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CN-122010570-A - (TiZrHfNbTa) C single-phase high-entropy ceramic powder and preparation method thereof

CN122010570ACN 122010570 ACN122010570 ACN 122010570ACN-122010570-A

Abstract

A (TiZrHfNbTa) C single-phase high-entropy ceramic powder and a preparation method thereof relate to the technical field of ceramic powder and solve the problem that the existing preparation technology of high-entropy carbide ceramic powder is difficult to be suitable for industrial mass production. The preparation method comprises the steps of respectively carrying out pre-grinding activation treatment on metal oxide and carbon source, mixing the metal oxide and the carbon source subjected to pre-grinding activation with mixed molten salt, carrying out ball milling in a solvent to form mixed slurry, casting the mixed slurry in a graphite square boat, drying to obtain pretreated powder, discharging glue from the pretreated powder, firing the pretreated powder, adopting a two-stage heat preservation process, carrying out heat preservation at the temperature of 800-1000 ℃ for 1-4 h at the temperature of 800-1400 ℃ at the first stage, carrying out ball milling and crushing on the fired powder, and carrying out acid washing, water washing and drying. The invention can realize mass production and low-cost preparation, and the comprehensive performance is suitable for the requirements of industrial production and application.

Inventors

  • KONG XIANGRUI
  • XU CHENGUANG
  • WANG YUJIN
  • LI YING
  • HUANG RONGXIA
  • CAO YUE
  • YU YANG
  • ZANG JINTING

Assignees

  • 吉林长玉特陶新材料技术股份有限公司

Dates

Publication Date
20260512
Application Date
20260127

Claims (10)

  1. 1. The preparation method of (TiZrHfNbTa) C single-phase high-entropy ceramic powder is characterized by comprising the following steps: S1, respectively carrying out pre-grinding activation treatment on metal oxide and a carbon source, wherein the metal oxide comprises TiO 2 、ZrO 2 、HfO 2 、Nb 2 O 5 and Ta 2 O 5 , and the carbon source is selected from carbon black, sucrose or flour; S2, mixing the metal oxide and the carbon source subjected to pre-grinding activation with mixed molten salt, and performing ball milling in a solvent to form mixed slurry, wherein the mixed molten salt is an equal-mass mixture of at least two of NaCl, KCl, caCl 2 ; S3, casting the mixed slurry in a graphite ark, and drying to obtain pretreated powder; S4, firstly discharging glue from the pretreated powder, and then firing, wherein the firing process is to adopt a two-stage heat preservation process under vacuum or argon atmosphere, wherein the first stage is heated to 800-1000 ℃, the heat preservation is carried out for 1-4 hours, the second stage is heated to 1200-1400 ℃, and the heat preservation is carried out for 1-2 hours; And S5, ball milling and crushing the fired mixed powder, and carrying out acid washing, water washing and vacuum drying to obtain (TiZrHfNbTa) C single-phase high-entropy ceramic powder.
  2. 2. The method for preparing (TiZrHfNbTa) single-phase high-entropy ceramic powder according to claim 1, wherein the molar ratio of metal oxide to carbon source is TiO 2 ：ZrO 2 ：HfO 2 ：Nb 2 O 5 ：Ta 2 O 5 ：C=6-10x-10y：10x：10y：1：1：32,, wherein x is 0.05-0.2 and y is 0.05-0.2.
  3. 3. The method for producing (TiZrHfNbTa) C single-phase high-entropy ceramic powder according to claim 2, wherein the purity of TiO 2 is 99.9%, the particle size is 1 μm, the purity of ZrO 2 is 99.5%, the particle size is 10 μm, the purity of HfO 2 is 99.5%, the particle size is 5 μm, the purity of Nb 2 O 5 is 99.9%, the particle size is 1.5 μm, the purity of Ta 2 O 5 is 99.9%, the particle size is 5 μm, the purity is 99.9% when the carbon source is carbon black, the particle size is 2.5 μm, and the purity is 99% when the carbon source is sucrose or flour.
  4. 4. The preparation method of (TiZrHfNbTa) C single-phase high-entropy ceramic powder according to claim 1, wherein the pre-grinding activation treatment process is that the size of a ZrO 2 grinding ball is 0.2-5 mm, the ball mass ratio is 2-8:1, the ball milling rotating speed is 300-500 rpm, and the ball milling time is 2-8 hours.
  5. 5. The preparation method of (TiZrHfNbTa) C single-phase high-entropy ceramic powder according to claim 1 is characterized in that the solvent is a mixed solvent of absolute ethyl alcohol and PVA deionized water solution, the mass ratio is 1 (0.33-3), and the mass fraction of PVA in the PVA deionized water solution is 0.2-2%.
  6. 6. The preparation method of (TiZrHfNbTa) C single-phase high-entropy ceramic powder according to claim 1, wherein in the step S2, the ratio of the pre-milled activated metal oxide to the carbon source to the mixed molten salt is 1:2-8, and the ball milling process is that the size of a ZrO 2 grinding ball is 0.2-5 mm, the ball material mass ratio is 2-8:1, the ball milling rotating speed is 600-700 rpm, and the ball milling time is 2-8 hours.
  7. 7. The method for preparing (TiZrHfNbTa) C single-phase high-entropy ceramic powder according to claim 1, wherein the drying temperature in step S3 is 90-100 ℃ and the drying time is 1-2 h.
  8. 8. The method for preparing (TiZrHfNbTa) C single-phase high-entropy ceramic powder according to claim 1, wherein the process of discharging the gel is to raise the temperature to 400-600 ℃ in vacuum or argon atmosphere, and keep the temperature for 1-4 hours.
  9. 9. The preparation method of (TiZrHfNbTa) C single-phase high-entropy ceramic powder according to claim 1, wherein in the ball milling and crushing process in the step S5, the size of a ZrO 2 grinding ball is 0.2-5 mm, the ball-material ratio is 2-8:1, the ball milling speed is 300-400 rpm, the ball milling time is 4-8 hours, the pickling solution is 5-10 vol.% dilute HCl or dilute HNO 3 , the pickling time is 1-2 hours, the water washing is carried out by using deionized water with the temperature of 80-90 ℃, the water washing times are 2-3 times, the drying temperature is 90-100 ℃ and the time is 2-4 hours.
  10. 10. A (TiZrHfNbTa) C single-phase high-entropy ceramic powder, characterized in that it is prepared by using the preparation method according to any one of claims 1 to 9.

Description

(TiZrHfNbTa) C single-phase high-entropy ceramic powder and preparation method thereof Technical Field The invention relates to the technical field of ceramic powder, in particular to (TiZrHfNbTa) C single-phase high-entropy ceramic powder and a preparation method thereof. Background The concept of the high-entropy ceramic is derived from high-entropy alloy, particularly a multi-element ceramic material consisting of five or more metal elements with equivalent content, and (TiZrHfNbTa) C is taken as a high-entropy carbide ceramic which is systematically researched in the first batch, so that the high-entropy ceramic not only inherits the core advantages of high melting point, high hardness, high strength, excellent thermal stability, oxidation resistance, corrosion resistance and the like of the traditional carbide ceramic, but also shows synergistic enhancement effects superior to the average value of each single-element carbide in the aspects of mechanical property, thermal property, irradiation resistance, ablation resistance and the like, and the high-entropy ceramic has wide application potential in extreme service environments (such as high temperature, strong corrosion, strong irradiation and the like). The preparation core of the high-performance ceramic material depends on high-quality ceramic powder, and key technical indexes of the high-performance ceramic material comprise high purity, fine granularity, narrow particle size distribution and high reactivity, and the indexes directly determine the comprehensive performance of subsequent ceramic products. At present, the main preparation method of the (TiZrHfNbTa) C powder mainly comprises a solid solution method, a chemical combination reaction method, a carbothermic reduction method and a precursor synthesis method, and although the methods have certain technical feasibility, the methods have obvious limitations. The solid solution method takes single-component carbide powder as a raw material, and forms high-entropy carbide powder through high-temperature solid solution reaction, as reported in document High entropy carbide: a novel class of multicomponent ceramics, the (TiZrHfNbTa) C powder with the particle size of 2 mu m is prepared at 1950 ℃, and the method has the core defects that the preparation temperature is too high, the purity and the particle size of the powder highly depend on the quality of raw carbide, so that the particle size of a synthesized product is generally larger, and the preparation requirement of high-performance ceramic on fine powder is difficult to meet. The chemical reaction method takes metal simple substance powder and carbon powder as raw materials, prepares target powder by means of mechanochemical synthesis, high-temperature heating synthesis or combustion self-propagating synthesis and the like, adopts a ball milling process for 50-70 h in literature "Synthesis of all equiatomic five-transition metals high entropy carbides of the IVB(Ti, Zr, Hf) and VB(V, Nb, Ta)groups by a low temperature route" to synthesize (TiZrHfNbTa) C powder with the particle size of 100-300 nm, but has obvious industrialization bottleneck, the raw materials of the metal powder are high in cost, and the high chemical activity of the metal simple substance makes the metal simple substance extremely easy to react with oxygen in air to introduce oxygen impurities in the preparation process, so that the purity of the powder is difficult to control, and the operation process requirement is harsh. The carbothermic reduction method takes metal oxide and graphite powder as raw materials, and high-entropy carbide powder is prepared through high-temperature vacuum carbothermic reduction reaction, and the literature SYNTHESIS OF SINGLE-PHASE HIGH-entropy carbide powders adopts a two-step process, namely, the carbothermic reduction is carried out at 1600 ℃ and then the solid solution treatment is carried out at 2000 ℃, so that (TiZrHfNbTa) C powder with the particle size of 0.55 mu m and the oxygen content of 0.2wt.% is synthesized. The precursor synthesis method comprises the steps of preparing a polymer precursor solution with elements uniformly dispersed at molecular level through polymerization reaction of metal-containing monomers, decomposing and chemically reacting the precursor through high-temperature heat treatment to finally form single-phase high-entropy carbide powder, dissolving transition metal chloride in ethanol in the literature 'Liquid pre-reactor-DERIVED HIGH-entropy carbide nanopowders', adding furfuryl alcohol to perform polymerization reaction at 60 ℃ to prepare a Liquid-phase precursor, and performing vacuum carbothermal reduction at 1400 ℃ and heat treatment at 2000 ℃ to obtain (TiZrHfNbTa) C powder. In summary, no mature high-entropy ceramic powder industrial mass preparation technology exists at home and abroad at present, the existing preparation method is limited to a laboratory small-batch synthesis stage, and common p