Process for making crack-free silicon carbide diffusion components

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, and c) 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.

Dependencies are inferred from the claim text.