Method for fabricating ceramic articles and ceramic articles produced thereby

Abstract

A method for fabricating a ceramic article which includes providing a batch comprising components of (i) a mixture of inorganic raw materials comprising talc, alumina, and silica; (ii) a binder comprising a water-soluble organic binder and a fibrous silicate mineral having a high aspect ratio in combination with a large surface area; and (iii) a polar solvent; mixing the batch components to form a homogenous and plasticized mass; shaping the plasticized mass into a green body wherein the green body has improved strength; and, sintering the green body by heating to a temperature and for a time to initiate and sufficiently achieve conversion of the green body into a fired ceramic article.

1 . A method for fabricating a ceramic article, comprising: 
 providing a batch comprising components of (i) a mixture of inorganic raw materials comprising talc, alumina, and silica; (ii) a binder comprising a water-soluble organic binder and a fibrous silicate mineral having a high aspect ratio in combination with a large surface area; and (iii) a polar solvent;    mixing the batch components to form a homogenous and plasticized mass;    shaping the plasticized mass into a green body; and    sintering the green body by heating to a temperature and for a time to initiate and sufficiently achieve conversion of the green body into a fired ceramic article.    
   
   
       2 . The method according to  claim 1  wherein the green body has improved strength in a temperature region between 300°-900° C. to resist cracking during the sintering as compared to a like green body without the fibrous silicate mineral.  
   
   
       3 . The method according to  claim 1  wherein the ceramic article has improved final strength after the sintering as compared to a like ceramic body without the fibrous silicate mineral.  
   
   
       4 . The method according to  claim 1  wherein the inorganic raw materials are present in an effective which in combination with the other batch components are capable of yielding a fired ceramic article whose main phase is cordierite.  
   
   
       5 . The method according to  claim 1  wherein the organic binder is a cellulose ether binder.  
   
   
       6 . The method according to  claim 5  wherein the cellulose ether binder is a methylcellulose binder.  
   
   
       7 . The method according to  claim 6  wherein the methylcellulose binder is added in an amount of 2.5-10% by weight super-addition.  
   
   
       8 . The method according to  claim 7  wherein the methylcellulose binder is added in an amount of 2.5-5% by weight super-addition.  
   
   
       9 . The method according to  claim 1  wherein the fibrous silicate mineral is attapulgite clay.  
   
   
       10 . The method according to  claim 1  wherein the fibrous silicate mineral is added in an amount of 2-10% by weight.  
   
   
       11 . The method according to  claim 8  wherein the fibrous silicate mineral is added in an amount of 5-10% by weight.  
   
   
       12 . The method according to  claim 1  wherein the fibrous silicate mineral is added in an amount of 1-3% by weight.  
   
   
       13 . The method according to  claim 1  wherein the batch includes other optional organic and inorganic components to be used as processing aids.  
   
   
       14 . The method according to  claim 13  wherein the batch includes a surfactant and a pore former.  
   
   
       15 . The method according to  claim 1  wherein the green body is a honeycomb structure.  
   
   
       16 . The method according to  claim 1  wherein the batch comprises 100% by weight cordierite-forming inorganic raw materials, 2.0 to 10.0% by weight attapulgite clay, and based on 100% by weight cordierite-forming raw materials 2.5 to 10% by weight methylcellulose, up to and including 3% by weight sodium stearate, up to and including 30% by weight graphite, and 25.0 to 40.0% by weight water, as solvent.  
   
   
       17 . The method according to  claim 16  wherein the batch comprises 100% by weight cordierite-forming inorganic raw materials, 5.0 to 10.0% by weight attapulgite clay, and based on 100% by weight inorganic raw materials 2.5 to 5.0% by weight methylcellulose, up to and including 3% by weight sodium stearate, up to and including 30% by weight graphite, and 25.0 to 40.0% by weight water, as solvent.  
   
   
       18 . The method according to  claim 1  wherein the batch comprises 100% by weight cordierite-forming inorganic raw materials, 1.0 to 3.0% by weight of the fibrous silicate mineral based on 100% by weight inorganic raw materials, and 2.5 to 10.0% by weight of the water-soluble organic binder.  
   
   
       19 . The method according to  claim 1  wherein the batch comprises 100% by weight cordierite-forming inorganic raw materials, 1.0 to 3.0% by weight attapulgite clay based on 100% by weight inorganic raw materials, and 2.5 to 10.0% by weight methylcellulose.  
   
   
       20 . The method according to  claim 19  wherein the batch further comprises up to and including 3% by weight sodium stearate, up to and including 30% by weight graphite, and 25.0 to 40.0% by weight water, as solvent.  
   
   
       21 . The method according to  claim 1  wherein the fibrous silicate mineral has an aspect ratio greater than 500 and a surface area greater than 100 m 2 /gm.  
   
   
       22 . The method according to  claim 1  further characterized by a median particle size of 1-2 microns.  
   
   
       22 . A ceramic article, comprising: 
 a predominant phase of cordierite having a composition, expressed on an oxide basis, of 33 to 41% of aluminum oxide, 46 to 53% of silica, and 11 to 17% magnesium oxide wherein said article is manufactured from a batch including    a mixture of inorganic raw materials comprising talc, alumina, and silica;    a binder comprising a water-soluble organic binder and a fibrous silicate mineral having an aspect ratio greater than 500, a surface area greater than 100 m 2 /gm; and    a polar solvent.