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CN-122010542-A - Whisker reinforced composite porous ceramic material and preparation method and application thereof

CN122010542ACN 122010542 ACN122010542 ACN 122010542ACN-122010542-A

Abstract

The invention discloses a whisker reinforced composite porous ceramic material, a preparation method and application thereof, which truly realizes the effective combination of the low thermal expansion characteristic of cordierite and the high strength characteristic of silicon carbide by combining factors such as the particle size of silicon carbide, sintering condition and the like based on a novel process of combining the silicon carbide with the cordierite, and aims to synchronously improve the thermal shock resistance and mechanical bearing capacity of the product so as to provide a DPF filter material with better performance. Furthermore, in order to optimize the filtering performance, mullite whiskers are grown in situ in the composite matrix, and a more efficient particulate matter trapping network is constructed, so that the three aspects of mechanical reliability, thermal stability and filtering efficiency are cooperatively improved.

Inventors

  • WEI NA
  • HUANG XIANPENG
  • CUI HONGZHI
  • SONG XIAOJIE
  • GONG XUEXIN

Assignees

  • 山东科技大学

Dates

Publication Date
20260512
Application Date
20260303

Claims (10)

  1. 1. The whisker reinforced composite porous ceramic material is characterized by comprising cordierite/silicon carbide composite honeycomb ceramic serving as a matrix and mullite whiskers in the matrix, wherein the cordierite/silicon carbide composite honeycomb ceramic is prepared by taking cordierite powder and silicon carbide powder as main raw materials, hydroxypropyl methylcellulose as a plasticizer, carbon powder as a pore-forming agent, titanium dioxide as a sintering aid and glycerol as a lubricant, adding a polyvinyl alcohol solution and deionized water, uniformly mixing, vacuum pugging and ageing, extruding by a honeycomb die, drying, and performing reaction sintering.
  2. 2. A preparation method of whisker reinforced composite porous ceramic material is characterized by firstly taking cordierite powder and silicon carbide powder as main raw materials, obtaining the composite porous honeycomb ceramic material through reaction sintering, and then using a vapor phase growth method to reinforce the surface of the composite porous wind wave ceramic material through dipping in dipping liquid to provide Si source and Al source required by synthesizing mullite whisker.
  3. 3. The method of preparing a whisker reinforced composite porous ceramic material according to claim 2, comprising the steps of: step 1, preparing cordierite/silicon carbide composite honeycomb ceramic Mixing 20-80wt.% of cordierite powder, 20-80wt.% of silicon carbide powder and 0-15wt.% of carbon powder, wherein the particle size of the silicon carbide powder is 200-500 meshes, adding titanium dioxide as a sintering aid, a polyvinyl alcohol aqueous solution as a binder, hydroxypropyl methylcellulose, deionized water and glycerol, mixing, pugging, ageing, extruding, and sintering to obtain the composite material; and 2, generating mullite whiskers in situ from the cordierite/silicon carbide composite honeycomb ceramic prepared in the step 1.
  4. 4. A method of producing a whisker reinforced composite porous ceramic material according to claim 3, wherein in step 1, 0 to 9wt.% of titanium dioxide, 0.27 to 0.33wt.% of polyvinyl alcohol, 7 to 9wt.% of hydroxypropyl methylcellulose, 29 to 35wt.% of deionized water and 4.5 to 5.5wt.% of glycerin are added in terms of the content relative to cordierite and silicon carbide powders.
  5. 5. A method of preparing a whisker reinforced composite porous ceramic material according to claim 3, wherein step 1 comprises the steps of: step 101, mixing the materials according to the required proportion; 102, performing ordinary mud refining and vacuum mud refining on the mixed raw materials; step 103, sealing and aging the mud block obtained in the step 102 to 44-52 h; step 104, using ceramic extrusion molding equipment to extrude and mold the mud block obtained in the step 103, and aging for 44-52h; and 105, sintering and preserving heat for 2-4 h at room temperature to 400 ℃ at 4 ℃ per minute, 400-1000 ℃ at 3 ℃ per minute and 1000-1150 ℃ at 2 ℃ per minute.
  6. 6. The method for preparing the whisker reinforced composite porous ceramic material according to claim 3, wherein in the step 2, silica sol, aluminum nitrate solution and ammonium fluoride solution are prepared respectively, the cordierite/silicon carbide composite honeycomb ceramic prepared in the step 1 is immersed in the three impregnating solutions prepared in the step 2 in sequence, the impregnating process is that firstly, the composite porous ceramic material is immersed in one impregnating solution, whisker formation is promoted at a low temperature to enable the whisker to be combined with a matrix, then the composite porous ceramic material is dried, then the composite porous ceramic material is moved into the other impregnating solution, the composite porous ceramic material is respectively put into the three impregnating solutions for repeating the steps, after the third drying, the honeycomb ceramic is put into a corundum crucible, sintered for 1-3 h at 900-1100 ℃ in a muffle furnace, and the composite porous ceramic material is taken out after natural cooling.
  7. 7. The method for preparing the whisker reinforced composite porous ceramic material according to claim 3, wherein the cordierite/silicon carbide composite honeycomb ceramic material serving as the substrate prepared in the step 1 has a porosity of not less than 49.24%, a flexural strength of not less than 3.01 MPa, no cracking at least 15 times during a thermal shock cycle at room temperature to 650 ℃, a trapping efficiency of not less than 87.45%, and an acid corrosion rate of not more than 1.42%.
  8. 8. The method for preparing a whisker reinforced composite porous ceramic material according to claim 3, wherein the method for preparing the cordierite/silicon carbide composite honeycomb ceramic material comprises mixing 40wt.% of cordierite powder, 60wt.% of silicon carbide powder and 6wt.% of carbon powder, wherein the particle size of the silicon carbide powder is 300 meshes, adding titanium dioxide as a sintering aid, a polyvinyl alcohol aqueous solution as a binder, and hydroxypropyl methylcellulose, deionized water and glycerin, mixing, pugging, aging, extrusion molding, and sintering.
  9. 9. Use of the whisker reinforced composite porous ceramic material of claim 1 in the preparation of a filter material.
  10. 10. Use of the whisker reinforced composite porous ceramic material of claim 1 in a diesel particulate trap.

Description

Whisker reinforced composite porous ceramic material and preparation method and application thereof Technical Field The invention belongs to the technical field of porous honeycomb ceramic filters, and particularly relates to a whisker reinforced composite porous ceramic material, and a preparation method and application thereof. Background The statements herein merely provide background information related to the present disclosure and may not necessarily constitute prior art. Diesel particulate traps (DPFs) are key aftertreatment devices that reduce exhaust particulate emissions, with the overall performance of the filter material directly affecting the reliability and life of the trap. The conventional substrate material of DPF is porous ceramic material, and the wall flow type honeycomb ceramic filter body material is prepared from silicon carbide (SiC), cordierite (2MgO.2Al 2O3·5SiO2), aluminum titanate (Al 2O3·TiO2), mullite (3 Al 2O3·2SiO2) and the like. Currently, commercial DPF filter bodies mainly use two materials, cordierite and silicon carbide. The cordierite material has low thermal expansion coefficient and excellent thermal shock resistance, so that thermal stress impact caused by severe fluctuation of exhaust temperature of a diesel engine can be effectively applied. However, its mechanical strength is relatively inadequate, with structural risks under mechanical vibration or high temperature loads. The prior art (CN 119118640A) discloses a cordierite carrier and a preparation method thereof, wherein the cordierite carrier is obtained by mixing, drying and sintering raw materials, and the method synthesizes the carrier with low expansion coefficient, but the material has poor mechanical property and low porosity and is difficult to use for a long time in the working environment. On the contrary, silicon carbide shows excellent mechanical strength, oxidation resistance and wear resistance by virtue of the characteristic of strong covalent bond, but the high thermal expansion coefficient leads to insufficient thermal shock resistance of the body, so that the requirements on a packaging structure in application are very severe, and the process complexity and cost are increased. The prior art (CN 120554139 a) discloses a method for synthesizing silicon carbide particle catcher in situ, which prepares the filter body by reacting metal silicon powder with graphite powder. Although the method can obtain the silicon carbide monomer with high strength, the high thermal expansion characteristic of the material is not improved at all, the thermal shock resistance is still challenging, and meanwhile, the compact sintered body has limitation in maintaining enough porosity to balance the filtration efficiency and the back pressure. In order to achieve both low thermal expansion and high mechanical properties, researchers combine silicon carbide and cordierite to prepare porous ceramics, li Dan discusses the influence of the content of cordierite and the particle size of different silicon carbides on properties including bending/flexural strength, porosity, shrinkage and the like of products in the research of the cordierite-combined silicon carbide porous ceramics in the article of the university of the same, but the acid resistance of the products is poor. Meanwhile, the cordierite addition amount is small, which indicates that the thermal expansion performance of the product is not researched. The mullite fiber is doped with ceramic matrix materials to improve the mechanical properties of ceramics, and the prior art (CN 103601480A) provides a preparation method of a filter body for capturing soot particles of a diesel engine, which comprises the following steps of uniformly mixing cordierite, silicon carbide and superfine mullite, adding auxiliary materials such as pore formers, binders, plasticizers, deionized water and the like, mixing, pugging, molding, microwave drying, a special hole sealing process and high-temperature sintering to obtain the filter body, wherein the softening temperature of the prepared filter body is more than or equal to 1510 ℃, and the filter body is suddenly changed for 3 times under 600 ℃ without cracking. The honeycomb carrier prepared by the technology has good high temperature resistance and thermal shock resistance, the softening temperature is more than or equal to 1510 ℃, and the honeycomb carrier does not crack after being subjected to rapid cooling and heating for 3 times at 600 ℃. However, in the technical scheme, the sintering temperature is as high as 1450 ℃, so that the production cost is high, and secondly, the thermal shock resistance cycle times of the filter body are limited, and the repeated use of materials is difficult to realize, so that the application in industrial mass production is restricted. Disclosure of Invention Aiming at the limitation of the prior art, the invention provides a whisker reinforced composite porous ceramic material, a preparation