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In this study we present the effect of negative bias applied to substrate and the pressure on the properties of TiC films (i.e. structure, Raman spectroscopy, electrical resistivity and hardness). The elaboration of our films has been carried out by RF-Magnetron Sputtering, 13.56 MHz, using two targets: titanium carbide and pure titanium. The film depositions have been done on silicon, glass and steel substrates. The total pressure was 10-60 mTorr. The attention was given to study the influence of different parameters, pressure and substrate-bias, on the properties of TiC layers. In this paper, a comparison between the properties of TiC prepared using pure titanium target and titanium carbide target is made. The deposited layers were characterized by XRD analysis, nanoindentation, four probe technique and Raman spectroscopy. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the influence of plasma deposition parameters (the pressure and the substrate bias voltage Vs) on structure, surface morphology, hardness and electrochemical behavior (studied by potentiodynamic polarization and optical microscope (OM) in aggressive environment NaCl 3.5 wt%) of TiAlN coatings. The coatings were deposited by reactive RF magnetron sputtering (13.56 MHz). They were carried out during 60 min and their thickness was approximately 1 μm. Structural analysis shown that TiAlN coating crystallized in cubic (fcc) and hexagonal (hcp) structure with orientations in (1 0 0), (1 1 1), (2 0 0), (1 1 0), (2 2 0) and (3 1 1) planes. The deposited coatings present maximum hardness ( H = 25.75 GPa) and Young's modulus ( E = 479.82 GPa) at low pressure (20 mTorr) and −60 V of negative substrate bias. Also, mechanical properties ( H & E ) were strongly influenced by coatings density and grain size. Electrochemical tests revealed that XC48 steel substrate covered with TiAlN coating exhibits excellent corrosion resistance. [ABSTRACT FROM AUTHOR]

Zirconium oxide (ZrO 2) thin films were grown onto 316L stainless steel by radio frequency magnetron sputtering (RFMS), at different substrate D.C. bias voltages (from 0 to −100 V). The deposition was performed using a pure zirconium target in the presence of an Ar-O 2 gas mixture. The characterization of the deposited films was performed using scanning Electron Microscope, atomic Force Microscopy, X-rays diffraction, Raman spectroscopy, nanoindentation and potentiodynamic polarization. The structures of all ZrO 2 films are crystalline. The monoclinic phase is predominant in the grounded films (0 V). However, the application of bias voltage depicts a tetragonal phase. Nanoindentation results reveal promoted values of the hardness of the ZrO 2 films. Corrosion behavior of the films was studied in Hank's solution using the potentiodynamic polarization method. The comparison between the uncoated samples and the coated ones showed a reduction in corrosion current density for coated samples. The minimum corrosion rate of the film deposited at −100 V was 0.04992 mpy, which is about 18 times less than that of the uncoated steel (0.88135 mpy). The optimum anti-corrosion performance and hardness were obtained for ZrO 2 deposited at a bias voltage of −100 V. • ZrO 2 films were deposited by magnetron sputtering from a metallic Zr target using oxygen as reactive gas. • ZrO 2 films with high hardness and high protective efficiency (94%) are demonstrated. • The hardness increases with the bias voltage applied to substrate. • Corrosion resistance is affected by negative bias voltage of ZrO 2 film. [ABSTRACT FROM AUTHOR]