COPPER-BORON NITRIDE INTERACTION IN HOT-PRESSED CERAMICS

Ceramics were prepared by hot pressing of chemical mixtures of turbost ratic boron nitride with copper. A positive effect of copper on boron nitride crystallization and densification has been found. Preferred or ientation of boron nitride grains has been revealed in such ceramics, being opposite to general experience: the c-axis of boron nitride crys tallites was arranged preferably within a plane perpendicular to the d irection of uniaxial pressure. Such an arrangement is interpreted as a result of the uniaxial compression of the boron nitride grains extens ively growing within the c crystallographic axis.