High-heat-resistance Al-Cu alloy and preparation method thereof

Abstract

The invention discloses a high-heat-resistance Al-Cu alloy and a preparation method thereof. The high-heat-resistance Al-Cu alloy is composed of, by mass, 4%-4.8% of Cu, 0.95%-1.20% of Fe, 1.4%-1.6% of Ni, 0.51%-0.6% of Mn, 0.45%-0.51% of Mg, 0.18%-0.25% of Ti, 0.25%-0.35% of Ce, impurities and the balance Al. The Al-Cu alloy prepared by adding compounded Mg, Fe, Ni, Mn, Ti and Ce elements and combining heat treatment has high heat resistance and excellent mechanical properties. The high-temperature strength of the Al-Cu alloy is improved in a mode of combining composite microalloying and heat treatment, the preparation process is simple, and the Al-Cu alloy can be used for batch production; the aluminum alloy disclosed by the invention is subjected to T5 heat treatment after being subjected to gravity casting forming, the tensile strength, the yield strength and the elongation percentage of the aluminum alloy in high-temperature environments of 300 DEG C and 350 DEG C respectively reach 267 MPa, 190 MPa and 5.5% and 220 MPa, 152 MPa and 6.7%, the tensile strength, the yield strength and the elongation percentage of the aluminum alloy can reach 143 MPa, 127 MPa and 7.8% or above in a high-temperature working environment of 400 DEG C, and the aluminum alloy has excellent heat resistance which is far higher than that of a conventional heat-resistant aluminum alloy; the material can be used for manufacturing high-heat-resistance parts such as automobile engine cylinders.

Description

Technical Field

[0001] The present invention relates to the field of aluminum alloy material preparation, and in particular to a high heat-resistant Al-Cu alloy and a preparation method thereof. Background Art

[0002] Cast aluminum alloys have been widely used in transportation, aerospace and other fields, especially in the automotive industry, due to their excellent mechanical properties, casting properties, low density, high thermal conductivity and electrical conductivity. With the increasing severity of environmental problems, the improvement of energy utilization has become increasingly important, and automobile lightweighting has become an effective means to improve energy utilization. The trend of replacing steel with aluminum has gradually emerged in the automotive industry, and the proportion of aluminum alloys used in structural parts has also increased year by year. However, components such as engine cylinder blocks, cylinder heads, and pistons need to work under high temperature conditions, which limits the further application of aluminum alloys. Al-Cu cast aluminum alloys have excellent heat resistance and are suitable for working environments of 300℃ to 350℃. However, when the temperature approaches 350℃, the high temperature performance of the alloy decreases significantly. Therefore, it is crucial to improve the strength of aluminum-copper alloys at high temperatures of 350℃ and above.

[0003] Chinese patent publication number CN 109402441 A discloses a method for preparing AlN and Al using ultrafine aluminum powder and air as raw materials. 2 O 3 A method for particle-reinforced aluminum-based composite materials, wherein the tensile strength of the composite material can reach a maximum of 130 MPa at 375°C. However, the preparation process of this method is complex, the cost is high, and it is difficult to control. Chinese patent CN 110724861B has developed an aluminum alloy material for engine cylinder heads, which improves the strength of the material by introducing elements such as Sc, and uses Sc to inhibit the damage of elements such as Ni to the toughness of the material, effectively refines the grains, improves the strength of the alloy, and can dissolve the impurity Fe and reduce the harmful effects of Fe. However, the use of scandium significantly increases the preparation cost and is not suitable for large-scale industrial production.

[0004] In summary, after extensive searching by the applicant, there are at least the above-mentioned technical problems to be solved in this field. Therefore, it is necessary to develop or improve a high heat-resistant Al-Cu alloy. Summary of the invention

[0005] Based on this, in order to solve the technical problems of poor high temperature resistance and mechanical properties of aluminum-copper alloys in the prior art at 350°C and above, the present invention provides a high heat-resistant Al-Cu alloy and a preparation method thereof. The specific technical scheme is as follows:

[0006] A high heat-resistant Al-Cu alloy is composed of the following components in percentage by mass: Cu: 4%-4.8%, Fe: 0.95%-1.20%, Ni: 1.4%-1.6%, Mn: 0.51%-0.6%, Mg: 0.45%-0.51%, Ti: 0.18%-0.25%, Ce: 0.25%-0.35%, the total amount of unavoidable impurity elements does not exceed 0.3%, the content of a single impurity element does not exceed 0.05%, and the balance is Al.

[0007] In addition, the present application also provides a method for preparing a high heat-resistant Al-Cu alloy, the preparation method comprising the following steps:

[0008] Preliminary batching: Calculate the required proportion of each raw material according to the designed alloy composition and raw materials, and determine the specific weight of each raw material based on the total weight;

[0009] Alloy melting: Aluminum ingots and raw materials containing Fe, Mn, Cu, and Ni are added to the resistance furnace in sequence, and the temperature is raised for smelting. After the raw materials are completely melted, raw materials containing Ti, Mg, and Ce are added in sequence, and electromagnetic stirring is performed to improve the uniformity of the melt composition.

[0010] First refining and composition adjustment: 0.05% to 0.15% refining agent and inert gas are introduced to purify the melt, and then samples are taken to test the composition and adjust the alloy composition;

[0011] Second refining: After removing the scum on the surface of the melt, the second refining treatment is carried out, and a refining agent with a mass fraction of 0.03% to 0.12% and an inert gas are introduced, and the temperature is kept at 720°C to 750°C for 10min to 20min, and then the surface scum is removed;

[0012] The melt after removing the surface scum is placed in a static state, and then the melt is introduced into the launder of the degassing and filtering device for online degassing and online filtering, and then cast, and after natural cooling, an ingot is obtained;

[0013] Heat treatment: The casting is subjected to T5 heat treatment, and the heat treatment process is: the furnace temperature is raised to 500°C to 550°C and maintained for 10h to 15h, then the casting is quickly taken out and quenched to room temperature, and then the temperature is raised to 150°C to 200°C and maintained for 6h to 10h, and air-cooled to obtain a high heat-resistant Al-Cu alloy.

[0014] Furthermore, the temperature of the smelting treatment is 750°C to 850°C.

[0015] Furthermore, the frequency of the electromagnetic stirring treatment is 1 Hz to 20 Hz, the power is 60 kW to 90 kW, the time is 5 min to 15 min, and the electromagnetic stirring method adopts a forward and reverse rotation alternating method, and the electromagnetic stirring steering time is 1 min to 5 min.

[0016] Furthermore, the temperature of the first refining treatment is 720° C. to 750° C., and the insulation time is 10 min to 30 min.

[0017] Furthermore, the static treatment time is 10 minutes to 30 minutes.

[0018] Furthermore, the online degassing time is 20 min to 30 min, and an inert gas is introduced into the online degassing, the pressure of the inert gas is 0.15 MPa to 0.35 MPa, and the flow rate is 50 L / min to 120 L / min.

[0019] Furthermore, after the online degassing, the hydrogen content in the melt is 0.02 mL / 100 gAl to 0.22 mL / 100 gAl.

[0020] Furthermore, the online filtration is performed using a ceramic filter plate, and the pore size of the filter plate is 10 mesh to 80 mesh.

[0021] Furthermore, the casting process speed is 15 mm / min to 30 mm / min, the temperature is 720°C to 750°C, and the flow rate of cooling water is 25 m 3 / h~30m 3 / h.

[0022] Compared with the prior art, this application has the following beneficial effects:

[0023] The present invention is based on Al-Cu alloy, and by adding compound Mg, Fe, Ni, Mn, Ti, Ce elements, combined with heat treatment, the Al-Cu alloy has high heat resistance and excellent mechanical properties. Among them, the addition of Mn element can inhibit the formation of needle-like iron-rich phases and promote the formation of iron-rich phases Al interconnected in space. 7 Cu 2 (FeMn) is formed, and after heat treatment, a high-density T phase (Al 20 Cu 2 Mn 3) and dislocations, which helps to improve the high temperature resistance of Al-Cu alloys. Adding Mg can promote the fine and uniform distribution of the θ' precipitate phase in the alloy, prevent the θ' precipitate phase from coarsening and increase thermal stability at high temperatures, and further improve the high temperature strength of the alloy. Adding an appropriate amount of Fe can improve the yield strength and tensile strength of Al-Cu alloys through the second phase strengthening mechanism. Adding Ni can improve the morphology of the needle-shaped iron-rich phase and form a thermally stable Al 9 FeNi and Al 7 Cu 2 (FeMn) iron-rich phase enhances the heat resistance of Al-Cu alloy. At the same time, adding Ce element can refine the grains and generate Al-Ce-M (M=Cu, Ti) intermetallic compounds with good thermal stability, thereby improving the high-temperature mechanical properties of the alloy. In summary, the present invention forms a synergistic combination of multiple strengthening strategies by adding different elements to improve the strength of Al-Cu alloy, making it more suitable for industrial applications. By adding transition metal elements, a coarse second phase structure with good thermal stability is formed, which significantly improves its high-temperature performance. The invention improves the high-temperature strength of the Al-Cu alloy by combining composite microalloying and heat treatment, is easy to prepare, and can be used for mass production; the aluminum alloy disclosed by the invention is subjected to T5 heat treatment after being formed by gravity casting, and the tensile strength, yield strength and elongation of the aluminum alloy under high-temperature environments of 300°C and 350°C are 267MPa, 190MPa, 5.5% and 220MPa, 152MPa, 6.7%, respectively, and can reach 143MPa, 127MPa, 7.8% or more under a high-temperature working environment of 400°C, has excellent heat resistance, which is much higher than the performance of conventional heat-resistant aluminum alloys, and can be used to manufacture high-heat-resistant parts such as automobile engine cylinder blocks. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with its embodiments. It should be understood that the specific implementation methods described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0026] A high heat-resistant Al-Cu alloy in one embodiment of the present invention is composed of the following components in mass percentage: Cu: 4% to 4.8%, Fe: 0.95% to 1.20%, Ni: 1.4% to 1.6%, Mn: 0.51% to 0.6%, Mg: 0.45% to 0.51%, Ti: 0.18% to 0.25%, Ce: 0.25% to 0.35%, the total amount of unavoidable impurity elements does not exceed 0.3%, the content of a single impurity element does not exceed 0.05%, and the balance is Al.

[0027] In addition, the present application also provides a method for preparing a high heat-resistant Al-Cu alloy, the preparation method comprising the following steps:

[0028] Preliminary batching: Calculate the required proportion of each raw material according to the designed alloy composition and raw materials, and determine the specific weight of each raw material based on the total weight;

[0029] Alloy melting: Aluminum ingots and raw materials containing Fe, Mn, Cu, and Ni are added to the resistance furnace in sequence, and the temperature is raised for smelting. After the raw materials are completely melted, raw materials containing Ti, Mg, and Ce are added in sequence, and electromagnetic stirring is performed to improve the uniformity of the melt composition.

[0030] First refining and composition adjustment: 0.05% to 0.15% refining agent and inert gas are introduced to purify the melt, and then samples are taken to test the composition and adjust the alloy composition;

[0031] Second refining: After removing the scum on the surface of the melt, the second refining treatment is carried out, and a refining agent with a mass fraction of 0.03% to 0.12% and an inert gas are introduced, and the temperature is kept at 720°C to 750°C for 10min to 20min, and then the surface scum is removed;

[0032] The melt after removing the surface scum is placed in a static state, and then the melt is introduced into the launder of the degassing and filtering device for online degassing and online filtering, and then cast, and after natural cooling, an ingot is obtained;

[0033] Heat treatment: The casting is subjected to T5 heat treatment, and the heat treatment process is: the furnace temperature is raised to 500°C to 550°C and maintained for 10h to 15h, then the casting is quickly taken out and quenched to room temperature, and then the temperature is raised to 150°C to 200°C and maintained for 6h to 10h, and air-cooled to obtain a high heat-resistant Al-Cu alloy.

[0034] In one embodiment, the temperature of the smelting process is 750°C to 850°C.

[0035] In one embodiment, the frequency of the electromagnetic stirring treatment is 1 Hz to 20 Hz, the power is 60 kW to 90 kW, the time is 5 min to 15 min, and the electromagnetic stirring method adopts alternating forward and reverse rotation, and the electromagnetic stirring steering time is 1 min to 5 min.

[0036] In one embodiment, the temperature of the first refining treatment is 720° C. to 750° C., and the holding time is 10 min to 30 min.

[0037] In one embodiment, the static treatment time is 10 minutes to 30 minutes.

[0038] In one of the embodiments, the online degassing time is 20 min to 30 min, and an inert gas is introduced into the online degassing, the pressure of the inert gas is 0.15 MPa to 0.35 MPa, and the flow rate is 50 L / min to 120 L / min.

[0039] In one of the embodiments, after the online degassing, the hydrogen content in the melt is 0.02 mL / 100 gAl to 0.22 mL / 100 gAl.

[0040] In one embodiment, the online filtration is performed using a ceramic filter plate, and the pore size of the filter plate is 10 mesh to 80 mesh.

[0041] In one embodiment, the casting process speed is 15 mm / min to 30 mm / min, the temperature is 720°C to 750°C, and the flow rate of cooling water is 25 m / min. 3 / h~30m 3 / h.

[0042] The above scheme can obtain Al-Cu alloy with high heat resistance and excellent mechanical properties at 350°C and above through optimization of composition and process.

[0043] The embodiments of the present invention will be described in detail below with reference to specific examples.

[0044] Embodiment 1:

[0045] A high heat-resistant Al-Cu alloy is composed of the following components in mass percentage: Cu: 4.8%, Fe: 0.97%, Ni: 1.46%, Mn: 0.6%, Mg: 0.51%, Ti: 0.18%, Ce: 0.28%, the total amount of unavoidable impurity elements does not exceed 0.3%, the content of a single impurity element does not exceed 0.05%, and the balance is Al.

[0046] A method for preparing a high heat-resistant Al-Cu alloy comprises the following steps:

[0047] Preliminary batching: Calculate the required proportion of each raw material according to the designed alloy composition and raw materials, and determine the specific weight of each raw material based on the total weight;

[0048] Alloy melting: Aluminum ingots and raw materials containing Fe, Mn, Cu, and Ni are added to the resistance furnace in sequence, and the temperature is raised. The raw materials are smelted at a temperature of 800°C. After the raw materials are completely melted, raw materials containing Ti, Mg, and Ce are added in sequence. The electromagnetic stirring is carried out at a frequency of 1Hz and a power of 90kw for 15min. The electromagnetic stirring method adopts a forward and reverse rotation alternating method. The electromagnetic stirring steering time is 1min to improve the uniformity of the melt composition.

[0049] First refining and composition adjustment: 0.15% refining agent and inert gas are introduced, and the first refining treatment is carried out at a temperature of 730°C for 30 minutes to purify the melt, and then samples are taken for composition testing and alloy composition adjustment;

[0050] Second refining: After removing the scum on the surface of the melt, the second refining treatment is carried out, and a refining agent with a mass fraction of 0.1% and an inert gas are introduced, and the temperature is kept at 730°C for 15 minutes, and then the surface scum is removed;

[0051] The melt after removing the surface scum is allowed to stand for 15 minutes, and then the melt is introduced into the flow channel of the degassing and filtering device for online degassing and online filtering, and the online degassing time is 20 minutes, and an inert gas is introduced during the online degassing, and the pressure of the inert gas is 0.15MPa and the flow rate is 80L / min; the online filtration is performed using a ceramic filter plate, and the pore size of the filter plate is 80 meshes; a melt with a hydrogen content of 0.18mL / 100gAl is obtained;

[0052] At a speed of 25 mm / min, a temperature of 730°C, and a cooling water flow rate of 25 m 3 / h, and after natural cooling, an ingot is obtained;

[0053] Heat treatment: The casting is subjected to T5 heat treatment, and the heat treatment process is: the furnace temperature is raised to 538°C and maintained for 12 hours, then the casting is quickly taken out and quenched to room temperature, and then the temperature is raised to 160°C and maintained for 8 hours, and air-cooled to obtain a high heat-resistant Al-Cu alloy.

[0054] Embodiment 2:

[0055] A high heat-resistant Al-Cu alloy is composed of the following components in mass percentage: Cu: 4.0%, Fe: 0.95%, Ni: 1.4%, Mn: 0.51%, Mg: 0.45%, Ti: 0.18%, Ce: 0.25%, the total amount of unavoidable impurity elements does not exceed 0.3%, the content of a single impurity element does not exceed 0.05%, and the balance is Al.

[0056] A method for preparing a high heat-resistant Al-Cu alloy comprises the following steps:

[0057] Preliminary batching: Calculate the required proportion of each raw material according to the designed alloy composition and raw materials, and determine the specific weight of each raw material based on the total weight;

[0058] Alloy melting: Aluminum ingots and raw materials containing Fe, Mn, Cu, and Ni are added to the resistance furnace in sequence, and the temperature is raised. The raw materials are smelted at a temperature of 780°C. After the raw materials are completely melted, raw materials containing Ti, Mg, and Ce are added in sequence. The electromagnetic stirring is carried out at a frequency of 10 Hz and a power of 75 kW for 10 minutes. The electromagnetic stirring method adopts a forward and reverse rotation alternating method. The electromagnetic stirring steering time is 2 minutes to improve the uniformity of the melt composition.

[0059] First refining and composition adjustment: 0.12% refining agent and inert gas were introduced, and the first refining treatment was carried out at a temperature of 730°C for 10 minutes to purify the melt, and then samples were taken for composition testing and alloy composition adjustment;

[0060] Second refining: After removing the scum on the surface of the melt, the second refining treatment is carried out, and a refining agent with a mass fraction of 0.05% and an inert gas are introduced, and the temperature is kept at 730°C for 20 minutes, and then the surface scum is removed;

[0061] The melt after removing the surface scum is allowed to stand for 15 minutes, and then the melt is introduced into the flow channel of the degassing and filtering device for online degassing and online filtering, and the online degassing time is 25 minutes, and an inert gas is introduced during the online degassing, and the pressure of the inert gas is 0.20 MPa and the flow rate is 80 L / min; the online filtration is performed using a ceramic filter plate, and the pore size of the filter plate is 80 meshes; a melt with a hydrogen content of 0.20 mL / 100 gAl is obtained;

[0062] At a speed of 20 mm / min, a temperature of 720°C, and a cooling water flow rate of 25 m 3 / h, and after natural cooling, an ingot is obtained;

[0063] Heat treatment: The casting is subjected to T5 heat treatment, and the heat treatment process is: the furnace temperature is raised to 530°C and maintained for 11 hours, then the casting is quickly taken out and quenched to room temperature, and then the temperature is raised to 180°C and maintained for 8 hours, and air-cooled to obtain a high heat-resistant Al-Cu alloy.

[0064] Embodiment 3:

[0065] A high heat-resistant Al-Cu alloy is composed of the following components in mass percentage: Cu: 4.3%, Fe: 1.0%, Ni: 1.5%, Mn: 0.53%, Mg: 0.47%, Ti: 0.2%, Ce: 0.28%, the total amount of unavoidable impurity elements does not exceed 0.3%, the content of a single impurity element does not exceed 0.05%, and the balance is Al.

[0066] A method for preparing a high heat-resistant Al-Cu alloy comprises the following steps:

[0067] Preliminary batching: Calculate the required proportion of each raw material according to the designed alloy composition and raw materials, and determine the specific weight of each raw material based on the total weight;

[0068] Alloy melting: Aluminum ingots and raw materials containing Fe, Mn, Cu, and Ni are added to the resistance furnace in sequence, and the temperature is raised. The raw materials are smelted at 850°C. After the raw materials are completely melted, raw materials containing Ti, Mg, and Ce are added in sequence. The electromagnetic stirring is carried out at a frequency of 20Hz and a power of 60kw for 15 minutes. The electromagnetic stirring method adopts a forward and reverse rotation alternating method. The electromagnetic stirring steering time is 5 minutes to improve the uniformity of the melt composition.

[0069] First refining and composition adjustment: 0.12% refining agent and inert gas were introduced, and the first refining treatment was carried out at a temperature of 730°C for 20 minutes to purify the melt, and then samples were taken for composition testing and alloy composition adjustment;

[0070] Second refining: After removing the scum on the surface of the melt, the second refining treatment is carried out, and a refining agent with a mass fraction of 0.08% and an inert gas are introduced, and the temperature is kept at 730°C for 20 minutes, and then the surface scum is removed;

[0071] The melt after removing the surface scum is allowed to stand for 30 minutes, and then the melt is introduced into the flow channel of the degassing and filtering device for online degassing and online filtering, and the online degassing time is 30 minutes, and an inert gas is introduced during the online degassing, and the pressure of the inert gas is 0.30MPa and the flow rate is 60L / min; the online filtration is performed using a ceramic filter plate, and the pore size of the filter plate is 80 meshes; a melt with a hydrogen content of 0.19mL / 100gAl is obtained;

[0072] At a speed of 25 mm / min, a temperature of 720°C, and a cooling water flow rate of 26 m 3 / h, and after natural cooling, an ingot is obtained;

[0073] Heat treatment: The casting is subjected to T5 heat treatment, and the heat treatment process is: the furnace temperature is raised to 550°C and maintained for 13 hours, then the casting is quickly taken out and quenched to room temperature, and then the temperature is raised to 180°C and maintained for 6 hours, and air-cooled to obtain a high heat-resistant Al-Cu alloy.

[0074] Comparative Example 1:

[0075] The difference between Comparative Example 1 and Example 1 is that no raw materials of Ti and Ce elements are added in Comparative Example 1, and the rest are the same as Example 1.

[0076] Comparative Example 2:

[0077] The difference between Comparative Example 2 and Example 2 is that 0.2% of the raw materials of the Mg element and 0.5% of the raw materials of the Ni element are added to Comparative Example 2, and the rest is the same as Example 2.

[0078] Comparative Example 3:

[0079] The difference between Comparative Example 3 and Example 3 is that 0.1% of the raw materials of the Ti element and 0.15% of the raw materials of the Ce element are added to Comparative Example 3, and the rest is the same as Example 3.

[0080] The samples prepared in Examples 1 to 3 and the comparative samples prepared in Comparative Examples 1 to 3 were subjected to performance tests, and high temperature tensile tests were performed at 300°C, 350°C and 400°C on a microcomputer-controlled electronic universal testing machine. The loading rate was 1 mm / min, and at least three groups of experiments were performed for each group of alloys. The test results are shown in Table 1.

[0081] Table 1: Mechanical properties test results

[0082]

[0083]

[0084] From the data analysis of Table 1, it can be seen that the present application is optimized by composition and component ratio, and after microalloying, high-temperature solid solution and aging treatment, an Al-Cu alloy with high heat resistance and excellent mechanical properties can be obtained. It can be seen from Comparative Examples 1 and 3 that higher contents of Ti and Ce are beneficial to improving the heat resistance of the casting. It can be seen from Comparative Example 2 that appropriately increasing the content of Mg and Ni can further improve the heat resistance of the casting. The high-temperature resistant aluminum alloy material prepared according to the design principle and method of the present invention fully meets the requirements of the automotive field for high strength and high toughness of materials, and can be used for the manufacture of automobile engine cylinders and pistons working at high temperatures.

[0085] In addition, the present application also studies the influence of process conditions on Al-Cu alloys, and makes several sets of comparative examples. The difference between comparative examples 4 to 7 and embodiment 3 is only that the process parameters of the heat treatment are different, and the others are the same as embodiment 3. The specific heat treatment process parameter conditions and the mechanical properties tested at 400°C are shown in Table 2.

[0086] Table 2: Test conditions and mechanical properties results

[0087]

[0088]

[0089] From the data analysis of Table 2, it can be seen that the present application optimizes the heat treatment process and combines the optimization of the composition and the ratio of the components to obtain an Al-Cu alloy with excellent mechanical properties above 350°C as a whole, which has a wider range of applications.

[0090] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0091] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A high heat-resistant Al-Cu alloy, characterized in that: The high heat-resistant Al-Cu alloy is composed of the following components in percentage by mass: Composition: Cu: 4% ~ 4.8%, Fe: 0.95% ~ 1.20%, Ni: 1.4% ~ 1.6%, Mn: 0.51% ~ 0.6%, Mg: 0.45% ~ 0.51%, Ti: 0.18% ~ 0.25%, Ce: 0.25% ~ 0.35%, the total amount of unavoidable impurity elements does not exceed 0.3%, the content of a single impurity element does not exceed 0.05%, and the balance is Al.

2. A method for preparing a high heat-resistant Al-Cu alloy, characterized in that: The preparation method is used to prepare the high heat-resistant Al-Cu alloy according to claim 1, and the preparation method comprises the following steps: Preliminary batching: Calculate the required proportion of each raw material according to the designed alloy composition and raw materials, and determine the specific weight of each raw material based on the total weight; Alloy melting: Aluminum ingots and raw materials containing Fe, Mn, Cu, and Ni are added to the resistance furnace in sequence, and the temperature is raised for smelting. After the raw materials are completely melted, raw materials containing Ti, Mg, and Ce are added in sequence, and electromagnetic stirring is performed to improve the uniformity of the melt composition. First refining and composition adjustment: 0.05% to 0.15% refining agent and inert gas are introduced to purify the melt, and then samples are taken to test the composition and adjust the alloy composition; Second refining: After removing the scum on the surface of the melt, the second refining treatment is carried out, and a refining agent with a mass fraction of 0.03% to 0.12% and an inert gas are introduced, and the temperature is kept at 720°C to 750°C for 10min to 20min, and then the surface scum is removed; The melt after removing the surface scum is placed in a static state, and then the melt is introduced into the launder of the degassing and filtering device for online degassing and online filtering, and then cast, and after natural cooling, an ingot is obtained; Heat treatment: The casting is subjected to T5 heat treatment, and the heat treatment process is: the furnace temperature is raised to 500°C to 550°C and maintained for 10h to 15h, then the casting is quickly taken out and quenched to room temperature, and then the temperature is raised to 150°C to 200°C and maintained for 6h to 10h, and air-cooled to obtain a high heat-resistant Al-Cu alloy.

3. The preparation method according to claim 2, characterized in that: The temperature of the smelting treatment is 750°C to 850°C.

4. The preparation method according to claim 2, characterized in that: The frequency of the electromagnetic stirring treatment is 1 Hz to 20 Hz, the power is 60 kW to 90 kW, the time is 5 min to 15 min, and the electromagnetic stirring method adopts a forward and reverse rotation alternating method, and the electromagnetic stirring steering time is 1 min to 5 min.

5. The preparation method according to claim 2, characterized in that: The temperature of the first refining treatment is 720° C. to 750° C., and the insulation time is 10 min to 30 min.

6. The preparation method according to claim 2, characterized in that: The standing treatment time is 10 min to 30 min.

7. The preparation method according to claim 2, characterized in that: The online degassing time is 20 min to 30 min, and an inert gas is introduced into the online degassing. The pressure of the inert gas is 0.15 MPa to 0.35 MPa, and the flow rate is 50 L / min to 120 L / min.

8. The preparation method according to claim 7, characterized in that: After the online degassing, the hydrogen content in the melt is 0.02 mL / 100 gAl to 0.22 mL / 100 gAl.

9. The preparation method according to claim 8, characterized in that: The online filtration is performed using a ceramic filter plate, and the pore size of the filter plate is 10-80 meshes.

10. The preparation method according to claim 9, characterized in that: The casting process speed is 15mm / min to 30mm / min, the temperature is 720℃ to 750℃, and the flow rate of cooling water is 25m 3 / h~30m 3 / h.

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