Search

CN-121974664-A - Preparation method of oxide eutectic ceramic with uniform refined nano eutectic structure

CN121974664ACN 121974664 ACN121974664 ACN 121974664ACN-121974664-A

Abstract

The invention discloses a preparation method of oxide eutectic ceramics with uniform refined nano eutectic structure, belonging to the technical field of ceramics. The preparation method comprises the steps of (1) preparing an oxide eutectic ceramic preform, namely taking Al 2 O 3 、RE 2 O 3 、ZrO 2 ceramic powder as an initial raw material, uniformly weighing and mixing according to a eutectic ratio, pressing into a ceramic blank, sintering at a high temperature, (2) solidifying to prepare oxide eutectic amorphous ceramic, namely scanning and melting the oxide eutectic amorphous ceramic by using a high-energy laser beam, and solidifying the oxide eutectic amorphous ceramic to form an amorphous ceramic sample, and (3) uniformly crystallizing the amorphous ceramic, namely placing the amorphous ceramic sample obtained in the step (2) into the heat treatment for uniform crystallization to obtain the oxide eutectic ceramic sample with the uniformly refined nano eutectic structure. The eutectic ceramic prepared by the invention has no coarse primary phase, dendrite and cellular structure, uniform and fine tissue, can reach nano scale, and has the characteristics of tissue refinement and uniformity.

Inventors

  • LIU HAIFANG
  • ZHANG BOWEN
  • WANG YUQING
  • QIAN HAO
  • LIU CHANG
  • FENG JING

Assignees

  • 昆明理工大学

Dates

Publication Date
20260505
Application Date
20260202

Claims (8)

  1. 1. The preparation method of the oxide eutectic ceramic with the uniform refined nano eutectic structure is characterized in that the eutectic ceramic structure consists of nano-scale uniform refined eutectic structures, and the preparation method comprises the following steps: (1) Weighing, mixing, drying and sieving Al 2 O 3 、RE 2 O 3 、ZrO 2 ceramic powder, pressing into a ceramic blank, and then sintering and densifying the ceramic blank at high temperature to obtain an oxide eutectic ceramic preform; (2) Scanning and melting the oxide eutectic ceramic preform by using a high-energy laser beam, and solidifying to form an amorphous ceramic sample; (3) And (3) performing heat treatment on the amorphous ceramic sample obtained in the step (2) to obtain the uniformly refined nano eutectic structure oxide eutectic ceramic sample.
  2. 2. The method of claim 1, wherein in the step (1), RE 2 O 3 is a rare earth oxide, wherein RE is a rare earth element including Sc, Y and lanthanoid.
  3. 3. The method for preparing the oxide eutectic ceramic with the uniform and refined nano-eutectic structure according to claim 1, wherein in the step (1), the composite ceramic powder pressed into the ceramic body can be specifically combined and uniformly mixed in any one of the following modes: (1) Comprises Al 2 O 3 and RE 2 O 3 , and the mole percentages of Al 2 O 3 and RE 2 O 3 are 82 percent and 18 percent; (2) Comprises Al 2 O 3 and RE 2 O 3 , and the mole percentage of Al 2 O 3 and RE 2 O 3 is 77 percent and 23 percent; (3) Comprises 65%, 16% and 19% of Al 2 O 3 、RE 2 O 3 and ZrO 2 , and the mole percentages of Al 2 O 3 、RE 2 O 3 and ZrO 2 ; (4) Including Al 2 O 3 、RE 2 O 3 and ZrO 2 , and 58%, 19% and 23% mole percent of Al 2 O 3 、RE 2 O 3 and ZrO 2 .
  4. 4. The preparation method of the oxide eutectic ceramic with the uniform and refined nano eutectic structure, which is disclosed in claim 1, is characterized in that in the step (1), the mixing mode is ball milling, wherein the ball milling condition is that absolute ethyl alcohol is used as a medium for wet ball milling, the ball milling rotating speed is 500-800r/min, and the ball milling time is 5-10 h.
  5. 5. The method for preparing the oxide eutectic ceramic with the uniform and refined nano-eutectic structure according to claim 4, wherein the drying condition in the step (1) is 100-150 ℃ for 10-15 hours, and the sieving condition is 150-mesh sieving.
  6. 6. The method for preparing the oxide eutectic ceramic with the uniform and refined nano eutectic structure according to claim 1, wherein in the step (1), the high-temperature sintering temperature is 1550-1620 ℃, and the heat preservation is carried out for 5-10h after sintering.
  7. 7. The method for preparing the oxide eutectic ceramic with the uniform and refined nano eutectic structure according to claim 1, wherein in the step (2), vacuum pumping is performed, high-purity argon is input as shielding gas, scanning is performed, the laser power for scanning and melting is 50-200W, and the scanning speed is 500-1500 mm/s.
  8. 8. The method for preparing the oxide eutectic ceramic with the refined nano eutectic structure according to claim 1, wherein in the step (3), the heat treatment temperature is 1300-1400 ℃, the heat preservation time is 10-20h, and the heating rate and the cooling rate are 2-5 ℃ per minute.

Description

Preparation method of oxide eutectic ceramic with uniform refined nano eutectic structure Technical Field The invention relates to the technical field of ceramics, in particular to a preparation method of oxide eutectic ceramics with uniform refined nano eutectic structures. Background Oxide eutectic ceramics are used as a composite ceramic material which is self-formed through a eutectic solidification process, and occupy a core position in the field of high-temperature structural materials by virtue of a unique 'in-situ self-generated phase synergistic action' mechanism. The core advantage of the composite material is derived from the synergistic effect of thermodynamic compatibility and microstructure of different oxide phases in a eutectic system, wherein in the eutectic reaction process, each component spontaneously forms a continuously distributed phase structure according to the stoichiometric ratio, the interface is free of impurity pollution, the bonding strength is high, the composite material has the high-temperature resistance of single oxide and the toughening advantage of the composite system, and the composite material has excellent high-temperature bending strength and high-temperature oxidation corrosion resistance, and is regarded as an ideal candidate material in extreme environments such as a hot end part of an aerospace engine. The oxide eutectic ceramic prepared by adopting the laser melting solidification technology has excellent comprehensive performance and has important application prospect in the aerospace field. With the development of aerospace technology, increasingly stringent requirements are placed on the performance of high temperature structural materials. Refining the microstructure size is a key core means to optimize material properties. However, when the structure size of the oxide eutectic ceramic is thinned to a micro-nano scale by adopting the existing solidification preparation technology, obvious structure non-uniformity phenomenon is easily caused, such as the combined action of thermodynamic equilibrium damage, dynamic condition unbalance, physical property limitation of the material and the like in the solidification process, so that coarse primary phases, dendrites and the like are generated in the ceramic, and meanwhile, a large number of large-angle grain boundaries are introduced, and the defects of the coarse primary phases, dendrites, cellular structures and the like can cause the problems of uneven structure, discrete mechanical properties, deterioration of high-temperature stability and the like of the oxide eutectic ceramic, and in the industries needing to bear ultrahigh temperature, high pressure, alternating load or corrosive environment for a long time, the defects can directly cause component failure, safety accidents or performance non-standard, such as the aerospace field, advanced manufacturing and extreme environment equipment field. How to realize uniform refinement and cooperative regulation of oxide eutectic ceramic solidification structures has become a bottleneck problem which is important in the field and needs to be solved. Disclosure of Invention In order to solve or partially solve the problems in the related art, the invention provides a preparation method of oxide eutectic ceramic with uniform refinement of a nano eutectic structure, and the method enables an amorphous sample to be uniformly crystallized to obtain the oxide eutectic ceramic sample with uniform refinement of a structure. In order to achieve the aim, the invention provides the following technical scheme that the preparation method of the oxide eutectic ceramic with the uniform refined nano eutectic structure is characterized in that the eutectic ceramic structure consists of the nano uniform refined eutectic structure, and the preparation method comprises the following steps: (1) Weighing, mixing, drying and sieving Al 2O3、RE2O3、ZrO2 ceramic powder, pressing into a ceramic blank, and then sintering and densifying the ceramic blank at high temperature to obtain an oxide eutectic ceramic preform; (2) Scanning and melting the oxide eutectic ceramic preform by using a high-energy laser beam, and solidifying to form an amorphous ceramic sample; (3) And (3) performing heat treatment on the amorphous ceramic sample obtained in the step (2) to obtain the uniformly refined nano eutectic structure oxide eutectic ceramic sample. Preferably, in step (1), the RE 2O3 is a rare earth oxide, where RE is a rare earth element, including Sc, Y, and lanthanoid. Preferably, in the step (1), the composite ceramic powder pressed into the ceramic body may be specifically combined and uniformly mixed by any one of the following modes: (1) Comprises Al 2O3 and RE 2O3, and the mole percentages of Al 2O3 and RE 2O3 are 82 percent and 18 percent; (2) Comprises Al 2O3 and RE 2O3, and the mole percentage of Al 2O3 and RE 2O3 is 77 percent and 23 percent; (3) Comprises 65%, 16% and 19% of Al 2O3、RE2