Papers by Keyword: Diamond Particles

Abstract: Ni-P diamond particles (20μm) composite coating on friction shims were prepared by electroless plating. Morphology and phase composition of the composite coating were measured by SEM with EDS and XRD. The friction coefficient of the coating was test with scratch test. The results showed that diamond particles distribution was uniform and not stacked by two steps for 10 min. The diamond particles were half embedded in the Ni-P substrate. The element of the coating was Ni,P,C and the phase composition was Ni and diamond. Adhesion of the composite coating was higher than that of the Ni-P coating. Friction coefficients of the Ni-P coating and Ni-P composite coating were 0.47 and 0.18. Half –naked diamond particles played a pinning role and prevented from wear of the coating to get the big friction coefficient and good wear resistance. This Ni-P composite coating on friction shims would improve friction shims technology and realize the production of localization of friction shims.

Abstract: Very fine diamond powder (1-3 ~m) was readily sintered under hydrothermal conditions, with new bond formation occurring between the diamond particles in a l0M-NaOH solution at 573 K maintained at 1 GPa pressure, for 24 hours. This new bonding material can be formed by carbonization, from a chlorinated hydrocarbon such as dichloromethane and 1, 1,1–trichloroethane. The carbonized material forms a new bond between the hydrogenated diamond particles by the release of hydrogen chloride. Using Raman spectroscopy and hydrogenated cubic boron nitride substrates it was indisputably demonstrated that diamond was synthesized under these alkaline hydrothermal conditions. The surface morphology of the hydrothermal product on the cubic boron was similar to the new growth on the diamond substrates.