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CN-121698657-B - Ceramic material, ceramic and preparation method thereof

CN121698657BCN 121698657 BCN121698657 BCN 121698657BCN-121698657-B

Abstract

The invention provides a ceramic material and a ceramic and a preparation method thereof, wherein the ceramic material comprises silicon carbide and multi-stage coated graphene, the multi-stage coated graphene comprises graphene particles, a metal layer and a soft carbon layer, the metal layer is coated on the surfaces of the graphene particles, and the soft carbon layer is coated on the surfaces of the metal layer.

Inventors

  • SONG QI
  • JIANG BIN
  • YU LEI
  • WANG HUIMING
  • LI NIE

Assignees

  • 雷索新材料(苏州)有限公司

Dates

Publication Date
20260512
Application Date
20260212

Claims (9)

  1. 1. The ceramic material is characterized by comprising silicon carbide and multi-stage coated graphene; the multi-stage coated graphene comprises graphene particles, a metal layer and a soft carbon layer, wherein the metal layer is coated on the surfaces of the graphene particles, and the soft carbon layer is coated on the surfaces of the metal layer; the metal layer comprises at least one of iron, nickel, cobalt and manganese; the preparation method of the multistage coated graphene comprises the following steps: Dispersing the graphene particles and metal chloride in a solvent, and adding an acidic solution to react, wherein the acidic solution comprises oxalic acid to obtain a primary coating product; adding a solution of a water-soluble polymer into the solution containing the primary coating product, dispersing, and drying to obtain precursor powder; and carrying out first heat treatment on the precursor powder at 100-200 ℃ and then carrying out second heat treatment at 400-600 ℃ under the anaerobic condition to obtain the multi-stage coated graphene.
  2. 2. The ceramic material according to claim 1, wherein a mass ratio of the metal layer to the soft carbon layer is 1 (0.5 to 2.5); And/or the mass ratio of the graphene particles to the metal layer is 1 (0.05-0.25).
  3. 3. The ceramic material of claim 1, wherein the graphene particles have a thickness of 1-3nm and a sheet diameter of 10-100 μm.
  4. 4. The ceramic material according to claim 1, further comprising a sintering aid, wherein the ceramic material comprises the following mass components, based on 100% of the ceramic material mass: 80-90% of silicon carbide, 5-15% of multi-stage coated graphene, 1-5% of sintering aid and 1-5% of binder.
  5. 5. A ceramic prepared from the ceramic material of any one of claims 1-4.
  6. 6. The method for preparing ceramic according to claim 5, comprising the steps of: Mixing silicon carbide powder, multilevel coated graphene, sintering aid and binder to prepare a blank; And performing gradient sintering on the green body in a protective atmosphere, wherein the soft carbon layer coated with graphene in multiple stages is converted into graphitized carbon to obtain ceramic, the gradient sintering comprises a first sintering, a second sintering and a third sintering, and the temperatures of the first sintering, the second sintering and the third sintering are sequentially increased.
  7. 7. The method of claim 6, wherein the first sintering temperature is 500-800 ℃; The temperature of the second sintering is 900-1500 ℃; the temperature of the third sintering is 1500-2000 ℃.
  8. 8. The method according to claim 6, wherein the metal chloride is one or more selected from the group consisting of ferric chloride, nickel chloride, cobalt chloride, and manganese chloride; and/or the water-soluble polymer is selected from one or more of chitosan, starch, sodium alginate, lignin sulfonate and water-soluble phenolic resin prepolymer.
  9. 9. The preparation method of claim 6, wherein the mass ratio of the graphene particles to the metal chloride is 1:0.1-0.5; and/or the mass concentration of the solution of the water-soluble polymer is 5-10%.

Description

Ceramic material, ceramic and preparation method thereof Technical Field The invention relates to the technical field of ceramics, in particular to a ceramic material, ceramic and a preparation method thereof. Background Silicon carbide ceramics are widely used in high temperature, corrosive and abrasive environments due to their excellent high temperature stability, wear resistance and chemical inertness. In order to enhance the conductivity, the prior art generally adopts a method of directly blending carbon materials such as graphene, carbon nanotubes or conductive carbon black with silicon carbide powder and then sintering, however, the method has obvious limitations that firstly, the physical blending is difficult to uniformly disperse the carbon materials in a ceramic matrix and form a complete and continuous conductive network, so that the conductivity of the composite material is limited, and secondly, when the adding amount of the carbon materials is increased to realize higher conductivity, the interface bonding between the carbon materials and the silicon carbide matrix is weak and the sintering densification process of ceramic particles can be blocked, so that the mechanical properties of the material, such as bending strength, are seriously reduced. Therefore, there is a need for a ceramic material with high conductivity and high mechanical strength, and a method for preparing the same. Disclosure of Invention The invention aims to provide a ceramic material, ceramic and a preparation method thereof, which are used for solving the problems of weak conductivity and reduced bending strength of silicon carbide ceramics in the prior art. The technical scheme adopted by the invention for solving the technical problems is as follows: in a first aspect, the present invention provides a ceramic material comprising silicon carbide and multi-stage coated graphene; the multistage coated graphene comprises graphene particles, a metal layer and a soft carbon layer, wherein the metal layer is coated on the surfaces of the graphene particles, and the soft carbon layer is coated on the surfaces of the metal layer. Optionally, the metal layer includes at least one of iron, nickel, cobalt, and manganese. Optionally, the mass ratio of the metal layer to the soft carbon layer is 1 (0.5-2.5); And/or the mass ratio of the graphene particles to the metal layer is 1 (0.05-0.25). Optionally, the thickness of the graphene particles is 1-3nm, and the sheet diameter of the graphene particles is 10-100 μm. Optionally, the ceramic material further comprises a sintering aid, wherein the ceramic material comprises the following components in percentage by mass based on 100% of the ceramic material: 80-90% of silicon carbide, 5-15% of multi-stage coated graphene, 1-5% of sintering aid and 1-5% of binder. In a second aspect, the present invention provides a ceramic prepared from the ceramic material described above. In a third aspect, the present invention provides a method for preparing the above ceramic, comprising the steps of: dispersing graphene particles and metal chloride in a solvent, and adding an acidic solution to react to obtain a primary coating product; adding a solution of a water-soluble polymer into the solution containing the primary coating product, dispersing, and drying to obtain precursor powder; performing first heat treatment on the precursor powder at 100-200 ℃ and then performing second heat treatment under the anaerobic condition at 400-600 ℃ to obtain multi-stage coated graphene; Mixing silicon carbide powder, the multilevel coated graphene, a sintering aid and a binder to prepare a blank; And performing gradient sintering on the green body in a protective atmosphere, wherein the soft carbon layer coated with graphene in multiple stages is converted into graphitized carbon to obtain ceramic, the gradient sintering comprises a first sintering, a second sintering and a third sintering, and the temperatures of the first sintering, the second sintering and the third sintering are sequentially increased. Optionally, the temperature of the first sintering is 500-800 ℃; The temperature of the second sintering is 900-1500 ℃; the temperature of the third sintering is 1500-2000 ℃. Optionally, the metal chloride is selected from one or more of ferric chloride, nickel chloride, cobalt chloride and manganese chloride; and/or the water-soluble polymer is selected from one or more of chitosan, starch, sodium alginate, lignin sulfonate and water-soluble phenolic resin prepolymer. Optionally, the mass ratio of the graphene particles to the metal chloride is 1:0.1-0.5; and/or the mass concentration of the solution of the water-soluble polymer is 5-10%. According to the multi-stage coated graphene disclosed by the invention, the graphene particles are used as conductive cores, the metal layer and the soft carbon layer are constructed on the surfaces, the metal layer is used as a catalyst in the subsequent sintering, so