Methods for applying a washcoat and heat treating a ceramic honeycomb, and treated articles
    2.
    发明申请
    Methods for applying a washcoat and heat treating a ceramic honeycomb, and treated articles 有权
    用于涂覆修补基面涂层和热处理陶瓷蜂窝体的方法以及处理过的制品

    公开(公告)号:US20090142541A1

    公开(公告)日:2009-06-04

    申请号:US11998288

    申请日:2007-11-29

    IPC分类号: B32B3/12 B05D3/02

    摘要: A method for treating a microcracked, ceramic substrate is provided that obviates the need for filling the microcracks of the substrate via a passivation step prior to sintering a layer of washcoat to the surfaces of the substrate that may either contain a catalyst, or provide a support layer for a catalyst subsequently applied. In the first step of the method, a slurry of particles of a washcoating composition is applied over the surface of the substrate such that particles of the composition are lodged into microcracks of the substrate. Next, the substrate is heat treated to between about 700° C. and 1300° C. The applicants have discovered that such heat treating not only sets the washcoating particles into the substrate, but also causes the microcracks in the substrate to permanently enlarge as a result of the resistance of the lodged particles of washcoating composition against the walls of the microcracks as they attempt to close as a result of thermal expansion of the substrate. The consequent enlargement of the microcracks advantageously reduces both the coefficient of thermal expansion (CTE) and the modulus of elasticity (Emod) of the resulting substrate without substantially reducing the modulus of rupture strength (MOR) of the resulting substrate such that the thermal shock parameter TSP=MOR/[CTE·Emod] remains substantially the same or is higher. The method is particularly applicable to ceramic honeycomb structures used as catalytic converters in automotive exhaust systems.

    摘要翻译: 提供了一种用于处理微裂纹陶瓷基底的方法,其消除了在将一层修补基面涂层烧结到可含有催化剂的基底表面之前经由钝化步骤填充基底的微裂纹的需要,或提供载体 随后应用催化剂层。 在该方法的第一步中,将一种洗涤涂层组合物的颗粒的浆料施加在基材的表面上,使得该组合物的颗粒浸入基材的微裂纹中。 接下来,将基板热处理至约700℃至1300℃。申请人已经发现,这种热处理不仅将洗涂层颗粒设置到基板中,而且还使得基板中的微裂纹作为 由于衬底的热膨胀,试图关闭时,洗涂组合物的填充颗粒抵抗微裂纹的壁的电阻的结果。 微裂纹的随之而来的扩大有利地降低了所得衬底的热膨胀系数(CTE)和弹性模量(Emod),而基本上不降低所得衬底的断裂强度模量(MOR),使得热冲击参数 TSP = MOR / [CTE.Emod]保持基本相同或更高。 该方法特别适用于汽车排气系统中用作催化转化器的陶瓷蜂窝结构。