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CN-122010537-A - Chopped/continuous alumina fiber synergistic toughening alumina-based composite material and preparation method thereof

CN122010537ACN 122010537 ACN122010537 ACN 122010537ACN-122010537-A

Abstract

The invention relates to the technical field of preparation of continuous oxide fiber toughening oxide-based composite materials, and particularly discloses a preparation method of a chopped/continuous alumina fiber synergistic toughening alumina-based composite material, which comprises the steps of preparing chopped Al 2 O 3 fibers; the preparation method comprises the steps of removing photoresist from Al 2 O 3 fiber cloth and chopped Al 2 O 3 fibers, preparing low-solid-phase-content Al 2 O 3 slurry and Al 2 O 3 slurry containing chopped Al 2 O 3 fibers, impregnating the Al 2 O 3 fiber cloth with the Al 2 O 3 slurry containing chopped Al 2 O 3 fibers, carrying out compression molding, drying and sintering at high temperature to obtain an Al 2 O 3(s,c) /Al 2 O 3 composite material rough blank, and carrying out densification treatment on the low-solid-phase-content Al 2 O 3 slurry and the Al 2 O 3 sol on the Al 2 O 3(s,c) /Al 2 O 3 composite material rough blank to obtain the composite material. The invention introduces the chopped alumina fiber to toughen the alumina fiber reinforced alumina-based composite material, not only has excellent mechanical property in the fiber direction, but also has excellent delamination resistance in the thickness direction.

Inventors

  • JIANG RU
  • ZENG WEI
  • XU RUYI
  • Gao Changchuang
  • ZHAN JIE
  • LIU YE
  • ZHOU XUN

Assignees

  • 湖南科技大学

Dates

Publication Date
20260512
Application Date
20260109

Claims (10)

  1. 1. The preparation method of the chopped/continuous alumina fiber synergistic toughening alumina-based composite material is characterized by comprising the following steps of: (1) Preparing chopped Al 2 O 3 fibers with the length of 0.1-5 mm; (2) Degumming the fiber, namely carrying out high-temperature heat treatment on the Al 2 O 3 fiber cloth and the chopped Al 2 O 3 fiber, and removing a surface gelatinous protective layer; (3) Dispersing Al 2 O 3 powder into deionized water, adding an acidic or alkaline solution, and performing ball milling to obtain Al 2 O 3 slurry with low solid content, dispersing Al 2 O 3 powder into deionized water, adding an acidic or alkaline solution, performing ball milling to obtain Al 2 O 3 slurry with high solid content, adding the chopped Al 2 O 3 fibers obtained in the step (1) into the Al 2 O 3 slurry with high solid content, and performing ball milling to obtain Al 2 O 3 slurry containing chopped Al 2 O 3 fibers; (4) Preparing a rough blank, namely dipping or brushing the Al 2 O 3 slurry containing the chopped Al 2 O 3 fibers in the step (3) into the Al 2 O 3 fiber cloth after the photoresist is removed in the step (2), then carrying out compression molding, drying and forming, and carrying out high-temperature sintering to obtain the rough blank of the Al 2 O 3(s,c) /Al 2 O 3 composite material; (5) And (3) densifying the rough blank, namely performing post densification on the rough blank of the Al 2 O 3(s,c) /Al 2 O 3 composite material obtained in the step (4) by adopting low solid-phase content Al 2 O 3 slurry, performing dip-drying-sintering treatment on the multi-period Al 2 O 3 slurry, and then performing post densification on the rough blank of the Al 2 O 3(s,c) /Al 2 O 3 composite material by adopting Al 2 O 3 sol, and performing dip-drying-sintering treatment on the multi-period Al 2 O 3 sol to finally obtain the chopped/continuous alumina fiber synergistic toughening alumina-based composite material.
  2. 2. The method according to claim 1, wherein the step (1) is specifically to cut the Al 2 O 3 fiber bundle (cloth) into chopped Al 2 O 3 fibers, screen and ultrasonically clean the chopped Al 2 O 3 fibers, and dry the chopped Al 2 O 3 fibers.
  3. 3. The method according to claim 1, wherein in the step (3), the average particle diameter of the Al 2 O 3 powder is 0.15 μm, the specific surface area is 12.0m 2 /g, the solid content of the low solid content Al 2 O 3 slurry is 20 to 40vol.%, the viscosity is 20 to 100 mPa.s, the content of the chopped Al 2 O 3 fibers in the Al 2 O 3 slurry containing the chopped Al 2 O 3 fibers is 0.5 to 5.0wt.%, the solid content of the Al 2 O 3 slurry containing the Al 2 O 3 chopped fibers is 50 to 55vol.%, and the viscosity is 500 to 1000 mPa.s.
  4. 4. The preparation method of the ball mill according to claim 1, wherein in the step (3), the acidic solution is nitric acid or hydrochloric acid, the alkaline solution is ammonia water, the ball milling process parameter is 300-500 rpm, and the ball milling time is 2-4 h.
  5. 5. The preparation method of the aluminum 2 O 3(s,c) /Al 2 O 3 composite material according to claim 1, wherein in the step (4), the drying process of the rough blank of the aluminum 2 O 3(s,c) /Al 2 O 3 composite material is that the temperature is raised to 100-200 ℃ in air for 0.5-2 hours, and the heat preservation time is 2-6 hours.
  6. 6. The method according to claim 1, wherein in the step (4), the high-temperature sintering process of the coarse Al 2 O 3(s,c) /Al 2 O 3 composite material blank is carried out by heating to 1100-1400 ℃ in air for 2-6 hours, preserving heat for 0.5-2.0 hours, and cooling to room temperature for 2-6 hours.
  7. 7. The preparation method of the low solid content Al 2 O 3 in the step (5) is characterized in that vacuum pressure is-0.1 MPa in the impregnation process of the low solid content Al 2 O 3 slurry, the impregnation time is 4-8 hours, the drying process is that the temperature is raised to 150-250 ℃ in the air for 1-4 hours, the heat preservation time is 1-4 hours, the high-temperature sintering process is that the temperature is raised to 600-1200 ℃ in the air for 1-4 hours, the heat preservation time is 0.5-2.0 hours, and the cooling is carried out to room temperature for 2-4 hours.
  8. 8. The preparation method of the aluminum-aluminum composite material according to claim 1, wherein in the step (5), vacuum pressure is-0.1 MPa in the impregnation process of the Al 2 O 3 sol, the impregnation time is 4-8 hours, the drying process is that the temperature is raised to 150-250 ℃ in the air for 1-4 hours, the heat preservation time is 1-4 hours, the high-temperature sintering process is that the temperature is raised to 600-1200 ℃ in the air for 1-4 hours, the heat preservation time is 0.5-2.0 hours, and the cooling time is 2-4 hours to room temperature.
  9. 9. The method according to claim 1, wherein in the step (5), the number of cycles of impregnation-drying-sintering of the low solid content Al 2 O 3 slurry and the number of cycles of impregnation-drying-sintering of the Al 2 O 3 sol are each 2 to 5.
  10. 10. The alumina-based composite material with synergistic toughening of chopped/continuous alumina fibers is characterized in that the composite material is prepared by the preparation method of any one of claims 1-9.

Description

Chopped/continuous alumina fiber synergistic toughening alumina-based composite material and preparation method thereof Technical Field The invention relates to the technical field of preparation of continuous ceramic fiber toughening ceramic matrix composite materials, in particular to a short cut/continuous alumina fiber synergistic toughening alumina matrix composite material and a preparation method thereof. Background The continuous alumina fiber toughened alumina-based (Al 2O3/Al2O3) composite material has excellent performances of high temperature resistance, oxidation resistance, high strength, high toughness and the like, and is an important candidate material for hot-end high-temperature parts in the aerospace field. The existing commercial Al 2O3/Al2O3 composite material mainly comprises two-dimensional Al 2O3 fiber cloth and a porous Al 2O3 matrix, wherein the two-dimensional Al 2O3 fiber cloth is a bearing phase, the porous Al 2O3 matrix is used for deflecting matrix cracks, and the two materials act cooperatively to promote the Al 2O3/Al2O3 composite material to have high toughness and high strength in the fiber direction. However, due to the high porosity of the matrix and the lack of reinforcing fibers in the thickness direction, cracks are generated in the matrix firstly in the bearing process, and then can propagate rapidly between fiber cloth layers, so that the mechanical property of the Al 2O3/Al2O3 composite material in the thickness direction is lower, particularly the delamination resistance is lower, and delamination failure is easy to occur under the action of high interlayer load. The Chinese patent document with publication number CN113651627A discloses a preparation method of an alumina fiber toughened alumina ceramic matrix composite, wherein the shear strength of the composite is only 6-12 MPa. The Chinese patent document with publication number CN119874392A discloses a continuous alumina fiber reinforced alumina-zirconia-based composite material with excellent force/heat/electricity comprehensive performance and a preparation method thereof, wherein the interlaminar shear strength of the composite material is 15-17 MPa. In conclusion, the interlaminar shear strength of the two-dimensional Al 2O3/Al2O3 composite material is lower than 20MPa and is only 15-20% of the tensile strength in the fiber direction, and the application of the Al 2O3/Al2O3 composite material in the aerospace field is severely limited by the low delamination resistance. In order to improve the delamination resistance, reinforcing fibers can be introduced in the thickness direction, namely, the reinforced and toughened Al 2O3/Al2O3 composite material of the three-dimensional fiber fabric is formed, but certain limitations still exist, namely, 1) the fibers are easy to brittle fracture and influence the mechanical properties of the composite material in the process of preparing the three-dimensional fiber fabric by adopting a braiding or sewing method because the Al 2O3 fibers have high modulus, and 2) the three-dimensional fiber fabric increases the preparation difficulty of the Al 2O3/Al2O3 composite material, such as low densification efficiency, long preparation period, high process cost, difficult formation of complex components and the like. For example, chinese patent document CN112851386a discloses a method for preparing a three-dimensional alumina fiber woven piece reinforced alumina composite material, wherein the bending strength of the Al 2O3/Al2O3 composite material is 175-399 mpa, which is lower than that of the two-dimensional Al 2O3/Al2O3 composite material, but no mention is made of delamination resistance. Therefore, a preparation method is needed to be explored, and the Al 2O3/Al2O3 composite material with high delamination resistance can be prepared. Disclosure of Invention In order to overcome the defects, the invention provides the chopped/continuous alumina fiber synergistic toughening alumina-based composite material and the preparation method thereof, which can improve the interlayer performance of the alumina fiber reinforced alumina-based composite material and also has excellent delamination resistance in the thickness direction. The specific technical scheme is as follows: The preparation method of the chopped/continuous alumina fiber synergistic toughening alumina-based composite material comprises the following steps: (1) Preparing chopped Al 2O3 fibers with the length of 0.1-5 mm; (2) Degumming the fiber, namely carrying out high-temperature heat treatment on the Al 2O3 fiber cloth and the chopped Al 2O3 fiber, and removing a surface gelatinous protective layer; (3) Dispersing Al 2O3 powder into deionized water, adding an acidic or alkaline solution, ball-milling to obtain Al 2O3 slurry with low solid content for impregnation, dispersing Al 2O3 powder into deionized water, adding an acidic or alkaline solution, ball-milling to obtain Al 2O3 slurry with high solid content, add