alloy can be appropriately adjusted by adjusting the proportion of the added titanium-carbon-boron alloy refining agent. For example, in some non-heat-treated aluminum alloys, the mass ratio of silicon to the sum of the masses of titanium, carbon, and boron is less than or equal to 200; preferably, the mass ratio of silicon to the sum of the masses of titanium, carbon, and boron is equal to 150, and the weight percentage ratio of titanium, carbon, and boron is in the range of 5-120:1:0.5-3.0; the amount of aluminum-titanium-carbon-boron alloy refining agent added is 0.2%-0.5% of the mass of the first aluminum alloy solution. The elongation can be further improved by controlling the weight percentages of titanium, carbon, and boron. For example, in some non-heat-treated aluminum alloys, the weight percentage of titanium is greater than or equal to 0.01% and less than or equal to 0.3%; the weight percentage of carbon is greater than or equal to 0.001% and less than or equal to 0.05%; and the weight percentage of boron is greater than or equal to 0.001% and less than or equal to 0.05%.

[0082] In step 203, strontium alloy is added to the second aluminum alloy melt for modification treatment to obtain a third aluminum alloy melt.

[0083] In step 204, the non-heat-treated aluminum alloy is obtained by casting based on the third aluminum alloy melt.

[0084] In this embodiment, a non-heat-treated aluminum alloy is obtained by adding strontium alloy to the second aluminum alloy melt for modification treatment. This non-heat-treated aluminum alloy can then be placed into a die-casting mold to form a one-piece die-casting part. The modification treatment with strontium alloy promotes the nucleation and growth process in the second aluminum alloy melt, resulting in a complete third aluminum alloy, thus improving the microstructure of the obtained non-heat-treated aluminum alloy and, to some extent, enhancing its mechanical properties. However, excessive strontium modification of the second aluminum alloy melt can easily lead to the formation of large, blocky ternary eutectic segregations, which can fragment the aluminum matrix and negatively impact the mechanical properties of the subsequently obtained non-heat-treated aluminum alloy. Therefore, the weight percentage of strontium can be controlled within the range of greater than or equal to 0.01% and less than or equal to 0.03%. After the third aluminum alloy melt is allowed to stand for a period of time, the non-heat-treated aluminum alloy can be obtained through casting for subsequent transportation and trading.

[0085] In the above embodiments, after the intermediate aluminum alloy melts, a first aluminum alloy melt can be obtained by standing and holding it at a certain temperature for a period of time, and then the first aluminum alloy melt is subjected to impurity removal treatment. For example, the first aluminum alloy melt can be degassed, and the degassed time can be controlled at about 5 minutes and the temperature can be controlled at about 730°C. Alternatively, the first aluminum alloy melt can be deslag-removed, for example, by adding a slag-removing agent to the first aluminum alloy melt.

[0086] To verify the above embodiments through experiments, the inventors used Alloys 1-6 from the table below and conducted comparative experiments. The weight percentage of each element in Alloys 1-6 is shown in the table below:

[0087] Alloy 1 7.0 0.15 0.3 0.54 0.22 0.05 0.02 0.52 Alloy 2 7.0 0.15 0.5 0.55 0.22 0.05 0.02 0.72 Alloy 3 7.0 0.15 0.65 0.55 0.22 0.05 0.02 0.87 Alloy 4 7.0 0.15 0.05 0.55 0.22 0.05 0.02 0.27 Alloy 5 7.0 0.15 0.3 0.54 0.5 0.05 0.02 0.8 Alloy 6 9.2 0.15 0.3 0.54 0.22 0.05 0.02 0.52

[0088] Alloys 1 through 6 were die-cast under the following die-casting process conditions:

[0089] 100 35 120

[0090] The mechanical properties of alloys 1-6 at a flow distance of 1000 mm are shown in the table below:

[0091] Alloy 1 126 256 10.2 Alloy 2 134 268 8.5 Alloy 3 136 270 6.2 Alloy 4 112 245 12.6 Alloy 5 128 258 7.3 Alloy 6 137 268 7.5

[0092] Compared to Alloy 1, when the weight percentage of copper in Alloy 2 increased from 0.3% to 0.5%, the yield strength and tensile strength of Alloy 2 increased significantly, while the elongation of Alloy 2 remained at a high level. When the weight percentage of copper in Alloy 3 increased from 0.3% to 0.65%, the yield strength and tensile strength of Alloy 3 increased more slowly than those of Alloy 2, but the elongation of Alloy 3 decreased significantly compared to Alloy 2, indicating that further increasing the copper content compared to Alloy 2 had limited effect. When the weight percentage of copper in Alloy 4 was less than 0.1%, the elongation of Alloy 4 increased significantly, but the yield strength and tensile strength of Alloy 4 were relatively low; therefore, the weight percentage of copper can be controlled within the range of greater than or equal to 0.1% and less than or equal to 0.5%. When the weight percentage of magnesium in Alloy 5 is increased from 0.22% to 0.5%, the yield strength and tensile strength of Alloy 5 do not increase significantly compared to Alloy 1, but the elongation of Alloy 5 decreases significantly compared to Alloy 1. When the weight percentage of silicon in Alloy 6 exceeds 9.0%, the yield strength and tensile strength of Alloy 6 increase significantly, but the elongation of Alloy 6 decreases significantly. Therefore, the weight percentage of silicon should be controlled below 9.0%. In summary, by adjusting the weight percentages of basic elements such as aluminum, iron, silicon, copper, magnesium, and manganese, Alloy 1 exhibits the best comprehensive mechanical properties at a distance of 1m from the gate, meeting the mechanical requirements for die castings of general dimensions.

[0093] Furthermore, this disclosure also provides a comparison between alloy obtained according to the processing method of this disclosure and alloy 1, as shown in the following table:

[0094] This disclosure alloy 7.0 0.19 0.55 0.22 0.3 0.05 0.02 0.128 0.002 0.003 Alloy 1 7.0 0.15 0.54 0.22 0.3 0.05 0.02 0 0 0

[0095] The mechanical properties of the disclosed alloy and alloy 1 at flow distances of 1000 mm and 1500 mm, as shown in the table above, are as follows:

[0096]

[0097] Compared with alloy 1, alloy 1 has a significant α-Al refinement effect. By utilizing the stability of B-doped TiC, stable nucleation particles of α-Al phase are formed, refining α-Al, especially the coarse pre-crystallized α-Al at the far end. At the same time, the alloy's flow properties are appropriately improved, resulting in good die-casting performance stability. The die-cast parts formed by alloy 1 have a tensile strength ≥250MPa, yield strength ≥120MPa, and elongation ≥7% at a flow distance of 1500mm, which meets the process requirements of the parts. Figure 3 The metallographic structure of the alloy disclosed herein at a flow distance of 1500 mm is... Figure 4 The metallographic structure of alloy 1 at a flow distance of 1500 mm is shown below. Figure 3 and Figure 4As shown, compared to the alloy of this disclosure, alloy 1 has coarse α-Al structure at the distal end, resulting in the enrichment of shrinkage porosity around the α-Al structure. This manifests as an elongation of 10.2% at a flow distance of 1000 mm, but a significant decrease to 5.6% at a flow distance of 1500 mm. In contrast, the alloy of this disclosure, through the refining effect of aluminum-titanium-carbon-boron refining agents, can refine the coarse pre-crystallized structure.

[0098] The α-Al microstructure reduces porosity around the α-Al structure and increases elongation. Comparatively, the addition of titanium, carbon, and boron can improve the mechanical properties of aluminum alloys at a distance from the gate, making them suitable for forming large castings.

[0099] Therefore, the above comparative experiments can further demonstrate that the processing method provided in this disclosure can refine the aluminum-titanium-carbon-boron alloy by adding an aluminum-titanium-carbon-boron alloy refining agent. This allows the subsequently obtained non-heat-treated aluminum alloy to form B-doped TiC and TiCB particles, which adhere to the abundant AlTi3 nucleation particles. This effectively improves the heterogeneous nucleation stability of AlTi3, making it a stable α-Al nucleation particle. It also refines coarse dendritic α-Al, reduces the decrease in elongation caused by the enrichment of shrinkage porosity or shrinkage cavities around α-Al, and improves the flow properties of the non-heat-treated aluminum alloy under limited process conditions, maintaining relatively stable mechanical properties of the non-heat-treated aluminum alloy as the flow distance increases.

[0100] Based on the non-heat-treated aluminum alloy in any of the above embodiments, this disclosure also provides a method for processing automotive die-cast parts, such as... Figure 5 As shown, this disclosure also provides a method for processing automotive die-cast parts, which may include the following steps:

[0101] In step 501, the non-heat-treated aluminum alloy is melted.

[0102] In step 502, a die casting process is performed based on the molten melt to obtain automotive die castings.

[0103] In this embodiment, the process conditions for die casting vary depending on the type of die casting machine. For the purposes of this disclosure, the elongation of non-heat-treated aluminum alloys decreases relatively slowly with increasing flow distance, allowing them to be used for forming large automotive die castings. Therefore, a large die casting machine can be used for the die casting process, and the mechanical stability of the automotive die castings can be guaranteed within the process conditions defined by the large die casting machine. Specifically, the automotive die castings can be obtained by die casting based on the non-heat-treated aluminum alloy, with casting pressure ranging from 20MPa to 70MPa, mold temperature from 60℃ to 160℃, and filling time from 60ms to 150ms. Of course, it is understood that in some embodiments, the die-cast automotive parts can be directly assembled into the vehicle, while in other embodiments, they can be modified by CNC machining or other processing methods before assembly into the vehicle. This disclosure does not impose any limitations on this.

[0104] This disclosure also provides a die-casting part for automobiles, which can be obtained using the processing method for die-casting parts for automobiles described in any of the above embodiments. The die-casting part for automobiles has a tensile strength ≥250MPa, a yield strength ≥120MPa, and an elongation ≥7% at a distance of 1.5m from the gate.

[0105] This automotive die-casting part can be subsequently used to manufacture integral die-casting parts for vehicle terminals. For example, this disclosure can also provide a vehicle terminal that may include a rear floor die-casting part, which can be formed based on the above embodiments to provide automotive die-casting parts. In the process of forming automotive die-casting parts based on non-heat-treated aluminum alloys, the good mechanical stability of non-heat-treated aluminum alloys allows them to maintain good elongation, yield strength, and tensile strength even with a large flow distance, making them particularly suitable for die-casting large parts for vehicle terminals.

[0106] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This disclosure is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0107] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A non-heat-treatable aluminum alloy, characterized in that, The non-heat-treated aluminum alloy comprises aluminum, iron, silicon, copper, magnesium, manganese, titanium, carbon, and boron. The iron element has a weight percentage greater than or equal to 0.1% and less than or equal to 0.3%. The weight percentage of silicon is greater than or equal to 6.5% and less than or equal to 7%. The weight percentage of copper is greater than or equal to 0.1% and less than or equal to 0.5%. The magnesium element has a weight percentage greater than or equal to 0.1% and less than or equal to 0.45%; The manganese element has a weight percentage greater than or equal to 0.4% and less than or equal to 0.8%. The weight percentage of titanium is greater than or equal to 0.01% and less than or equal to 0.3%. The weight percentage of carbon is greater than or equal to 0.001% and less than or equal to 0.05%. The weight percentage of boron is greater than or equal to 0.001% and less than or equal to 0.05%. The sum of the weight percentages of the copper and magnesium elements is less than or equal to 0.8%; The weight percentages of the titanium, carbon, and boron elements are in the range of 5-120:1:0.5-3.

0. The ratio of the mass of silicon to the sum of the masses of titanium, carbon, and boron is less than or equal to 200.

2. The non-heat-treatable aluminum alloy according to claim 1, characterized in that, The non-heat-treated aluminum alloy also includes vanadium, with the weight percentage of vanadium being greater than or equal to 0.05% and less than or equal to 0.1%.

3. The non-heat-treatable aluminum alloy according to claim 1, characterized in that, The non-heat-treated aluminum alloy also contains strontium, with a weight percentage of strontium greater than or equal to 0.01% and less than or equal to 0.03%.

4. A method for processing a non-heat-treated aluminum alloy according to any one of claims 1-3, characterized in that, include: The intermediate aluminum alloy is melted to obtain a first aluminum alloy melt, wherein the intermediate aluminum alloy includes silicon-aluminum alloy, iron-aluminum alloy, copper-aluminum alloy, magnesium-aluminum alloy, and manganese-aluminum alloy; An aluminum-titanium-carbon-boron alloy refining agent is added to the first aluminum alloy melt for refining treatment to obtain a second aluminum alloy melt. The aluminum-titanium-carbon-boron alloy refining agent is used to refine the coarse pre-crystallized α-AL structure generated during the casting of the non-heat-treated aluminum alloy. Strontium alloy was added to the second aluminum alloy melt for modification treatment to obtain a third aluminum alloy melt; The non-heat-treated aluminum alloy is obtained by casting based on the third aluminum alloy melt.

5. The processing method according to claim 4, characterized in that, Also includes: The first aluminum alloy melt is subjected to degassing treatment; The first aluminum alloy melt is subjected to slag removal treatment.

6. The processing method according to claim 4, characterized in that, The amount of the aluminum-titanium-carbon-boron alloy refining agent added is 0.2%-0.5% of the mass of the first aluminum alloy melt.

7. The processing method according to claim 4, characterized in that, The intermediate aluminum alloy also includes a vanadium-aluminum alloy.

8. The processing method according to claim 4, characterized in that, In the non-heat-treated aluminum alloy, the ratio of the mass of silicon to the sum of the masses of titanium, carbon, and boron is less than or equal to 200.

9. The processing method according to claim 4, characterized in that, The weight percentages of titanium, carbon, and boron range from 5-120:1:0.5-3.

0.

10. The processing method according to claim 4, characterized in that, In the non-heat-treated aluminum alloy, the weight percentage of silicon is greater than or equal to 6.5% and less than or equal to 7%. The weight percentage of iron is greater than or equal to 0.1% and less than or equal to 0.3%; The weight percentage of copper is greater than or equal to 0.1% and less than or equal to 0.5%; The magnesium content is greater than or equal to 0.1% and less than or equal to 0.45% by weight. The weight percentage of strontium is greater than or equal to 0.01% and less than or equal to 0.03%; The weight percentage of manganese is greater than or equal to 0.4% and less than or equal to 0.8%.

11. The processing method according to claim 4, characterized in that, The sum of the weight percentages of copper and magnesium is less than or equal to 0.8%.

12. The processing method according to claim 4, characterized in that, In the non-heat-treated aluminum alloy, the weight percentage of titanium is greater than or equal to 0.01% and less than or equal to 0.3%. The weight percentage of carbon is greater than or equal to 0.001% and less than or equal to 0.05%; The weight percentage of boron is greater than or equal to 0.001% and less than or equal to 0.05%.

13. A method for processing automotive die-cast parts, characterized in that, include: Melt the non-heat-treated aluminum alloy according to any one of claims 1-3; The automotive die-casting part is obtained by die-casting the molten material.

14. The processing method according to claim 13, characterized in that, The die-casting process based on the molten melt to obtain the automotive die-casting part includes: The die casting process is based on the molten melt, with casting pressure ranging from 20 MPa to 70 MPa, mold temperature ranging from 60℃ to 160℃, and filling time ranging from 60 ms to 150 ms.

15. A die-casting part for automobiles, characterized in that, The automotive die casting is obtained by the processing method described in claim 13 or 14. The automotive die casting has a tensile strength ≥250MPa, a yield strength ≥120MPa, and an elongation ≥7% at a distance of 1.5m from the gate.

16. A vehicle terminal, characterized in that, Includes a rear floor die casting, said rear floor die casting including the automotive die casting as described in claim 15.

Images