Arc Deposition Research Articles

Effect of the C/N ratio modification on the corrosion behavior and performance of carbonitride coatings prepared by cathodic arc deposition

This study focuses on investigating carbonitride coatings, specifically CNTi-(Zr, ZrNb, and ZrSi), as promising candidates for enhancing the durability and efficiency of Ti6Al4V materials used in nuclear fusion technology. X-ray diffraction analysis identified distinct phases, including TiN, ZrN, ZrC, and TiC. The corrosion studies showed complete degradation of the TiN, ZrC, and ZrN phases in the TiZrCN coating after tests, while the TiC phase exhibited relative stability. The surface morphologies and elemental mapping analysis demonstrated the loss of homogeneity in element distribution after corrosion process. The addition of Si and Nb elements into TiZrCN significantly influenced the coatings' corrosion behavior, with breakaway corrosion observed in CNTi- (Zr and ZrSi) coatings and localized corrosion in CNTi-(ZrNb) coatings. Notably, the CNTi-(ZrSi) coating formed an oxide phase in the presence of NaCl, whereas the CNTi-(ZrNb) coating exhibited continuous resistance and a low corrosion rate. Irradiation was carried out for the generation of active isotopes, showing that no radioactive isotopes were formed in any of the investigated samples.

High temperature oxidation of CrAl-coated Zr–1 Nb alloy in 1000 – 1300 °C steam

The CrAl coating of 13 µm thick on Zr–1 Nb alloy prepared by filtered cathodic vacuum arc deposition with Cr70Al30 target exhibited excellent steam oxidation resistance below 1200 °C, but its protective properties were obviously weakened at 1300 °C. The mass gain of CrAl-coated alloy was 7.8%, 6.5%, 16.6% and 66.0% of that of bare alloy after 3600 s oxidation at 1000 °C, 1100 °C, 1200 °C and 1300 °C, respectively. The addition of a little Al in CrAl coating was beneficial to further suppress oxygen diffusion into alloy substrate due to the hindering effect of Al2O3 against oxygen atoms.

(AlCrMoTiNi)1-XNX high entropy ceramic with high hardness and toughness prepared by co-filtered cathodic vacuum arc deposition

High entropy ceramic (HEC) coatings have become candidates for new protective coating due to their high strength. However, the hardness - toughness balance of the ceramic coatings is still a difficult problem to solve. The strong nitride forming elements Al, Ti, Cr, Mo, and the non-nitride forming element Ni were selected as the components of the (AlCrMoTiNi)1-XNX HEC coatings to regulate the hardness and toughness. When x = 0 and 0.29, the composite structure of amorphous and metallic Ni phase is observed in these coatings. When x = 0.37, 0.40, and 0.45, the phase structure changes to the composite structure of nanoscale face-centered cubic (FCC) phase, metallic Ni, and amorphous phase. When x = 0.45, the maximum hardness of the HEC coating is 31.25 GPa, and it also has high toughness with a KIC value of 3.25 MPa m1/2. The HEC coating with high hardness and toughness also presents excellent wear resistance and corrosion resistance. Therefore, the (AlCrMoTiNi)0.55N0.45 HEC coating has potential as a protective coating applied in various areas.

Quaternary ZrCuCa-based thin films metallic glasses deposited by cathodic arc deposition

The current study’s aim is to obtain quaternary ZrCuCa based thin films using a physical vapor deposition method (PVD) - cathodic arc approach – in order to improve the surface properties of 316L stainless steel and Ti6Al4V implantable materials. The developed ZrCuCa-based layers could be potential candidates in the medical industry if they are able to combine their exceptional mechanical properties with the corrosion resistance of amorphous metallic glasses. Furthermore, addition of Mo, Mg, Si, and Sr was taken into consideration for the ZrCuCa structure and the resulted quaternary systems were analysed in detail, through electrochemical tests and bioactivity assay, which were carried out in synthetic body fluid (SBF) at human body temperature (37 °C). Surface morphology and roughness of the specimens before and after the tests were also evaluated. The results showed that regardless the substrate type, the roughness of the surface has increased for all coatings from 19 nm for 316L, and 50 nm for Ti6Al4V, to 2000 nm). The adhesion of obtained coatings was reached from 8 N to 18, the coatings on Ti6Al4V alloy was found to be from 12 N to 18 N, while on 316L steel was from 8 N to 15 N, indicating that the coatings deposited on Ti alloy have a better adhesion. The corrosion current density parameter for ZrCuCaMo and ZrCuCaMg sjowe the lowest value (316L: 21.99 µA/cm2 and 11.37 µA/cm2; Ti6Al4V: 1.62 µA/cm2 and 13.37 µA/cm2), indicating the best corrosion resistance. The mass evolution of the coatings deposited on 316L was ranged from the −0.47 mg to 1.37 mg, while for those deposited on Ti6Al4V, the values were ranged from −0.08 mg to 2.66 mg, indicating a degradation and biomineralization process, respectively. In conclusion, the electrochemical studies and bioactivity experiments demonstrated that the suggested coatings improve the substrate’s behaviour in simulated conditions, highlighting their potential as biomaterials.

Efficiency of cathodic arc-grown N-doped TiO2 films for the photocatalytic reduction of Cr(VI) under UV-Vis irradiation

The photocatalytic activity of undoped and N-doped TiO2 anatase films with different thicknesses prepared by cathodic arc deposition on glass substrates is reported. After TiO2 deposition, the doping of the films was carried out by plasma immersion ion implantation in a nitrogen environment. The composition of the films was studied by x-ray photoelectron spectroscopy, the surface morphology was analyzed by atomic force microscopy and the crystalline structure was examined by x-ray diffraction. The thickness was determined by observing the film cross section with scanning electron microscopy. The transmittance of the films in the UV-Vis range was studied as well. The photocatalytic activity of the films was evaluated through the efficiency in the reduction of Cr(VI) in the presence of ethylenediaminetetraacetic acid under UV-Vis irradiation. N-doped films presented a higher photocatalytic efficiency than undoped films: Cr(VI) reduction after 5 h irradiation augmented from 58% (pure TiO2) to 85% (N-doped TiO2) for films of 300 nm thickness, and from 69% to 85% for films with a thickness of 440 nm. On the other hand, pure TiO2 films of 790 nm thickness were more efficient (99% of Cr(VI) reduction) but the effect of doping on the photocatalytic activity was negligible.

Comparison of Plasma Surface Hardening with Vibratory Arc Deposition

Comparison of Plasma Surface Hardening with Vibratory Arc Deposition

Substrate bias effects on cathodic arc deposited Cr coatings

We investigate the effects of substrate bias on cathodic arc deposition of Cr coatings without external substrate heating at four different substrate bias levels, floating, −30, −50, and −70 V. After 10 min of deposition, the substrate temperature reaches 180, 210, 230, and 260 °C for floating potential, −30, −50, and −70 V, respectively. Time-of-flight energy elastic recoil detection analysis shows that all grown coatings are of high purity, with no coating containing more than 0.2 at.% of C and/or O. Increasing the substrate bias also reduces the number of macroparticles, steers the texture from preferred [110]- to [100]-orientation and induces a residual compressive stress of ∼450 MPa in the coatings. The hardness of the coatings remains at a constant 7.5 GPa irrespective of the substrate bias. The four-point probe resistivity of the grown coatings is 15–17 μΩcm regardless of substrate bias, close to the 12.9 μΩcm of bulk Cr.

Features of Tribooxidation of the High-Entropy Coating (AlCrZrTiTa)N during Dry High-Speed Cutting

The high-entropy PVD coating (AlCrZrTiTa)N, characterized by its high hardness (50–60 GPa), elastic modulus above 300 MPa, and high heat resistance up to 1300 °C, is used for coating cutting tools operating under extreme metalworking conditions. The nanostructured monolayer 3 μm PVD coating was deposited on cutting plates in the hybrid arc deposition PVD coater. The coating had an amorphous nanocrystalline microstructure with a grain size of about 10–50 nm. The samples of SS 304 steel were investigated during dry high-speed (600 m/min) cutting. Raman spectroscopy was used to study the formation of tribooxides on the tool surface at the running-in stage of the cutting. After 130 m of cutting, Cr2O3 oxide appears on the wear surface while other elements are bound with N atoms. When the cutting length is increased to up to 260 m, oxide Al2O3 · ZrO2 (mullite) and amorphous oxides TaO2 and CrO2 are formed. The method EELFS made it possible to determine the amorphous nanocrystalline structure of triboceramics based on CrO2 and Al2O3 · ZrO2. The nearest atomic surrounding of Cr-Cr, O-O, and Cr-O and their subsequent comparison with the available literature data allow us to calculate the equilibrium lattice constants of the CrO2 unit cell, which are equal to (a, b) = 4.3754 Å and c = 0.5927. The triboceramic films on the base of non-equilibrium mullite Al2O3·ZrO2 have an amorphous structure. In the first coordination sphere, the interatomic distances of Zr-O and Al-O were 1.79 and 1.89 Å. An accelerated adaptive reaction to extreme external stimuli, at the very beginning of the running-in stage, is established. The tribological adaptability of the high-entropy ultra-fine amorphous nanocrystalline coating under extremely loaded dry high-speed cutting is based on non-equilibrium phenomena: the partial oxidation of fragments of the nitride and dynamic formation of protective tribooxides, which have a good thermal barrier and frictional properties. These factors interact synergistically and determine the life of the cutting tool.

Effect of Thermal Shock on Properties of a Strongly Amorphous AlCrTiZrMo High-Entropy Alloy Film.

AlCrTiZrMo high-entropy alloy (HEA) films with strong amorphization were obtained by co-filter cathode vacuum arc deposition, and the effect of thermal shock on the films was investigated in order to explore the protection mechanism of HEA films against mechanical components in extreme service environments. The results show that after annealing at 800 °C for 1 h, the formation of a dense ZrTiO4 composite oxide layer on the surface actively prevents the oxidation from continuing, so that the AlCrTiZrMo HEA film exhibits excellent oxidation resistance at 800 °C in air. In the friction-corrosion coupling environment, the AlCrTiZrMo HEA film annealed at 800 °C for 1 h shows the best tribocorrosion resistance due to the stable dense microstructure and excellent mechanical properties, and its ΔOCP, COF and wear rate possess the smallest values of 0.055, 0.04 and 1.34 × 10-6 mm-3·N-1·m-1.

Structure and Mechanical Behavior of Heat-Resistant Steel Manufactured by Multilayer Arc Deposition

The manuscript demonstrates the structure and the mechanical behavior of a material manufactured by multilayer arc deposition. Three-dimensional printing was performed using OK Autrod 13.14 wire on a substrate of heat-resistant 12Cr1MoV steel in the standard gas metal arc welding (GMAW) mode and in the coldArc mode with reduced heat input. The printed materials have 40–45% higher strength and 50–70% lower ductility compared to the substrate. The microhardness of the printed materials is higher than the substrate, but it is reduced at the transition regions between the deposited layers. These regions have been studied using optical microscopy and digital image correlation. Such layer boundaries are an additional factor in reducing the plasticity of the material. The increase in strength and decrease in ductility for printed materials compared to the ferrite–pearlitic substrate is associated with a high cooling rate and the formation of a mixture of acicular and allotriomorphic ferrite, which have higher hardness. The structure of the obtained layers along the height is non-uniform and undergoes changes during the deposition of new layers. The main difference between the 3D printing modes is the reduced heat input in the coldArc mode, which results in less heat accumulation and faster cooling of the wall. Thus, a more dispersed and solid structure was formed compared with GMAW. It was concluded that the cooling rate and the level of heat input are the main factors affecting the structure formation (martensitic, bainitic, or ferritic), the height and quality of the surface, and the mechanical properties of the printed wall.

Cathodic arc deposition of nanocrystalline titanium nitride thin film on fluorine doped tin oxide coated glass substrate: Crystal structural, microstructural, mechanical, optical and electrical properties

The nanocrystalline titanium nitride (TiN) films were deposited on fluorine doped tin oxide (FTO) coated glass substrates for the first time by cathodic arc deposition. The crystalline phase and orientation, growth morphology, surface roughness, hardness, scratch adhesion, electrical resistivity, optical absorption and bandgap of the TiN films were investigated. The GI-XRD confirmed the formation of cubic TiN and crystallographic orientation growth. The 2150 nm thick TiN film showed (111) orientation due to columnar growth patterns, while the 650 nm TiN film formed with the (200) orientation. The grain size of TiN films was 50–200 nm by FESEM and AFM analyses, and it was formed as elongated nanocrystals of 65–125 nm width and 120–250 nm lengths. The microhardness of the 650, 1000 and 2150 nm TiN thin films was measured to be 836, 943 and 1281 HV0.05 respectively. The scratch adhesion test demonstrated a good adhesive strength up to a critical load of 10 N and beyond the delamination occurred. The electrical resistivity of TiN film found to vary with thickness, the 650 nm TiN film showed a low resistivity of 16 × 10-6 Ω cm, which is comparable with the electrical resistivity of platinum and magnetron sputtered TiN film. The UV-Vis-NIR diffused reflectance spectroscopic studies of the TiN thin film showed a sharp absorption at 448 nm due to plasmon absorption and Tauc plot showed direct band gap of 2.1 eV. The results demonstrated that cathodic arc deposited nanocrystalline TiN thin film deposited on FTO glass substrate can be used as counter electrode for dye sensitized solar cell (DSSC) applications.

Structure and Properties of NbMoCrTiAl High-Entropy Alloy Coatings Formed by Plasma-Assisted Vacuum Arc Deposition

The paper analyzes the structure and properties of metal, cermet, and ceramic NbMoCrTiAl high-entropy alloy (HEA) coatings formed on solid substrates by plasma-assisted vacuum arc deposition (from multicomponent gas-metal plasma through Nb, Mo, Cr, and TiAl cathode evaporation in argon and/or a mixture of argon and nitrogen). The analysis shows that all coatings represent a nanocrystalline (3–5 nm) multilayer film. The metal coating has a bcc lattice (a = 0.3146 nm). The ceramic coating has an fcc lattice (an uncertain lattice parameter due to highly smeared diffraction peaks). The coating hardness increases in the order of metal, cermet, and then ceramic, reaching 43 GPa at Young’s modulus equal to 326 GPa. When heated in air, the metal and cermet coatings start to oxidize at 630–640 °C, and the ceramic coating at 770–780 °C.

Effect of ultrasonic intensity on microstructure and mechanical properties of steel alloy in direct energy deposition-Arc

To study the effect of ultrasonic intensity on the microstructure and mechanical properties during the direct energy deposition-Arc (DED-Arc) of ER70S-6 steel alloy, an ultrasound assisted DED-Arc system was developed by coupling ultrasonic energy with the electric arc deposition process. The propagation and vibration distribution of ultrasound in the substrate were analyzed by numerical simulation method. Deposition layers were fabricated using different ultrasonic amplitudes, and the microstructure, microhardness and tensile properties of the fabricated parts were systematically investigated. The results show that as the ultrasonic intensity increased, the grain refinement area expanded from the center of the molten pool to the surrounding area, and the grain morphology transforms from coarse columnar grains to fine equiaxed grains. When the ultrasonic amplitude was 15 μm, the grain refinement area of the cross-section was 94.6%, the average grain size was significantly increased to about grade 6. The microhardness increased by 10.6%. Thousands of ultrasonic cavitation events not only enhance the supercooling and wettability of the melt pool to promote nucleation, but also break the columnar grains into small grains by intense shock waves, which significantly improve the microstructure homogeneity and mechanical properties. The research provides an alternative approach to overcoming the long-standing problem of coarse columnar grains in the field of DED-Arc.

(AlCrNbSiTi)N/TiN multilayer films designed by a hybrid coating system combining high-power impulse magnetron sputtering and cathode arc deposition

We designed a hybrid physical vapor deposition coating system equipped with high-power impulse magnetron sputtering (HiPIMS) and cathode arc deposition (CAD) systems. With this technique, we fabricated (AlCrNbSiTi)N/TiN multilayer films consisting of alternating layers of (AlCrNbSiTi)N, a high-entropy alloy nitride (HEAN) with enhanced thermal stability, and TiN, a material known for its high hardness. For this hybrid coating system, a new nucleation and growth model was proposed to explain the thin film deposition phenomenon. Film growth occurred through a self-induced repeated nucleation mechanism. The effects of the modulation period on the microstructural, mechanical, and oxidation resistance properties of the coatings were investigated using scanning electron microscopy, transmission electron microscopy (TEM), X-ray diffraction, and nanoindentation. All coatings exhibited a B1-NaCl-type face-centered cubic crystal structure. High-resolution TEM imaging revealed misfit dislocations between the HEAN and TiN layers and low-angle boundary dislocations between the subgrains. The 64-layer coating displayed outstanding mechanical, oxidation resistance, and tribological properties compared with those of previously reported multilayer coatings. The plastic deformation index, H3/E2, of the mono- and multilayer coatings increased from 0.17 to 0.37 GPa. After oxidation at 800 °C for 2 h in an ambient atmosphere, the thickness of the oxidation layer decreased from 1228 to 85 nm. Furthermore, the maximum flank wear of a coated tool after the milling test was less than that of the uncoated tool (201 vs. 528 μm), suggesting a large improvement in lifetime.

Grain refinement of Fe3Al-based iron aluminide fabricated using wire-arc additive manufacturing

The preparation of Fe3Al-based iron aluminide compounds through WAAM presents significant potential for various applications. However, iron aluminide wire is difficult to prepare due to its inherent brittleness, twin (Fe + Al) wires forming is commonly used at present, this method tends to produce large columnar grain sizes owing to excessive heat input, which also constrains the performance of material. To address these challenges, this study proposed a method based on a single Fe3Al flux-cored wire and weaving arc deposition technique to refine the grain size and improve the mechanical properties through the addition of TiC particles. The mechanical properties and microstructure of as-prepared Fe3Al were also investigated to reveal the strengthening mechanism. In short, this research provided new insight for preparing iron-aluminum compounds through WAAM.

A comparison of plasma generation, plasma transport, and film formation for a DC vacuum arc source with Ti–X compound cathodes (X = W, C, Al, and Si)

This investigation reports the influence of Ti–C and Ti–W cathode composition on an industrial-scale dc vacuum arc plasma source. Further, we analyze the influence of plasma generation and plasma properties on the resulting cathode surface after the operation and on basic film properties. The results are compared with previous work focused on Ti–Al and Ti–Si compound cathodes. For all Ti–X compound cathodes (X = W, C, Al, and Si), a direct correlation between plasma ion energy/charge and the cohesive energy of the cathode was demonstrated, with a small number of exceptions to a limited set of specific cathode compositions. Hence, the “velocity rule” and effects from different electron temperatures were suggested to be important for gaining a more detailed understanding of plasma properties. A discrepancy was found between the cathode and plasma ion composition, though the difference was reduced in a corresponding comparison between the cathode and the deposited film composition. A significant contribution of a flux of neutrals and/or macroparticles to the final film composition was, therefore, suggested. The effect of the melting point of the cathode phase composition on the intensity of macroparticle generation and the smoothness of the cathode surface operation was also investigated. The presented results contribute to the fundamental understanding of vacuum arc plasma generation and transport and are of importance for further development and applicability of Ti-based coatings from arc deposition.

DC vacuum arc deposition system with an anode generating magnetic field for preparation of TiN films

In this study, a coiled anode that generates a magnetic field using a DC arc was designed and employed in a cathodic vacuum-arc deposition system. Its performance was evaluated by the formation of TiN films with and without a magnetic field. When the magnetic field was applied by the coiled anode, the deposition rate was approximately 1.5 times faster than that without the magnetic field. In addition, a reduction in the number of droplets with films of the same thickness was expected. Furthermore, the hardness of the film was improved by approximately 10% with the magnetic field of the coiled anode, resulting in a very hard film of 43.7 GPa. These results suggest that the coiled anode is effective in reducing the number of droplets and is promising for the formation of super-hard films, which are preferred for cutting tools.

Microstructure, mechanical properties and optical reflectance of TiNiN films deposited on silicon substrates using cathodic arc evaporation

Variations in applied substrate bias during cathodic arc deposition may impose intriguing consequences on the mechanical and optical properties of TiNiN coatings. Here, TiNiN films were fabricated onto Si substrates using a Ti95Ni5 (at.%) alloy target via cathodic arc evaporation employing a range of substrate bias voltages varying from 0 to -150 V. The aim of this study was to investigate the microstructures, mechanical performance, and optical properties of the TiNiN films in terms of the employed substrate potential. A significant enhancement (57%) in hardness for the TiNiN film was attained at -50 V as compared to zero substrate potential. This was principally attributed to the evolution of a fine, equiaxed nanocomposite structure, in association with the induction of a very high compressive residual stress at -50 V. In contrast, a maximum optical reflectance of 73% in the near-infrared range was determined for the coating synthesised at -150 V. It is speculated that incidence of fewer macroparticles on the film surface at elevated negative potentials, due to the induction of a higher repulsive force, may reduce the scattering of light incident on the coating's surface, promoting improved spectral reflectivity.

Wear and Corrosion Performance of Ti-6Al-4V Alloy Arc-Coated TiN/CrN Nano-Multilayer Film

The objective of this study was to investigate the effect of varying bias parameters (−50 V, −100 V, and −150 V) on the properties of TiN/CrN multilayer films deposited on Ti-6Al-4V alloy using the cathodic arc deposition (CAD) technique. The deposited films were characterized for their composition, structure, morphology, thickness, adhesion, and hardness. Wear and polarization tests were also conducted to determine the optimal bias condition for wear and corrosion resistance. The results showed that the TiN/CrN films possessed a nano-multilayered structure comprising TiN and CrN phases. The hard coating significantly increased the surface hardness of Ti-6Al-4V alloy up to three–five times. The coated specimens demonstrated superior wear resistance compared to the uncoated, with the −150 V specimen exhibiting the least wear rate. Furthermore, the −150 V specimen had the highest polarization impedance value, indicating the best corrosion resistance compared to the other bias conditions. In short, the use of CAD-coated TiN/CrN multilayer film enhanced the surface properties of Ti-6Al-4V alloy, with the best wear and corrosion resistance achieved at −150 V bias. These novel findings have significant implications for improving the performance and durability of Ti-6Al-4V alloy components in various industrial applications.

High entropy alloy thin films on SS304 substrates: Evolution of microstructure and interface modulated by energetic condensation in nanoscale

High entropy alloys (HEAs), as a novel material in the 21st century, possess several advantages, such as excellent corrosion & oxidation resistance and high mechanical properties. HEA thin films show these favourable properties with lower material costs than their bulk counterparts. Studying the HEA film-substrate interface represents challenges but is of extreme importance for the understanding of growth mechanisms with important implications for film adhesion. However, most HEA films were deposited on monocrystalline silicon substrates with limited practical applicability. Further, where commercial stainless steel, aluminium or titanium alloy substrates were used, the microstructure and chemistry at the interface were neglected. Here, we deposited AlCrFeCoNiCu0.5 HEA thin films on stainless steel 304 (SS304) substrates using cathodic arc deposition with different substrate biases. The crystallography and microstructure were investigated using an X-ray and electron-microscopy based chatacterization. A transition of an incoherent to semi-coherent interface was observed from 0 V to -50 V of the substrate bias. Energy dispersive spectroscopy demonstrated a transition of Cr2O3 to aluminum oxide across the interface. The nanoindentation tests revealed the significant improvement of mechanical properties of SS304 with HEA coatings. High-strength HEA (8.0 ± 0.2 GPa) thin films with semi-coherent interfaces were manufactured on SS304.