Preparation And Performance Study Of The Nano-diamond / Metal (ni, Co) Complexes

In this dissertation, superfine-nickel was prepared by the method of reduction using hydrazine hydrate as reducer, NiCl₂·6H₂O as raw material. Using nano-diamond (ND) as crystal nucleus, by reduction of nickel salt solution, the nickel particles were deposited on the surface of ND, thus the ND/Ni composites with core-shell structure were prepared. The prepared superfine-nickel and ND/Ni composites were characterized by XRD, TEM and SEM spectrometer. Besides, several factors influencing the particle size and morphology of superfine Ni and ND/Ni composites were also discussed, such as the category of dispersant, the category of solvent and reaction temperature. The results indicated that the obtained superfine Ni and ND/Ni composites were face-centered cubic and spherical-like particles with good dispersibility.Superfine-cobalt and ND/Co composites were separately prepared by hydrazine hydrate reduction method and poly-alcohol reduction method. The effect of fabrication condition on the structure and morphology were studied by XRD,TEM and SEM spectrometer. The results indicated that the obtained superfine-cobalt and ND/Co composites by hydrazine hydrate reduction method were hexagonal structure, but the obtained products by poly-alcohol reduction method were mixed crystalline in main of face-centered cubic structure. Compared with pure superfine metal powders, the size of ND/Ni composites obtained by above methods were smaller, the size distribution was narrower.The catalysis performance of superfine-nickel, superfine-cobalt and ND/Metal (M = Ni, Co) composites for the thermal decomposition of ammonium perchlorate (AP) was analyzed by DSC. The results showed that, to some degree, they could catalyze the decomposition of AP, the effect of pure Co powders were better than that of Ni powders, and that of ND/Metal (M = Ni, Co) composites were better than pure metal powders.The friction performance of paraffin lubricant with superfine-nickel and ND/Ni composites as additive was measured on MMW-1A Friction and Wear Tester. And the effects of the content of different additives and different load on the friction performance of samples were also discussed, it was found that superfine-nickel and ND/Ni composites as lubricant additive showed preferable friction-reducing and anti-wear properties.