Abstract: This invention is a process for making crack-free silicon carbide components wherein the level of free silica in the raw batch is controlled.

Abstract: A method for producing a crack-free recrystallized silicon carbide body, icluding the steps of:a) providing a raw powder batch including:i) at least 40 w/o fine fraction having a particle size of less than 10 microns, the fine grain fraction including silicon carbide and fine free carbon, wherein the fine free carbon is present in an amount of at least 0.10 w/o of the raw batch, the fine free carbon having a surface area of at least 10 m.sup.2 /g,ii) at least 40 w/o coarse grain fraction having a particle size of at least 30 microns, the coarse grain fraction including silicon carbide and coarse free carbon, wherein the coarse free carbon is present in an amount of at least 0.10 w/o of the coarse grain fraction,the raw batch having a total silica content of at least 0.5 w/o,the raw batch having a total silicon carbide content of at least 96 w/o,b) forming the raw batch into a green body, andc) recrystallizing the green body to provide a recrystallized silicon carbide body having a density of between 2.

Abstract: This invention relates to a method for producing a crack-free sintered silicon carbide body, comprising the steps of:a) providing a raw powder batch comprising:i) at least 40 w/o fine grain fraction having a particle size of less than 10 microns, the fine grain fraction comprising silicon carbide,ii) at least 40 w/o coarse grain fraction having a particle size of at least 30 microns, the coarse grain fraction comprising silicon carbide and less than 0.10 w/o free carbon,the raw batch having a total silica content of at least 0.5 w/o,the raw batch having a total silicon carbide content of at least 96 w/o,b) forming the raw batch into a green body, andc) recrystallizing the green body to provide a recrystallized silicon carbide body having a density of between 2.0 g/cc and 2.8 g/cc.