Study on analytical method of free carbon in silicon carbide powder

摘要

To optimize the sample pretreatment conditions for determining the free carbon contents in silicon carbide by a partial combustion method, the evaporation components generated during the heating process were analyzed using a multiphase carbondeterminator and an infrared spectrometer. A certain amount of organic carbon which causes analytical error of the free carbon content was detected in SiC powders used recently as advanced ceramics. The organic carbon was not completely removed by heating in vacuum, because it was easily changed to amorphous carbon in the heating process. Therefore, the profile for CO{sub}2 detection was measured, which is based on the difference in temperature at which the combustion of organic and graphitic carbonoccurs. A method for the application of this profile to separating determination of both the carbons in SiC powder was proposed.