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A cathodic-arc evaporation system with plasma-enhanced duct equipment was used to deposit TiZrN, TiZrCN, and TiZr/a-C coatings. Reactive gases (N 2 and C 2 H 2 ) activated by the Ti and Zr plasma in the evaporation process was used to deposit the TiZrCN and TiZr/a-C coatings with different C and nitrogen contents. The crystalline structures and bonding states of coatings were analyzed by X-ray diffraction and X-ray photoelectron spectroscopy. The microbial activity of the coatings was evaluated against Staphylococcus aureus (Gram-positive bacteria) and Actinobacillus actinomycetemcomitans (Gram-negative bacteria) by in vitro antibacterial analysis using a fluorescence staining method employing SYTO9 and a bacterial-viability test on an agar plate. The cell compatibility and morphology related to CCD-966SK cell-line human skin fibroblast cells on the coated samples were also determined using the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, reverse-transcriptase-polymerase chain reaction, and scanning electron microscopy. The results suggest that the TiZrCN coatings not only possess better antibacterial performance than TiZrN and TiZr/a-C coatings but also maintain good compatibility with human skin fibroblast cells. [ABSTRACT FROM AUTHOR]

The surface characteristics of biomaterials play an important role in their interaction with biological systems. Tantalum (Ta) oxides and their coatings have been proved to increase their applications in the biomedical fields such as medical devices and dental implants by improving their osseointegration and corrosion resistance. In this study, Ta and amorphous tantalum oxide coatings were deposited by using magnetron sputtering. A hydrophilic crystalline β-Ta 2 O 5 coating was obtained by rapid thermal annealing of the deposited tantalum oxide coating at 700 °C. In this study, Staphylococcus aureus and Actinobacillus actinomycetemcomitans ( A. actinomycetemcomitans ) are Gram-positive and Gram-negative bacteria, respectively, that exhibit physiological commensalism on the human skin and oral areas. Both bacteria were chosen as the model for in vitro anti-bacterial analyses by a fluorescence staining method employing Syto9. The cytocompatibility of human skin fibroblast cells (CCD-966SK) on the coatings was also determined using an MTT assay. It showed that the amorphous tantalum oxide coatings possessed good antibacterial performance, while the hydrophilic crystalline tantalum oxide coatings exhibited outperformed human skin fibroblast cellular biocompatibility. [ABSTRACT FROM AUTHOR]

Recently, multicomponent CrAlSiN and TiAlSiN coatings have been developed in order to gain high hardness and good thermal stability. In this study, the influence of TiAlN, CrAlSiN and TiAlSiN coatings on the wear behavior and cutting performance of the carbide cutting tools was investigated in dry machining of a Ti–6Al–4V alloy. TiAlN, CrAlSiN and TiAlSiN coatings were deposited on tungsten carbide milling inserts by using cathodic arc evaporation. The deposited TiAlN, CrAlSiN and TiAlSiN possess high hardness of 31 ± 1 GPa, 36 ± 2 and 35 ± 2 GPa, respectively. After annealing at 700 °C in air, the hardness of the CrAlSiN and TiAlSiN still keeps as high as 35–36 GPa, while the hardness of TiAlN decreases to 26 GPa. The main wear modes for the TiAlSiN-, TiAlN coated- and uncoated tools are abrasion and adhesion. The nanocrystalline TiAlSiN coatings retard the tool wear as compared to the TiAlN-coated tools. At a high cutting speed of 350 m/min, the tool life of the CrAlSiN coatings exceeds the TiAlSiN-, and TiAlN-coated and uncoated tools by 2.9, 4.2 and 9.5 times, respectively. The CrAlSiN coatings show high wear resistances in dry machining of Ti–6Al–4V alloys, and thus possess the best cutting performance. [ABSTRACT FROM AUTHOR]

Abstract: Tantalum is considered a highly biocompatible metal with high corrosion resistance. Metal-doped amorphous carbon films are gaining interest as an effective surface modifier for medical devices. In this study, tantalum (Ta), TaC/amorphous carbon (a-C), and Ta-containing amorphous hydrogenated carbon films (Ta-C:H) were synthesized using a twin-gun magnetron sputtering system to improve biological properties and explore potential applications for surgical implants or devices. Reactive C2H2, activated by the tantalum plasma in the magnetron sputtering process, was used to deposit the Ta-C:H coatings. The deposited TaC/a-C coatings, in which TaC was embedded in the amorphous carbon matrix as a nanocomposite film, exhibited favorable cell viability of the human osteosarcoma cell line (MG-63), similar to uncoated titanium. Among the examined materials, Ta-C:H coatings exhibited the highest biocompatibility for WS1 human fetal skin fibroblast cells derived from soft tissues and demonstrated the highest biological performance. [Copyright &y& Elsevier]

The phenomenon of glass-to-mold sticking is a major problem for industrial glass forming processes. Recently, multicomponent CrAlSiN films attracted considerable industrial interest because of their excellent tribological performance and high oxidation resistance at high temperatures exceeding 800°C. Metal plasma ion implantation has being successfully developed for further improving wear, corrosion and physical properties of engineering materials. In this study, Mo and carbon ions were implanted into the multicomponent CrAlSiN film by using a metal-plasma ion implantation apparatus. The accelerating voltage of metal ions was set at 40kV with implantation doses of 1×1017 ions/cm2 for Mo and 2×1017 ions/cm2 for carbon. After Mo and carbon ion implantation, molybdenum carbides were found in the implanted layer of CrAlSiN. The wettability of the ion implanted CrAlSiN films by molten glass at 500°C in controlled air under 1.7Pa was measured by using a sessile drop method. Mo and carbon ion implanted CrAlSiN films showed the lowest wettability of all tested samples, which is attributed to a reduced adhesion of molten glass at high temperature. The ion implanted CrAlSiN films showed an anti-sticking characteristic superior to the as-deposited CrAlSiN films. Results of this study demonstrate the potential of metal plasma ion implantation in improving the anti-sticking behavior of the CrAlSiN films by molten glass. [ABSTRACT FROM AUTHOR]