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CN-121992257-A - High-strength high-toughness high-modulus aluminum-copper alloy and preparation method thereof

CN121992257ACN 121992257 ACN121992257 ACN 121992257ACN-121992257-A

Abstract

The invention relates to a high-strength high-toughness high-modulus aluminum-copper alloy and a preparation method thereof, belongs to the technical field of aluminum alloy materials, and solves the problems that the existing cast aluminum alloy is insufficient in mechanical property and rigidity, and a traditional fluoride salt in-situ method is easy to cause crucible corrosion, easy to generate agglomeration, easy to remain salt particles to be mixed and the like. The preparation method of the aluminum-copper alloy breaks through the traditional fluoride salt in-situ reaction thought, but adds AlTi10, alB3 and AlTi5B1 intermediate alloy powder, and is matched with strong, multi-angle and continuous electromagnetic stirring, so that tens of times more nano-grade precipitated phases (Al 3 Ti、TiB 2 and Ti-rich layer TiB 2 composite phases) are precipitated in the alloy matrix than in the traditional method, and grains are effectively refined, grain boundaries are pinned and the matrix is strengthened. The alloy prepared by the method has the tensile strength of 560MPa at room temperature, the elongation of 14 percent and the elastic modulus of 82GPa, simultaneously has good high temperature resistance, and can be popularized and applied in batches in the field of aviation and aerospace as a novel lightweight design material.

Inventors

  • HUANG LI
  • SUN JINBAO
  • DU XUCHU
  • LUO CHUANBIAO
  • LI SHASHA
  • PAN JUNJIE
  • LIU JIANJUN
  • WANG WEIKAI

Assignees

  • 中国航发北京航空材料研究院

Dates

Publication Date
20260508
Application Date
20241101

Claims (10)

  1. 1. The preparation method of the high-strength high-toughness high-modulus aluminum-copper alloy comprises the following steps: S1, sequentially adding pure Al, alCu50 intermediate alloy, alZr4 intermediate alloy, alMn10 intermediate alloy, alSc intermediate alloy and pure Cd according to the weight ratio, and stirring to obtain a melt; s2, adding AlTi10 intermediate alloy powder into the melt according to the weight ratio, and stirring the melt by adopting electromagnetic stirring; s3, adding AlB3 and AlTi5B1 intermediate alloy powder into the melt according to the weight ratio, and stirring the melt by adopting electromagnetic stirring; S4, casting to obtain a casting; s5, performing heat treatment on the obtained casting.
  2. 2. The preparation method according to claim 1, wherein in the preparation process, the addition amount of each element is 4.9-5.3% by weight of Cu, 0.3-0.5% by weight of Mn, 3.2-3.3% by weight of Ti, 0.15-0.20% by weight of Cd, 0.05-0.13% by weight of Zr, 1.5-1.6% by weight of B, 0.006-0.05% by weight of Sc, less than or equal to 0.05% by weight of Fe, and the balance of Al and other impurities, wherein the content of the other impurities is less than or equal to 0.1%.
  3. 3. The method of claim 2, wherein the Ti and B elements are added in the form of AlTi10, alB3, and AlTi5B1 micron-sized master alloy powders.
  4. 4. The method according to claim 1, wherein in S2, the AlTi10 master alloy is added in powder form, and the average particle diameter D50 of the powder is 120 to 200 μm.
  5. 5. The method according to claim 4, wherein after the step S2 is added to the master alloy powder, the master alloy powder is stirred by electromagnetic stirring for 10 to 15 minutes.
  6. 6. The method according to claim 1, wherein in S3, alB3 and AlTi5B1 intermediate alloy are added in the form of powder, and the average particle diameter D50 of the powder is 120-200 μm.
  7. 7. The method according to claim 6, wherein after the step S3 is performed with addition of the master alloy powder, the master alloy powder is stirred by electromagnetic stirring for 15 to 25 minutes.
  8. 8. The method of claim 1, wherein the intermediate alloy powders of AlTi10, alB3 and AlTi5B1 are mixed with the oxide powder before being added to the melt, wherein the oxide powder is TiO 2 、Al 2 O 3 or ZnO powder.
  9. 9. A high strength, high toughness, high modulus aluminum copper alloy prepared by the method of any one of claims 1-8.
  10. 10. The high-strength high-toughness high-modulus aluminum-copper alloy according to claim 9, wherein the high-strength high-toughness high-modulus aluminum-copper alloy comprises, by weight, 4.9-5.3% of Cu, 0.3-0.5% of Mn, 3.2-3.3% of Ti, 0.15-0.20% of Cd, 0.05-0.13% of Zr, 1.5-1.6% of B, 0.006-0.05% of Sc, less than or equal to 0.05% of Fe, the balance of Al and other impurities, and the balance of impurities is less than or equal to 0.1%.

Description

High-strength high-toughness high-modulus aluminum-copper alloy and preparation method thereof Technical Field The invention relates to the technical field of aluminum alloy materials, in particular to a high-strength high-toughness high-modulus aluminum-copper alloy and a preparation method thereof. Background The cast aluminum-copper alloy is a high-strength cast aluminum alloy which is more applied at present, and with the further improvement of the requirements of light weight and reliability of equipment, the cast aluminum-copper alloy has higher requirements on the room temperature, high temperature mechanical properties and rigidity of the alloy. For cast aluminum alloys, the means to increase strength is typically by alloying element strengthening and heat treatment strengthening. These strengthening processes have been very mature over decades, but the lifting effect brought about by them has been very limited. Researches show that the micro-nano reinforced particles with larger volume mass fraction are introduced into the alloy, so that the alloy performance can be further improved. At present, two main modes of introducing composite reinforced particles with large volume mass fraction into aluminum alloy are powder metallurgy, wherein one mode is to uniformly mix alloy powder with reinforced particles (such as SiCp, tiB 2 and TiC particles) and then produce a finished product by forging, extrusion and other modes. The method has the advantages of simple structure of the product due to process limitation, high manufacturing cost and mechanical processing. And the other is that the mixed salt of K 2TiF6 and KBF 4 is added into the molten aluminum liquid through the in-situ reaction of the fluorine salt, the fluorine salt is decomposed at high temperature and is subjected to displacement reaction with the molten aluminum to generate micro-nano TiB 2 particles, so that the particles are uniformly distributed in the matrix to play a role in compound reinforcement. The method has the advantages that the crucible is corroded greatly, the reaction degree and speed of the fluoride salt are difficult to control, the in-situ generated TiB 2 particles are easy to agglomerate, meanwhile, the problem of sedimentation and agglomeration of TiB 2 particles also exists in the casting waiting process, and in addition, the added salt is easy to remain in an aluminum melt, so that inclusion is caused, and the performance of the casting is very unfavorable. Disclosure of Invention In view of the above analysis, the embodiment of the invention aims to provide a high-strength high-toughness high-modulus aluminum-copper alloy and a preparation method thereof, which are used for solving the problems that the existing cast aluminum alloy is insufficient in mechanical property and rigidity and is difficult to further improve the performance. In one aspect, the embodiment of the invention provides a preparation method of a high-strength high-toughness high-modulus aluminum-copper alloy, which comprises the following steps: S1, sequentially adding pure Al, alCu50 intermediate alloy, alZr4 intermediate alloy, alMn10 intermediate alloy, alSc intermediate alloy and pure Cd according to the weight ratio, and stirring to obtain a melt; s2, adding AlTi10 intermediate alloy powder into the melt according to the weight ratio, and stirring the melt by adopting electromagnetic stirring; s3, adding AlB3 and AlTi5B1 intermediate alloy powder into the melt according to the weight ratio, and stirring the melt by adopting electromagnetic stirring; S4, casting to obtain a casting; s5, performing heat treatment on the obtained casting. Further, in the preparation process, the addition amount of each element is 4.9-5.3% by weight of Cu, 0.3-0.5% by weight of Mn, 3.2-3.3% by weight of Ti, 0.15-0.20% by weight of Cd, 0.05-0.13% by weight of Zr, 1.5-1.6% by weight of B, 0.006-0.05% by weight of Sc, less than or equal to 0.05% by weight of Fe, the balance of Al and other impurities, wherein the content of the other impurities is less than or equal to 0.1%. Further, ti and B elements were added in the form of AlTi10, alB3, and AlTi5B1 micron-sized master alloy powders. In S2, the AlTi10 master alloy is added in the form of powder, and the average particle diameter D50 of the powder is 120-200 mu m. And further, after the intermediate alloy powder is added in the S2, stirring is performed by adopting electromagnetic stirring, wherein the stirring time is 10-15 min. In S3, alB3 and AlTi5B1 intermediate alloy are added in powder form, and the average particle diameter D50 of the powder is 120-200 μm. And further, after the intermediate alloy powder is added in the S3, stirring is performed by adopting electromagnetic stirring, wherein the stirring time is 15-25 min. Furthermore, before the intermediate alloy powder of AlTi10, alB3 and AlTi5B1 is added into the melt, the intermediate alloy powder is uniformly mixed with oxide powder and then added, whe