Crystal-oriented mechanism of dynamic recrystallization nucleation in cubic boron nitride

Structural transformations occurring at 8 GPa and 2400 degrees C in twinned cubic boron nitride (cBN) with a tripler texture [112] have been explored by electron microscopy using the thin foil procedure. The following reconst ructions have been established: destruction of the texture that occurs by r otation about the [220] axis, fragmentation of twinned grains, detwinning o f large fragments by rotation about the [110] axis and formation of nuclei of a primary recrystallization from fragments with no twins. (C) 1998 Elsev ier Science S.A.