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CN-118005384-B - High-entropy rare earth silicate ceramic nano powder and preparation method and application thereof

CN118005384BCN 118005384 BCN118005384 BCN 118005384BCN-118005384-B

Abstract

The invention discloses high-entropy rare earth silicate ceramic nano powder and a preparation method and application thereof. The preparation method of the high-entropy rare earth silicate ceramic nano powder comprises the following steps of 1) dissolving rare earth oxide powder in an acid solution to prepare a rare earth salt solution, adding urea and silicon dioxide powder, then carrying out gelation reaction to obtain gel, 2) igniting the gel, carrying out combustion synthesis and grinding to obtain precursor powder, and 3) calcining the precursor powder to obtain the high-entropy rare earth silicate ceramic nano powder. The high-entropy rare earth silicate ceramic nano powder has the excellent characteristics of small particle size, uniform element distribution, large component space, no impurity and the like, and the preparation method has the advantages of high synthesis speed, simple and controllable equipment, simple and controllable process, low industrialization cost and the like, is suitable for being applied to hot-end parts of aerospace engines, and has very wide application prospects.

Inventors

  • CHU YANHUI
  • ZHAO SHIXIN
  • WEI PENG
  • ZHUANG LEI

Assignees

  • 华南理工大学

Dates

Publication Date
20260505
Application Date
20240102

Claims (7)

  1. 1. The preparation method of the high-entropy rare earth silicate ceramic nano powder is characterized by comprising the following steps of: 1) Dissolving rare earth oxide powder into an acid solution to prepare rare earth salt solution, wherein the rare earth oxide powder consists of at least four of Sc 2 O 3 powder, Y 2 O 3 powder, sm 2 O 3 powder, eu 2 O 3 powder, gd 2 O 3 powder, dy 2 O 3 powder, ho 2 O 3 powder, er 2 O 3 powder, tm 2 O 3 powder, yb 2 O 3 powder and Lu 2 O 3 powder, adding urea and silicon dioxide powder, and performing gelation reaction to obtain gel; 2) Igniting the gel to perform combustion synthesis and grinding to obtain precursor powder; 3) Calcining the precursor powder to obtain high-entropy rare earth silicate ceramic nano powder; The particle size of the silicon dioxide powder in the step 1) is 40 nm-60 nm; The ratio of the total molar quantity of the rare earth oxide powder to the molar quantity of urea in the step 1) is 1:2.50-2.75; The ratio of the total molar weight of rare earth atoms in the rare earth salt solution to the molar weight of silicon atoms in the silicon dioxide powder in the step 1) is 1:0.4-0.5 or 1:1.05-1.15, and is not 1:0.5; The gelation reaction is carried out at the temperature of 80-120 ℃ for 3-5 hours; The ignition temperature of the combustion synthesis is 400-600 ℃ and the synthesis time is 3-10 min; the specific operation of the calcination in the step 3) is that the temperature rising rate is controlled to be 6-8 ℃ per minute, the temperature is raised to 1250-1350 ℃ from the room temperature, the temperature is kept for 0.5-3 h, and the temperature is cooled to the room temperature along with a furnace.
  2. 2. The method according to claim 1, wherein the rare earth oxide powder in step 1) is composed of at least four of Sc 2 O 3 powder, Y 2 O 3 powder, sm 2 O 3 powder, eu 2 O 3 powder, gd 2 O 3 powder, dy 2 O 3 powder, ho 2 O 3 powder, er 2 O 3 powder, tm 2 O 3 powder, yb 2 O 3 powder and Lu 2 O 3 powder according to an equimolar ratio.
  3. 3. The preparation method of the rare earth oxide powder according to claim 1, wherein the particle size of the rare earth oxide powder in step 1) is 1-3 μm, the purity is not less than 99.9%, the purity of the urea in step 1) is analytically pure, and the purity of the silicon dioxide powder in step 1) is not less than 99.9%.
  4. 4. A high entropy rare earth silicate ceramic nano powder, characterized by being prepared by the preparation method of any one of claims 1-3.
  5. 5. The high-entropy rare earth silicate ceramic nano powder according to claim 4, wherein the average particle size of the high-entropy rare earth silicate ceramic nano powder is 60-80 nm.
  6. 6. An environmental barrier coating comprising the high entropy rare earth silicate ceramic nano powder of claim 4 or 5.
  7. 7. An aerospace engine wherein the hot end component surface is covered with the environmental barrier coating of claim 6.

Description

High-entropy rare earth silicate ceramic nano powder and preparation method and application thereof Technical Field The invention relates to the technical field of high-entropy ceramics, in particular to high-entropy rare earth silicate ceramic nano powder and a preparation method and application thereof. Background The high-entropy rare earth silicate (belonging to a high-entropy oxide system) has the excellent characteristics of good high-temperature phase stability, excellent corrosion resistance, excellent physical and chemical compatibility with a silicon-based ceramic matrix, and the like, is considered as the best candidate material of the next-generation environmental barrier coating, and has very wide application prospect on the hot end part of an aerospace engine. At present, the preparation method of the high-entropy rare earth silicate ceramic powder mainly comprises a solid-phase reaction method and a sol-gel method. The solid phase reaction method has the advantages of low cost, large yield, simple preparation process and the like, is the most commonly used method for synthesizing the high-entropy rare earth silicate ceramic powder (for example, ：Equiatomic quaternary(Y1/4Ho1/4Er1/4Yb1/4)2SiO5 silicate:A perspective multifunctional thermal and environmental barrier coating material,Xiaomin Ren,Zhilin Tian,Jie Zhang,JingyangWang.Scripta Materialia,2019,168:47-50),, but the method has the problems of high synthesis temperature (more than or equal to 1550 ℃), coarse powder particle size (30-40 mu m), uneven element distribution, impurity-containing phase, small component space and the like, and severely limits the development and the application of the high-performance high-entropy rare earth silicate ceramic. Therefore, the development of the preparation method of the high-entropy rare earth silicate ceramic powder has the advantages of simple and controllable equipment, simple and controllable process, low industrialization cost, convenience and rapidness, and the preparation of the high-entropy rare earth silicate ceramic nano powder with small particle size, uniform element distribution, high purity and large component space has very important significance. Disclosure of Invention The invention aims to provide high-entropy rare earth silicate ceramic nano powder and a preparation method and application thereof. The technical scheme adopted by the invention is as follows: the preparation method of the high-entropy rare earth silicate ceramic nano powder comprises the following steps: 1) Dissolving rare earth oxide powder into an acid solution to prepare rare earth salt solution, wherein the rare earth oxide powder consists of at least four of Sc 2O3 powder, Y 2O3 powder, sm 2O3 powder, eu 2O3 powder, gd 2O3 powder, dy 2O3 powder, ho 2O3 powder, er 2O3 powder, tm 2O3 powder, yb 2O3 powder and Lu 2O3 powder, adding urea and silicon dioxide powder, and performing gelation reaction to obtain gel; 2) Igniting the gel to perform combustion synthesis and grinding to obtain precursor powder; 3) Calcining the precursor powder to obtain the high-entropy rare earth silicate ceramic nano powder. Preferably, the rare earth oxide powder in the step 1) is composed of at least four of Sc 2O3 powder, Y 2O3 powder, sm 2O3 powder, eu 2O3 powder, gd 2O3 powder, dy 2O3 powder, ho 2O3 powder, er 2O3 powder, tm 2O3 powder, yb 2O3 powder, and Lu 2O3 powder according to an equimolar ratio. Preferably, the particle size of the rare earth oxide powder in the step 1) is 1-3 mu m, and the purity is more than or equal to 99.9%. Preferably, the acid solution in the step 1) is at least one of nitric acid solution and hydrochloric acid solution. Preferably, the urea (CO (NH 2)2) of step 1) is analytically pure in purity. Preferably, the particle size of the silicon dioxide powder in the step 1) is 40 nm-60 nm, and the purity is more than or equal to 99.9%. Preferably, the ratio of the total molar amount of the rare earth oxide powder in the step 1) to the molar amount of urea is 1:2.50-2.75. Preferably, the ratio of the total molar amount of the rare earth atoms in the rare earth salt solution in the step 1) to the molar amount of the silicon atoms in the silicon dioxide powder is 1:0.4-0.5 (synthesizing high-entropy rare earth monosilicate powder), or the ratio of the total molar amount of the rare earth atoms in the rare earth salt solution in the step 1) to the molar amount of the silicon atoms in the silicon dioxide powder is 1:1.05-1.15 (synthesizing high-entropy rare earth disilicate powder). Preferably, the gelation reaction in the step 1) is carried out at the temperature of 80-120 ℃ for 3-5 hours. Preferably, the gelation reaction of step 1) is performed in a stirred state. Preferably, the ignition temperature of the combustion synthesis in the step 2) is 400-600 ℃ and the synthesis time is 3-10 min. Preferably, the grinding time in the step 2) is 20-30 min. Preferably, the specific operation of the calcination in th