Pulsed Bias Arc Ion Plating Research Articles

Study of TiCuN/ZrN multilayer coatings with adjustable combination properties deposited on TiCu alloy

Orthopedic metal implant materials such as titanium alloy may face the problem of friction wear during long-term implantation. TiCu alloy has been proved to have excellent mechanical properties, biofunctionability and biocompatibility. In order to further improve its wear resistance, a multilayer coating composed of high hardness TiCuN and ZrN were deposited on the surface of TiCu by axial magnetic field enhanced pulsed bias arc ion plating (AMFE-AIP) system. Then, the corresponding relationship among the modulation period (Λ), the microstructure of the TiCuN/ZrN multi-layers and the influence properties were analyzed. The results showed that in the multi-layers, there existed a “Cu nail/bridge” structure which was biased perpendicular to the direction of the film. With the decrease of the Λ, the maximum stress on the coating surface during the sliding process was decreased, the adhesion, wear resistance of the film and the release of Cu ions from the film were gradually increased, which resulted in the improvement of anti-bacteria and cell proliferation promotion properties. This study indicated that the TiCuN/ZrN multilayer coating is promised to be a new kind of biofunctionalized coating with properties that can be regulated on demand for adapting various implant environment of titanium alloy implants.

Monitoring cracks of metal structure based on grating thin-film sensor

The hole edge of a metal structure is the most likely crack position in an aircraft structure. The quantitative monitoring of a hole-edge crack is important for structural health monitoring. Therefore, this paper presented a grating thin-film sensor based on the potentiometric method. Firstly, the anodic oxidation process was used to prepare thin film on 2A12-T4 aluminum alloy matrix to prevent the aluminum alloy matrix from interfering with the monitoring signal of the sensor. Then the DC superimposed pulsed bias arc ion plating technique was used to prepare the grating thin-film sensor on the surface of the specimen. The output characteristics of the grating thin-film sensor are obtained with its finite element model, and the factors affecting the sensitivity of the sensor are analyzed. Finally, the fatigue crack monitoring tests were carried out to verify the quantitative monitoring capability of the grating thin film sensor. The experimental results show that it is feasible for the grating thin-film sensor to quantitatively monitor the fatigue crack at the hole edge of an aircraft metal structure.

Conductive and tribological properties of TiN-Ag composite coatings under grease lubrication

TiN-Ag composite coatings were prepared by pulsed bias arc ion plating. X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) were applied to analyze the compositions of the coatings. Tribological properties of the coatings were studied using an MFT-R4000 ball-on-disk friction tester in the presence of lubricating greases containing multilayer graphene. Scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) were used to analyze the worn surface compositions of the lubricating films. The results show that with the decrease in Ag in the film, hardness increased but electrical conductivity decreased. The coating with 10 at% Ag content shows the best friction-reducing and anti-wear properties, which can be attributed to the moderate content of Ag embedded in the TiN crystal gap that enhanced the grain bonding force to improve the anti-wear and self-lubricating ability. Graphene can be adsorbed on the coating as a solid lubricant.

Effects of texture geometry on the tribological performance of brass with a TiN coating under lubricated rotation

Pin-on-disc experiments are conducted to investigate the tribological performance of untextured and textured brass surfaces with TiN coatings under oil lubrication. The surface texture is designed as a dimple pattern with different diameters and depths for the transverse surfaces of brass pins. After texturing, a TiN coating is deposited through pulsed-bias arc ion plating in a pure N2 atmosphere using a Ti target. Three dimple diameters are used, namely 130 μm, 150 μm, and 170 μm, along with three dimple depths, namely 15 μm, 40 μm, and 60 μm. The TiN coating is around 5 μm thick. Friction tests are conducted under different rotation speeds and loads, and the interfacial adhesion is assessed via a scratch test. Compared to the untextured surface, the textured one offers improved tribological behavior in mixed lubrication because the dimples generate hydrodynamic lift. To reduce friction in the case of higher speed and lower load, the optimum texture parameters are a diameter of 150 μm and a depth of 40 μm.

Characterization and mechanical properties of TiN/TiAlN multilayer coatings with different modulation periods

The TiN/TiAlN nanomultilayer coatings with different modulation periods were deposited successfully on M2 high-speed steel by a pulsed bias arc ion plating system. The effect of modulation period on the microstructure and mechanical properties was investigated. With the increasing of deposition period, the Al contents in TiN/TiAlN multilayer coatings monotonically increased continuously a little from 0.135 to 0.142, whereas the Ti and N contents were nearly constant. The microstructure TiN/TiAlN multilayer coatings were crystallized with preferred orientation in (111) crystallographic planes. At modulation period of 164 nm, the nanohardness reached a maximum of 38.9 GPa. The Young’s modulus values were in the range of 418–591 GPa. The adhesion strength reached a maximum of 66.2 N at modulation period of 54 nm.

Effects of Layer Thickness on the Microstructures of TiN/AlTiN Multilayer Coatings

TiN/AlTiN multilayer coatings were deposited on tungsten carbide cutting tool by applying a direct current on a pulsed bias arc ion plating system. The effect of pulsed bias layer thickness on sample properties was investigated. The amount of grain size decreased with increasing layer thickness. The crystal structure of the coatings was determined using a D8 Advance Bruker X-ray diffractometer with CuKa (λ = 1.5405 Å) radiation. TiN/AlTiN multilayer coatings were crystallized with orientations in the (111), (200), (222), and (311) crystallographic planes, and the microstructure was enhanced with preferred orientation in the (111) plane. Compared with the substrate, all the specimens coated with TiN/AlTiN multilayer coatings exhibited better X-ray diffraction properties.

Crack monitoring method based on Cu coating sensor and electrical potential technique for metal structure

Advanced crack monitoring technique is the cornerstone of aircraft structural health monitoring. To achieve real-time crack monitoring of aircraft metal structures in the course of service, a new crack monitoring method is proposed based on Cu coating sensor and electrical potential difference principle. Firstly, insulation treatment process was used to prepare a dielectric layer on structural substrate, such as an anodizing layer on 2A12-T4 aluminum alloy substrate, and then a Cu coating crack monitoring sensor was deposited on the structure fatigue critical parts by pulsed bias arc ion plating technology. Secondly, the damage consistency of the Cu coating sensor and 2A12-T4 aluminum alloy substrate was investigated by static tensile experiment and fatigue test. The results show that strain values of the coating sensor and the 2A12-T4 aluminum alloy substrate measured by strain gauges are highly coincident in static tensile experiment and the sensor has excellent fatigue damage consistency with the substrate. Thirdly, the fatigue performance discrepancy between samples with the coating sensor and original samples was investigated. The result shows that there is no obvious negative influence on the fatigue performance of the 2A12-T4 aluminum alloy after preparing the Cu coating sensor on its surface. Finally, crack monitoring experiment was carried out with the Cu coating sensor. The experimental results indicate that the sensor is sensitive to crack, and crack origination and propagation can be monitored effectively through analyzing the change of electrical potential values of the coating sensor.

Structure and optical property of Cr-O films deposited by pulsed bias arc ion plating

A series of uniform and transparent Cr-O films were synthesized on the silicon and quartz glass substrates at different bias voltages by pulsed bias arc ion plating. Effects of bias voltage on surface morphology, phase structure, composition, chemical valence states, hardness and optical property of the films were investigated by field emission scanning electron microscopy, grazing incident X-ray diffraction, X-ray photoelectron spectroscopy, nanoindentation and ultraviolet-visible spectrophotometer, respectively. Results indicate that the bias voltage can improve the quality of the films significantly and plays an important role in the film properties. Macroparticles and holes are observed on the surface of the films if without application of bias voltage, while the films prepared with bias voltage are uniform and smooth. The crystalline phase of the film is of amorphous structure if without bias voltage. While the bias voltage applies and increases from -100 V to -500 V, the Cr2O3 phase appears and changes into CrO phase. The crystal plane (104), (116) of the Cr2O3 phase and (200) of the Cr phase are observed in the film at the bias voltage of -100 V. When the bias voltage is above -200 V, the crystal planes (311) and (400) of the CrO phase can be observed. In order to further obtain the structure information, a detailed XPS study is performed. Chromium in the films shows different valence states, namely metallic Cr, Cr2+, Cr3+ and Cr6+. Thereby, the main components of the polycrystalline films are Cr2O3 and CrO phases, meanwhile, and the films also contain a small amount of CrO3 and metal Cr phases. The films under different bias voltage show good mechanical properties and the hardness of all the films is above 19 GPa. With the increase of bias voltage the hardness first increases and then decreases, reaching a maximum value of 24.4 GPa at the bias voltage of -300 V. The films show good optical transmittance and its highest value can be up to 72%. As the bias voltage rises, it is observed first the red shift and then blue shift of the absorption edge. And the optical band gap reaches the maximum value of 1.88 eV when the bias voltage is -200 V. Therefore, Cr-O functional films can be synthesized by pulsed bias arc ion plating and the phase structure and properties can be effectively adjusted.

Effects of Pulse Bias Duty Cycle on Composition, Structure and Hardness of Ti–Cu–N Nanocomposite Films Deposited by Pulse Biased Arc Ion Plating

Science and Technology Development Project of Jilin Provincial Science and Technology Department [20140520100JH, 20140204043GX]; Science and Technology Development Project of Jilin Municipal Science and Technology Bureau [201467008]; Research Fund for the Doctoral Program of Northeast Dianli University [BSJXM-201224]

Effect of pulsed bias voltage on the structure and mechanical properties of Ti–C–N composite films by pulsed bias arc ion plating

The influence of pulsed bias voltage on the structure and mechanical properties of Ti–C–N composite films prepared by pulsed bias arc ion plating was systematically investigated. The microstructure, surface morphology and bonding structure of the films were evaluated with grazing incidence X-ray diffraction, high resolution transmission electron microscopy, Raman and X-ray photoelectron spectroscopy, and scanning electron microscope. The mechanical properties such as hardness and elastic modulus were measured by nano-indentation. A composite structure consisting of nanocrystallites Ti(C,N) and amorphous carbon is observed. The surface morphology indicates that the size and amount of macroparticles at the film surface decrease with the increase of bias voltage. Applying a bias voltage of −300V in Ti–C–N films induces strong crystalline characteristic. However, other bias voltages cause a tendency to a lower degree of crystallinity and an enhanced fraction of amorphous phase. With increasing the bias voltages from −100V to −700V, the corresponding hardness and elastic modulus increase firstly and then decrease, reaching a maximum value of 32.5GPa and 367.4GP at the bias voltage of −300V.

The Research of N/C-Codoped TiO<sub>2</sub> Films Deposited by Arc Ion Plating

The N/C co-doped TiO2thin films were successfully deposited on medical glass slide by pulsed negative bias arc ion plating. The influence of pulsed negative bias, annealing temperature on films properties was investigated. Film structure, surface morphologies and optical properties were measured with XRD, SEM and UV-VIS transmittance spectroscope. The results show that the most absorption edges of the as-deposited films increase with the rising of the pulse negative bias, and the maximum of 540 nm is achieved under-600V bias. The films absorption edges increase in different degree after annealing at 400°Cfor 2h and 4h, and the best extension can increase 46nm after annealing. The interaction of the annealing treatment and bias functions enhance the N and C reaction activities and extend absorption edge. The greatest absorption edge dater of the co-doped TiO2films under the negative pulse bias for 0V can reach 550nm after the annealing at 400°Cfor 2h. The crystal morphology become inconspicuously with the bias increasing from 0V to-300V, which is corresponding to the XRD result, the anatase diffraction peaks weaken obviously.

Deposition and characterization of Ti–Cx–Ny nanocomposite films by pulsed bias arc ion plating

A series of Ti–Cx–Ny films with different compositions were deposited by pulsed bias arc ion plating. In order to investigate their dependences on compositions, the surface morphology, composition, microstructure, and mechanical properties were assessed by means of scanning electron microscope, X-ray photoelectron spectroscopy, Raman spectroscopy, grazing incident X-ray diffraction, high resolution transmission electron microscopy, and nano-indentation. The results indicated that the as-deposited films were Ti–Cx–Ny nanocomposite films consisting of the nanocrystalline Ti(C,N) embedded in amorphous carbon matrix. A pronounced crystalline phase was observed in the film with high Ti and N contents. The film hardness and elastic modulus decreased with the increase of C/Ti arc current ratio, and a maximum hardness of 37 GPa was obtained with the Ti content of 45.6 at.% and the N content of 38.8 at.%. At high carbon concentration, the films exhibited amorphous structure and more disordered C–C and C–N soft phases were produced with less Ti incorporated into the film.

Influences of nitrogen flow rate on the structures and properties of Ti and N co-doped diamond-like carbon films deposited by arc ion plating

In this paper, Ti–C–N nanocomposite films are deposited under different nitrogen flow rates by pulsed bias arc ion plating using Ti and graphite targets in the Ar/N2 mixture gas. The surface morphologies, compositions, microstructures, and mechanical properties of the Ti–C–N films are investigated systematically by field emission scanning electron microscopy (FE-SEM), x-ray photoelectron spectroscopy (XPS), grazing incident x-ray diffraction (GIXRD), Raman spectra, and nano-indentation. The results show that the nanocrystalline Ti(C,N) phase precipitates in the film from GIXRD and XPS analysis, and Raman spectra prove the presence of diamond-like carbon, indicating the formation of nanocomposite film with microstructures comprising nanocrystalline Ti(C,N) phase embedded into a diamond-like matrix. The nitrogen flow rate has a significant effect on the composition, structure, and properties of the film. The nano-hardness and elastic modulus first increase and then decrease as nitrogen flow rate increases, reaching a maximum of 34.3 GPa and 383.2 GPa, at a nitrogen flow rate of 90 sccm, respectively.

Synthesis of Cu doped TiN composite films deposited by pulsed bias arc ion plating

The Ti–Cu–N films with different compositions were deposited by pulsed bias arc ion plating. The effect of Cu on the structure and mechanical properties of these films is investigated by means of electron probe micro-analyzer (EPMA), grazing incident X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron spectroscopy (FE-SEM) and nanoindentation, respectively. It is shown that the Ti–Cu–N film with low Cu content presents a pronounced columnar growth. The hardness enhancement in Ti–Cu–N films from 23GPa for pure TiN to maximum of 37GPa with 0.6 at.% Cu content might be correlated with the change of nanocomposite structure. Meanwhile, with further addition of Cu, the columnar structure is replaced by a dense globular structure, and the film hardness is greatly reduced due to excess soft metallic Cu. Therefore, pulsed bias arc ion plating as an effective tool can tailor the structure and mechanical properties of Ti–Cu–N composite films.

Effects of modulation ratio on microstructure and properties of TiN/TiAlN multilayer coatings

TiN/TiAlN multilayer coatings were deposited on M2 high speed steel by a pulsed bias arc ion plating system. The effect of modulation ratio on the microstructure, mechanical and wear properties was investigated. TiN/TiAlN multilayer coatings were crystallized with orientations at the (111), (200) (222) and (311) crystallographic planes and the microstructure was strengthened at (111) preferred orientation. The average atom ratio of N was about 0.39. With the increase of TiN modulation ratio from 50s:100s to 100s:50s, the atom ratio of Ti increased from 0.42 to 0.518 and the atom ratio of Al decreased from 0.193 to 0.084. At modulation ratio of 60s:90s, the hardness of TiN/TiAlN multilayer coatings reached the maximum of 40.7GPa, which was 4.5 times that of the substrate. The adhesion strength reached the maximum of 74N at modulation ratio of 100s:50s. Friction and wear analysis was carried out by pin-on-disc tester at room temperature. Compared with the substrate, all the specimens coated with TiN/TiAlN multilayer coatings exhibited better tribological properties.

Influence of Annealing Treatment on N-Doped TiO<sub>2</sub> Films Deposited by Pulsed Negative Bias Arc Ion Plating

The N-doped TiO2thin films were deposited on medical glass slide by pulsed negative bias arc ion plating. The influence of pulsed negative bias, annealing temperature and time on films properties was investigated. Film structure, surface morphologies and optical properties were measured with XRD, SEM and UV-VIS transmittance spectroscope. Photo-catalytic performance of the films was evaluated by degrading methyl orange. The results show that the absorption edges of the as-deposited films increase with the rising of the pulse negative bias, and the maximum of 550 nm is achieved under -600V bias. The films absorption edges increase in different degree after annealing at 400°Cand 500°Cfor 2h, and the best extending can increase 22nm after annealing. The diffraction peak intensity and surface grain size increase with increasing the annealing temperature and time. The grain size of films after annealing at 400°C for 4h is largest of all the films. The pulsed negative bias and annealing treatment not only indecrease TiO2thin films the UV catalytic performance, but also extend the catalytic properties to the sunlight.

Deposition, microstructure and hardness of TiN/(Ti,Al)N multilayer films

In this work, TiN/(Ti,Al)N multilayer films were deposited on stainless steel substrates with alternatively switching Ti and TiAl alloy targets sources on and off by pulse biased arc ion plating. The crystallography structures and cross-sectional structures of TiN/(Ti,Al)N multilayer films were evaluated by X-ray diffraction analysis (XRD) and by TEM, respectively. The hardness and film/substrate adhesion were determined by nanoindentation and scratch test, respectively. A complex set of microstructures has been found between TiN and (Ti,Al)N layers, at the interface, another layered interfacial region which consists of extremely fine sub-layers, which results from the rotation of the specimen in the deposition chamber. The hardness values of the multilayers exhibit higher hardness compared with that of monolithic (Ti,Al)N film.

Honeycomb-like nanocomposite Ti-Ag-N films prepared by pulsed bias arc ion plating on titanium as bipolar plates for unitized regenerative fuel cells

Honeycomb-like nanocomposite Ti-Ag-N films are prepared by pulsed bias arc ion plating, and for the first time served as surface modification layer on TA1 titanium as bipolar plates for unitized regenerative fuel cells (URFCs). Phase structure and surface morphology of the coated samples are investigated by XRD and SEM. Corrosion resistance of bare Ti plates and Ti-Ag-N coated samples is evaluated in simulated URFC conditions, and the interface contact resistance (ICR) between bipolar plates and carbon papers is measured before and after potentiostatic polarization tests. Ti 2N phase with a preferred orientation of (1 1 0) plane is observed in the Ti-Ag-N film. SEM observation indicates that the film appears honeycomb-like and forms a nanocomposite microstructure with Ag nanoparticles embedded in Ti 2N matrix. Compared to bare titanium plates, the coated sample shows improved corrosion resistance and ultra-low ICR (2 mΩ cm 2 under a compaction pressure of 1.4 MPa). The superior conductivity of the coated sample is attributed to nanocomposite microstructure containing highly conductive Ag nanoparticles, and honeycomb-like rough surface obtained in this study. Nanocomposite Ti-Ag-N coated titanium bipolar plate exhibits prominent interfacial conductivity and excellent corrosion resistance at high potential, being a promising candidate as bipolar plate for applications in URFCs.

CrN/Cr multilayer coating on 316L stainless steel as bipolar plates for proton exchange membrane fuel cells

CrN/Cr multilayer coating is prepared on 316L stainless steel as bipolar plates for proton exchange membrane fuel cell (PEMFC) by pulsed bias arc ion plating (PBAIP). Interfacial conductivity of the bipolar plate with CrN/Cr multilayer is improved obviously, presenting an interfacial contact resistance (ICR) of 8.4 mΩ cm −2 under 1.4 MPa. The results tested by potentiodynamic and potentiostatic measures in simulated PEMFC environments show that the bipolar plate with CrN/Cr multilayer has good anticorrosion performance. The corrosion current density of the bipolar plate with CrN/Cr multilayer is approximately 10 −8.0 A cm −2 at 0.6 V (vs. SCE) in a 0.5 M H 2SO 4 + 5 ppm F − solution at 70 °C with pressured air purging. The results of SEM and ICR before and after corrosion tests indicate that the bipolar plate with CrN/Cr multilayer is considerably stable electrochemically. The bipolar plate with CrN/Cr multilayer combined the prominent interfacial conductivity and the excellent corrosion resistance, showing great potential of application in PEMFC.

Ti–Cu–N hard nanocomposite films prepared by pulse biased arc ion plating

In this work, Ti–Cu–N hard nanocomposite films were deposited on high-speed-steel (HSS) substrates using a TiCu (88:12 at.%) single multi-component target by pulse biased arc ion plating. The influence of pulse bias voltages was examined with regard to elemental composition, structure, morphology and mechanical properties of the films. The Cu atomic content of Ti–Cu–N films was determined by Electron Probe Micro-Analyzer (EPMA). The structure and morphology were examined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Hardness and film/substrate adhesion were determined by nanoindenter and scratch test, respectively. The results showed that the content of Cu appeared to be in the range of 1.75–4.5 at.%, depending on pulse bias voltages. The films exhibit a preferred orientation TiN (1 1 1) texture when the substrate bias voltages were −100 V and −300 V, while the preferred orientation change to be a preferred orientation TiN (2 2 0) one when the substrate bias voltages increase to −600 V and −900 V. And no obvious sign of metal copper phase was observed. The SEM morphologies showed some macroparticles (MPs) on the surface of the films and the relative content of the MPs decreased significantly when the substrate bias voltages increased from −100 to −900 V. The maximum value (74 N) of the film/substrate adhesion of the films was obtained when the substrate bias voltage was −600 V with Cu content of 1.75 at.%. Hardness enhancement was observed, the value of the hardness increased firstly and reached a maximum value of 31.5 GPa, corresponding to Cu content of 1.75 at.%, and then it decreased when the substrate bias voltage changed from −100 to −900 V. The hardness enhancement was discussed related to the concept for the design of hard materials.