Cathodic Arc Deposition Research Articles

Investigation of the Properties of TixCr1-xN Coatings Prepared by Cathodic Arc Deposition

The structure, composition and mechanical properties of TixCr1-xN coatings have been investigated. Processing by cathodic arc evaporation using cathodes with different arc currents was performed to obtain coatings with compositions x=0.52, x=0.59, x=0.68, x=0.72 and x=0.81, The TixCr1-xN hard coatings were characterized by nanoindentation, scanning electron microscopy and X-ray diffraction. The results showed the coatings consisted of B1-NaCl type cubic structure, the Cr content promoted a (200) preferred crystallographic orientation and has a dramatic influence on the hardness of TixCr1-xN coatings, which indicted the alloy-strengthening of the Cr element on TiN-based coatings.

Oxidation Resistance of Vacuum Plasma Sprayed CoNiCrAlY Coatings Modified by Filtered Cathodic Vacuum Arc Deposition Aluminizing

The vacuum plasma sprayed CoNiCrAlY coatings are modified by filtered cathodic vacuum arc deposition aluminizing. The microstructure and oxidation resistance of the coatings are investigated. The parabolic law is obeyed for the aluminized coatings after oxidation at 1100 °C for 100 h. Its parabolic kinetic constant is 0.080 mg2/cm4 h, which is lower than that of as-sprayed coatings. The continuous and dense Al2O3 scale is formed earlier due to the increase of Al concentration, and the spinels hardly exist. The oxidation resistance is improved obviously after filtered cathodic vacuum arc deposition aluminizing.

Tantalum oxide nanocoatings prepared by atomic layer and filtered cathodic arc deposition for corrosion protection of steel: Comparative surface and electrochemical analysis

A comparative study by Time-of-Flight Secondary Ions Mass Spectrometry and X-ray Photoelectron Spectroscopy, i–E polarization curves and Electrochemical Impedance Spectroscopy of the corrosion protection of low alloy steel by 50nm thick tantalum oxide coatings prepared by low temperature Atomic Layer Deposition (ALD) and Filtered Cathodic Arc Deposition (FCAD) is reported. The data evidence the presence of a spurious oxide layer mostly consisting of iron grown by transient thermal oxidation at the ALD film/substrate interface in the initial stages of deposition and its suppression by pre-treatment in the FCAD process. Carbonaceous contamination (organic and carbidic) resulting from incomplete removal of the organic precursor is the major cause of the poorer sealing properties of the ALD film. No coating dissolution is demonstrated in neutral or acid 0.2M NaCl solutions. In acid solution localized corrosion by pitting proceeds faster with the ALD than with the FCAD coating. The roles of the pre-existing channel defects exposing the substrate surface and of the spurious interfacial oxide promoting coating breakdown and/or delamination are emphasized.

On the high temperature stability of γ-Al2O3/Ti0.33Al0.67N coated WC–Co cutting inserts

Abstract The high temperature stability of γ-Al2O3 films deposited using filtered cathodic arc and plasma assisted chemical vapor deposition on Ti0.33Al0.67N coated WC–Co cutting inserts is investigated. X-ray diffractometry reveals that filtered cathodic arc deposited films transform partially into the thermodynamically stable α-Al2O3 phase at a temperature of 1000°C. The γ to α-Al2O3 transformation for plasma assisted chemical vapor deposition grown films is observed at 900°C. These results are in qualitative agreement with differential scanning calorimetry measurements. Transmission electron microscopy on filtered cathodic arc and plasma assisted chemical vapor deposition films annealed at 900°C reveals the existence of hexagonal AlN in the Ti0.33Al0.67N interlayer, as well as Al depletion at the Al2O3/Ti0.33Al0.67N interface. After annealing the plasma assisted chemical vapor deposition sample at 900°C, α-Al2O3 grains with a size of ∼100 nm are observed inside the γ-Al2O3 matrix, while for filtered cathodic arc samples only the γ-phase is identified. Transmission electron microscopy analysis on both filtered cathodic arc and plasma assisted chemical vapor deposition samples annealed at 1000°C shows that the original Al2O3/Ti0.33Al0.67N/WC–Co layer architecture is no longer intact. The formation of TiO2 is detected along the growth direction of the Al2O3 films. The present study suggests that not only the morphology and the impurities incorporated into γ-Al2O3 but also stability of the Ti0.33Al0.67N interlayer determine the high temperature stability of γ-Al2O3/Ti0.33Al0.67N coated hardmetal.

Transparent and conductive indium doped cadmium oxide thin films prepared by pulsed filtered cathodic arc deposition

Indium doped cadmium oxide (CdO:In) films with different In concentrations were prepared on low-cost glass substrates by pulsed filtered cathodic arc deposition (PFCAD). It is shown that polycrystalline CdO:In films with smooth surface and dense structure are obtained. In-doping introduces extra electrons leading to remarkable improvements of electron mobility and conductivity, as well as improvement in the optical transmittance due to the Burstein–Moss effect. CdO:In films on glass substrates with thickness near 230nm show low resistivity of 7.23×10−5Ωcm, high electron mobility of 142cm2/Vs, and mean transmittance over 80% from 500 to 1250nm (including the glass substrate). These high quality pulsed arc-grown CdO:In films are potentially suitable for high efficiency multi-junction solar cells that harvest a broad range of the solar spectrum.

Chemically synthesized one-dimensional zinc oxide nanorods for ethanol sensing

One-dimensional (1D), single-phase (002) crystalline zinc oxide (ZnO) nanorod (NR) based conductometric sensors have been developed and investigated toward ethanol (C2H5OH) vapor. The ZnO NRs were chemically deposited onto conductometric transducer of alumina substrates employing a simple hydrothermal method. To facilitate the nucleation of ZnO NRs for oriented growth from the substrate, a seed layer of ZnO nanoparticles was pre-deposited employing filtered cathodic vacuum arc (FCVA) deposition technique onto the substrate containing pre-patterned interdigital electrodes (IDTs). Micro-characterization studies revealed that the NRs have a single crystal 1D structure with an average diameter of 30–50nm. The developed sensors were exposed toward ethanol of different concentrations at temperature up to 330°C. An optimum sensor operational temperature was found between 280 and 310°C. At this temperature range, high sensitivity, fast response and fast recovery in conjunction with a stable baseline occur. The long-term stability test of the developed sensors confirmed that they are highly stable with only less than 3% variation of the dynamic performances (baseline resistance, sensitivity, response and recovery time).

Characterization and antibacterial performance of bioactive Ti–Zn–O coatings deposited on titanium implants

Titanium (Ti)-based materials have been used for dental and orthopedic implants because of their excellent biological compatibility, superior mechanical strength, and high corrosion resistance. The hypothesis of this present study was to manufacture the Zn-doped TiO2 layer possessing the biocompatibility and antibacterial ability on the surface of Ti specimens. TiO2, ZnO, and Ti(Zn)O2 coatings were deposited on polished pure Ti substrates using a cathodic arc deposition system. Murine osteoblasts (MC3T3-E1) and human Staphylococcus aureus (S. aureus) were cultured onto the surface with different deposited coatings, respectively. The biocompatibility was examined by cell viability and osteogenic gene expression. The antibacterial ability was determined by SYTO9 nucleic acid staining. A porous Zn-doped TiO2 coating was successfully produced. The ZnO exhibited a fibrous structure with nanorods showing a hydrophobic feature (contact angle approximately 89°). These material properties affected the following biological performance. The antibacterial testing found no apparent difference between the uncoated Ti plate and the TiO2 coating. However, significantly lower numbers of S. aureus were observed on ZnO and Ti(Zn)O2 coatings compared to that on the uncoated Ti. The biocompatible testing exhibited that TiO2 and Ti(Zn)O2 coatings enhanced greater cell viability and proliferation than the uncoated Ti plate and ZnO coating. The osteogenic gene expression of Dlx-5 and osterix also improved for the TiO2 and Ti(Zn)O2 coatings. However, a significant inhibition of cell viability was found for the ZnO coating. These findings suggested that the composite Ti(Zn)O2 coating with a lower content of Zn (7.6±1.3at.%) not only improved antibacterial activity, but also maintained the biocompatibility to bone cells.

Mesoporous surfaces by phase separation of Al–Si thin films

Phase separated Al–Si films were deposited by simultaneous filtered cathodic vacuum arc (FCVAD) and magnetron sputter deposition. The deposited films were etched to remove the nanocolumns of Al to produce a Si mesoporous structure. The pore size ranged from 3nm to 6nm with narrow distribution in size. The pore separation ranged from 6.5nm to 11.5nm. The results are interpreted using a model to describe the pore size as a function of the depositing particle impingement energy.

Formation of cubic structured (Al1 − xCrx)2 + δO3 and its dynamic transition to corundum phase during cathodic arc evaporation

Mixed aluminum–chromium oxide coatings in the form of (Al,Cr)2O3 solid solutions have attracted extensive research interest during the past years due to their successful use for challenging wear applications and the comparative ease of their moderate-temperature deposition by physical vapor deposition techniques. During our research into the reactive cathodic arc deposition of this type of coating, we found a previously unobserved transition between two crystalline aluminum–chromium oxide structures. During the early growth stage, films arc-deposited from Al0.55Cr0.45 targets form a first zone, that was found to contain exclusively the metastable cubic fcc-(Al1−xCrx)2+δO3 phase. This kinetically favored phase is reproducibly followed by the growth of a second zone made of the initially expected corundum phase, α-(Al1−xCrx)2+δO3, as observed by TEM. This dynamic transition has a significant effect on the film properties. XPS studies and structural data show that the formation of fcc-(Al1−xCrx)2+δO3 with a (200) preferred orientation arises from the initial presence of a metastable monoxide (M1−xO) film, which is stabilized by the incorporation of metal vacancies (31%) in the B1 structure. However, as the thickness of coating increases, the thermodynamic aspect becomes more important as compared to kinetics and leads to a loss of structural stability in the cubic layer, which is a kinetically favored phase. As a result, the system will transform into the metastable corundum α-(Al1−xCrx)2+δO3, which is thermodynamically more stable than the cubic phase. In this paper, formation of fcc-(Al1−xCrx)2+δO3 and its transformation to corundum phase are discussed in detail with respect to the structural and electronic properties of the different phases.

Cathodic arc deposited (Cr,Six)N coatings: From solid solution to nanocomposite structure

This paper aims to investigate the effect of silicon addition on the microstructure and mechanical properties of CrN coatings with an emphasis on their stability at high temperature. Thin films were deposited onto M2 tool steels using a cathodic arc deposition process. Silicon was introduced using duplex Cr–Cr3Si targets, allowing Si enrichment within the 0.6–10.8at.% range.The microstructure of the films was characterized by SEM and TEM, while their crystalline structure at room temperature and after high temperature annealing treatments (up to 1000°C) was determined by XRD analyses. Mechanical properties were deduced from nanoindentation measurements and from residual stress experiments.A minimum content of 2at.% was evidenced as the solubility limit of Si in CrN. Below this value, Si substituted Cr in the CrN lattice to form a solid solution. Above 2at.% Si, a nanocomposite bi-phased structure appeared, composed of Si-poor CrN nanograins surrounded by an amorphous Si-rich CrN matrix. Si addition induced significant grain shrinkage, without a significant effect on hardness at room temperature. For (Cr,Six)N films annealed at high temperatures, the nanocomposite structure allowed a delay in structural transformations linked to nitrogen losses, preserving better and more stable mechanical properties.

Electrical, optical, and structural properties of thin films with tri-layers of AZO/ZnMgO/AZO grown by filtered vacuum arc deposition

Abstract Transparent conductive oxides (TCO) are indispensable as front electrode for most of thin film electronic devices such as transparent electrodes for flat panel displays, photovoltaic cells, windshield defrosters, transparent thin film transistors, and low emissivity windows. Thin films of aluminum-doped zinc oxide (AZO) have shown to be one of the most promising TCOs. In this study, three layered Al-doped ZnO (AZO)/ZnMgO/AZO heterostructures were prepared by filtered cathodic arc deposition (FCAD) on glass substrates. The objective is to find a set of parameters that will allow for improved optical and electrical properties of the films such as low resistivity, high mobility, high number of charge carriers, and high transmittance. We have investigated the effect of modifications in thickness and doping of the ZnMgO inner layer on the structural, electrical, and optical characteristics of the stacked heterostructures.

The microstructure and mechanical properties of multilayer diamond-like carbon films with different modulation ratios

The multilayer DLC films consisting of sp2-rich DLC layers (soft DLC) and sp3-rich DLC layers (hard DLC) with different modulation ratios (thickness ratio of the hard DLC to soft DLC) ranging from 2:1, 1:1 to 1:2 had been deposited on Si (100) wafer and Ti–6Al–4V alloy substrates by filtered cathodic vacuum arc (FCVA) deposition. The effect of modulation ratio on the microstructure and properties of the multilayer DLC films including sp3 content, residual stress, mechanical properties, adhesion strength and wear resistance were studied by Raman spectroscopy, profilometry technique, nanoindenter, Vickers indentation test, scanning electron microscopy (SEM) and ball-on-disc reciprocating friction test. The results showed that the sp3 content and the hardness of the multilayer DLC films decreased with modulation ratios decreasing. The stress of the multilayer DLC films could be effectively reduced and the stress decreased with the modulation ratio decreasing. The multilayer DLC film with modulation ratio of 1:1 had the best wear resistance due to a balance between hardness and residual stress.

Biological Behavior of Osteoblast-like Cells on Titania and Zirconia Films Deposited by Cathodic Arc Deposition

Cathodic arc deposition technique was used to deposit zirconia (ZrO(2)) films and titania (TiO(2)) films on titanium (Ti) disks respectively. The surface topography was characterized by scanning electron microscopy and atomic force microscopy. The element composition of the films was detected by X-ray photoelectron spectroscopy. The phase of films was identified by thin film X-ray diffraction. The biological behavior of osteoblast-like MG63 cells cultured on Ti, TiO(2) and ZrO(2) was investigated and the possible signaling molecules involved was studied by the gene expressions of integrin β1, extracellular related kinase 1/2 (ERK1/2), and c-fos. The results indicated that both the TiO(2) and ZrO(2) films were amorphous. Scanning electron microscopy study showed that the adhesion of MG63 cells on TiO(2) and ZrO(2) films was significantly enhanced compared to Ti. The CCK8 assay indicated that the TiO(2) and ZrO(2) films promoted the proliferation of MG-63 cells. The alkaline phosphatase (ALP) activity test and the production of type collagen I (COLI) by immunofluorescence showed that both the TiO(2) and ZrO(2) films can enhance ALP activity and COLI expression of MG-63 cells. In addition, the ALP activity on ZrO(2) films was higher than on TiO(2) films at day 4, which indicate ZrO(2) films may lead to promotion of a more osteoblastic phenotype of MG-63 cells than TiO(2) films. Real-time polymerase chain reaction analysis demonstrated that The gene expression of integrin β1, ERK1/2, and c-fos was higher on TiO(2) and ZrO(2) films than on Ti. The present work suggests that the amorphous ZrO(2) films produced by cathodic arc deposition may be favorable for orthopedic implant applications and worth further study.

Proliferation and differentiation of osteoblastic cells on silicon-doped TiO2 film deposited by cathodic arc

This study aimed at the proliferation and differentiation of osteoblastic cells on silicon-doped TiO2 and pure TiO2 films prepared by cathodic arc deposition. The films were examined by X-ray photo-electron spectroscopy, which showed that silicon was successfully doped into the Si-TiO2 film. Meanwhile, no significant difference was found between the surface morphology of silicon-doped TiO2 and pure TiO2 films. When osteoblastic cells were cultured on silicon-doped TiO2 film, accelerated cell proliferation was observed. Furthermore, cell differentiation was evaluated using alkaline phosphatase (ALP), type I collagen (COL I) and osteocalcin (OC) as differentiation markers. It was found that ALP activity, the expression levels of OC gene, COL I gene and protein were up-regulated on silicon-doped TiO2 film at 3 and 5 days of culture. Moreover, no significant difference was found in apoptosis between the cells cultured on silicon-doped TiO2 and pure TiO2 films. Therefore, findings from this study indicate that silicon-doped film favors osteoblastic proliferation and differentiation, and has the potential for surface modification of implants in the future.

Phase formation and microstructure evolution of arc ion deposited Cr2AlC coating after heat treatment

Due to the excellent oxidation and hot corrosion resistance and matched thermal expansion coefficient to normal alloys, Cr2AlC has potential applications as high-temperature protective coating. In the present work, the preparation of Cr2AlC coating has been achieved through cathodic arc deposition method combined with heat post-treatment. It was found that the coating, deposited from Cr2AlC compound target in the unintentional heating condition, was amorphous. After annealing at 620°C in Ar for 20h, the amorphous Cr–Al–C coating happened to crystallize and transformed to crystalline Cr2AlC as the major phase. It is obvious that the formation temperature of Cr2AlC was decreased from about 1050°C for sintered bulk to around 620°C for the as-deposited coating, resulting from the homogeneous mixture of the Cr, Al and C at atomic level in the Cr–Al–C coating. Apart from crystalline Cr2AlC, the annealed coating also contained AlCr2 and little Cr7C3. AlCr2 formed due to the loss of C during deposition, and little Cr7C3 always existed in the sintered Cr2AlC compound target as impurity phase.

Structural and mechanical properties of Cr–Al–O–N thin films grown by cathodic arc deposition

Coatings of (CrxAl1−x)δ(O1−yNy)ξ with 0.33⩽x⩽0.96, 0⩽y⩽1 and 0.63⩽δ/ξ⩽1.30 were deposited using cathodic arc evaporation in N2/O2 reactive gas mixtures on 50V negatively biased WC–10wt.% Co substrates from different Cr and Al alloys with three different Cr/Al compositional ratios. For N2<63% of the total gas, ternary (Cr,Al)2O3 films containing <1at.% of N forms; as determined by elastic recoil detection analysis. Increasing the N2 fraction to 75% and above results in formation of quaternary oxynitride films. Phase analyses of the films by X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy show the predominance of cubic Cr–Al–N and cubic-(Cr,Al)2O3 solid solutions and secondary hexagonal α-(Cr,Al)2O3 solid solution. High Cr and Al contents result in films with higher roughness, while high N and O contents result in smoother surfaces. Nanoindentation hardness measurements showed that Al-rich oxide or nitride films have hardness values of 24–28GPa, whereas the oxynitride films have a hardness of ∼30GPa, regardless of the Cr and Al contents. Metal cutting performance tests showed that the good wear properties are mainly correlated to the oxygen-rich coatings, regardless of the cubic or corundum fractions.

Numerical and Experimental Study of Residual Stress of Multilayer Diamond-Like Carbon Films Prepared by Filtered Cathodic Vacuum Arc Deposition

The high-hardness diamond-like carbon (DLC) films synthesized by filtered cathodic vacuum arc (FCVA) deposition may have high residual stress, which will cause the DLC film/substrate interfacial crack and film failure. Therefore, it is essential to analyze and control the residual stress during the DLC deposition. In this paper, the low-hardness DLC monolithic layer films (rich in sp <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> content, soft DLC), the high-hardness DLC monolithic layer films (rich in sp <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> content, hard DLC), and a series of soft/hard DLC multilayer films with modulation ratio of 1 : 1 and modulation periods ranging from 70 to 280 nm are deposited, respectively, on Si (100) wafer and Ti-6Al-4V by FCVA technology with periodic adjustments of the substrate negative bias. The effects of modulation periods (bilayer thickness) on residual stress and wear resistance of multilayer DLC films are studied. The results show that the residual stress decreases in soft/hard multilayer DLC films with decreasing modulation periods, and the films with modulation period of 140 nm have excellent wear resistance. ANSYS finite-element software is used to simulate the residual stress generation during FCVA deposition in the DLC film on a silicon substrate. The result of the finite-element simulation is consistent with that of the experiment, and the finite-element technique has a potential application in the optimization process of DLC multilayer films.

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.

Effect of alloyed target vis-à-vis pure target on machining performance of TiAlN coating

Typically closed-field unbalanced magnetron sputtering (CFUBMS) and controlled cathodic arc deposition techniques having four or six pure or alloyed targets are employed for commercial titanium aluminium nitride (TiAlN) coating of cutting tools. The role of the use of alloyed target vis-à-vis pure target on the coating characteristics and the machining performance of TiAlN-coated tools has not been studied in detail. In the present work, TiAlN coating has been deposited on cutting tools using a pulsed DC, dual-cathode CFUBMS system to capture the role of the type of target on machining performance. The deposition rate in the case of the alloyed target has been found to be much higher as compared to the pure target. Such coatings deposited from alloyed targets also provided significantly better machining performance in dry turning of low-carbon and high-carbon steel. Dry turning of SAE 1070 high-carbon steel at 160 m/min did not yield more than 100 μm of average flank wear on the same insert coated using alloyed targets for a machining time of more than 3 min.

빗각 증착으로 제조된 TiN 박막의 특성

Oblique angle deposition (OAD) is a physical vapor deposition where incident vapor flux arrives at non-normal angles. It has been known that tilting the substrate changes the properties of the film, which is thought to be a result of morphological change of the film. In this study, OAD has been applied to prepare single and multilayer TiN films by cathodic arc deposition. TiN films have been deposited on cold-rolled steel sheets and stainless steel sheet. The deposition angle as well as substrate temperature and substrate bias was changed to investigate their effects on the properties of TiN films. TiN films were analyzed by color difference meter, scanning electron microscopy, nanoindenter and x-ray diffraction. The color of TiN films was not much changed according to the deposition conditions. The slanted and zigzag structures were observed from the single and multilayer films. The relation between substrate tilting angle (<TEX>${\alpha}$</TEX>) and the growth column angle (<TEX>${\beta}$</TEX>) followed the equation of <TEX>$tan{\alpha}=2tan{\beta}$</TEX>. The indentation hardness of TiN films deposited by OAD was low compared with the ones prepared at normal angle. However, it has been found that <TEX>$H^3/E^2$</TEX> ratio of 3-layer TiN films prepared at OAD condition was a little higher than the ones prepared at normal angle, which can confirm the robustness of prepared films.