High-manganese Al-Cu alloy composition and heat treatment process for La and Ce alloying in metal mold casting

Abstract

This invention discloses a high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting. The designed alloy composition contains Mn and Mg elements, and alloying is achieved through La or Ce elements, which can refine α-Al grains, fully utilize the role of Mn, reduce segregation and suppress hot cracking tendency, and improve the microstructure uniformity of alloy ingots or castings. The designed as-cast alloy, after solution treatment and graded aging treatment, yields a final sample with a tensile strength of not less than 552 MPa and an elongation of not less than 7.2%. This invention differs from refining α-Al grains by adding refining agents or inoculants to promote nucleation of particles in the aluminum melt. Instead, it achieves grain refinement through composition design and under general solidification technology conditions, simplifying the melting process and casting process.

Description

Technical Field

[0001] This invention relates to the field of cast aluminum alloys, and in particular to a solidification technology capable of controlling casting defects in cast aluminum-copper alloy ingots or castings, and improving the uniformity of the solidification structure and the service performance of the ingots or castings. Specifically, it relates to a high-manganese content aluminum-copper alloy composition and its heat treatment process for lanthanum and cerium alloying in metal mold casting. Background Technology

[0002] Cast aluminum alloys, especially those possessing high strength, excellent wear resistance, and corrosion resistance, are experiencing increasing market demand. Improving the performance of existing cast aluminum alloys and developing new series of alloys to meet diverse application needs remains an important task. Aluminum (Al)-copper (Cu) casting alloys, as an important type of aluminum alloy, have attracted widespread attention from academia and industry due to their excellent mechanical properties. In particular, these alloys often exhibit extremely high tensile strength and creep resistance in the 200℃~350℃ temperature range, meeting the service requirements of aerospace components and enabling the replacement of titanium with aluminum. In recent years, the demand for lightweight equipment in the automotive, medical equipment, and wind power generation equipment sectors has been gradually increasing, promoting the development and application of cast aluminum alloys for large load-bearing structural components.

[0003] For many years, high-strength Al-Cu casting alloys with a Cu content of 4.0~6.0 wt.% have achieved good service performance by replacing forging with casting, replacing steel with aluminum, and integral casting in many structural components. However, since its liquid forming process is mainly sand casting, it is difficult to obtain high-quality ingots or castings through metal mold casting or investment casting. More importantly, in terms of strength, the tensile strength of the same Al-Cu casting alloy using sand casting can only reach 60%~80% of that of metal mold casting; and in terms of plasticity, the elongation of the alloy can only reach 22%~44% of that of metal mold casting. These defects significantly reduce its advantages compared with ordinary aluminum alloys. The difficulty of metal mold casting of Al-Cu alloys lies in its wide crystallization range (633 ℃~544 ℃), large solidification shrinkage, and pasty solidification characteristics. The casting properties of this alloy, such as fluidity, hot crack resistance, and airtightness, are poor, and it is highly sensitive to wall thickness, easily producing casting defects such as segregation and hot cracking.

[0004] Rare earth elements, due to their unique properties, can improve the as-cast microstructure of alloys, refine grains, alter solidification characteristics, reduce segregation, and suppress hot cracking tendency, thus finding widespread application in various aluminum alloys. With the continuous development of rare earth alloying theory, studying the role of single rare earth elements in aluminum alloys will become a trend. On the other hand, manganese (Mn) is one of the common alloying elements in Al-Cu alloys. A small amount of Mn can play a solid solution strengthening role in the α-Al phase of the alloy, thereby increasing the strength of α-Al and improving the alloy's resistance to hot cracking. Furthermore, Mn can form composite phases with other elements in the alloy (such as magnesium (Mg)) to reduce the amount of Al2Cu phase, decrease grain boundary segregation, and increase alloy strength, which also helps improve the alloy's mechanical properties. However, published literature shows that the Mn content is usually relatively low, especially in cast Al-Cu alloys, often below 0.4 wt.%. Adding more Mn can easily lead to a decrease in the high-temperature mechanical properties of the alloy. This greatly limits the full utilization of Mn's properties. To overcome the compositional limitations of Mn and synergize with the role of Mg, this alloying method not only improves the performance of aluminum alloys but also opens up new directions for future material innovation and application. Summary of the Invention

[0005] Objective of this invention: The objective of this invention is to provide a high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting. This process achieves α-Al grain refinement, synergistically reduces segregation and inhibits hot cracking, and improves the microstructure uniformity of alloy ingots or castings. Unlike methods that refine α-Al grains by adding refining agents or inoculants to promote nucleation of particles in the aluminum melt, this invention achieves grain refinement through compositional design and general solidification techniques, simplifying the smelting and casting processes. The designed as-cast alloy, after solution treatment and graded aging treatment, yields a final sample with a tensile strength of not less than 552 MPa and an elongation of not less than 7.2%.

[0006] Technical Solution: A high-manganese Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting. Through the design of Mn and Mg elements, the composition fully utilizes the role of Mn and synergistically enhances the alloying effect of La and Ce, reducing segregation and suppressing hot cracking tendency, thereby improving the microstructure uniformity of alloy ingots or castings. Specifically, it includes the following steps:

[0007] Step (1) Use industrial pure aluminum, Al20Cu (Al-20 wt.% Cu) master alloy, Al20Mn (Al-20 wt.% Mn) master alloy, Al20Mg (Al-20 wt.% Mg) master alloy, Al10TiV (Al-10 wt.% Ti-1.0 wt.% V) master alloy and Al10Zr5B (Al-10 wt.% Zr-1.0 wt.% B) master alloy as raw materials. The alloying elements are added using Al10La (Al-10 wt.% La) and Al10Ce (Al-10 wt.% Ce) master alloy as raw materials. Calculate and weigh each raw material that meets the design composition.

[0008] The alloy composition ranges as follows: Cu: 4.60 wt.% - 6.60 wt.%, Mn: 0.40 wt.% - 0.95 wt.%, Mg: 0.20 wt.% - 0.32 wt.%, Ti and Zr total content not exceeding 0.40 wt%, V and B total content not exceeding 0.3 wt%, other impurities total content not exceeding 0.15 wt.%, and the content of a single impurity component not exceeding 0.02 wt.%, with the balance being Al; additionally, alloying elements La or Ce are added, with the addition amount being 0.10 wt.% - 0.30 wt.% of the weight of the alloy to be prepared.

[0009] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The process includes heating, melting, adding materials to replenish the element content caused by burning loss, adding alloying elements La or Ce, degassing, refining, and heat preservation to obtain alloy melt.

[0010] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 220℃-350℃;

[0011] Step (4) Use general casting technology to perform metal mold gravity casting and metal mold low pressure casting. The melt in step (2) is introduced into the mold in step (3) according to the melt injection method selected according to different casting processes. Then, it is naturally cooled or forced cooling is used to obtain ingots or castings. Then, solution treatment and graded aging treatment are performed.

[0012] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation. The temperature range is 480℃-580℃ and the heat preservation time is 12-18 hours. Take out the ingot or casting and place it in an environment that can achieve a cooling rate of 3000℃ / h-10000℃ / h for cooling, i.e., quenching to room temperature. The time for transferring it from the furnace to the water should not exceed 10 seconds.

[0013] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace or a forced-air drying oven for heat preservation. The temperature range is 210℃-230℃. After heat preservation for 30-45 minutes, lower the temperature (or transfer it to another device) to 130℃-160℃ and continue heat preservation for 8-10 hours, or lower the temperature to 165℃-180℃ and continue heat preservation for 4-6 hours, or lower the temperature to 185℃-205℃ and continue heat preservation for 2-5 hours. Cool with the furnace or remove the ingots or castings and let them cool naturally to obtain the final ingot or casting product.

[0014] As an optimization: the alloying element La added in step (2) is added in the form of Al10La, and the alloying element Ce is added in the form of Al10Ce.

[0015] As an optimization: the cooling method in step (4) is water cooling or air cooling.

[0016] As an optimization: the environment in step (5) to achieve a cooling rate of 3000℃ / h-10000℃ / h is water or a water-soluble quenching liquid of polymer.

[0017] Beneficial Effects: This invention provides an Al-Cu alloy applicable to metal mold casting. By designing an Al-Cu alloy composition with a high Mn content and a Cu content of 4.60 wt.% to 6.60 wt.%, and alloying the alloy with La and Ce elements, it achieves α-Al grain refinement, reduces segregation, suppresses hot cracking tendency, and improves the microstructure uniformity of the alloy ingot or casting. Further heat treatment enhances the alloy's mechanical properties. The designed as-cast alloy, after solution treatment and graded aging treatment, yields a final sample with a tensile strength of not less than 552 MPa and an elongation of not less than 7.2%. This invention does not involve the emission of waste gas or wastewater and will not pollute the environment. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the solidification structure of Embodiment 1 of the present invention.

[0019] Figure 2 This is a schematic diagram of the solidification structure of Embodiment 3 of the present invention.

[0020] Figure 3 This is a schematic diagram of the solidification structure of Embodiment 5 of the present invention.

[0021] Figure 4 This is a schematic diagram of the sample structure of Embodiment 9 of the present invention.

[0022] Figure 5 This is a schematic diagram of the sample structure of Embodiment 10 of the present invention.

[0023] Figure 6 This is a schematic diagram of the sample structure of Embodiment 12 of the present invention. Detailed Implementation

[0024] The technical solutions in the embodiments of the present invention will be clearly and completely described below, so that those skilled in the art can better understand the advantages and features of the present invention, thereby making a clearer definition of the scope of protection of the present invention. The embodiments described in this invention are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. Example 1

[0025] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0026] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition is Cu: 4.60 wt.%, Mn: 0.40 wt.%, Mg: 0.20 wt.%, Ti and Zr elements are each 0.20 wt%, V and B elements are each 0.15 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.10 wt.%;

[0027] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0028] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 220 ℃;

[0029] Step (4) Using general casting technology, pour the material from step (2) into the mold of step (3), and then let it cool naturally to obtain an ingot or casting, which is then heat-treated.

[0030] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 480 ℃ for 12 hours. Remove the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0031] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation at a temperature of 210 ℃ for 30 minutes. Then, reduce the temperature to 130 ℃ and continue heat preservation for 8 hours. Cool the furnace to room temperature to obtain ingots or castings.

[0032] Example 2

[0033] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0034] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 6.60 wt.%, Mn: 0.95 wt.%, Mg: 0.32 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.05 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity component does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloy element La is 0.30 wt.%;

[0035] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0036] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 350 ℃;

[0037] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then cooled to room temperature with water to obtain an ingot or casting, which is then heat-treated.

[0038] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation. The temperature range is 580 ℃ and the heat preservation time is 18 hours. Take out the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0039] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace or a forced-air drying oven for heat preservation. The temperature is 230 ℃ and the heat preservation time is 45 minutes. Then, reduce the temperature to 160 ℃ and continue to preserve for 10 hours. Cool the furnace to room temperature to obtain the final ingot or casting product.

[0040] Example 3

[0041] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0042] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 5.60 wt.%, Mn: 0.65 wt.%, Mg: 0.26 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.1 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.20 wt.%;

[0043] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0044] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 285°C;

[0045] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then naturally cooled to room temperature to obtain an ingot or casting, which is then heat-treated.

[0046] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 530 ℃ for 16 hours. Remove the ingot or casting and transfer it to water to cool to room temperature. The time from the furnace to the water should not exceed 10 s.

[0047] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation. The temperature range is 220 ℃. After heat preservation for 40 minutes, the temperature is reduced to 145 ℃ and heat preservation is continued for 9 hours. The ingots or castings are then cooled with the furnace to obtain the ingots or castings.

[0048] Example 4

[0049] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0050] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition is Cu: 4.60 wt.%, Mn: 0.40 wt.%, Mg: 0.20 wt.%, Ti and Zr elements are each 0.20 wt%, V and B elements are each 0.15 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.10 wt.%;

[0051] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0052] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 220 ℃;

[0053] Step (4) Using general casting technology, pour the material from step (2) into the mold of step (3), and then let it cool naturally to obtain an ingot or casting, which is then heat-treated.

[0054] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 480 ℃ for 12 hours. Remove the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0055] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation at a temperature of 210 ℃ for 30 minutes. Then, reduce the temperature to 165 ℃ and continue heat preservation for 4 hours. Alternatively, cool the ingots or castings in the furnace or remove them and allow them to cool naturally to obtain the ingots or castings.

[0056] Example 5

[0057] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0058] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition is Cu: 4.60 wt.%, Mn: 0.40 wt.%, Mg: 0.20 wt.%, Ti and Zr elements are each 0.20 wt%, V and B elements are each 0.15 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.10 wt.%;

[0059] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0060] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 220 ℃;

[0061] Step (4) Using general casting technology, pour the material from step (2) into the mold of step (3), and then let it cool naturally to obtain an ingot or casting, which is then heat-treated.

[0062] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 480 ℃ for 12 hours. Remove the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0063] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation at a temperature of 210 ℃ for 30 minutes. Then, reduce the temperature to 180 ℃ and continue heat preservation for 6 hours. Cool with the furnace to obtain ingots or castings.

[0064] Example 6

[0065] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0066] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition is Cu: 4.60 wt.%, Mn: 0.40 wt.%, Mg: 0.20 wt.%, Ti and Zr elements are each 0.20 wt%, V and B elements are each 0.15 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.10 wt.%;

[0067] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0068] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 220 ℃;

[0069] Step (4) Using general casting technology, pour the material from step (2) into the mold of step (3), and then let it cool naturally to obtain an ingot or casting, which is then heat-treated.

[0070] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 480 ℃ for 12 hours. Remove the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0071] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation at a temperature of 210 ℃ for 30 minutes. Then, reduce the temperature to 185 ℃ and continue heat preservation for 2 hours. Remove the ingots or castings and allow them to cool naturally to obtain the ingots or castings.

[0072] Example 7

[0073] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0074] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 6.60 wt.%, Mn: 0.95 wt.%, Mg: 0.32 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.05 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity component does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloy element La is 0.30 wt.%;

[0075] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0076] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 350 ℃;

[0077] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then cooled to room temperature with water to obtain an ingot or casting, which is then heat-treated.

[0078] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation. The temperature range is 580 ℃ and the heat preservation time is 18 hours. Take out the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0079] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace or a blower drying oven for heat preservation. The temperature is 230 ℃ and the heat preservation time is 45 minutes. Then, reduce the temperature to 205 ℃ and continue to preserve for 5 hours. Cool the furnace to room temperature to obtain the final ingot or casting product.

[0080] Example 8

[0081] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0082] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 6.60 wt.%, Mn: 0.95 wt.%, Mg: 0.32 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.05 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity component does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloy element La is 0.30 wt.%;

[0083] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0084] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 350 ℃;

[0085] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then cooled to room temperature with water to obtain an ingot or casting, which is then heat-treated.

[0086] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation. The temperature range is 580 ℃ and the heat preservation time is 18 hours. Take out the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0087] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace or a forced-air drying oven for heat preservation. The temperature is 230 ℃ and the heat preservation time is 45 minutes. Then, reduce the temperature to 195 ℃ and continue to preserve for 3 hours. Remove the ingots or castings and let them cool naturally to room temperature to obtain the final ingot or casting product.

[0088] Example 9

[0089] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0090] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 5.60 wt.%, Mn: 0.65 wt.%, Mg: 0.26 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.1 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.20 wt.%;

[0091] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0092] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 285°C;

[0093] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then naturally cooled to room temperature to obtain the casting, which is then heat-treated.

[0094] Step (5) Solution treatment: Place the casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 530°C for 16 hours. Remove the casting and transfer it to water to cool to room temperature. The time from the furnace to the water should not exceed 10 seconds.

[0095] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation. The temperature range is 220 ℃. After heat preservation for 40 minutes, the temperature is reduced to 145 ℃ and heat preservation is continued for 8 hours. The furnace is then cooled to room temperature to obtain the final casting product.

[0096] Example 10

[0097] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0098] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 5.60 wt.%, Mn: 0.65 wt.%, Mg: 0.26 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.1 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.20 wt.%;

[0099] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0100] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 285°C;

[0101] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then naturally cooled to room temperature to obtain the casting, which is then heat-treated.

[0102] Step (5) Solution treatment: Place the casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 530°C for 16 hours. Remove the casting and transfer it to water to cool to room temperature. The time from the furnace to the water should not exceed 10 seconds.

[0103] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation. The temperature range is 220 ℃. After heat preservation for 40 minutes, the temperature is reduced to 150 ℃ and heat preservation is continued for 6 hours. The ingots or castings are then removed and naturally cooled to room temperature to obtain the final ingot or casting product.

[0104] Example 11

[0105] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0106] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 5.60 wt.%, Mn: 0.65 wt.%, Mg: 0.26 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.1 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.20 wt.%;

[0107] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0108] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 285°C;

[0109] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then naturally cooled to room temperature to obtain an ingot or casting, which is then heat-treated.

[0110] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 530 ℃ for 16 hours. Remove the ingot or casting and transfer it to water to cool to room temperature. The time from the furnace to the water should not exceed 10 s.

[0111] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation. The temperature range is 220 ℃. After heat preservation for 40 minutes, the temperature is reduced to 185 ℃ and heat preservation is continued for 4 hours. The furnace is then cooled to room temperature to obtain the final ingot or casting product.

[0112] Example 12

[0113] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0114] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 5.60 wt.%, Mn: 0.65 wt.%, Mg: 0.26 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.1 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element La is 0.20 wt.%;

[0115] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element La (in the form of Al10La)), degassing, refining, and heat preservation to obtain alloy melt.

[0116] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 285°C;

[0117] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then naturally cooled to room temperature to obtain the casting, which is then heat-treated.

[0118] Step (5) Solution treatment: Place the casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 530°C for 16 hours. Remove the casting and transfer it to water to cool to room temperature. The time from the furnace to the water should not exceed 10 seconds.

[0119] Step (6) Graded aging treatment: After cooling in step (5), the casting is placed in a muffle furnace for heat preservation. The temperature range is 220 ℃ and the heat preservation time is 40 minutes. Then the temperature is reduced to 205 ℃ and the heat preservation time is continued for 5 hours. The ingot or casting is then taken out and naturally cooled to room temperature to obtain the casting product.

[0120] Example 13

[0121] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0122] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La, and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition is Cu: 4.60 wt.%, Mn: 0.40 wt.%, Mg: 0.20 wt.%, Ti and Zr elements are each 0.20 wt%, V and B elements are each 0.15 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the amount of alloy element Ce added is 0.10 wt.%;

[0123] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element Ce (in the form of Al10Ce)), degassing, refining, and heat preservation to obtain alloy melt.

[0124] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 220 ℃;

[0125] Step (4) Using general casting technology, pour the material from step (2) into the mold of step (3), and then let it cool naturally to obtain an ingot or casting, which is then heat-treated.

[0126] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 510 ℃ for 16 hours. Remove the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0127] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation at a temperature of 220 ℃ for 45 minutes. Then, reduce the temperature to 140 ℃ and continue heat preservation for 9 hours. Cool the furnace to room temperature to obtain the final ingot or casting product.

[0128] Example 14

[0129] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0130] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 6.60 wt.%, Mn: 0.95 wt.%, Mg: 0.32 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.05 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity component does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloy element La is 0.30 wt.%;

[0131] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element Ce (in the form of Al10Ce)), degassing, refining, and heat preservation to obtain alloy melt.

[0132] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 350 ℃;

[0133] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then cooled to room temperature with water to obtain an ingot or casting, which is then heat-treated.

[0134] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation. The temperature range is 560 ℃ and the heat preservation time is 12 hours. Take out the ingot or casting and transfer it to water for cooling to room temperature. The time from the furnace to the water should not exceed 10 s.

[0135] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace or a forced-air drying oven for heat preservation. The temperature is 210 ℃ and the heat preservation time is 35 minutes. Then, reduce the temperature to 150 ℃ and continue to preserve for 10 hours. Cool the furnace to room temperature to obtain the final ingot or casting product.

[0136] Example 15

[0137] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0138] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La, and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition range is Cu: 5.60 wt.%, Mn: 0.65 wt.%, Mg: 0.26 wt.%, Ti and Zr elements are each 0.10 wt%, V and B elements are each 0.1 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the addition amount of alloying element Ce is 0.20 wt.%;

[0139] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element Ce (in the form of Al10Ce)), degassing, refining, and heat preservation to obtain alloy melt.

[0140] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 285°C;

[0141] Step (4) Using general casting technology, the melt from step (2) is poured into the mold from step (3), and then naturally cooled to room temperature to obtain an ingot or casting, which is then heat-treated.

[0142] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 490 ℃ for 14 hours. Remove the ingot or casting and transfer it to water to cool to room temperature. The time from the furnace to the water should not exceed 10 s.

[0143] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation. The temperature range is 230 ℃. After heat preservation for 30 minutes, the temperature is reduced to 185 ℃ and heat preservation is continued for 3 hours. The ingots or castings are then cooled with the furnace to obtain the ingots or castings.

[0144] Example 16

[0145] A high-manganese-content Al-Cu alloy composition and its heat treatment process for La and Ce alloying in metal mold casting includes the following steps:

[0146] Step (1) Using industrial pure aluminum, Al20Cu, Al20Mn, Al20M, Al10TiV, Al10Zr5B, Al10La and Al10Ce master alloys as raw materials, calculate and weigh each raw material that meets the design composition; the designed alloy composition is Cu: 4.60 wt.%, Mn: 0.40 wt.%, Mg: 0.20 wt.%, Ti and Zr elements are each 0.20 wt%, V and B elements are each 0.15 wt%, the total content of other impurities does not exceed 0.15 wt.%, and the content of a single impurity element does not exceed 0.02 wt.%, with the balance being Al; the amount of alloy element Ce added is 0.10 wt.%;

[0147] Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The conventional process includes heating, melting, adding materials (to replenish the element content reduction caused by burning and to add alloying element Ce (in the form of Al10Ce)), degassing, refining, and heat preservation to obtain alloy melt.

[0148] Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 220°C;

[0149] Step (4) Using general casting technology, pour the material from step (2) into the mold of step (3), and then let it cool naturally to obtain an ingot or casting, which is then heat-treated.

[0150] Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation at a temperature of 480℃ for 12 hours. Remove the ingot or casting and transfer it to water to cool to room temperature. The time from the furnace to the water should not exceed 10 seconds.

[0151] Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace for heat preservation at a temperature of 210°C for 30 minutes. Then, reduce the temperature to 165°C and continue heat preservation for 4 hours. Alternatively, cool the ingots or castings in the furnace or remove them and allow them to cool naturally to obtain the ingots or castings.

[0152] It should be noted that the embodiments described in this invention are only used to illustrate the technical solutions of this invention, and are not intended to limit the scope of protection of this invention. Although this invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this invention without departing from the essence and scope of the technical solutions of this invention.

Claims

1. A heat treatment process for high-manganese-content Al-Cu alloys used in metal mold casting of La and Ce alloys, characterized in that: By designing with Mn and Mg elements, the role of Mn is fully utilized and its alloying effect is synergistic with that of La and Ce elements to reduce segregation and suppress hot cracking tendency, thereby improving the microstructure uniformity of alloy ingots or castings; specifically, the following steps are included: Step (1) Use industrial pure aluminum, Al20Cu: Al-20 wt.% Cu master alloy, Al20Mn: Al-20 wt.% Mn master alloy, Al20Mg: Al-20 wt.% Mg master alloy, Al10TiV: Al-10 wt.% Ti-1.0 wt.% V master alloy and Al10Zr5B: Al-10 wt.% Zr-1.0 wt.% B master alloy as raw materials. The alloying elements are added using Al10La: Al-10 wt.% La and Al10Ce: Al-10 wt.% Ce master alloy as raw materials. Calculate and weigh each raw material that meets the design composition. The alloy composition ranges as follows: Cu: 4.60 wt.% - 6.60 wt.%, Mn: 0.40 wt.% - 0.95 wt.%, Mg: 0.20 wt.% - 0.32 wt.%, Ti and Zr total content not exceeding 0.40 wt%, V and B total content not exceeding 0.3 wt%, other impurities total content not exceeding 0.15 wt.%, and the content of a single impurity component not exceeding 0.02 wt.%, with the balance being Al; additionally, alloying elements La or Ce are added, with the addition amount being 0.10 wt.% - 0.30 wt.% of the weight of the alloy to be prepared. Step (2) Using general smelting technology, the raw materials in step (1) are placed into a graphite crucible in sequence according to the general smelting technology specifications to prepare Al-Cu alloy. The process includes heating, melting, adding materials to replenish the element content caused by burning loss, adding alloying elements La or Ce, degassing, refining, and heat preservation to obtain alloy melt. Step (3) Heat the metal casting mold with an inner cavity of cylindrical and square to 220℃-350℃; Step (4) Use general casting technology to perform metal mold gravity casting and metal mold low pressure casting. The melt in step (2) is introduced into the mold in step (3) according to the melt injection method selected according to different casting processes. Then, it is naturally cooled or forced cooling is used to obtain ingots or castings. Then, solution treatment and graded aging treatment are performed. Step (5) Solution treatment: Place the ingot or casting from step (4) into a muffle furnace for preheating and heat preservation. The temperature range is 480℃-580℃ and the heat preservation time is 12-18 hours. Take out the ingot or casting and place it in an environment that can achieve a cooling rate of 3000℃ / h-10000℃ / h for cooling. The environment that achieves a cooling rate of 3000℃ / h-10000℃ / h is water. Quench to room temperature and the time from the furnace to the water should not exceed 10 seconds. Step (6) Graded aging treatment: After cooling ingots or castings in step (5), place them in a muffle furnace or a forced-air drying oven for heat preservation. The temperature range is 210℃-230℃. After heat preservation for 30-45 minutes, lower the temperature to 130℃-160℃ and continue heat preservation for 8-10 hours, or lower the temperature to 165℃-180℃ and continue heat preservation for 4-6 hours, or lower the temperature to 185℃-205℃ and continue heat preservation for 2-5 hours. Cool with the furnace or remove the ingots or castings and let them cool naturally to obtain the final ingot or casting product.

2. The heat treatment process for high-manganese Al-Cu alloys used in metal mold casting with La and Ce alloys as described in claim 1, characterized in that: The alloying element La added in step (2) is added in the form of Al10La, and the alloying element Ce is added in the form of Al10Ce.

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