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Showing papers by "Xianting Zeng published in 2000"


Journal ArticleDOI
TL;DR: In this paper, three advanced hard coatings, CrTiN alloy, TiN/NbN multilayer and a multilayered C-composite, were field-tested and compared for their stamping wear resistance.
Abstract: Three advanced hard coatings, CrTiN alloy, TiN/NbN multilayer and a multilayered C-composite, were field-tested and compared for their stamping wear resistance. All coatings were deposited onto SKH51 steel punches using an unbalanced magnetron sputtering system. Parametric studies of substrate bias, deposition pressure, composition, and structure effects on the coatings’ performance were conducted to determine the optimum deposition conditions. A 25-ton open-frame stamping machine was used for the stamping test on cold rolled carbon steel. Wear characteristics of the coated and uncoated punches were analysed using shearing and stripping force diagrams and optical microscopy. The results showed that: (1) all three coatings significantly improved the wear resistance and stamping performance; and (2) CrTiN coating out-performed the other two, owing to its high hardness, good adhesion and moderate friction coefficient.

22 citations


Journal ArticleDOI
TL;DR: In this article, parallel electron energy loss spectroscopy (PEELS) analysis was used to quantify the sp2/sp3 bonding in carbon films, which showed that higher sp3 fraction often associates with lower Raman peak ratio (IdIg).
Abstract: Amorphous carbon coatings (a-C, a-C:H) of less than 100 nm thick were deposited on KBr pellets and silicon wafer substrate via magnetron sputtering of graphite target in argon, argon/hydrogen and argon/nitrogen atmosphere. Parallel electron energy loss spectroscopy (PEELS) analysis was used to quantify the sp2/sp3 bonding in carbon films. Stand-alone films of amorphous carbon were produced by sputtering onto compressed KBr pellets and then floating off is distilled water for PEELS study. Raman spectroscopy was used to measure the peak intensity ratio of D-band to that of the G-band (IdIg). It shows that higher sp3 fraction often associates with lower Raman peak ratio (IdIg). At the same time, G-band peak position Pg decreases while sp3 fraction increases.

3 citations