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CN-121990831-A - Doped corrosion-resistant dioxin-resistant silicon carbide wear-resistant ceramic material

CN121990831ACN 121990831 ACN121990831 ACN 121990831ACN-121990831-A

Abstract

The invention provides a doped corrosion-resistant dioxin-resistant silicon carbide wear-resistant ceramic material, which relates to the technical field of advanced ceramic materials and comprises, by weight, 80-95 parts of silicon carbide powder, 1-10 parts of a functional dopant, 2-8 parts of a sintering aid, 2-5 parts of a toughening agent, 0.5-3 parts of a dispersing agent and 0.5-10 parts of a binder. The core function dopant is anatase TiO 2 inner core and core-shell structure nano powder containing mixed valence Ce/Sn silicate outer shell, and is prepared by sol-gel and heat treatment. The invention can successfully endow the material with long-acting and stable capabilities of resisting chemical corrosion and catalyzing and degrading dioxin at high temperature on the basis of keeping high strength and high wear resistance of the silicon carbide ceramic, and is suitable for extreme environments such as garbage incineration, chemical industry and the like.

Inventors

  • YUAN GENFANG

Assignees

  • 宜兴市中电耐磨耐火科技有限公司

Dates

Publication Date
20260508
Application Date
20260409

Claims (10)

  1. 1. The doped corrosion-resistant dioxin-resistant silicon carbide wear-resistant ceramic material is characterized by comprising, by weight, 80-95 parts of silicon carbide powder, 1-10 parts of functional dopants, 2-8 parts of sintering aids, 2-5 parts of toughening agents, 0.5-3 parts of dispersing agents and 0.5-10 parts of binders; The functional dopant is core-shell structure nano composite powder with an anatase phase TiO 2 inner core and a mixed valence Ce/Sn containing crystalline silicate outer shell, and the preparation method is as follows: (1) Carrying out ultrasonic treatment on anatase TiO 2 nano powder by dilute nitric acid, washing, and dispersing the powder in absolute ethyl alcohol to obtain TiO 2 dispersion; (2) Dissolving tetraethoxysilane in absolute ethyl alcohol, adding acid to adjust pH to 2-4, and obtaining acid-catalyzed silicate solution; (3) Mixing the metal salt solution with an acid-catalyzed silicate solution, adding the TiO 2 dispersion liquid, and slowly dropwise adding a water-ethanol mixed solution under the conditions of nitrogen protection, heating and stirring for hydrolysis-polycondensation reaction to form an amorphous coating layer; (4) After the reaction is finished, centrifugally collecting a solid product, washing and drying to obtain primary powder; (5) And (3) carrying out heat treatment on the primary powder at 340-360 ℃ in an oxygen atmosphere, then carrying out heat treatment at 600-900 ℃ in a nitrogen atmosphere, and cooling along with a furnace to obtain the functional dopant.
  2. 2. The doped corrosion-resistant dioxin-resistant silicon carbide wear-resistant ceramic material according to claim 1, wherein in the preparation process (1) of the functional dopant, the grain size of anatase phase TiO 2 nano powder is 20-50nm, and the dosage ratio of anatase phase TiO 2 nano powder to concentrated nitric acid is 1g to 100ml.
  3. 3. The doped corrosion-resistant and dioxin-resistant silicon carbide wear-resistant ceramic material according to claim 1, wherein in the preparation process (2) of the functional dopant, the metal salt is at least one of ceric ammonium nitrate, ceric nitrate, stannous chloride and stannic tetrachloride.
  4. 4. The doped corrosion-resistant and dioxin-resistant silicon carbide wear-resistant ceramic material according to claim 1, wherein in the preparation process (3) of the functional dopant, the mass ratio of TiO 2 to ethyl orthosilicate is 1:0.1-0.5, and the molar ratio of metal ions in metal salt to silicon in ethyl orthosilicate is 1:5-100.
  5. 5. A doped corrosion-resistant and dioxin-resistant silicon carbide wear-resistant ceramic material according to claim 1, wherein the silicon carbide matrix is formed by mixing four silicon carbide micro powders with different particle sizes of 0.1-10 μm according to a specific proportion, wherein the micro powders with the particle sizes of 0.1-1 μm account for 20-30%, the micro powders with the particle sizes of 1-5 μm account for 20-30%, the micro powders with the particle sizes of 5-20 μm account for 25-27%, and the micro powders with the particle sizes of 20-50 μm account for 20-25%.
  6. 6. A doped corrosion-resistant and dioxin-resistant silicon carbide wear-resistant ceramic material according to claim 1, characterized in that the sintering aid is a composite of Al 2 O 3 and a rare earth oxide, the rare earth oxide is at least one of Y 2 O 3 、Sc 2 O 3 、Yb 2 O 3 , and the molar ratio of Al 2 O 3 to rare earth oxide is 2.5-3.5:1.5-2.5.
  7. 7. A doped corrosion and dioxin resistant silicon carbide wear resistant ceramic material according to claim 1, wherein said toughening agent is chopped carbon fiber or graphene nanoplatelets.
  8. 8. A doped corrosion and dioxin resistant silicon carbide wear resistant ceramic material according to claim 1, wherein said dispersant is at least one of polyacrylic acid, sodium polycarboxylate, sodium humate, tetramethyl ammonium hydroxide or polyethylene glycol.
  9. 9. A doped corrosion and dioxin resistant silicon carbide wear resistant ceramic material according to claim 1, wherein said binder is at least one of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl methyl cellulose or polyvinylpyrrolidone.
  10. 10. A method for preparing a doped corrosion-resistant dioxin-resistant silicon carbide wear-resistant ceramic material according to any one of claims 1 to 9, comprising the steps of: S1, preparing a functional doping agent; S2, raw material mixing, namely weighing each component according to parts by weight, ball-milling and mixing silicon carbide powder, a functional doping agent, a sintering aid, a toughening agent and a dispersing agent for 4-12 hours at a rotating speed of 200-400rpm to obtain uniform slurry, and obtaining uniform slurry; S3, granulating and forming, namely drying the ball-milled slurry at 80-120 ℃, sieving, adding a binder for granulating, and performing dry pressing forming at 10-100MPa to obtain a ceramic green body, wherein the green body can be further subjected to cold isostatic pressing treatment, the pressure is 100-300MPa, and the pressure is maintained for 1-5min so as to improve the density and uniformity of the green body; S4, glue discharging and sintering, namely heating the green body to 400-600 ℃ at 0.5-2 ℃ per min, preserving heat for 1-3h, discharging glue, heating to 1800-2200 ℃ at 5-10 ℃ per min in inert atmosphere or vacuum, preserving heat for 0.5-3h, sintering, and cooling to room temperature along with a furnace to obtain the doped corrosion-resistant and dioxin-resistant silicon carbide wear-resistant ceramic material.

Description

Doped corrosion-resistant dioxin-resistant silicon carbide wear-resistant ceramic material Technical Field The invention relates to the technical field of advanced ceramic materials, in particular to a doped corrosion-resistant and dioxin-resistant silicon carbide wear-resistant ceramic material. Background Silicon carbide ceramics are widely used in the fields of mechanical sealing, wear-resistant parts, cutting tools and the like due to high hardness, high wear resistance, good thermal stability and chemical stability. However, in extremely severe environments such as waste incineration, chemical metallurgy, etc., equipment components are not only subjected to severe material wear, but are also exposed to high temperature, acidic/alkaline corrosive atmospheres, and persistent organic pollutants such as dioxins for a long period of time. The traditional silicon carbide ceramic or oxide ceramic has limited high-temperature corrosion resistance although being wear-resistant, does not have the function of degrading toxic gases, has short service life, and can cause secondary pollution due to adsorption or permeation of toxic substances on the surface of the material. Although the traditional silicon carbide ceramic has excellent mechanical properties, the traditional silicon carbide ceramic has relatively single function and lacks active corrosion resistance and catalytic purification capability. The sintering performance and the compactness of the silicon carbide are improved by adding sintering aids (such as Al 2O3, Y2O3 and the like), so that the mechanical performance and the corrosion resistance of the silicon carbide are improved to a certain extent. Attempts have also been made to support catalytic components (e.g., tiO 2) on ceramic surfaces to achieve photocatalytic functions. However, the simple surface loading has the problems of easy abrasion, falling-off and short service life of the catalytic layer, and the catalytic component is directly doped into the ceramic matrix, and the catalytic component is often deactivated or the mechanical property of the ceramic matrix is often damaged due to high-temperature sintering. On the premise of not sacrificing the inherent excellent mechanical property and wear resistance of the silicon carbide ceramic, the stable and long-acting corrosion resistance and the ability of catalyzing and degrading dioxin are endowed, and the technical problem to be solved in the field is urgent. Disclosure of Invention The invention provides a doped corrosion-resistant and dioxin-resistant silicon carbide wear-resistant ceramic material, which aims to solve the technical problems of stable, long-term and effective corrosion resistance and dioxin catalytic degradation capability of the traditional silicon carbide ceramic on the premise of inherent excellent mechanical properties and wear resistance. The technical scheme provided by the embodiment of the invention is as follows: The doped anti-corrosion anti-dioxin silicon carbide wear-resistant ceramic material provided by the embodiment of the invention comprises, by weight, 80-95 parts of silicon carbide powder, 1-10 parts of functional dopants, 2-8 parts of sintering aids, 2-5 parts of toughening agents, 0.5-3 parts of dispersing agents and 0.5-10 parts of binders; The preparation method of the functional dopant comprises the following steps: (1) Dispersing anatase phase TiO 2 nano powder in 0.1mol/L dilute nitric acid solution, carrying out ultrasonic treatment for 1h, centrifugally collecting, washing twice with deionized water and ethanol respectively, and re-dispersing the washed TiO2 nano powder in absolute ethanol to prepare ethanol dispersion with the concentration of about 20 mg/mL; (2) Dissolving metal salt in ethanol-water mixed solution (4:1, v/v), magnetically stirring for 5-10min to completely dissolve to obtain 3-8wt% metal salt solution, magnetically stirring Tetraethoxysilane (TEOS) and absolute ethanol to completely dissolve for 5-10min to obtain 10-20wt% silicate solution, adding concentrated hydrochloric acid to pH=2-4, and stirring for 4-6min to obtain acid-catalyzed silicate solution; (3) Slowly dripping a metal salt solution into an acid catalyzed silicate solution, uniformly mixing, adding an anatase phase TiO 2 nano powder dispersion liquid into the mixed system, heating to 50-70 ℃ under the protection of nitrogen, slowly dripping 10mL of mixed liquid consisting of deionized water and absolute ethyl alcohol according to the volume ratio of 1:1, controlling the dripping speed to be 1-2 drops/second, and keeping the dripping speed to be about 1-2 hours, wherein the process is the key of forming uniform coating, slowly hydrolyzing to promote the silicate hydrolysate to be uniformly nucleated and grown on the surface of TiO 2 nano crystal, keeping the constant temperature at 60 ℃ after the dripping is finished, and continuously stirring for reacting for 12-24 hours to fully polycondensate and solidify the