Patent ID: 8133430
Filing Date: 2012-03-13
Classification: C04B,F23N

Abstract:
1. A method for manufacturing an impregnated silicon carbide (SiC) hot surface igniter body from polycrystalline silicon carbide, comprising the steps of: forming a slip cast SiC ceramic body; drying the slip cast SiC ceramic body to thereby form a porous green body having open porosity; vacuum-pressure impregnating said green body with an allylhydridopolycarbosilane (AHPCS) resin; curing the impregnated ceramic body at a peak temperature between approximately 250° C. to 450° C. in an inert atmosphere; slicing and slotting the cured impregnated body with a manufacturer-selected igniter shape; pyrolyzing the cured and impregnated ceramic body at a temperature as low as 650° C. in an inert atmosphere to form a ceramic-bonded particulate SiC ceramic composite bisque product, thereby forming a permanent bonding amorphous phase at temperatures as low as 650° C. enabling an improved process strength; the pyrolized ceramic body having a first wide cross-section portion and a second narrow cross-section portion perpendicular to the first cross-section; orienting said pyrolized ceramic body in a recrystallization furnace in a first orientation with said first wide cross-section portion parallel to the field of gravity; recrystallizing said pyrolized ceramic body at a minimum temperature of 1800° C. in an inert gas atmosphere, whereby said amorphous phase enables said recrystallization step without orienting said first wide cross-section portion perpendicular to said field of gravity; and wherein said step of orienting further comprises the steps of: positioning a plurality of pyrolized ceramic bodies in said first orientation whereby respective said first wide cross-section portions contact respective first wide cross-section portions of adjacent pyrolized ceramic bodies prior to said step of recrystallizing.