This paper reports the ability to use a commercial polysilazane as mat
rix precusor for the manufacture of ceramic matrix composites. By pyro
lysis under nitrogen in the temperature range 1000-1400 degrees C this
polysilazane leads to an amorphous silicon carbonitride with a cerami
c yield around 65 wt%. The rheological behaviour and the thermal decom
position of the polysilazane have been studied. Parameters for the imp
regnation and pyrolysis cycles required by the manufacture of composit
es are also proposed.