Effect of Graphite Intercalation Compounds Prepared by Molten Salts Method on High-pressure Synthetic B-doped Diamond

摘要

B-doped diamond abrasive is an excellent grinding material owing to its high oxidation resistance, mechanical strength and inertness with ferrous metal. This paper presents a new method for synthesis of B-doped diamond grits using graphite intercalation compounds (GICs) prepared by molten salts method. GICs refer to the compounds that form through intercalating other atoms, ions or molecules into graphite planar layers. H{sub}3BO{sub}3-GICs were prepared through the reaction of graphite with molten boric acid in vacuum. The stage structures of GICs were analyzed by the mean of XRD. Annealing treatment was performed to remove the impurities. Diamond was synthesized at high pressure and high temperature conditions using B-doped GICs as carbon sources. The structure and properties of the synthetic diamond were investigated using Fourier transform infrared absorption spectra (FTIR), Raman spectra and scanning election microscope (SEM). The oxidation temperature and the resistance of the synthetic diamond were measured. The results show that B-doped black diamond grits were synthesized using H{sub}3BO{sub}3GICs with the mixed stages. The stages and boron contents of GICs were controlled through adjusting the ratio of H{sub}3BO{sub}3 and graphite. The lower stages of GICs, the darker color of the diamond transformed from the GICs. Boron doping in diamond gave rise to high oxidation temperature and low resistance.