Papers by Keyword: Multi-Arc Ion Plating

Abstract: ZrTiN hard coatings were deposited by multi-arc ion plating on tungsten carbide substrates, using separated Ti and Zr targets in nitrogen and argon atmosphere, combined with ion bombardment of samples surface. The films exhibited a dense and fine grained structure with no columnar growth structure. ZrTiN coatings deposited reveal a (111) preferred crystal orientation. For the coatings, solid solutions were formed. The coatings possessed a higher microhardness value (approx. 2700 Hv_0.05) than their binary counterparts. The increased microhardness was probably due to a solid solution strengthening mechanism while depositing. The thickness of the coatings were between 2.0 and 2.3 μm. The adhesive strength of the coating-substrate system was up to more than 70N.

Abstract: Approximately 2 μm thick CrN and CrAlN coatings were synthesized on silicon and spring steel substrate by multi-arc ion plating technology. The nanoindentation techniques, Auger electron spectroscopy (AES) analysis, scanning electron microscopy, X-ray diffraction and oxidation furnace were used to investigate the mechanical property, oxidation resistance and microstructure of the coatings. The XRD data showed that the CrN and CrAlN coatings exhibited B1 NaCl structure. Nanoindentation measurements showed that as-deposited CrN and CrAlN coatings exhibited a hardness of 19 and 30 GPa respectively. Compared with CrN coatings, the CrAlN composite coatings show much better oxidation resistance. And the oxidation resistance ability will enhance with increasing Al content, because A12O3 will form after oxidation in high temperature condition which could reduce the diffusivity ability of oxygen.

Abstract: A new TiCN-coated aluminum foil for capacitor was prepared by multi-arc ion plating method. The effects of cooling process and mass flow ratio of C2H2 to N2 for deposition on specific capacitance were investigated. Using SEM and XRD, the surface micrograph and phase transformation were analyzed and the temperature sensitivity of specific capacitance was discussed. The results show that specific capacitance of TiCN-coated aluminum foils was as high as 1600μF/cm2, which is higher than the traditional etching process increases by about 2-fold. It was found that composite foil has a strong temperature sensitivity, with the temperature increasing, the aluminum foil surface of TiCN particles were found a gradual trend of growing up, crystal structure from amorphous to crystalline transition, when the temperature was higher than 200°C, the specific capacitance decreased more quickly.

Abstract: Ti(C,N)-based cermets were coated with a TiN/TiAlN coating using ion plating technology. The sliding wear test was performed for the coated cermets and the microstructure, composition and surface roughness of the coated cermets under different velocities and loads were characterized. The results showed that the friction coefficients of the coated cermets were lower than that of the neat cermets. Under the same load, the adhesion phenomenon of the counterpart materials on the specimens was improved and the mean friction coefficient increased with increasing sliding speed. Under the same sliding velocity, the average friction coefficient of the coated cermets was lower under higher load. The wear mechanisms were mainly adhesive wear and abrasive wear.

Abstract: The most common metallic coatings used in today’s gas turbine engines are MCrAlX (where M is Ni and/or Co and X is one or more reactive elements such as Y, Hf, etc.) type overlay coatings. However, overlay coating techniques (plasma and flame spraying or physical vapor deposition) are line-of-site processes, and so, it is possible not to deposit coating on some surface of the complex turbine components. The diffusion aluminide coatings can solve this problem. A NiCoCrAlY and diffusion aluminide coating were prepared on K38G cast alloy by multi-arc ion plating and low pressure chemical vapor deposition (LP-CVD) techniques, respectively. The isothermal oxidation behavior of K38G and the coatings was studied in air at 900 and 1000 oC. Their hot corrosion behaviors in the presence of 75 wt.% Na2SO4+K2SO4 and 75wt.%Na2SO4+NaCl film at 900oC were studied. The results showed that the two kinds coatings exhibited low oxidation rate at 900 and 1000oC and the presence of salt accelerated the oxidation rate. The NiCoCrAlY coating showed the better hot corrosion resistance than the aluminide coating.