In-situ carbon content adjustment in polysilazane derived amorphous SiCN bulk ceramics

The paper is concerned with in-situ carbon content adjustment in amorphous bulk silicon carbonitride ceramic matrices prepared by thermal polymer to ceramic conversion of crosslinked and compacted poly(hydridomethyl)silazane powders (NCP200). Heat treatment under inert (Ar) or reactive (Ar/NH3, NH3) atmosphere was applied for carbon content adjustment. Isothermal annealing steps at various intermediate temperatures were included into the schedule. Optimal annealing temperatures were found to be in the range from 500 - 550°C. Results are presented. Different possible chemical reactions are considered.