Abstract:
Disclosed are ceramic honeycomb articles which are composed predominately of a crystalline phase cordierite composition. The porous cordierite ceramic honeycomb articles has a plurality of cell channels and intersecting porous walls and possess a microstructure characterized by a pore size distribution wherein greater than or equal to 75% of the pore size distribution of the porosity of the porous walls, by volume, have a pore diameter (d v ) wherein d v v v90 -7 /°C from 25°C to 800°C. The articles exhibits high filtration efficiency coupled with low pressure drop across the filter. Additionally, high porosity articles having porosity greater than or equal to 40% and low surface roughness of Ra
Abstract:
Disclosed are cement compositions for applying to honeycomb substrates. The cement compositions contain an inorganic powder batch composition; a binder; a liquid vehicle; and an elastic modulus reducing additive. The elastic modulus reducing additive can contain a ceramic fiber or a monohydrated alumina. The cement compositions are well suited for forming ceramic diesel particulate wall flow filters. Also disclosed herein are end plugged wall flow filters that include the disclosed cement compositions and methods for the manufacture thereof.
Abstract:
A method is disclosed for manufacturing a zircon composition, the method comprising contacting a zircon powder with a sintering aid, wherein the sintering aid is in the form of a liquid, a sol, or a combination thereof. Also disclosed are methods for forming the zircon composition into a desired shape and for firing a composition to produce a ceramic body. The zircon composition and ceramic body produced by the described methods are also disclosed.
Abstract:
A composite material consisting essentially of ZrSiO 4 and sintering additives selected from Type I, Type II and Type III sintering additives and combinations thereof in amounts indicated below: Type I: 0.0 - 0.1 wt% selected from Fe 2 O 3 , SnO 2 , oxide glasses, and mixtures and combinations thereof; Type II: 0.1 - 0.8 wt% selected from TiO 2 , SiO 2 , VO 2 , CoO, NiO, NbO, and mixtures and combinations thereof; Type III: 0.0 - 0.8 wt% selected from Y 2 O 3 , ZrO 2 , CaO, MgO, Cr 2 O 3 , Al 2 O 3 , and mixtures and combinations thereof wherein the amount of sintering additives are weight percentages on an oxide basis of the total weight of the composition, as well as method for making such composite material. The present invention is particularly useful for making large-size refractory bodies resistant to creep at an elevated operating temperature, such as an isopipe for fusion draw glass making processes.
Abstract translation:基本上由ZrSiO4组成的复合材料和选自I型,II型和III型烧结添加剂的烧结添加剂及其组合,其数量如下所示:I型:0.0-0.1重量%选自Fe2O3,SnO2,氧化物玻璃和混合物, 其组合; II型:选自TiO 2,SiO 2,VO 2,CoO,NiO,NbO中的0.1-0.8wt%,以及它们的混合物和组合; III型:选自Y 2 O 3,ZrO 2,CaO,MgO,Cr 2 O 3,Al 2 O 3的0.0-0.8重量%,以及其混合物和组合,其中烧结添加剂的量是基于组合物总重量的氧化物的重量百分比,以及 作为制造这种复合材料的方法。 本发明特别可用于制造在升高的工作温度下耐蠕变的大尺寸耐火材料,例如用于熔融拉制玻璃制造工艺的等压槽。
Abstract:
A method of forming an improved sealed joint between two or more shaped ceramic structures includes providing at least first and second ceramic structures joined together by a joint comprising one or more of silicon, a silicon alloy and a silicon compound, the joint including an exposed portion interior of the joined structures, then converting at least a portion of the one or more of silicon, a silicon alloy, and a silicon compound of the joint to silicon nitride and/or silicon carbide, desirably at least at an interior exposed portion of the joint, so as to provide increased chemical resistance for the joint when aggressive chemicals are used within device formed from the sealed-together ceramic structures. The ceramic structures desirably comprise silicon carbide.
Abstract:
Disclosed are cordierite bodies having relatively low density with good mechanical strength. The porous cordierite bodies generally include a primary cordierite ceramic phase as defined herein. Also disclosed are methods for making and using the cordierite bodies.
Abstract:
Disclosed are cordierite bodies having relatively high porosity and controlled pore size. The porous cordierite bodies generally include a primary cordierite ceramic phase as defined herein. Also disclosed are methods for making and using the cordierite bodies.
Abstract:
A method for manufacturing a refractory ceramic body is disclosed. The method comprises contacting a zirconia precursor, a silica precursor, a sol-gel forming agent, and a preformed zircon. The method can further comprise forming the composition into a desired shape and firing the desired shape to form a dense, creep resistant refractory body. An article made by the methods above is disclosed, wherein a fine particle zircon is formed within and/or between grains of a preformed zircon.
Abstract:
Glass-bonded ceramics made of non-microcracked non-oxide or oxide ceramic particles which are bound together by glass into a unitary non-microcracked structure are disclosed. Such ceramics are suitable for use in substrates and filters, such as a diesel particulate filter.
Abstract:
Composite cordierite honeycomb structures especially suitable for diesel exhaust filtration applications comprise a non-oxide polycrystalline phase constituting 10-70 % by weight, with the remainder of the ceramic material constituting a cordierite phase, the non-oxide polycrystalline phase being selected from the group consisting of carbides, nitrides, and borides. Preferably the non-oxide phase is either polycrystalline silicon carbide or polycrystalline silicon nitride and has a particle aspect ratio of less than 3. Inventive ceramic bodies are porous with an open porosity of at least 30 %, preferably between 40 % and 60 %, and a median pore size of at least 5 micrometers, more preferably greater than 8 micrometers and less than 12 micrometers.