PROCESS FOR MAKING CRACK-FREE SILICON CARBIDE DIFFUSION COMPONENTS

摘要

PURPOSE: A method for producing a crack-free sintered silicon carbide body is provided to prevent the problem of cracking during recrystallization in bimodal silicon carbide blends. CONSTITUTION: A method comprises 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; and c) recrystallizing the green body to obtain a recrystallized silicon carbide body having a density of between 2.0 g/cc and 2.8 g/cc.