L.I.Gladkikh, Z.I.Kolupaeva, A.V.Bochko*, N.N.Kuzin**
Received July 16, 1998
The phase composition and substructure characteristics of
superhard boron nitride polycrystals produced by sintering of the
wurtzite type boron nitride at temperatures from 1670 to 1900 K
have been studied by X-ray structure analysis. The sintered samples
contain all three known BN modifications: wurtzite, sphalerite and
graphite-like, the latter being in a stressed (compressed) state.
The lattice periods, the coherently scattering domain size, concentrations
of extrinsic and deformation stacking faults in the wurtzite phase
have been determined as functions of the sintering temperature. The
deformation stacking faults effect on the phase transformation BNwO
BNsph has been revealed.