Preparation Of Alumina-diamond Nanocomposite By Detonation

Alumina is very important as abrasive in applications of polishing, but hardness isn’t high enough leading to low efficiency of polishing and service life short. Nano-diamond has very good thermal conductivity, high hardness and wear resistance, but high costs of production. Thermal conductivity of alumina is poor, belonging to semiconductor materials, and alumina owns high temperature stability, certain hardness and resistance to wear. Cost of production of alumina is cheap. If we can make nano-compound material of alumina and diamond, it would bring great benefits of economic and high value of research.In this paper, nano-compound material were prepared by detonation method, in which the RDX were mixed with nitric acid aluminum, boric acid and so on. The detonation products were characterized by XRD(X-ray Diffraction) and TEM(Transmission Electron Micrioscope). The results indicated that α-alumina and γ-alumina exist in every kind of detonation products from XRD. The content of Nano-diamond is most in detonation products prepared by sol-gel. Average pore diameter of α-alumina is43nm; Observed by TEM, the shape of nano-compound material is spherical and has good dispersity, of which structure is made of outer package lining, of which the diameter is between50nm and150nm.Observed by BET, specific surface area and of detonation products will increase and average pore diameter is invariant along with the ratio of nano-diamond and alumina heightening when the ratio of RDX is invariant in explosives; specific surface area of detonation products will decrease and average pore diameter will heighten along with the ratio of RDX heightening in explosives when the ratio of nano-diamond and alumina is invariant. Following the results of XRD,TEM and BET, the detonation product is most conforms to the requirements when the ratio of nano-diamond and aluminium hydroxide is9to12and the ratio of RDX is84%in explosives, and nano-compound material is at most. The diameter of this detonation product is relatively uniform, which has excellent decentralization. By calculating the explosion heat, explosion temperature and explosive pressure of the explosives, we have obtained the parameters of detonation environment of experiments, and laid the foundation about nanometer composite materials made by detonation synthesis. These data provide reference for growth of grain in the explosion, and provides certain experience for researchers who study nanometer material by detonation synthesis. In this paper, nano-compound material, made by detonation synthesis, has uniform distribution and good dispersity, and combines closely, and has little micro pore by analysis of specific surface area. This method had advantages of simple technology process, fast synthesis and low-cost equipment, and had potential of mass products and application to study of other nano materials.