Synthesis of nano-diamond/alumina composite by detonation method

The nano-diamond/alumina composite was prepared by detonation with the boron-nano diamond, the aluminum isopropoxide and the RDX as raw materials in the present paper. The phase, morphology and structure of the explosive products were analyzed by X-ray diffraction, field emission scanning electron microscopy and transmission electron microscopy. The results indicated that the pressure and the temperature generated by explosion led the alumina to tightly coat the nano-diamond particles and to the composite nano-diamond/ alumina particles formation, bonding with alumina. The size of the nano-diamond particle remained unchanged at 2-10 nm and the composite particle size increased to 50-200 nm. The alumina coating layer increased antioxidant properties of nanodiamond, increased the grain size composition of the polycrystalline powder. The Boron element had certain effects onto the oxidation coating, such as the diamond particles oxidation prevention during the preparation, the graphitization losses inversion, the detonation temperature increase and the high temperature alumina composite particles proportion increase. The aluminum reduced gradually, which could lead to an increase in the density of the explosive composition, the detonation synthesis temperature to be reduced, the high-temperature alumina (such as the alpha-Al2O3) to decrease and all other alumina crystal types to increase.