Cathodic Arc Deposition Research Articles

Effect of electroless nickel interlayer on wear behavior of CrN/ZrN multilayer films on Cu-alloyed ductile iron

This study utilized electroless nickel as an interlayer, then coated nanoscale CrN/ZrN multilayer on Cu-alloyed ductile iron through cathodic arc deposition method. Morphology and structure of the coatings were analyzed by using field emission scanning electron microscopy (FESEM), X-ray diffractometer (XRD), and transmission electron microscopy (TEM). Moreover, Rockwell-C indentation, nanoindention, and ball-on-disk wear tests were all carried out to explore the properties of the coatings consisting of adhesion, hardness, elastic modulus, friction coefficient, and wear rate, respectively. The results showed that electroless nickel had a major amorphous phase while the CrN/ZrN multilayer coatings exhibited alternate nanocrystalline CrN and ZrN phases. Compared with single coating of electroless nickel or CrN/ZrN, the CrN/ZrN multilayer coatings with an electroless nickel interlayer exhibited higher hardness (31.1GPa) and elastic modulus (256.4GPa). Consequently, the ductile iron with the duplex coatings could be available to reduce both the friction coefficient and wear rate.

Kinetics of Ni:C thin film composition formation at different temperatures and contents of nickel

Experimentally observed surface segregation of nickel during Ni:C thin films growth is analyzed by kinetic model. The model is built considering experimental results where microstructure evolution as a function of the substrate temperature and metal content of C:Ni nanocomposite films grown by pulsed filtered cathodic arc deposition is investigated. The kinetic model includes processes of adsorption, chemical diffusion, surface segregation. Chemical diffusion and surface segregation are allowed in a layer near the surface. The experimental depth profile curves taken from literature were fitted by using proposed model. Thereby the values of depth dependent surface segregation and chemical diffusion coefficients are determined in the system. It is shown by modeling that with the increase of temperature the process of nickel surface segregation becomes dominant.

Preparation and blood compatibility of carbon/TiO2 nanocomposite

A carbon/TiO2 nanocomposite, which consists of carbon film with various sp3C content and TiO2 nanowire arrays, has been synthesized, in which the top surface of TiO2 nanowire arrays prepared using hydrothermal method on fluorine-doped tin oxide glass were coated with carbon thin films. The carbon thin films with a higher, medium and lower sp3C content were deposited by pulsed magnetic filtered cathodic vacuum arc deposition, plasma-enhanced chemical vapor deposition and magnetron sputtering deposition, respectively. The surface morphology and structure of TiO2 nanowire arrays were investigated by scanning electron microscopy, transmission electron microscope and X-ray diffraction. The sp3C content in carbon films was characterized using Raman spectroscopy. The blood compatibility of the samples including the TiO2 nanowire arrays, carbon films and carbon/TiO2 nanocomposite was assessed by tests of platelet adhesion in vitro. Results showed that the carbon/TiO2 composite can effectively improve the anticoagulant function compared to the single materials. It is believed that the excellent blood compatibility of the carbon/TiO2 nanocomposite is attributed to a joint function of surface properties adjusted by nanowire arrays and electronic structure of carbon thin films.

Drug loading and release of Tobramycin from hydroxyapatite coated fixation pins

This paper evaluates the loading and release properties of Tobramycin incorporated by adsorptive loading from a solution into plasma sprayed and biomimetically coated Hydroxyapatite (HA) fixation pins. The aim of this study is to contribute towards designing a functional implant surface offering local release of the antibiotic agent to prevent post-surgical infections. Cathodic arc deposition is used to coat stainless steel fixation pins with a bioactive, anatase phase dominated, TiO₂ coating onto which a HA layer is grown biomimetically. The loading and release properties are evaluated by studying the subsequent release of Tobramycin using high performance liquid chromatography and correlated to the differences in HA coating microstructure and the physical conditions under loading. The results from these studies show that a dual loading strategy consisting of a solution temperature of 90 °C and a pressure of 6 bar during a loading time of 5 min release a sufficient amount of Tobramycin to guarantee the inhibition of Staphylococcus aureus up to 2 days for plasma sprayed HA coatings and for 8 days for biomimetic coatings. The present study emphasizes the advantages of the nanoporous structure of biomimetically deposited HA over the more dense structure of plasma sprayed HA coatings in terms of antibiotic incorporation and subsequent sustained release and provides a valuable outline for the design of implant surfaces aiming for a fast-loading and controlled, local drug administration.

Nano-Scale Multi-Layered Coatings for Cutting Tools Generated Using Assisted Filtered Cathodic-Vacuum-Arc Deposition (AFCVAD)

The subject of this study were nano-nanoscale multilayer coatings formed using the process of filtered cathodic vacuum arc deposition in assisting high-energy ions of chromium. We used a special emitter (implantor) to generate chromium ions with high energy. Such key parameters of coatings as composition, structure, a thickness, hardness, adhesion in relation to a substrate obtained at various energy of chrome ions have been studied. It is establish the positive change of key properties of coating deposited on carbide inserts WC/CrC/Co, WC / (Co-Re), TiC/TaC/Co at assisted impact of ions Cr at ion acceleration voltage within the range of 10-40 kV. The results of measurement of parameters of coatings with use nanoindentometer are consistent with the X-ray analysis of the stresses in the coating (XSA study). The mechanisms of the effect of modified properties of coatings formed in assisting the filtered cathodic vacuum arc deposition on the properties of the carbide inserts in cutting structural steels and hard-to-cut nickel alloys have confirmed the high efficiency of the deposition process developed coatings and coating compositions.

Nanoscratch properties of extremely thin diamond-like carbon films

Scratch properties of extremely thin (targeted at 0.03–5.0-nm-thick) diamond-like carbon (DLC) films deposited by the filtered cathodic vacuum arc (FCVA) and electron cyclotron resonance chemical vapor deposition (ECR-CVD) methods are investigated. The difference in profiles and friction coefficients of scratches in both the corn and edge directions are evaluated. The difference of scratch properties between deposition methods is clearly evaluated by the scratching in the corn direction. When scratching in the corn direction, the friction coefficient and wear depth of the FCVA-DLC film increased rapidly at critical load, whereas those of the ECR-CVD-DLC film increased gradually even beyond this critical load. These results are deduced to be caused by the differences in the hardness and brittleness of the films. The dependence of nanoscratch friction force and scratch profile on DLC film thickness can reveal differences in mechanical properties that correspond to atomic-scale thickness.

Deposition of Ti-Al-N Films by Using a Cathodic Vacuum Arc with Pulsed Bias

Ti-Al-N hard films have been prepared by cathodic arc deposition by using an unipolar pulsed bias. In the present study, Ti-Al-N films were deposited on stainless steel and silicon wafers. The deposition rate, micrograph, preferred orientation and composition were systematically investigated by usingx-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), and a scanning electron microscope (SEM). It is shown that substate bias duty cycle and frequency have a great effect on film structure. A simple explanation for the results is also presented.

Effect of the metal concentration on the structural, mechanical and tribological properties of self-organized a-C:Cu hard nanocomposite coatings

The influence of the metal content (Cu: 0–28at.%) on the structural, mechanical and tribological properties of amorphous carbon films grown by pulsed filtered cathodic vacuum arc deposition is investigated. Silicon and AISI 301 stainless steel have been used as substrate materials. The microstructure, composition and bonding structure have been determined by scanning electron microscopy, combined Rutherford backscattered spectroscopy-nuclear reaction analysis, and Raman spectroscopy, respectively. The mechanical and tribological properties have been assessed using nanoindentation and reciprocating sliding (fretting tests) and these have been correlated with the elemental composition of the films. A self-organized multilayered structure consisting of alternating carbon and copper metal nanolayers (thickness in the 25–50nm range), whose formation is enhanced by the Cu content, is detected. The nanohardness and Young’s modulus decrease monotonically with increasing Cu content. A maximum value of the Young’s modulus of about 255GPa is obtained for the metal-free film, whereas it drops to about 174GPa for the film with a Cu content of 28at.%. In parallel, a 50% drop in the nanohardness from about 28GPa towards 14GPa is observed for these coatings. An increase in the Cu content also produces an increment of the coefficient of friction in reciprocating sliding tests performed against a corundum ball counterbody. As compared to the metal free film, a nearly four times higher coefficient of friction value is detected in the case of a Cu content of 28at.%. Nevertheless, the carbon–copper composite coatings produced a clear surface protection of the substrate despite an overall increase in wear loss with increasing Cu content in the range 3–28at.%.

Structural and Mechanical Properties of Nanostructured TiAlCrN Thin Films Deposited by Cathodic Arc Deposition

AbstractThis work has aims to study and develop the novel nanostructural quaternary thin film material for cutting tools and other applications with both high hardness value and good thermal stability at high temperature. The quaternary compound of TiAlCrN superhard coating material was deposited on tungsten carbide (WC-Co) substrates using cathodic arc deposition techniques at the deposition temperature of 623 K. The structures of the coatings were fundamentally examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), and atomic force microscopy (AFM). The coating hardness and elastic modulus tests were performed and investigated by nanoindentation testing method. The maximum hardness and elastic modulus values as measured by nanoindentation tests are at 53 GPa and 887 GPa, respectively. Scratch tests were performed on thin films deposited in various conditions. The critical loads to the coating failure of the resultant coatings are above 75 N.

Characterization of multilayer nitride coatings by electron microscopy and modulus mapping

Abstract This paper discusses multi-scale characterization of physical vapour deposited multilayer nitride coatings using a combination of electron microscopy and modulus mapping. Multilayer coatings with a triple layer structure based on TiAlN and nanocomposite nitrides with a nano-multilayered architecture were deposited by Cathodic arc deposition and detailed microstructural studies were carried out employing Energy Dispersive Spectroscopy, Electron Backscattered Diffraction, Focused Ion Beam and Cross sectional Transmission Electron Microscopy in order to identify the different phases and to study microstructural features of the various layers formed as a result of the deposition process. Modulus mapping was also performed to study the effect of varying composition on the moduli of the nano-multilayers within the triple layer coating by using a Scanning Probe Microscopy based technique. To the best of our knowledge, this is the first attempt on modulus mapping of cathodic arc deposited nitride multilayer coatings. This work demonstrates the application of Scanning Probe Microscopy based modulus mapping and electron microscopy for the study of coating properties and their relation to composition and microstructure.

Synthesis and Characterization of Filtered-cathodic-vacuum-arc-deposited TiO2 Films for Photovoltaic Applications

Titanium dioxide (TiO2) is well-known as a photovoltaic and photocatalytic material. For improvement in the dye-sensitized solar cell (DSSC) performance efficiency, the photocatalyst TiO2 layer would be desired in nanoporous anatase. In this research, TiO2 films were synthesized on glass or p-type silicon substrate using our in-house Filtered Cathodic Vacuum Arc Deposition (FCVAD) system. The deposition was operated at varied oxygen (O2) partial pressures of 10−4, 10−3, 10−2 to 10−1 torr with fixed 0 or 250-V bias and 600-V arc for 10 or 20 minutes. The film transparency increased with increasing of the O2 pressure, indicating increase in the structure required for applications in dye-sensitized solar cells. The films were characterized using the Energy-Dispersive X-ray spectroscopy (EDS) and Raman spectroscopy techniques. The EDS confirmed that the transparent deposited films contained stoichiometric titanium and oxygen under the medium O2 pressure. Raman spectra confirmed that the films were TiO2 containing some rutile but no anatase which needed annealing to form. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used for evaluation of the film's surface morphology and thickness. The result showed that increasing of the O2 pressure decreased the thickness to a nanoscale but increased the amount of TiO2.

Formation of thin DLC films on SiO2/Si substrate using FCVAD technique

Diamond-like carbon (DLC) films deposited on SiO2/Si substrate are attractive for novel sensitive and selective chemical sensors. According to the almost never ending of size reduction, a nm-thickness layer of the film is greatly required. However, formation of such a very thin DLC film on SiO2/Si substrate is challenging. In this experiment, DLC films were formed using our in-house Filtered Cathodic Vacuum Arc Deposition (FCVAD) facility by varying the bias voltage of 0V, −250V and −450V with the arc voltage of 350V, 450V, 550V, 650V and 750V for 10min. Raman spectroscopy was applied for characterization of the film qualities and Transmission Electron Microscopy (TEM) was applied for cross sectional analysis. Results showed that films of thickness ranging from 10–50nm were easily acquired depending on deposition conditions. Deconvolution of Raman spectra of these samples revealed that, when fixing the substrate bias but increasing the arc voltage from 350 to 750V, the ratio between D-peak and G-peak intensity, namely ID/IG ratio, tended to reduce up to the arc voltage of 450V, then increased up to the arc voltage of 650V and finally decreased again. On the other hand, when fixing the arc voltage, the ID/IG ratio tended to decrease continuously as the increasing of bias voltage. It can be concluded that the bonding structure would evolve from a graphitic-like structure to a diamond-like structure as the substrate bias increases. Additionally, the sp3 site should be maximized at the arc voltage ∼450V for fixed bias voltage. It is expected that, at −450V bias and 450V arc, sp3 fractions could be higher than 60%. However, in some cases, e.g. at low arc voltages, voids formed between the film and the amorphous SiO2 substrate. Electron energy loss spectroscopy (EELS) of the C edge across the DLC indicated that the thicker DLC film had uniform chemistry and structure, whereas the thin DLC film showed changes in the edge shape, indicating a gradual change in its properties between the edges and the core.

Influence of bias voltage on properties of AlCrN coatings prepared by cathodic arc deposition

AlCrN coatings were prepared by vacuum cathodic arc deposition. This low-temperature technique has been chosen due to its versatility, allowing the industrial up-scaling.In this study, the attention was focused on the correlation of the bias voltage with the resulting mechanical–tribological properties. For this purpose, the bias voltage was varied from 0 to −150V. Indeed, the variation of grain sizes from 24 to 16nm as well as the residual stresses from −0.68 to −8.94GPa lead to obtain different mechanical–tribological properties. In this context, the sample deposited at −100V exhibited an enhanced hardness (50±2GPa) and an acceptable wear resistance.

Adhesion of osteoblast-like cell on silicon-doped TiO2 film prepared by cathodic arc deposition

Silicon-doped TiO2 (Si-TiO2) and pure TiO2 films were deposited on titanium substrates by cathodic arc deposition technique. The surface characteristics of the films, such as surface topography, elemental composition and wettability, were studied. About 4.6% Si was incorporated into the Si-TiO2 films with a water contact angle of about 83°. The adhesive behaviors of osteoblast-like MG63 cells on both films were investigated through cell counting assay, immunocytochemistry, real-time PCR and western blotting analysis. Cells cultured on the Si-TiO2 films had a greater cellular viability, stronger cytoskeleton and focal adhesion, and more cellular spreading than those on the pure TiO2 films. Moreover, the expression levels of integrin β1 and focal adhesion kinase (FAK) genes, FAK and the phosphorylation of FAK proteins were up-regulated in cells cultured on the Si-TiO2 films. These results indicated that the Si-TiO2 films possess significantly enhanced cytocompatibility and provide potential solutions for the surface modification of implants in the future.

Nanotribology properties of extremely thin diamond-like carbon films at high temperatures with and without vibration

Extremely thin diamond-like carbon (DLC) films were deposited by filtered cathodic vacuum arc (FCVA) and electron cyclotron resonance-chemical vapour deposition (ECR-CVD) methods. The nanotribological properties of these films at high temperatures were evaluated using atomic force microscopy. At room temperature (RT), the FCVA-DLC films showed superior nanowear resistance than the ECR-CVD-DLC films. Conversely, at high temperatures in vacuum, the wear increased rapidly. The friction force of the FCVA-DLC films was low at RT in air and vacuum, but it was very high at high temperatures in vacuum. The lubricous adsorbate was removed by sliding at high temperatures. Hard brittle wear debris produced by high friction acted as an abrasive and increased the wear. In contrast, the friction force of the ECR-CVD-DLC films was low at high temperatures, corresponding to a low wear rate. Thus, the lubricous tribochemical products reduced the friction and wear. When the samples were vibrated, the wear depth of the FCVA-DLC films decreased at high temperatures, while that of the ECR-CVD-DLC films increased. Removal of the hard abrasive wear debris from the FCVA-DLC films decreased the wear by vibration, while removal of lubricous tribochemical products of the ECR-CVD-DLC films increased the wear by vibration.

Structural, optical, and electrical properties of indium-doped cadmium oxide films prepared by pulsed filtered cathodic arc deposition

Indium-doped cadmium oxide (CdO:In) films were prepared on glass and sapphire substrates by pulsed filtered cathodic arc deposition (PFCAD). The effects of substrate temperature, oxygen pressure, and an MgO template layer on film properties were systematically studied. The MgO template layers significantly influence the microstructure and the electrical properties of CdO:In films, but show different effects on glass and sapphire substrates. Under optimized conditions on glass substrates, CdO:In films with thickness of about 125 nm showed low resistivity of 5.9 × 10−5 Ωcm, mobility of 112 cm2/Vs, and transmittance over 80 % (including the glass substrate) from 500 to 1500 nm. The optical bandgap of the films was found to be in the range of 2.7 to 3.2 eV using both the Tauc relation and the derivative of transmittance. The observed widening of the optical bandgap with increasing carrier concentration can be described well only by considering bandgap renormalization effects along with the Burstein–Moss shift for a nonparabolic conduction band.

Oxidation Resistance and Corrosion Resistance of AlTiCrON Multilayered Coatings on AISI M2 Tool Steel

This study utilized the reaction of O2/N2 gases and Al0.67Ti0.33/Cr (99.9%) dual targets to synthesize (Ti,Al)ON/CrON multilayered coatings on AISI M2 steel by cathodic arc deposition system. Thermal stability and corrosion resistance of the multilayered coatings for aluminum die casting applications, along with coating structure were investigated. The results showed that the structure of multilayered coatings was a B1 NaCl type. The formation of oxide phases by introducing oxygen to react with Al, Cr, and Ti elements was confirmed by XPS. The thermal stability of oxygen-doped AlTiN/CrN coatings was higher than that of one without oxygen. After the immersion tests in Al-alloy melt, the oxygen-doped AlTiN/CrN coatings deposited at the O2/N2 ratio value of 0.3 had the best improvement on the corrosion resistance among all the coated specimens.

Effect of the oxidation temperature on microstructure and conductivity of ZnxNy thin films and their conversion into p-type ZnO:N films

Transparent p-type ZnO:N thin films have been fabricated by the oxidation of n-type ZnxNy films. The ZnxNy thin films on glass substrate were deposited by pulsed filtered cathodic vacuum arc deposition using metallic zinc (99.999%) as a cathode target in pure nitrogen plasma. The properties of the films were examined after oxidation between 350 and 550°C in air atmosphere. The atomic force microscopy (AFM) analysis revealed that the surface morphology was smooth. As-deposited ZnxNy films were opaque and conductive (ρ=4.36×10−3Ωcm,ND=7.70×1021cm2/Vs) due to excess of Zn in the structure. After oxidation between 350 and 500°C, p-type ZnO:N thin films were obtained. The lowest resistivity of 44.50Ωcm with a hole concentration and Hall mobility of 2.08×1017cm−3 and 0.673cm2/Vs, respectively, was obtained after oxidation at 450°C. However, when the oxidation temperature reached to 550°C, the conduction type of the ZnO:N film was changed from p-type to n-type. X-ray photoemission spectroscopy (XPS) analysis confirmed the formation of ZnN bonds and substitution incorporation of oxygen for nitrogen on the surface of the film. Besides, with a further increase of oxidation temperature to 550°C, the decrease of N concentration in the sample was also confirmed by XPS analysis.

Development of Wear-resistant Complex for High-speed Steel Tool when Using Process of Combined Cathodic Vacuum Arc Deposition

The paper studies the technique for increasing efficiency of high-speed steel tools by forming wear-resistant complexes when using processes of combined cathodic vacuum arc deposition with filtration vapour ion flow. Based on analysis of the causes of premature destruction of standard coatings on high-speed steel tools, provisions were designed to increase the effectiveness of wear-resistant coatings by increasing their operating life till partial or complete destruction. For that purposes, architecture of wear- resistant complex was developed for formation on substrates of high-speed steel. Wear-resistant complex includes thermally stabilizing layer and three-element multi-layered composition nano-dispersion coating, and it can be formed by using the combined process of cathodic vacuum arc deposition with filtration vapour ion flow. The paper presents data on the optimization of the conditions for formation of the wear-resistant complex elements that provide a significant increase in tool life of high-speed steel tool both with continuous and interrupted cutting.

Adhesion, proliferation and differentiation of osteoblasts on zirconia films prepared by cathodic arc deposition

Zirconia films were prepared on titanium by cathodic arc deposition technique. The surface topography and element composition of the films were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy, respectively. Osteoblast-like MG63 cells were cultured on the surface of the zirconia films in vitro, and cell behaviour was investigated, with titanium as control. The results obtained from scanning electron microscopy and immunofluorescence studies showed that the MG63 cells on ZrO2 films spread better than those on Ti. The CCK8 assay indicated that the zirconia films promoted the proliferation of MG63 cells. The results of alkaline phosphatase (ALP) activity test and the expression of osteogenic marker genes, such as ALP, collagen I and osteocalcin, demonstrated that the differentiation of MG63 cells might be enhanced by zirconia films. In addition, the zirconia films possibly regulated osteoclastogenic gene expression by stimulating the expression of osteoprotegerin and reducing the expression of receptor activator of nuclear factor-kappaB ligand. The present work suggests that the ZrO2 film is worth further consideration for orthopedic implant applications.