SHOCK WAVE SYNTHESIS OF DIAMOND CRYSTAL GRIT

SYNTHETIC DIAMOND CAN BE PRODUCED BY SHOCK WAVE COMPRESSION OF GRAPHITIC OR AMORPHOUS CARBONACEOUS STARTING MATERIALS. COMMERCIAL SHOCK WAVE PROCESSING HAS MET LIMITED SUCCESS BECAUSE OF THE INABILITY TO PRODUCE SUFFICIENTLY LARGE CRYSTALLINE DIAMOND. RECENT EXPERIMENTAL RESULTS HAVE IDENTIFIED NEW STARTING MATERIALS FROM WHICH EXTRAORDINARILYLARGE, WELL ORDERED DIAMOND HAS BEEN PRODUCED BY SHOCK WAVE COMPRESSION. CLASSICAL CRYSTAL GROWTH THEORY SUGGESTS THAT THIS INCREASE IN DIAMOND CRYSTALLITE SIZE MIGHT BE DUE TO A DECREASE IN THE NUCLEATION DENSITY AND/OR AN INCREASE IN THECRYSTAL GROWTH RATE. PHASE I OF THIS PROJECT STUDIES THESE EFFECTS BY SYSTEMATICALLY VARYING THE STARTING MATERIAL COMPOSITION AND SHOCK WAVE CONDITIONS. THE PRODUCTS ARE BEING CHARACTERIZED FOR YIELD, SIZE DISTRIBUTION, CRYSTALLINE ORDER, AND CRYSTALLINE MORPHOLOGY.