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CN-121976096-A - High specific strength and high specific modulus aluminum alloy and preparation method thereof

CN121976096ACN 121976096 ACN121976096 ACN 121976096ACN-121976096-A

Abstract

The invention provides an aluminum alloy with high specific strength and high specific modulus and a preparation method thereof. By constructing a novel Al-Mg-Zn alloy system taking Mg as a main additive element, wherein the content of Mg is 10-15 wt% and the content of Zn is 3-5 wt%, and high-modulus TiB 2 particles (5-10 wt%) are introduced on the basis of the Al-Mg-Zn alloy so as to remarkably improve the specific modulus and the strengthening effect of the material. The preparation process comprises smelting and casting, homogenizing and annealing treatment, plastic deformation, solution treatment and aging treatment, and is simple and reasonable, and the aluminum alloy obtained after the treatment by the method has the characteristics of high specific strength and high specific modulus, and can meet the requirements of the fields of aerospace, traffic equipment and the like on high-performance light structural materials.

Inventors

  • HUANG YIPING
  • GENG JIWEI
  • WANG JIANWEI
  • Xiao Yakai
  • WANG QIAN
  • LI YUGANG
  • XIA PEIKANG
  • CHEN DONG
  • WANG HAOWEI

Assignees

  • 上海交通大学

Dates

Publication Date
20260505
Application Date
20260218

Claims (10)

  1. 1. The aluminum alloy with high specific strength and high specific modulus is characterized by comprising the chemical components of 10-15 wt.% of Mg, 3-5 wt.% of Zn, 5-10 wt.% of TiB 2 , the balance of Al and unavoidable impurities, wherein the particle size of TiB 2 is 0.5-1 mu m, the particle size is normally distributed, tiB 2 particles in the aluminum alloy are uniformly dispersed in an aluminum alloy matrix, the aluminum alloy matrix is a fine equiaxed crystal structure with the average grain size of 4-5 mu m, a nano-scale T 'phase is precipitated in the matrix, and the T' phase is dispersed and distributed and forms a precipitation enrichment area near the TiB 2 particles.
  2. 2. The high specific strength and high specific modulus aluminum alloy according to claim 1, wherein the aluminum alloy has a tensile strength of 730-770 MPa, an elastic modulus of 78-85 GPa, a density of 2.63-2.69 g/cm 3 , a specific strength of 275-291 MPa cm 3 /g, and a specific modulus of 29.4-31.6 GPa cm 3 /g.
  3. 3. A preparation method of an aluminum alloy with high specific strength and high specific modulus is characterized by comprising the following steps: (1) Smelting and casting, namely weighing industrial pure aluminum, industrial pure zinc, industrial pure magnesium and TiB 2 particle master batch in proportion, and proportioning, wherein 10-15 wt.% of Mg, 3-5 wt.% of Zn, 5-10 wt.% of TiB 2 , the balance of Al and unavoidable impurities, wherein the particle size of TiB 2 is 0.5-1 mu m, the particle size is normally distributed; (2) Homogenizing treatment, namely homogenizing annealing the cast ingot; (3) Plastic deformation, namely, plastic processing and forming are adopted for the annealed material; (4) Solution treatment, namely, carrying out solution treatment on the aluminum alloy obtained in the step (3), wherein the solution treatment comprises the steps of heating, heat preservation and water quenching; (5) Aging treatment, namely aging treatment is carried out on the material with supersaturated solid solution.
  4. 4. The method of claim 3, wherein the melting temperature in the step (1) is 700-800 ℃ and the time is 30-90 min.
  5. 5. The method of claim 3, wherein the homogenizing annealing is a single-stage homogenizing treatment.
  6. 6. The method of claim 5, wherein the homogenizing annealing process is annealing at 400-480 ℃ for 2-10 hours.
  7. 7. The method of claim 3, wherein the plastic deformation is hot extrusion, extrusion molding is performed at 350-450 ℃, the extrusion speed is 0.5-1.5 mm/s, the extrusion is performed to obtain bars with the diameter of 10-20 mm, and water cooling is performed.
  8. 8. The method of claim 3, wherein the solution treatment process is performed by maintaining the bar after plastic deformation in an air furnace at 470-520 ℃ for 30-120 min and then performing water quenching.
  9. 9. The method of claim 3, wherein the aging treatment is a two-stage aging process, the two-stage aging process is pre-aging for 24-100 hours at 50-90 ℃ and then aging for 12-80 hours at 120-250 ℃.
  10. 10. The preparation method of the ceramic material, according to claim 3, wherein the components comprise 10-15 wt.% of Mg, 4-5 wt.% of Zn and 5-8 wt.% of TiB 2 , the smelting temperature is 700 ℃, the smelting time is 90 min, the homogenizing annealing treatment process is that annealing is carried out within a range of 480 ℃ for 2h, plastic deformation is carried out at 400 ℃ and extrusion speed of 1 mm/s, water quenching is carried out after the temperature is maintained at 480 ℃ for 60min, and the temperature is maintained at 60 ℃ for 100 h and the temperature is maintained at 120 ℃ for 60 h.

Description

High specific strength and high specific modulus aluminum alloy and preparation method thereof Technical Field The invention relates to the technical field of aluminum alloy material preparation, in particular to an aluminum alloy with high specific strength and high specific modulus and a preparation method thereof. Background The aluminum alloy has the advantages of light weight, high strength, damage resistance, corrosion resistance and the like, and is the most commonly used light structural material. In particular to a deformation series aluminum alloy which is widely applied to the aviation field. The rapid growth of the aerospace industry has placed a greater demand for high performance aluminum alloy materials. The density of the aluminum alloy material is reduced, the structural weight can be further reduced, and the strength and the rigidity of the aluminum alloy material can be improved, so that the bearing capacity and the structural stability of the aviation component can be enhanced. Therefore, developing an aluminum alloy material with high specific strength and high specific modulus has important practical significance for the light weight design and performance improvement of high-performance aviation structural materials. However, since the strength and rigidity are essentially different, the strength is mainly dependent on lattice defects to block dislocation movement, the rigidity (elastic modulus) is mainly determined by interatomic chemical bonds and crystal structures, whereas the conventional strengthening method (such as grain boundary refinement, precipitation strengthening, solid solution strengthening, etc.) is mainly used for improving the strength by blocking dislocation movement, but the rigidity of interatomic bonds is not generally changed significantly, so that the elastic modulus is basically maintained before and after strengthening, and therefore, the strength and rigidity are difficult to cooperatively improve. In recent years, in order to break through the technical bottleneck that the strength and the elastic modulus of the aluminum alloy are difficult to be simultaneously improved by the traditional strengthening means, the prior art is advanced in that high-modulus ceramic particles such as TiB 2 are introduced into an aluminum alloy matrix. TiB 2 has high elastic modulus, high hardness and good thermal stability, and can realize the synchronous improvement of strength and rigidity to a certain extent through the load transfer effect between the TiB 2 and an aluminum substrate, so that the TiB 2 is widely paid attention. The existing research and application of reinforcing the mechanical properties of aluminum alloy by adding TiB 2 particles are generally based on the development of a traditional high-strength wrought aluminum alloy system, in particular to Al-Zn-Mg-Cu alloy. The alloy depends on Zn, mg and Cu elements to form eta phase precipitation strengthening, and can obtain higher absolute strength, so the alloy is regarded as an ideal matrix for introducing ceramic reinforcing phases. In the system, tiB 2 particles are mainly used for making up the problem of relatively insufficient elastic modulus of a matrix, and the technical route aims at further improving the rigidity on the basis of keeping high strength. For example, chinese patent application CN114032429a (high-elongation, high-modulus TiB 2 particle reinforced aluminum matrix composite and method for preparing the same) discloses a technical solution for realizing high modulus, high strength and high elongation of Al-Zn-Mg-Cu based alloy by adding TiB 2 particles. However, the technical solution of introducing TiB 2 particles into Al-Zn-Mg-Cu high-strength aluminum alloy to improve strength and elastic modulus, although improving the rigidity performance of the material to a certain extent, has the limitation that is difficult to avoid. On one hand, the alloy itself depends on high-content Zn and Cu elements to form eta phase precipitation strengthening, the density of an alloy matrix is higher, tiB 2 particles are further introduced to increase the overall density of the material, so that the strength and modulus of the material are improved, but the specific strength and specific modulus are difficult to be obviously improved, on the other hand, in order to obtain a remarkable rigidity improving effect, the content or the size of TiB 2 particles is required to be improved in the prior art, the problems of particle aggregation, interface discontinuity and the like are easily introduced, and further, the plasticity, damage tolerance and processability of the alloy are adversely affected. The above problems are particularly pronounced in large-sized deformation members for aviation. Although the Al-Mg-Zn-based alloy matrix uses Mg as the main alloying element, has a low density and has potential lightweight advantages, in the prior art, the system is rarely used as a preferred matrix for strengthening