Search

Multilayer cubic boron nitride (c-BN) coatings represent a new deposition method that can improve adhesion on metal substrates. The multilayer c-BN system in this study consisted of a TiAlN interlayer (2– 3.5 μm), boron carbide (~ 1 μm), and a c-BN (~ 2 μm) gradient layer. This multilayer c-BN structure, exceeding 5 μm in thickness, showed outstanding adhesion in atmospheric conditions even with high residual stress. Compared to monolayer c-BN coatings, the multilayer c-BN films had lower elastic moduli, and their critical loads were twice as high. The adhesion of the multilayer c-BN system was significantly improved because of the induced stress relaxation.

Transparent lms with low resistivity have been intensively investigated for display device applications, such as at panel displays, solar cells and touch panels, because of their electrodes having low resistivity and high transparency. In this study, the optical and the electrical properties of ITO lms synthesized by using a DC magnetron sputtering system with an ITO (SnO2 : 10 wt.%) target onto a glass, polycarbonate (PC) substrate at various oxygen gas ow rates were investigated and the surface morphologies of ITO thin lms prepared at various lm thicknesses were measured. As a result, ITO thin lms could be prepared with resistivity of 5 8 10 4 -cm and a transmittance of 85 % at a wavelength of 550 nm.

We have deposited Ti(C,N) thin films on Si(100) and D2 steel substrates in the temperature range of 200–300 °C using tetrakis diethylamidotitanium (TDEAT) and titanium isopropoxide (TIP) by pulsed dc plasma-enhanced metalorganic chemical vapor deposition (PEMOCVD). Radical formation and ionization behaviors in plasma are analyzed in situ by optical emission spectroscopy at various pulsed bias voltages and gas conditions. H2 and He+H2 gases are used as carrier gases to compare plasma parameters, and the effect of N2 and NH3 as reactive gas is also evaluated by the reduction of the C content of the films. Polycrystalline Ti(C,N) thin films were successfully grown on either D2 steel or Si(100) surfaces with TDEAT at temperatures as low as 200 °C. For TIP, however, only TiOCN thin films were obtained on Si(100) substrates. The best deposition process is evident for H2 and N2 gas atmospheres and bias voltage of 600 V. The higher film hardness is about 1760 Hk 0.01, but depends on gas species and bias voltage. ...

We have deposited thick SiC thin films on graphite substrates in the temperature range of 700–850 °C using single-molecular precursors by both thermal metal–organic chemical-vapor deposition (MOCVD) and plasma-enhanced MOCVD (PEMOCVD) methods for oxidation-protection wear and tribological coating. Hexamethyldisilane (HMDS), (CH3)3Si–Si(CH3)3, was used as a single-source precursor, and hydrogen and Ar were used as a bubbler and carrier gas. A highly oriented polyerystalline cubic SiC layer in the [111] direction was successfully deposited on graphite at temperatures as low as 800 °C with HMDS by PEMOCVD. For thermal MOCVD, on the other hand, only amorphous SiC layers were obtained at 850 °C. From this study, we confirmed that PEMOCVD was a highly effective process in improving the characteristics of the SiC layers compared to those grown by thermal MOCVD. The mechanical and oxidation-resistant properties have been assessed. The optimum SiC film was obtained at 850 °C and rf power of 200 W. The maximum depo...

The Korea Superconducting Tokamak Advanced Research (KSTAR) Project is the major effort of the Korean National Fusion Program (KNFP) to develop a steady-state-capable advanced superconducting tokamak to establish a scientific and technological basis for an attractive fusion reactor. Major parameters of the tokamak are: major radius 1.8 m, minor radius 0.5 m, toroidal field 3.5 Tesla, and plasma current 2 mA with a strongly shaped plasma cross-section and double-null divertor. The initial pulse length provided by the poloidal magnet system is 20 s, but the pulse length can be increased to 300 s through non-inductive current drive. The plasma heating and current drive system consists of neutral beam, ion cyclotron waves, lower hybrid waves, and electron–cyclotron waves for flexible profile control. A comprehensive set of diagnostics is planned for plasma control and performance evaluation and physics understanding. The project has completed its conceptual design phase and moved to the engineering design phase. The target date of the first plasma is set for year 2002.