Research On Preparing Cordierite With Three-dimensional Connection Structure And Regulating Its Performance

In this paper,the first principle calculation was used as the performance theory support,and the particle-stabilized microemulsion was the preparation process.Through the study of the inorganic particle colloidal surface chemistry and the stability of the slurry system,the process parameters were optimized to prepare three-dimensional connected Porous Cordierite with "hole-window" structure and toughen the matrix to discuss its toughening mechanism.(1)Through first-principle calculations,the crystal structure of Cordierite was predicted,which had a high degree of symmetry in different axis projections.The band width based on density functional theory was difficult to jump.DOS had X-axis symmetry,and its Fermi energy level was in the range where the DOS value was zero,and had certain insulation.The hightemperature Cordierite lattice vibration effect diagram was basically consistent with room temperature,and had excellent high temperature resistance.This experiment was based on quantum mechanics and predicted the physical and chemical properties of Cordierite by simulating the laws of electron motion,providing theoretical support for its excellent properties.(2)The study on the surface chemistry of inorganic particles and the stability of the slurry system found that the absolute value of Zeta potential was the lowest when the p H value was 10,and the stability of the precursor was the best.CMC as a binder,PAA as a dispersant and PG as a surfactant could obtain a slurry with a solid content of 40 vol %.The prepared porous Cordierite had a complete structure,a smooth surface without defects,and a small shrinkage rate.Particle-stabilized microemulsion overcomed the disadvantages of other preparation processes which lead to the complex pore structure,large pore size span and uneven distribution of porous Cordierite.Three-dimensionally connected porous Cordierite ceramics with complete pore structure,uniform pore size distribution and high porosity were prepared after hightemperature sintering.(3)Using corn starch and sucrose as pore-forming agents could significantly increase the porosity,optimize the pore size,and successfully prepare porous Cordierite with "hole-window" structure.Experimental studies have found that an appropriate amount of pore-forming agent had a positive effect on the microstructure,mechanical properties and thermal conductivity of porous Cordierite.The stable Cordierite phase inhibited the chemical corrosion of porous Cordierite in strong acid and alkali media.Using corn starch and sucrose as porogens,the preparation of porous Cordierite with "hole-window" structure controlled by particle-stabilized microemulsion had potential application prospects in catalyst support and filtration.(4)Regular hexagonal α-Al2O3 powder particles prepared by the molten salt method was used as matrix reinforcement raw materials to papere porous Cordierite.The template grain growth technology as a starting point to toughen the foam ceramic and discusses the toughening mechanism.When the raw material particle size was 20 nm,the amount of Zr O2 added was 4 wt%,and the amount of Al F3 added was 3 wt%,the fracture toughness of porous Cordierite was greatly improved.Adding mullite fiber destroied the stability and compatibility of colloidal particles,leading to unsuccessful foaming and poor toughening effect.In this experiment,the control pore structure and the matrix toughening mechanism were integrated,and the foam ceramic matrix was strengthened and toughened successfully on the basis of preparing a threedimensional through porous Cordierite ceramic.