Effects of the synthesis of intermetallic compounds on the growth and consolidation of detonation diamond nanocrystals

The synthesis of intermetallic compounds belonging to the nickel-aluminum system in the presence of detonation nanodiamond (DND) particles leads to a significant change in the structure of consolidated nanocrystals. The broadening of (111), (220), and (311) X-ray diffraction reflections usually decreases by an order of magnitude, which indicates that the size of nanocrystals increases in approximately the same proportion. This effect significantly depends on the state of the surface of diamond nanoparticles. The X-ray data suggest that aluminum present in the initial metal-diamond mixture actively interacts with oxygen adsorbed on the surface of particles, which leads to the formation of Al₂O₃ oxide. The interaction between particles via cleaned interfaces at high temperatures leads to the activation of recrystallization processes.