Metal Vapor Vacuum Arc Source Research Articles

ENHANCING UV PROTECTION AND HYDROPHOBIC ABILITIES OF POLYESTER TEXTILES BY NOVEL SURFACE MODIFICATION TECHNIQUES

In this study, water vapour permeability, wrinkle recovery, UV protection and contact angle properties of ion implanted Polyester (PES) fabrics were investigated. In order to achieve this goal; our Metal Vapor Vacuum Arc (MEVVA) source implanted Pb, Ag, Ag+N, Ti+O and Cr+O to the PES fabrics with 5x1016 ion/cm2 and 30 kV acceleration voltage. The test results were compared with unimplanted PES fabric. The results indicated that UV Protection and contact angle values increased significantly and also almost no change observed at water vapour permeability and wrinkle recovery. These results also varied on severly with different ion species.

Effects of the implantation of Sn ions in W; chemical state, crystal structure and hardness

Prior to the practical application of liquid metals as facing material for fusion reactor, the nature of the interaction layer between liquid metal and tungsten substrate should be studied deeply. In the present work, by means of ion implantation technique using a metal vapor vacuum arc source (MEVVA), Sn ions were injected into a W matrix and a W-Sn modified layer was prepared. The chemical state, crystal structure and nano-indentation hardness of the modified layer were investigated and characterized with the use of X-ray photoelectron spectroscopy (XPS), an X-ray diffractometer (XRD) and a nano-indentor. The results indicate that, after the injection of Sn ions into the W matrix, Sn atoms interacted intensively with W, leading to the generation of a large number of point defects (such as vacancies and self-interstitial atoms) and the decrease of average grain size from 16.7 to 11.9 nm. Additionally, chemical shifts appeared, i.e., the binding energy values of W 4f7/2, W 4f5/2, W 5p3/2 and W 4p1/2 in the modified layer was reduced by 0.3 eV, 0.3 eV, 0.4 eV, 1–1.4 eV, respectively. The binding energy values of Sn 3d5/2 and Sn 3d3/2 decreased, with a chemical shift of 0.6–0.7 eV and 0.1–0.3 eV, respectively. The nano-indentation hardness of the modified layer was enhanced; specifically, when the indentation depth was 26.3 nm, the hardness reached a peak value of 13.8 GPa. In the modified layer, the surface chemical states are quite complex, mainly including SnO, WO3, SnO2 and WC.

Effect of titanium ion implantation and deposition on hydrogenation behavior of Zr-1Nb alloy

In order to study the effect of titanium ion implantation and deposition on hydrogenation behavior of Zr–1Nb alloy, the samples were subjected to plasma immersion implantation and deposition (PIII&D) of titanium ions at the bias voltage of 0.5–1.5kV using a filtered metal vapor vacuum arc source. The crystalline structure, surface morphology and depth distributions of elements in the surface layer of the samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and glow-discharge optical emission spectroscopy (GD-OES), respectively. Hydrogen saturation was performed from hydrogen atmosphere at 673K temperature and 2atm. pressure. It was found that hydrogen absorption rate by Zr–1Nb alloy decreased after PIII&D. The modified layers contained a mixing zone of titanium and zirconium, which decreases with increasing bias voltage. Hydrogenation causes the formation of titanium hydrides and lattice distortions of α–Zr at the low bias voltage that does not occur at higher bias voltages. The hydrogenation behavior of modified zirconium alloy was discussed.

In vitro studies on silver implanted pure iron by metal vapor vacuum arc technique

Pure iron has been verified as a promising biodegradable metal for absorbable cardiovascular stent usage. However, the degradation rate of pure iron is too slow. To accelerate the degradation of the surface of pure iron, silver ions were implanted into pure iron by metal vapor vacuum arc (MEVVA) source at an extracted voltage of 40keV. The implanted influence was up to 2×1017ions/cm2. The composition and depth profiles, corrosion behavior and biocompatibility of Ag ion implanted pure iron were investigated. The implantation depths of Ag was around 60nm. The element Ag existed as Ag2O in the outermost layer, then gradually transited to metal atoms in zero valent state with depth increase. The implantation of Ag ions accelerated the corrosion rate of pure iron matrix, and exhibited much more uniform corrosion behavior. For cytotoxicity assessment, the implantation of Ag ions slightly decreased the viability of all kinds of cell lines used in these tests. The hemolysis rate of Ag ion implanted pure iron was lower than 2%, which was acceptable, whereas the platelet adhesion tests indicated the implantation of Ag ions might increase the risk of thrombosis.

Local structure study of the Ni nanoparticles embedded in SiO2 by ion implantation

The extended x-ray absorption fine structure (EXAFS) and the Atomic force microscopy (AFM) have been used to study the local structural information of Ni nanoparticles implanted into glass. Three different concentrations of nickel nanoparticle samples were fabricated by metal vapor vacuum arc (MEVVA) source on amorphous silicon dioxide substrate at room temperature. With the increase of Ni ion implantation, the interatomic distance and the nearest neighbor coordination number of the nearest Ni–Ni bond and Ni–O bond of nickel nanoparticle presents certain regular change.

Surface properties of W-implanted TiN coatings post-treated by low temperature ion sulfurization

TiN coatings were implanted with W ions by metal vapor vacuum arc (MEVVA) source at dose of 9×1017ions/cm2, and then they were post-treated by low temperature ion sulfurization (LTIS) at 160°C. The W-implanted TiN samples were characterized before and after post-treatment of LTIS, using Scanning Electron Microscopy (SEM), Scanning Auger Microprobe (SAM), X-ray diffraction (XRD), and Nano Indenter System. Friction and wear properties were evaluated using a ball-on-disc tribometer under dry sliding in air. After post-treatment of LTIS, XRD results showed no diffraction peaks of tungsten sulfides on surfaces of W-implanted TiN coatings; W-implanted TiN coatings were sputtered by the sulfur plasma with about 36% reducing of W depth. Further, the nano-hardness decreased mainly due to the amount decreasing of Ti2N and the formation of more metal oxides on surfaces of W-implanted TiN coatings after LTIS. As a result, LTIS treatment could not well improve tribological properties of W-implanted TiN coatings.

Influence of Surface Nanocrystallization on Ti Ion Implantation of Pure Iron

In order to increase the depth or concentration of Ti ion implantation of pure iron, the surface mechanical attrition treatment (SMAT), which can fabricate a nanometer-grained surface layer without porosity and contamination in a pure iron plate, was used before ion implantation. Ti ion was implanted into the SMA treated sample and coarse-grained counterpart by using a metal vapor vacuum arc source implanter. The changing of depth and concentration of Ti was studied in a function of implantation time. By optical microscopy, transmission electron microscopy and X-ray diffraction, the grain size of the nano structured surface was studied. Micro-hardness, friction and wear behavior of nano surface layers were studied. By energy dispersive X-ray spectroscopy and Auger electron spectroscopy, the chemical composition and concentration of Ti ion in the surface implantation layer were studied. Experimental results showed that the concentration of Ti increased dramatically compared with untreated coarse-grained samples, which is attributed to the existence of higher density of defects (supersaturated vacancies, dislocations, non-equilibrium grain boundaries etc.) and compression stress field in the SMA treated nanocrystallined surface layer. The interaction between the defects and the implanted solute atoms leads to the increment of solid solubility. But the implantation depth showed inconspicuous change. It is shown that the ion range is just relevant to the energy and mass of the ion, dose of injection, the mass and density of target material.

Room temperature ferromagnetism studies in Fe ion implanted indium oxide films

Diluted magnetic semiconductor based on indium oxide has been prepared by Fe ion implantation. Pure In2O3 films are Fe ion implanted by metal vapor vacuum arc source with doses of 5×1015, 1×1016 and 4×1016cm−2, respectively. The implanted samples are separately annealed in vacuum and O2 subsequently. The structure of In2O3 films is characterized by X-ray diffraction and high resolution transmission electron microscopy. X-ray photoelectron spectroscopy measurements are applied to research the electronic state of the implanted ions. Superconducting quantum interference device measurements at room temperature disclose that both pure and Fe implanted In2O3 films are ferromagnetic, and the ferromagnetism is enhanced with the increase of implantation dose. The ferromagnetic mechanism is discussed. The bound magnetic polarons formed by Fe ion implantation and the oxygen vacancy may be responsible for the observed results.

Extended X-ray absorption fine structure analysis of the local structure of iron nanoparticles

Local structural information of iron nanoparticles and phase shift effects in the near-surface region of iron nanocrystal have been studied. Three iron nanoparticle samples were fabricated by metal vapor vacuum arc (MEVVA) source on amorphous silicon dioxide substrate at room temperature. We employed the extended X-ray absorption fine structure (EXAFS) method to investigate the local information of iron nanoparticles. The local structures of iron nanoparticles are concentration-dependent: the interatomic distance and the nearest neighbor coordination number are positively related to ion concentration of the implanted Fe+ ions.

Surface properties of Mo-implanted PVD TiN coatings using MEVVA source

To further improve the tribological properties of TiN coatings used on mechanical parts, Mo ions were implanted into PVD TiN coatings with Metal Vapor Vacuum Arc (MEVVA) source at the implantation dose as high as 1×1018ions/cm2. Surface morphology, microstructures, and nano-hardness of TiN coatings were investigated by optical profilometer, X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), and Nano Indenter System. The tribological properties were investigated on a ball-on-disk friction and wear tester. The XRD results demonstrated that the diffraction peak of Ti2N appeared in the Mo-implanted TiN coatings. However, there was obvious decrease of nano-hardness due to the soft Molybdenum phase and its oxides. It was approved that Mo-implanted TiN coatings could greatly improve their tribological properties and that the implantation at dose of 1×1018ions/cm2 could result in much lower friction coefficient. The existence of soft molybdenum, lubricious molybdenum oxides and titanium oxides resulted in the remarkable reducing of the friction coefficient of TiN coatings with Mo-implantation.

Microstructure and tribological properties of W-implanted PVD TiN coatings on 316L stainless steel

In order to further enhance the tribological properties of TiN coatings used on mechanical parts, W ion implantation with Metal Vapor Vacuum Arc (MEVVA) source was carried out on PVD TiN coatings at the implantation dose as high as 9 × 1017 ions/cm2. The microstructures of the TiN coatings were investigated by Scanning Auger microprobe (SAM), X-ray diffraction (XRD), and X-ray photoelectron spectroscope (XPS). The surface morphology and Nano-hardness were examined by an optical profilometer and Nano Indenter System, respectively. Also, the tribological properties were investigated on a ball-on-disc friction and wear tester. The results demonstrated that TiN coating with W-implantation at 9 × 1017 ions/cm2 showed remarkably sputtering effects on the surfaces, and sharply decreased the friction coefficient and wear rate by 63.74% and 56.55% respectively. Based on the hard phases of TiN, Ti2N and WN, the existence of soft tungsten, lubricious tungsten oxides and titanium oxides resulted in the remarkable reducing of the friction coefficient of TiN coatings with W-implantation.

Synthesis of graphene by MEVVA source ion implantation

Ion implantation provides a new synthesis route for graphene, and few-layered graphene synthesis by ion implantation has been reported. Here we show the synthesis of a single layer of high-quality graphene by Metal Vapor Vacuum Arc (MEVVA) source ion implantation. Polycrystalline nickel and copper thin films are implanted with MEVVA source carbon ions at 40kV, followed by high-temperature thermal annealing and quenching. A Raman spectrum is applied to probe the quality and thickness of the prepared graphene. A single layer of high-quality graphene is grown on the nickel films, but not on the copper films. The growth mechanisms on the nickel and copper films are explained. MEVVA source ion implantation has been widely applied in industrial applications, demonstrating that this synthesis method can be generalized for industrial production.

Investigation of magnetism in Fe and Cu ion implanted indium oxide films

Diluted magnetic semiconductor based on indium oxide has been prepared by transition metal ion implantation. Fe and Cu ions have been implanted into pulsed laser deposition prepared pure In2O3 films by metal vapor vacuum arc source with doses from 5×1015cm−2 to 1×1017cm−2, respectively. The implanted samples are annealed in the air subsequently. The structure of In2O3 films is characterized by X-ray diffraction. X-ray photoelectron spectroscopy measurements are applied to confirm the electronic state of the implanted ions. Superconducting quantum interference device measurements at room temperature disclose that the diamagnetic In2O3 films turned to be ferromagnetic after Fe and Cu ion implantation. The correlation between ferromagnetism and implantation conditions is tested. The ferromagnetism is attributed to the bound magnetic polarons formed by Fe, Cu ion implantation.

DUPLEX Al2O3/DLC COATING ON 15SiCp/2024 ALUMINUM MATRIX COMPOSITE USING COMBINED MICROARC OXIDATION AND FILTERED CATHODIC VACUUM ARC DEPOSITION

Microarc oxidation (MAO) treatment produces a thick Al2O3 coating on the 15SiCp/2024 aluminum matrix composite. After pretreatment of Ti ion implantation, a thin diamond-like carbon film (DLC) was deposited on the top of polished Al2O3 coating by a pulsed filtered cathodic vacuum arc (FCVA) deposition system with a metal vapor vacuum arc (MEVVA) source. The morphology and tribological properties of the duplex Al2O3 /DLC multiplayer coating were investigated by Raman spectroscopy, scanning electron microscopy (SEM) and SRV ball-on-disk friction tester. It is found that the duplex Al2O3 /DLC coating had good adhesion and a low friction coefficient of less than 0.07. As compared to a single Al2O3 or DLC coating, the duplex Al2O3 /DLC coating on aluminum matrix composite exhibited a better wear resistance against ZrO2 ball under dry sliding, because the Al2O3 coating as an intermediate layer improved load support for the top DLC coating on 15SiCp/2024 composite substrate, meanwhile the top DLC coating displayed low friction coefficient.

Surface modification of hard alloy by Y ion implantation under different atmosphere

To enhance the properties of hard alloy, rare-earth metal yttrium (Y) was implanted into its surface by using Metal Vapor Vacuum Arc (MEVVA) source implantor. The experiments were finished under different vacuum conditions with/without aerating nitrogen in the chamber. The metallograph and phase formation of sample were characterized and analyzed with metallurgical microscope and X-ray diffraction. The results show that there exist new phases of C, YC2, Y2O3, and WN in the sample surface. Moreover, it can be found that the performances of sample surface (such as microhardness, friction coefficient and corrosion resistance) are evidently improved, and that nitrogen atmosphere plays a very important role in farther promoting these performances. The surface modification of hard alloy is not only affected by the implantation itself, but also related to the microstructure transformation, which can be partly induced by the atmosphere.

Corrosion resistance and blood compatibility of lanthanum ion implanted pure iron by MEVVA

Pure iron is a potential material applying for coronary artery stents based on its biocorrodible and nontoxic properties. However, the degradation characteristics of pure iron in vivo could reduce the mechanical stability of iron stents prematurely. The purpose of this work was to implant the lanthanum ion into pure iron specimens by metal vapor vacuum arc (MEVVA) source at an extracted voltage of 40 kV to improve its corrosion resistance and biocompatibility. The implanted fluence was up to 5 × 10 17 ions/cm 2. The X-ray photoelectron spectroscopy (XPS) was used to characterize the chemical state and depth profiles of La, Fe and O elements. The results showed lanthanum existed in the +3 oxidation state in the surface layer, most of the oxygen combined with lanthanum and form a layer of oxides. The lanthanum ion implantation layer could effectively hold back iron ions into the immersed solution and obviously improved the corrosion resistance of pure iron in simulated body fluids (SBF) solution by the electrochemical measurements and static immersion tests. The systematic evaluation of blood compatibility, including in vitro platelets adhesion, prothrombin time (PT), thrombin time (TT), indicated that the number of platelets adhesion, activation, aggregation and pseudopodium on the surface of the La-implanted samples were remarkably decreased compared with pure iron and 316L stainless steel, the PT and TT were almost the same as the original plasma. It was obviously showed that lanthanum ion implantation could effectively improve the corrosion resistance and blood compatibility of pure iron.

GE‐MXRF analysis of multilayer films

AbstractPolycapillary x‐ray optics (capillary x‐ray lens) is now popular in x‐ray fluorescence (XRF) analysis. Such an x‐ray lens can collect x‐rays emitted from an x‐ray source in a large solid angle and form a very intense x‐ray microbeam which is very convenient for micro x‐ray fluorescence (MXRF) analysis. In this paper, a new method called grazing exit micro x‐ray fluorescence analysis (GE‐MXRF), which combines an x‐ray lens used to form an intense XRF source was developed and applied in multilayer film analysis. Such a method can give the information of film composition, density, and thickness. Through two‐dimensional scan of the film sample, the information of film uniformity can be acquired; meanwhile, this method is also useful in adjusting experiment condition during the film preparation with metal vapor vacuum arc (MEVVA) source ion implantation. Copyright © 2008 John Wiley & Sons, Ltd.

Modification of friction and wear properties of PET membrane fabrics by MEVVA ion implantation

Polyethylene terephthalate (PET) membrane fabrics were modified by Ti, W, Ti + N, Cr + N and C + N implantations using a metal vapor vacuum arc (MEVVA) source at an accelerating voltage of 30 kV with doses ranging from 1 × 10 15 to 5 × 10 16 ions cm −2 in TUBITAK Textile Research Center in Izmir. After implantation, changes in the mechanical properties of the samples were investigated. The results indicated that friction coefficient and wear loss values decreased significantly. This decrease depended on the used ion species and the doses. The surface morphologies of samples were examined by SEM and AFM. The changes in chemical structure were observed by IR spectra.

Influence of aluminum ions implantation on corrosion behavior of zircaloy-2 alloy in 1 M H2SO4

The specimens were implanted with aluminum ions with fluence ranging from 1×1016 to 1×1017 ions/cm2 to study the effect of aluminum ion implantation on the aqueous corrosion behavior of zircaloy-2 by metal vapor vacuum arc source (MEVVA) at an extraction voltage of 40 kV. The valence states and depth distributions of elements in the surface layer of the samples were analyzed by X-ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES), respectively. Transmission electron microscopy (TEM) was used to examine the microstructure of the aluminum-implanted samples. Glancing angle X-ray diffraction (GAXRD) was employed to examine the phase transformation due to the aluminum ion implantation. The potentiodynamic polarization technique was employed to evaluate the aqueous corrosion resistance of implanted zircaloy-2 in a 1 M H2SO4 solution. It is found that a significant improvement was achieved in the aqueous corrosion resistance of zircaloy-2 implanted with aluminum ions. Finally, the mechanism of the corrosion behavior of aluminum-implanted zircaloy-2 was discussed.

The corrosion behavior of Ce-implanted magnesium alloys

The aim of this study was to investigate the effect of cerium ion implantation on the corrosion behavior of AZ31 magnesium alloys. Samples were implanted with doses of 5 × 10 16, 1 × 10 17 and 5 × 10 17 ion/cm 2, respectively, using a metal vapor vacuum arc (MEVVA) source at an extraction voltage of 45 kV. Auger electron spectrometry (AES) and X-ray photoelectron spectroscopy (XPS) were used to analyze the depth distribution and the valence states of elements in the implanted layer, respectively. The potentiodynamic polarization technique was applied to evaluate the corrosion resistance of the implanted samples in a 3.5 wt.% NaCl solution saturated with Mg(OH) 2. The results showed that under an optimal dose the corrosion resistance of the implanted sample was improved compared with that of the bare sample. Finally, the corrosion mechanism of the Ce-implanted samples was discussed.