Combined Magnetron Sputtering Research Articles

Development of a method of increasing the wear resistance of forging dies in the aspect of tool material, thermo-chemical treatment and PVD coatings applied in a selected hot forging process

The article discusses the wear of forging tools intended for hot forging processes. It presents the results of an experimental research of a selection of methods to improve the durability of forging tools in an industrial die forging process. Improved durability was obtained by the application of thermo-chemical treatment in the form of nitriding and the use of hybrid layers composed of a nitrided layer combined with PVD coatings deposited on the surface. In addition, various nitriding processes were applied and the influence of the phase structure of the nitrided layer was examined. The use of a new coating in this type of application based on non-stoichiometric chromium nitride (CrNx) with the thickness of 12 μm was analyzed. This type of coating was obtained with the use of an innovative technology combining magnetron sputtering and arc evaporation.The obtained effect of increased durability was verified by means of a comprehensive tool analysis after operational tests, compared with the obtained durability results for the traditionally used tools made of Unimax steel. The research included, among others, determination of the amount of wear by 3D scanning, analysis of the changes in the surface layer of the tools in selected areas using a scanning electron microscope (SEM), observation of the microstructure and measurements of the microhardness. The conducted operational tests and analysis showed that, by means of the proposed methods of increasing durability, the tool life was extended. The best effect was obtained owing to the use of a hybrid layer composed of a nitrided layer (type α) and a coating of 12 μm thickness, because the tools were more resistant to abrasive wear in the analyzed key areas. Studies have confirmed the legitimacy of using hybrid methods combining many techniques simultaneously for increased durability of forging tools.

Hydrogen permeability of non-stoichiometric tungsten oxides

This paper presents results from an investigation of the permeation rate of gaseous hydrogen through a double-layer membrane by the classic gas accumulation method at 400 °C. Dense 8-micrometer thick tungsten films were grown on highly permeable 40 mm diameter Eurofer substrates by the combined magnetron sputtering and high energy ion bombardment method. By in-situ exposure of the tungsten side to pure oxygen at 0.9 bar for 2 hours, a noticeable decrease in permeation rates at 400°C was achieved, expressed as the permeation rate reduction factor, which ranged from 3.8 to 38. Oxide characterisation followed after permeation rate tests. Focused ion beam cross-section after the oxidation/permeation rate cycle revealed an oxide layer thickness between 80 and 100 nm. X-ray diffraction and Raman analyses revealed a mixture of many non-stoichiometric oxide types after the oxidation/permeation rate cycles. Their corresponding hydrogen permeability at 400°C in the range from 8.1 × 10−18 – 5.7 × 10−17 mole H2/s/m/Pa0.5 was calculated from measured data.

Realizing Double Graded CIGSe Absorbers With the R2R Hybrid-CIGSe-Process

This article presents an approach for industrial roll-to-roll (R2R) deposition of Cu(In,Ga)Se2 (CIGSe) thin films on stainless steel foil for use as absorber layers in flexible thin-film solar cells. The hybrid-CIGSe-deposition-process combines magnetron sputtering with evaporation techniques and allows the realization of a double graded CIGSe layer, reaching a conversion efficiency of currently up to 14.0% (w/o antireflective coating). The influence of different power settings of the individual magnetrons on the gallium profile is described. For a deeper understanding of differences between a static and an R2R process, a calculated flux diagram is presented. In the second part of this contribution, the homogeneity of the industrial scale samples is discussed by comparing the change in CGI and GGI over the foil width of 30 cm. The hybrid-CIGSe-deposition-process excels in a straightforward scalability for industrial usage due to the application of planar magnetron sputtering sources as metal vapor supply.

Insight into high temperature performance of magnetron sputtered Si-Ta-C-(N) coatings with an ion-implanted interlayer

Challenges related to the application of wear resistant coatings at high temperatures require the development of novel materials with an exceptional combination of mechanical, chemical and tribological properties. The present paper is focused on understanding of relationships between structure, composition and high-temperature performance of the Si-Ta-C-(N) coatings. The coatings were produced using combined magnetron sputtering (MS) and ion implantation (CMSII) technique. It was found that ion implanted coatings demonstrated better thermal shock resistance compared to MS Si-Ta-C-(N) coatings. The Si-Ta-C-(N) coatings revealed a nanocomposite structure consisting of 2–3 nm fcc TaC(N) grains and amorphous a-Si and a-SiC(N) phases. The composition and structure of amorphous matrix and nanocrystallites strongly affected tribological performance of the Si-Ta-C-(N) coatings. The N-doped coatings exhibited exceptionally good tribological performance due to a higher ductility of N-rich amorphous a-SiCN and a-SiNx matrix, and fcc Ta(C,N)-based crystallites compared with the a-Si + a-SiC, and fcc TaC-based phases in N-free coating. The Si-Ta-C-(N) coatings easily withstood oxidation annealing at 800 °C due to the formation of a 200 nm protective TaSiOx amorphous layer. Oxidation annealings revealed that under thin protective TaSiOx layer crystalline components of coatings did not change when Si and C from the amorphous matrix started to diffuse towards the substrate at 800 °C but even after redistribution of elements and formation of oxide scale the coatings demonstrated reasonably high hardness – 13–16 GPa. Triboactivated formation of TaSiOx fibers which could slide/roll against the same TaSiOx tribolayer during high-temperature tribotests resulted in low coefficient of friction values (0.23 at 800 °C) and absence of wear.

A novel Zr-Y modified silicide coating on Nb-Si based alloys as protection against oxidation and hot corrosion

To protect Nb-Si based alloys from oxidation and hot corrosion attacks at high temperatures, a novel Zr-Y modified silicide coating is fabricated by combining magnetron sputtering and pack cementation. It has been shown that the coating exerts a superior oxidation resistance (mass gain of 1.6 mg/cm2) than Si-Y coating (mass gain of 4.2 mg/cm2), which is attributed to forming a thin, compact and continuous SiO2 scale and favorable scale/coating interface. Due to possessing much better scale adherence and reduced formation rate of scale, the coating possesses a better hot corrosion resistance than substrate alloy and Si-Y coating.

New approach for an industrial low-temperature roll-to-roll CI(G)Se hybrid sputter coevaporation deposition process

A new industrial approach for the production of CuInSe2 (CISe) absorber layers in a roll-to-roll process is described. This process is used by Sunplugged GmbH and combines magnetron sputtering with thermal coevaporation. A CISe-based device with a conversion efficiency of more than 10% has been fabricated from absorbers grown on polyimide at low temperature. The characteristic properties of a copper-poor ([Cu]/[In] = 0.73) CISe layer, deposited by Sunplugged's industrial process, are compared to those of a state-of-the-art, more copper-rich ([Cu]/[In] = 0.93) layer, grown in a molecular beam epitaxy system at Helmholtz-Zentrum Berlin. The presence of a so called vacancy-compound in low [Cu]/[In] CISe devices exhibiting an increased bandgap energy is visible by external quantum efficiency measurements, Raman scattering, and scaps simulations.

Fabrication of WO3/TiO2 core-shell nanowire arrays: Structure design and high electrochromic performance

Unique WO3/TiO2 core-shell nanowire heterostructures are rationally constructed based on a solvothermal method combining magnetron sputtering. High resolution transmission electron microscopy (HRTEM) analysis evidences the existence of a semi-coherent interface between a hexagonal phase WO3 core and anatase TiO2 shell. X-ray photoelectron spectroscopy and optical absorption spectra suggest an interfacial interaction between the WO3 core and TiO2 shell. The WO3/TiO2 core-shell nanowires exhibit superior electrochromic performance in both visible and near infrared regions with large optical modulation (87.0% at 1500 nm and 85.3% at 633 nm), short bleaching–coloration times (1.1 s and 3.0 s), decent coloring efficiency (102.1 cm2 C−1) and excellent cycling stability (95.6% after 3000 cycles). The obtained WO3/TiO2 core-shell nanowire heterostructures may find great potential in producing electrochromic nanodevices and other energy-efficient applications.

Hard yet tough CrN/Si3N4 multilayer coatings deposited by the combined deep oscillation magnetron sputtering and pulsed dc magnetron sputtering

Hard yet tough coatings with simultaneously high hardness and toughness represent a new class of high-performance coatings, which are vital for tribological applications due to the enhanced surface/interface properties. In this work, CrN/Si3N4 multilayer coatings with various Si content were reactively deposited by the combined deep oscillation magnetron sputtering and pulsed dc magnetron sputtering. The as-deposited coatings exhibit smooth surface morphology, well-defined nc-CrN/a-Si3N4 interfaces, uniform thickness and highly dense architecture. Microstructure evolution is induced by Si content changing from scaly nanocolumnar to densely packed fibrous grains to tapered crystallites. These features allow the achievement of the increased properties in terms of high hardness of 30.6 GPa, H/E* of 0.099, H3/E*2 of 0.387, elastic recover We of 58.5% and fracture toughness KIC of 3.69 MPa·m1/2. Hard yet tough CrN/Si3N4 multilayer coatings show excellent tribological properties by enhanced cooperative deformability through energy dissipation and stress relaxation at well-arranged nc-CrN/a-Si3N4 interfaces to reduce crack initiation and propagation, and adhesion failure, thanks to the enhanced H, H/E*, H3/E*2, We and KIC. Meanwhile, under limited normal load conditions, uniform tribolayers (Cr2O3, FeO(OH), Fe2O3 and Fe3O4) caused by tribochemical reaction on the worn surface also act to make contributions towards reducing friction and wear as a lubricant.

Tailored wettability of plasma polymers made of C–F, C–H, and N–H

AbstractNew trends toward green technologies and broad utilization of polymers have led to intense research on surfaces with controlled wettability. This study demonstrates an easy method to control the wettability (estimated by static water contact angle [WCA]) of a polymer surface by introducing a proper ratio of C–F, C–H, and N–H bonds. The preparation method combines magnetron sputtering from a polytetrafluoroethylene (PTFE) target and plasma‐enhanced chemical vapor deposition (PECVD) from a nitrogen/acetylene mixture, making it environment‐friendly, unlike PECVD from hydrocarbons/fluorocarbons. The proposed method allows depositing plasma polymers with WCAs from 110° to 17° by varying only the gas composition. The corresponding plasma polymers consist of C:F (magnetron sputtering of PTFE), C:F:N:H (reactive magnetron sputtering and PECVD), and a‐C:H (PECVD from acetylene).

Tribological behaviors in air and seawater of CrN/TiN superlattice coatings irradiated by high-intensity pulsed ion beam

Surface integrity and interface structure of coating materials play a key role in tribological and corrosion behaviors in harsh working environments in nuclear power plants. In this work, we focus on the investigations of tribological behaviors in air and seawater of CrN/TiN superlattice coatings deposited by the combined deep oscillation magnetron sputtering with pulsed dc magnetron sputtering, which were irradiated by high-intensity pulsed ion beam (HIPIB) with ion energy density of 1–3 J/cm2 and shot number of 1–5. At 1 J/cm2, the increased shot number leads to a broaden (111) peak of face-centered cubic crystal structure, indicating grain size refinement. At 3 J/cm2, the increased shot number results in the coarsening grain, and superlattice structure gradually disappeared at 2 shots, finally the coatings fell off from substrate at 5 shots. The highest hardness (H), H/E* (E*, effective Young’s modulus) and H3/E*2 of the coatings irradiated at 1 J/cm2 and 5 shots are achieved at 38.7 GPa, 0.1 and 0.387, respectively. The increased ion energy density and shot number result in the decrease in Rockwell C HF adhesion level from HF1 to HF6. At 1 Jcm−2 and 1 shot, tribological behavior of irradiated coatings in air was dominated by oxidative wear with coefficient of friction (COF) of 0.51 and specific wear rate of 4.2 × 10−7mm3N−1m−1. The irradiated coatings show excellent tribocorrosion properties in seawater with high open circuit potential of 0.32 V, low COF of 0.14 and specific tribocorrosion rate of 6.1 × 10−8mm3N−1m−1 without pitting corrosion under moderate HIPIB irradiation due to high surface integrity and stability of well-defined interfaces and dense microstructure. With an increase of energy density and shot number, wear mechanism in air changes to severe adhesive and oxidative wear, while tribocorrosion mechanism is gradually dominated by plough wear coupled with pitting corrosion.

Hybrid magnetron sputtering and pulsed laser ablation for the deposition of composite ZnO-Au films

A hybrid technique that combines magnetron sputtering (MS) of zinc oxide and pulsed laser deposition (PLD) of gold was used to synthesize ZnO-Au composite thin films. Three different laser pulse fluence values of 4.5, 13.6 and 20.9 J cm−2 were used. Films of ZnO and Au were deposited separately by MS and PLD respectively to compare the growth by the individual and hybrid techniques. For the hybrid technique, no significant changes on the Zn concentration are observed when varying the laser pulse fluence, whilst the concentrations of O decreased and Au increased. The gold was incorporated uniformly throughout the thicknesses of the films as a second phase of nanoparticles. The presence of the gold did not modify the crystal orientation of the ZnO, which was a hexagonal wurtzite-phase with the c-axis perpendicular to the substrate. The ZnO-Au films were found to be thicker than the sum of the thicknesses of the Au and ZnO produced individually by MS and PLD, indicating that the hybrid technique incremented the net deposition rate. The emission of the laser ablation plume species, specifically neutral atoms of gold, was studied by optical emission spectroscopy to compare the individual PLD and MS-PLD processes.

Preparation of P-type LaSe2 films with conductivity and mid-infrared transparency by combining magnetron sputtering and selenized annealing

LaSe2 films were prepared on sapphire (0001) substrates by combining magnetron sputtering and selenized annealing. The influence of selenized annealing time on the structures and photoelectric properties of the thin films were investigated using glancing incident X-ray diffraction, fourier transform infrared spectrometry and Hall effect measurements. The results showed that the film had a perfect monoclinic structure and a smooth surface morphology. The average transmittance in the mid-infrared range was greater than 55%, and the highest was 65%. The LaSe2 films had a higher carrier concentration (∼1019 cm−3) and conductivity (∼1.9 S/cm) than those of other P-type transparent conductive films, which showed that LaSe2 was a potential new P-type material.

Screening alloy electrocatalysts by combining magnetron sputtering and scanning electrochemical microscopy

ABSTRACTA high-throughput approach for developing materials is revolutionizing the current trial-and-error mode with great potential for accelerating the process. Here, we propose a simple approach combining multitarget sputtering and scanning electrochemical microscopy for the screening of hydrogen evolution reaction (HER) electrocatalysts. The ternary Co–Ni–Cu system is used as to demonstrate the feasibility of the strategy. The optimized composition for a HER catalyst is determined to be Co14Ni53Cu33.

Characterization of commercial thermoelectric organic composite thin films

A series traditional thermoelectric films, including n-type Bi, Bi2Te3, and p-type Sb, Sb2Te3, were synthesized with CH3NH3I by combining magnetron sputtering and thermal evaporation method. It is found that the Seebeck coefficients for all the composite films have enhanced although the electrical conductivities reduced due to the decreased carrier concentration. This leads to an obvious improvement of the power factor, especially for p-type Sb2Te3-based organic–inorganic hybrid films. As expected, a maximum power factor value around 2.3 mWm−1K−2 has been achieved for the composition of Sb2Te3/CH3NH3I in range of the whole measured temperature, which is nearly seven times higher than that of pristine Sb2Te3 film. By combination with the reduced thermal conductivity, a ZT value nearly 1.0 has been obtained at 380 K for the composition of Sb2Te3/CH3NH3I.

Thin WBx and WyTi1−yBx films deposited by combined magnetron sputtering and pulsed laser deposition technique

The coatings of tungsten borides (WBx) and tungsten borides doped with titanium (WyTi1−yBx) were deposited by using combined magnetron sputtering - pulsed laser deposition technique. In the case of WBx coatings, pure tungsten target was evaporated by a laser pulse at 1064 nm wavelength and pure boron target was sputtered by a magnetron. In the case of WyTi1−yBx coatings, the W2B5 target was sputtered by the magnetron and titanium target was evaporated by the laser pulse at 1064 nm wavelength. The content of titanium dopant changed from 1.1 to 5.5 at.%. The microstructure, chemical and phase composition of deposited coatings were investigated by means of Scanning Electron Microscopy, Energy Dispersive X-Ray Spectroscopy, X-Ray Photoelectron Spectroscopy and X-Ray Diffractometry, respectively. The Vickers hardness and Young's modulus were determined by using the nanoindentation test. Nanocrystalline WB coatings with dominant WB2 phase were obtained at a substrate temperature of 520 °C. The coatings were superhard with a hardness of 47–50 GPa and the mean value of surface roughness was <6 nm. The WBx coatings doped with 5.5 at.% Ti had hardness similar to the coatings sputtered by magnetron from W2B5 target.

Helium depth profile measurements within tungsten coatings by using Glow Discharge Optical Emission Spectrometry (GDOES)

In the present paper results concerning the implementation of the Glow Discharge Optical Emission Spectrometry (GDOES) for measure the He depth profile within W coatings are given. The He emission line situated at 587.5 nm was used in this respect. W coating containing He up 10 at.% and with thickness of 5 μm have been obtained by Combined Magnetron Sputtering and Ion Implantation (CMSII) method. The coatings structure and morphology was investigated using Scanning Electron Microscopy (SEM) measurements. The He retention within the coatings was evaluated by using Thermal Desorption Spectroscopy (TDS). Time-of-Flight Elastic Recoil Detection Analysis (TOF ERDA) measurements has been used to determine chemical composition of the coatings. Results of TOF-ERDA measurements results were used to calibrate the GDOES equipment. Using these data the GDOES depth profiles of the He within W coatings have been obtained.

Enhanced Photoelectrochemical Properties of Ti3+ Self-Doped Branched TiO2 Nanorod Arrays with Visible Light Absorption

A novel Ti3+ self-doped branched rutile TiO2 nanorod arrays (NRAs) was successfully grown on an F-doped tin oxide (FTO) transparent conductive glass by a combined hydrothermal and magnetron sputtering method. Surface morphology, structure, optical properties, and photoelectrochemical behavior of the branched TiO2 NRAs are determined. Using TiO2 nanoparticles (NPs) deposited on the top of the nanorods as seeds, TiO2 nanobranches can easily grow on the top of the nanorods. Moreover, the Ti3+ defects in the TiO2 NPs and associated oxygen vacancies, and the nanobranches expend the optical absorption edge of the TiO2 NRAs from 400 nm to 510 nm. Branched TiO2 NRAs exhibit excellent photoelectrochemical properties compared to the pure TiO2 NRAs, as revealed by photoelectrochemical measurements. This enhanced photoelectrochemical properties is induced by the increased surface area and expanded optical absorption range. Due to their favorable characteristics, these novel branched TiO2 NRAs will provide a new path to the fabrication of hierarchical nanostructured materials.

Preparation of Vanadium Oxide Thin Films under Different Annealing Conditions

A novel method was used to fabricate VXOY thin films by combining magnetron sputtering and vacuum annealing processes on Al2O3 ceramic substrates, which greatly improved the success rate of the experiments and reduced the experimental requirements for the instruments. The substrate was magnetron sputter coated further oxidized in a tube furnace to produce a uniform V2O5 surface, then annealed at high temperatures. XRD and SEM measurements were performed on the obtained films under different annealing conditions. Characterization results of the samples indicate that the highly reproducible VO2 thin films can be achieved by controlling the process parameters of the magnetron sputtering and vacuum annealing. The experimental results are of great guidance value in VO2 thin film preparation.

Synergetic catalytic properties of gold nanoparticles planted on transparent titanium dioxide nanotube array bed

To improve the photo-induced catalytic activity of Au nanoparticles and enhance the adhesion between Au nanoparticles and the substrate, a layer of TiO2 nanotube array was fabricated on F− doped tin oxide conductive glass by combining magnetron sputtering method with anodic oxidation technology before the Au nanoparticles were deposited by vacuum thermal evaporation of Au. The structure, compositions and optical property of the as-prepared materials were characterized by grazing incidence X-ray diffraction, scanning electron microscopy, transmission electron microscope and UV-Vis spectrophotometer. Catalytic properties of all samples were evaluated by testing the anodic oxidation of methanol in the alkaline electrolyte. Due to the synergetic catalytic properties of titanium dioxide nanotube array and Au nanoparticles, dramatic improvements in electro-catalytic ability (2.4 ×), photo-induced electro-catalytic activity (7.94 ×) and durability were realized in comparison with Au/FTO electrode, suggesting a facile method to improve the catalytic ability and durability of noble metal catalyst.

Structural properties of hydrogenated Al-doped diamond-like carbon films fabricated by a hybrid plasma system

Hydrogenated Al-doped diamond-like carbon films were prepared in a hybrid plasma system combines magnetron sputtering and anode layer ion source, which allows independent control of the incorporated-Al content and carbon film structure. In order to achieve gradual structure and property transition from substrate to DLC film, a functionally gradient interlayer Cr/CrCx/CrxAlyC was tailored deposited. The influence of methane flow rate on chemical composition, morphologies, and microstructure of the resultant films were studied. The residual stress, mechanical and tribological properties were investigated by using laser stress-tester, nano-indentation and ball-on-disc tribo-meter, respectively. The results suggested that the Al-DLC films have a characteristic of amorphous structure and the incorporated Al atoms were dissolved in the matrix without bonding with C atoms. A significant residual stress reduction was found in Al-doped DLC film compared with pure one (3.8 GPa). The Al-DLC film deposited at the optimum methane flow rate exhibited a unique combination of desirable properties, including moderate hardness, good adhesion strength, low friction coefficient and good wear resistance, which make it a promising candidate as protective films for engineering applications.