Indexed by:期刊论文

Date of Publication:2012-01-01

Journal:DIAMOND AND RELATED MATERIALS

Included Journals:SCIE、EI

Volume:21

Page Number:50-57

ISSN No.:0925-9635

Key Words:Tribochemical polishing; CVD diamond film; Material removal mechanism; Polishing plate; Mechanical alloying; Hot-press sintering

Abstract:A novel polishing plate is most important for tribochemical polishing (TCP) diamond. This paper investigated the mechanisms of TCP and pointed out the requirements for the polishing plate. Unpaired d electrons, vertical aligned principle, high hardness and oxidation resistance at elevated temperature were general requirements for polishing plate. Based on these requirements. FeNiCr alloy polishing plate was prepared by the combination technique of mechanical alloying and hot-press sintering. Optical microscope, scanning electron microscope, Talysurf surface profiler, X-ray diffraction, electron probe microanalysis and Raman spectroscope were employed to characterize the prepared polishing plate and identify the removal mechanism. It was found that FeNiCr alloy polishing plate had higher hardness and oxidation resistance than stainless steel 304 and cast iron. FeNiCr alloy polishing plate obtained a material removal rate of 3.7 mu m/min, which was higher than that of stainless steel 304 plate, cast iron plate and TiAl alloy plate. The mechanism for TCP can be described as converting diamond into graphite through friction heating and the interaction of the diamond with a catalytic metal disk; the catalytic metal acted on the diamond surface by means of their unpaired d electrons. If the metal structure of polishing plate was suitable to vertically bond with several carbon atoms on diamond surface, diamond would tend to convert into graphite more easily. Finally the non-diamond carbon was removed by mechanical friction, oxidation and diffusion into metal disk. (C) 2011 Elsevier B.V. All rights reserved.