摘要:
This invention provides a system and method for establishing proper quantities of components in the initial mixture to be used in the fabrication of a porous ceramic substrate. The components typically consist of a solvent, a bulk fiber such as mullite, an organic binder for use in extrusion of the green substrate, a glass/clay bonding phase that bonds the fibers upon high-temperature curing and a pore former that defines gaps between the particles and is vaporized out of the substrate during curing. By identifying the controllable factors related to each of the components, and adjusting the factors to vary the resulting strength and porosity of the cured substrate, an optimized strength and porosity performance can be achieved. The controlling factors for each component include its relative weight percent in the mixture. The fiber component is also controlled via fiber diameter, diameter uniformity, and fiber length-to-diameter aspect ratio. Likewise, pore former is also controlled by particle size and shape and particle density. The bonding phase may also be controlled based upon its contribution to the viscosity at sintering temperature.
摘要:
A fibrous ceramic material comprises a plurality of fibers having a modified aluminosilicate compositional structure (i.e., x(RO).y(Al2O3).z(SiO2) or w(MO).x(RO).y(Al2O3).z(SiO2)). The fibrous ceramic material is form by combining two or more x(RO).y(Al2O3).z(SiO2) or w(MO).x(RO).y(Al2O3).z(SiO2) precursors in which at least one of the two or more precursors is in fiber form. The resulting fibrous ceramic material has a low coefficient of thermal expansion (i.e., ≦4.7×10-6/° C.).
摘要翻译:纤维状陶瓷材料包括多个具有改性的硅铝酸盐组成结构的纤维(即,x(RO)y(Al 2 O 3)z(SiO 2)或w(MO)x(RO)y(Al 2 O 3) SiO 2))。 纤维状陶瓷材料是通过组合两种或多种x(RO)y(Al 2 O 3)z(SiO 2)或w(MO)x(RO)y(Al 2 O 3)z(SiO 2)前体形成的,其中至少 两种或更多种前体之一是纤维形式。 所得到的纤维状陶瓷材料的热膨胀系数(即,n1E = 4.7×10-6 /℃)。
摘要:
A fibrous ceramic material comprises a plurality of fibers having a RxMg2Al4+xSi5−xO18 or RxMg2−xAl4Si5O18 compositional structure. The fibrous ceramic material is form by combining two or more RxMg2Al4+xSi5−xO18 or RxMg2−xAl4Si5O18 precursors in which at least one of the two or more RxMg2Al4+xSi5−xO18 or RxMg2−xAl4Si5O18 precursors is in fiber form. The fibrous ceramic material is shaped to form a fibrous body in which at least about 20% of all fibers therein are aligned in a substantially common direction.
摘要:
A method is provided for producing a highly porous substrate. More particularly, the present invention enables fibers, such as organic, inorganic, glass, ceramic, polymer, or metal fibers, to be combined with binders and additives, and extruded, to form a porous substrate. Depending on the selection of the constituents used to form an extrudable mixture, the present invention enables substrate porosities of about 60% to about 90%, and enables process advantages at other porosities, as well. The extrudable mixture may use a wide variety of fibers and additives, and is adaptable to a wide variety of operating environments and applications. Additives can be selected that form inorganic bonds between overlapping fibers in the extruded substrate that provide enhanced strength and performance of the porous substrate in a variety of applications, such as, for example, filtration and as a host for catalytic processes, such as catalytic converters.
摘要:
A highly porous substrate is provided using an extrusion system. More particularly, the present invention enables the production of a highly porous substrate. Depending on the particular mixture, the present invention enables substrate porosities of about 60% to about 90%, and enables advantages at other porosities, as well. The extrusion system enables the use of a wide variety of fibers and additives, and is adaptable to a wide variety of operating environments and applications. Fibers, which have an aspect ratio greater than 1, are selected according to substrate requirements, and are typically mixed with binders, pore-formers, extrusion aids, and fluid to form a homogeneous extrudable mass. The homogeneous mass is extruded into a green substrate. The more volatile material is preferentially removed from the green substrate, which allows the fibers to form interconnected networks. As the curing process continues, fiber to fiber bonds are formed to produce a structure having a substantially open pore network. The resulting porous substrate is useful in many applications, for example, as a substrate for a filter or catalyst host, or catalytic converter.
摘要:
A fibrous ceramic material comprises a plurality of fibers having a RxMg2Al4+xSi5−xO18 or RxMg2−xAl4Si5O18 compositional structure. The fibrous ceramic material is form by combining two or more RxMg2Al4+xSi5−xO18 or RxMg2−xAl4Si5O18 precursors in which at least one of the two or more RxMg2Al4+xSi5−xO18 or RxMg2−xAl4Si5O18 precursors is in fiber form. The fibrous ceramic material is shaped to form a fibrous body in which at least about 20% of all fibers therein are aligned in a substantially common direction.
摘要翻译:一种纤维状陶瓷材料包括多个具有R x 2 M 2 H 2 Al 4+ x 5 Si 5-x SUB的纤维 或者R x 2 x x 2 O x Si x O 2 O 3 组成结构。 纤维状陶瓷材料是通过组合两个或更多个R 2 M 2 H 2 Al 4+ x 3 Si 5-x SUB 或者R x 2 x x 2 O x Si x O 2 O 3 其中两个或更多个R x 2 Al 2+ 4+ x Si 3+中的至少一个的前体, 或者R x 2 x x Al x Si 2 O x Si x Si x Si x Si x Si x Si x Si x Si x 前体是纤维形式。 纤维状陶瓷材料成形为形成纤维体,其中至少约20%的纤维在基本上共同的方向上排列。
摘要:
A porous substrate produced by an extrusion process consisting essentially of bonded fibers is fabricated as a segmented substrate by joining a plurality of substrate segments with an adhesive that comprising fibers. The adhesive is bonded to fibers in the substrate segments to provide mechanical strength of the segmented substrate. The fibers in the adhesive provide a reduced elastic modulus in the adhesive layer that maintains a highly elastic structure between the segments in order to mitigate thermally induced mechanical stress when thermal gradients develop within the porous substrate during operation. The segmented porous fibrous substrate disclosed can be fabricated from a variety of materials to provide for effective filtration and as a catalytic host in various applications, including exhaust filtration of internal combustion engines.
摘要:
A highly porous substrate is provided using an extrusion system. More particularly, the present invention enables the production of a highly porous substrate. Depending on the particular mixture, the present invention enables substrate porosities of about 60% to about 90%, and enables advantages at other porosities, as well. The extrusion system enables the use of a wide variety of fibers and additives, and is adaptable to a wide variety of operating environments and applications. Fibers, which have an aspect ratio greater than 1, are selected according to substrate requirements, and are typically mixed with binders, pore-formers, extrusion aids, and fluid to form a homogeneous extrudable mass. The homogeneous mass is extruded into a green substrate. The more volatile material is preferentially removed from the green substrate, which allows the fibers to form interconnected networks. As the curing process continues, fiber to fiber bonds are formed to produce a structure having a substantially open pore network. The resulting porous substrate is useful in many applications, for example, as a substrate for a filter or catalyst host, or catalytic converter.
摘要:
A fibrous ceramic material comprises a plurality of fibers having a modified aluminosilicate compositional structure (i.e., x(RO).y(Al2O3).z(SiO2) or w(MO).x(RO).y(Al2O3).z(SiO2)). The fibrous ceramic material is form by combining two or more x(RO).y(Al2O3).z(SiO2) or w(MO).x(RO).y(Al2O3).z(SiO2) precursors in which at least one of the two or more precursors is in fiber form. The resulting fibrous ceramic material has a low coefficient of thermal expansion (i.e., ≦4.7×10−6/° C.).
摘要翻译:纤维状陶瓷材料包括多个具有改性的硅铝酸盐组成结构的纤维(即,x(RO)2,(Al 2 O 3 O 3))z(SiO ))。 纤维状陶瓷材料是通过组合两种或更多种x(RO)2(α2 O 3 O 3),z(SiO 2/2) 或w(MO)x(RO)2(O 2 O 3 O 3)z(SiO 2)前体,其中至少 两种或更多种前体之一是纤维形式。 所得到的纤维状陶瓷材料具有低的热膨胀系数(即<= 4.7×10 -6 -6℃)。
摘要:
A highly porous substrate is provided using an extrusion system. More particularly, the present invention enables the production of a highly porous substrate. Depending on the particular mixture, the present invention enables substrate porosities of about 60% to about 90%, and enables advantages at other porosities, as well. The extrusion system enables the use of a wide variety of fibers and additives, and is adaptable to a wide variety of operating environments and applications. Fibers, which have an aspect ratio greater than 1, are selected according to substrate requirements, and are typically mixed with binders, pore-formers, extrusion aids, and fluid to form a homogeneous extrudable mass. The homogeneous mass is extruded into a green substrate. The more volatile material is preferentially removed from the green substrate, which allows the fibers to form interconnected networks. As the curing process continues, fiber to fiber bonds are formed to produce a structure having a substantially open pore network. The resulting porous substrate is useful in many applications, for example, as a substrate for a filter or catalyst host, or catalytic converter.