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Abstract: The collective influence of crucial electrodeposition parameters (temperature, deposition voltage and bath composition) on the properties of Zn–Ni films electrodeposited in a choline chloride–urea eutectic-based ionic liquid was investigated. The microstructures, chemical compositions, phase structures and corrosion behaviors of electrodeposited films were analyzed using scanning electron microscope, energy dispersive X-ray spectroscopy, X-ray diffraction and linear cyclic voltammetry, respectively. The surface morphologies and chemical compositions of the films were strongly dependent on the electrodeposition parameters. It was found that the amounts of nickel in the Zn–Ni alloy films were significantly higher than that present in the electrolytes and was always above 50%, indicating normal codeposition mechanism. Electrodeposition of high Zn content alloy is favorable at high electrodeposition voltages, high temperatures and high Zn (II)/Ni (II) ratios. Electrochemical measurements shows that under the conditions considered, the Zn–Ni film from 0.45M Zn (II)–0.05M Ni (II) deposited at 55°C and 0.8V exhibits the highest barrier corrosion resistance compared with the other films and this was attributed to a dense, smooth and crack free morphology with optimum Zn content. [Copyright &y& Elsevier]

Abstract: This work attempts to reveal the microstructure of interface and the relation between interface mixing and hardening mechanism in TiN/CNx multilayer films. The growth and microstructure of these interfacial layers are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Investigation result indicates that the interface species are mainly composed of Ti–C–N, the growth of interlayer mainly depends on the deposition temperature. The thickest interlayer (about 2.5nm) is produced at 300°C, and the interlayer disappears at 500°C. Nanoindentation testing indicates that the film with a maximum interlayer thickness of about 2.5nm exhibits superhardness up to 40GPa. Based on the experimental results, it is suggested that the interfacial intermixing and the crystal quality of TiN are the main reasons for the superhardness effect in TiN/CNx nanostructured multilayers. [ABSTRACT FROM AUTHOR]

Abstract: An a-C/a-C: Ti multilayer film with a bilayer period of 40 nm was deposited on medical Ti6Al4V alloy using a closed field unbalanced magnetron sputtering. The microstructure and chemical composition of the multilayer film were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. The mechanical and tribological properties were evaluated from nanoindentation, Rockwell and scratch tests, and ball-on-disk tribometer. Nanoindentation tests showed that the hardness of the multilayer film reached 25 GPa with good toughness. Due to the interface effect, the adhesion strength of the nanomultilayer was significantly improved. In humid air without lubrication, the a-C/a-C: Ti nanomultilayer film had a low friction coefficient of 0.080 and wear rate of 1.95×10−16 m3 N−1 m−1 at a load of 10 N. While in Hanks' solution, the film exhibited lower friction coefficient of 0.074 and wear rate of 4.25×10−17 m3 N−1 m−1. [Copyright &y& Elsevier]

Abstract: TaN/a-CNx multilayer films with modulation periods of 8.5–12nm are deposited on Si wafers and titanium alloy substrate using direct current magnetron sputtering. The morphology and structure of the films are characterized by scanning electron microscopy, X-ray diffraction and transmission electron microscopy. Mechanical and tribological properties are tested by nanoindention and ball-on-disk tribometer. Columnar structure exists in single TaN film and TaN/a-CNx multilayer with 0.5nm-CNx, while the columnar crystalline can be better interrupted by thicker a-CNx layers. The hardness of all the TaN/a-CNx multilayers is higher than that of the single TaN film. The maximum hardness of 31.0GPa and the friction coefficient of 0.12 are obtained in the multilayer film with 2nm-CNx. According to our research, the thickness of a-CNx in multilayer is best to distribute within 1–2nm. The wear rates under 5N are in the order of 10−15 m3 m−1 N−1 for the multilayer films and increased by 1 order of magnitude 10−14 for the TaN film (1.6×10−14 m3 m−1 N−1). [Copyright &y& Elsevier]