Thin solid films
December 1, 2016
, Pages 188-196
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Into the naturalvapor deposition(PVD) high power pulsemagnetron sputtering(HPPMS) or high-power pulsed magnetron sputtering (HiPIMS) is a technology that has been frequently studied in recent years. HPPMS offers the possibility to produce coatings with lower roughness, denser microstructure and bettermechanical propertiescompared to direct current magnetron scattering (dcMS). However, HPPMS is known to have a much lower deposition rate due to its low duty cycle compared to dcMS. Therefore, from an economic point of view, dcMS is more efficient compared to HPMS technology. One approach to overcome this problem is hybrid dcMS/HPPMS technology, whereby dcMS and HPPMS cathodes are used simultaneously to combine the benefits of both technologies. In hybrid processes, the effect of dcMS and HPPMS on plasma and coating properties is of critical interest. Therefore, in the present work measurements forplasma propertiesas well as coating properties using dcMS, hybrid dcMS/HPPMS, and HPPMS (Cr,Al)N processes were performed. The (Cr,Al)N coating system as well as the steel substrates used were chosen to address the application in plastics processing. In the first step of this work plasmas of the dcMS, hybrid dcMS/HPPMS and HPPMS processes were analyzed. Dependences of plasma properties on the type of process as well as on pulse parameters such as pulse length tonand frequency f were investigated. The most significant effect was found depending on the type of procedure. In the second step (Cr,Al)N coatings are produced using the same process parameters. Similar behavior to the plasma properties was observed for the coating properties. In the third step the plasma and coating properties measurements were correlated. It has been shown that changes in plasma and coating properties are significantly correlated. Therefore, coating development can be simplified by predicting the properties of the most effective coatingplasma diagnostics.
High power pulsed magnetron sputtering (HPPMS) or high power pulsed magnetron sputtering (HiPIMS) is a new technological variant of physical vapor deposition (PVD) , , . It is known as an advance of direct current (dc) and medium frequency (mf) magnetro sputtering (MS). For example, compared to dcMS plasma which has an ionization rate of about 1%, HPPMS technology provides much higher ionization up to 90%, depending on the target material and process parameters , ,  , , . Several studies discuss the effect of higher ionization on coating properties , , , . According to their results, HPPMS technology offers excellent advantages in terms of adhesion, hardness and dense morphology. The effect of HPMS pulse parameters on (Cr,Al)N coatings has been investigated previously , . It was reported that decreasing the pulse length tonat constant frequency f affects the mechanical properties as well as the microstructure  and the chemical composition of the coatings . HPMS plasma has also been the subject of plasma diagnostic experiments. Investigations of coating processes by optical emission spectroscopy (OES) have shown a significant increase in the ion/neutral ratio from HPPMS plasmas compared to conventional dcMS . In addition, an increase in Cr ion content with respect to a shorter pulse length tonobserved via a time-resolved OES . The positive effect of the HPMS pulse length tonin plasma properties has also been found , . In these works the ion energy distribution function (IEDF) was analyzed by means of a retardation field energy analyzer (RFEA). E ion energy increaseIobserved with reduced pulse length tonand thus reduced duty cycle. However, the reduced duty cycle causes a lower deposition rate for HPMS compared to dcMS , . Therefore, from an economic point of view dcMS is more efficient compared to HPMS technology. One approach to overcome this issue is to use hybrid dcMS/HPPMS technology, whereby dcMS and HPPMS cathodes are used simultaneously to combine the benefits of both technologies , . In hybrid processes, the effect of dcMS and HPPMS on plasma and coating properties is crucial. First approaches are reported where the effect of the Al/Cr ratio in the target on the properties of (Cr,Al)N coatings was tested , . It could be shown that the coating properties can be classified among the coating properties of (Cr,Al)N synthesized via dcMS and HPMS processes , .
To the best of our knowledge, a study of (Cr,Al)N coatings deposited via hybrid dcMS, HPPMS, and dcMS/HPPMS processes, including coating and plasma properties, has not yet been reported. In the present work, measurements of plasma properties as well as coating properties deposited using dcMS, dcMS/HPPMS hybrid and HPMS (Cr,Al)N processes with varying pulse parameters are presented. The (Cr,Al)N coating system was chosen due to its mechanical properties , which are beneficial for the addressed application of this work, the coating of tools for the plastics processing industry. Changes in plasma composition during (Cr,Al)N processes were investigated by OES. The IEDF was determined by the RFEA. The coatings were analyzed for microstructure by scanning electron microscopy (SEM) as well as global hardness and indentation modulus with nanodentations. In addition, the chemical composition of the coatings was analyzed by energy dispersive X-ray spectroscopy (EDS). Finally, the measured plasma and coating properties were compared and correlated with the dcMS and HPPMS ratio in the hybrid dcMS/HPPMS processes and the HPMS pulse parameters.
Coating unit configuration and process parameters
The investigations presented were carried out using an industrial-scale PVD coating unit, CC800/9 Custom, CemeCon AG, Würselen, Germany. The coating chamber has dimensions of 1000mm×1000mm×1000mm. The coating unit has two cathodes, one equipped with a dcMS power supply and one with an HPMS power supply. The angle between the cathodes and the wall is about 45° (Fig. 1). The dcMS as well as the cathode HPMS were used for the presented investigations. On both cathodes a chrome target
Evaluation of plasma parameters
In the first step the described dcMS, dcMS/HPPMS hybrid and HPPMS (Cr,Al)N processes were investigated about the plasma near the dcMS and HPPMS cathodes by means of OES. Representative spectra for each type of process are shown in Fig. 2. The OES spectra were normalized with respect to the wavelength λ of the excited Ar atoms λArI=357.86 nm. Since the plasma of the hybrid dcMS/HPPMS process could only be analyzed in the cathode dcMS and HPPMS separately, an arithmetic average of the two normalized
In this work the effect of hybrid dcMS, dcMS/HPPMS and HPMS (Cr,Al)N reactive processes with varying plasma pulse parameters and coating properties was studied. Correlations between plasma properties and process type as well as pulse parameters such as pulse length tonand the frequency f could be found. The most significant influence could be identified depending on the type of procedure. Furthermore, it was shown that the dependence of Al I/Cr I and
The authors gratefully acknowledge the financial support of the German Research Foundation,German Research Foundation(DFG) (TRR 87/2 2014), within the framework of the interregional collaborative research center TRR87/2 (SFB-TR 87) of subprojects A4 and C6.
- K.Sarakinoset al.
High-power magnetron pulsed scattering: a review on the scientific and engineering state of the art
Surf. Coat. Technol.
- V.Kuznetsovet al.
A new pulsed magnetron scattering technique using very high target power densities
Surf. Coat. Technol.
A review comparing cathodic arcs and high power pulsed magnetron scattering (HiPIMS)
Surf. Coat. Technol.
- G.Greczynskiet al.
The role of Tin+ and Aln+ ion irradiation (n=1,2) during the growth of Ti1−xAlxN alloy film in a hybrid HIPIMS/magnet mode
Surf. Coat. Technol.
- MI.Lewinet al.
Comparison of Al-Si-N nanocomposite coatings deposited by HIPIMS and DC magnetron sputtering
Surf. Coat. Technol.
- K.Bobzinet al.
Mechanical properties and oxidation behavior of (Al,Cr)N and (Al,Cr,Si)N coatings for cutting tools deposited by HPMS
Thin solid films
- M.Lattemanet al.
Investigation of Pulsed Magnetron Pretreated Interfaces for Adhesion Enhancement of Hard Coatings on Steel
- N.Bagcivanet al.
Effect of HPMS pulse length and inert gas mixture on properties of (Cr, Al)N coatings
Thin solid films
- A.P.Halfwayet al.
Effect of high power densities on the synthesis of pulsed plasma magnetrons
- K.Bobzinet al.
Effect of HPMS pulse parameters on reactive gas N2 and properties of (Cr, Al)N coatings
Surf. Coat. Technol.
Analysis of the Ion Energy Distribution in the Substrate During a HPMS (Cr,Al)N Process Using a Retarding Field Energy Analyzer and an Energy Resolution Mass Spectrometer
Thin solid films
Distortion-free, single-phase metastable Ti0·38Al0.62N alloys with high hardness: metal ion energy versus momentum effects during film growth by hybrid pulsed pulsed/dc high-power tracer magnetron
Thin solid films
Investigation of plastic behavior of HPMS CrN, AlN and CrN/AlN-multilayer coatings using finite element simulation and nanoindentations
(Cr1−xAlx)N: comparison of direct current, pulsed medium frequency and high power pulsed scattering magnetrons for injection molding parts
Thin solid films
HiPIMS of MoS
2– Current-voltage characteristics
2022, Letters of Materials
High Power Impulse Magnetron Sputtering (HiPIMS) as a high ionization sputtering technique is widely used to tailor the structure and properties of thin films. However, investigations of process-related effects are mainly obtained from HiPIMS of single-component metal targets, while examinations of complex targets are rarely found. Therefore, HiPIMS of MoS2targets were conducted under a variation of pulse duration and frequency. During the process, the current and voltage values were measured in order to investigate the characteristics of the discharge mode. Time-dependent current waveforms reveal a functional gas autopsy for HiPIMS of MoS2. By reducing the pulse frequency or pulse duration, the peak current increases and the contribution of self-wetting and relative gas dilution is enhanced, leading to a reduced deposition rate.
Synthesis and characterization of Ta-B-C coatings prepared by co-sputtering DCMS and HiPIMS
This study reports the deposition and properties of Ta-B-C coatings from the co-inspection of tantalum, boron carbide and graphite targets using high-power pulsed magnetron spectroscopy (HiPIMS). It was possible to influence the microstructure of the deposited coatings by changing the deposition temperature or by applying RF-induced self-bias to the substrates without changing their chemical composition. The only identified crystalline phase from the present Ta-B-C system was TaC. The boron content of the coatings shows that the TaC crystallite size can be changed by a factor of 10 by changing the power on the boron carbide target. The mechanical properties of the coatings measured immediately after synthesis yield a hardness greater than 40 GPa. After relaxation of the internal stress in the coatings (after one year) and structural changes, the hardness of all coatings was close to 36 GPa. According to a priori calculations, B incorporation into the fcc lattice of TaC combined with C vacancies leads to a lower (higher) shear-to-volume ratio (Poisson's ratio), providing a good basis for improved ductility. Overall, the Ta–B–C system shows good potential as a new hard protective coating.
Microstructure and properties of TiAlCrN ceramic coatings deposited by hybrid HiPIMS/DC co-plane magnetron
2021, Ceramics International
TiAlCrN ceramic coatings were prepared using a hybrid deposition technique consisting of High Power Pulse Magnetron Scattering (HiPIMS) and DC Magnetron Scattering (DCMS). The chemical composition, phase structure, morphologies, mechanical and tribological properties of such coatings were systematically investigated. The results showed that the Ti element content increased monotonically from 0 at.% to 22 at.% with increasing Ti target strength. TiAlCrN ceramic coatings showed a competitive growth tendency between (111) and (200) crystal plane through energetic ion bombardment. The higher Ti target strength resulted in stronger compressive intrinsic stress, which significantly suppressed the precipitation of the hcp-AlN phase. By enhancing the ion bombardment, the diffusion energy and nucleation rate of atoms on the growing surface increased, which caused a denser structure and ultra-smooth surface. Hardness and hardness also varied as a function of Ti target power, with a maximum hardness of 28.3 GPa under a Ti target power of 5 kW. Positive correlation between bond strength (i.e., scratch test critical load) and H3/ MI2The ratio was found to indicate a strong dependence of adhesion properties on hardness for TiAlCrN ceramic coatings in this study, which was in good agreement with the literature. In terms of tribological behavior, the lowest wear rate of 8.9×10-17M3N-1M-1was obtained for the TiAlCrN ceramic coating deposited at a Ti target power of 5 kW.
A comparative investigation of TiC hetero-epitaxial thin films deposited by magnetron sputtering using either a hybrid DCMS/HiPIMS or a reactive DCMS process
2021, Applied Surface Science
A hybrid direct current magnetron scattering/high power pulsed magnetron (DCMS/HiPIMS) technique was used to improve the structural and electrical properties of titanium carbide (TiC) single crystal thin films. TiC hetero-epitaxial films, ∼60 nm thick, were grown on MgO (001) substrates at temperatures ranging from 200°C to 800°C, by simultaneous sputtering of Ti and C targets fed by DCMS and HiPIMS, respectively. The films' composition and structural, morphological and electrical properties were investigated in comparison with those of a set of samples deposited at the same temperatures by reactive-DCMS (R-DCMS) in Ar/CH4atmosphere. The composition and FWHM of the rocking curves of films deposited by R-DCMS differed from TiC0,84in TiC0,94and from 1.38° to 0.64°, respectively, as the growth temperature increased. Contraction0,94- TiC0,96The layers were deposited by a hybrid DCMS/HiPIMS method at temperatures higher than 400°C, fully stretched over their entire thickness, with a FWHM of rocking curves of about 0.13°. The electrical resistivity values measured for these films were about 155 μΩ cm, significantly close to those corresponding to bulk TiC0,95single crystals. The resistivity of the R-DCMS films is 6% to 23% higher compared to that of the DCMS/HiPIMS-grown samples, depending on the growth temperature.
Physical vapor deposition technology for coated cutting tools: A review
2020, Ceramics International
Due to various difficult-to-machine materials and increasingly severe machining conditions, more and more attention has been paid to physical vapor deposition (PVD) technology in recent decades for the deposition of hard coatings on cutting tools. In conjunction with the state of industrial application of PVD technology, this paper reviews the main PVD techniques for coated cutting tools from the perspective of total PVD coating equipment, including cathodic arc evaporation and magnetron sputtering, as well as hybrid of their techniques and plasma etching which is critical to the adhesion strength of the coating is also involved. Regarding hard coating deposition on cutting tools, the basic principle, cathode configuration, magnetron and power supply are described. Issues related to target ionization ratio, coating deposition rate, coating properties, and industrial application of numerous PVD techniques are also highlighted. Regarding plasma etching, inert gas ion etching and metal ion etching are discussed. Finally, this paper summarizes and perspectives PVD technology used for coated cutting tools.
Understanding the deformation and cracking behavior of Cr-based coatings deposited by hybrid direct current and high power pulse magnetron: From nitrides to oxynitrides
2019, Thin Solid Films
Such improvements include, for example, hardness, wear resistance under abrasive conditions or chemical stability in aggressive environments [1-13]. A further improvement of the mechanical properties of Cr-based nitride and oxynitride coatings can be achieved through high power pulsed magnetron scattering (HPPMS, also known as HiPIMS) . Among the characteristics of HPMS technology are short pulse lengths to the tune of several microseconds  and fpulse frequencies ≥ 10 Hz [15,16].
The increasing demand to reduce corrosion and wear in modern tribological systems places high demands on hard coatings deposited by physical vapor deposition (PVD) technology in numerous technical applications, e.g. A possible approach to excessive wear resistance is tool coating with hard PVD coatings of the Cr-Al-O-N system. Each of the components can provide the coating with particular characteristics in terms of its performance under different loading conditions. Therefore, continuous improvement in modern surface engineering requires comprehensive knowledge of the elastoplastic deformation and cracking behavior of such coatings. To this end, several modifications and extensions of established experiments are required to overcome the limitations involved in the characterization of thin hard coatings, e.g., as a result of μm ranges. In the present work, three CrN, (Cr,Al)N and (Cr,Al)ON coatings deposited on a quenched and tempered AISI 420 steel substrate were investigated. All coating systems were deposited via a hybrid technology, consisting of direct current and high power pulsed magnetron sputtering (dcMS/HPPMS). The deformation and cracking behavior of the coatings and coating/substrate joints was studied by applying static loadings with nanoindentation and Rockwell tests as well as dynamic loading conditions using nanoscratch tests. Complementary quantitative investigations were performed through depth profiling using confocal laser scanning microscopy (CLSM). Qualitative analyzes of the Rockwell indentations and nanoscratch marks were performed by scanning electron microscopy (SEM). Based on the results, accurate analyzes of the force-displacement curves of nanodentations can improve the understanding about the possible crack formation in the coatings. Compared to (the binary) CrN, the ternary (Cr,Al)N coating system shows more promising characteristics in terms of elastic-plastic deformation behavior and crack resistance. The crack resistance is reduced through the incorporation of oxygen into the ternary nitride and the deposition of quaternary oxynitrides (Cr,Al)ON. This character of oxynitrides can be observed by considering only static loadings and thus, application of both static and dynamic loading conditions is required to obtain accurate knowledge of the deformation and cracking behavior of thin hard coatings.
Structural properties and preparation of Si-rich Si1−xCx thin films by RF magnetron
Applied Surface Science, Volume 363, 2016, pp. 477-482
Si-rich silicon carbide (Si1−XdoX) prepared radio frequency (2MHz, 13.56MHz and 27.12MHz) magnetron thin films. Their structural properties were investigated by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM). The effect of ion energy on film deposition was also analyzed with a retardation field energy analyzer. The results show that the compositions of the films are related to the energy of the ions impacting the SiC target. At the lowest firing power, Si rich in Si1−XdoX(1−X=0.57–0.90) thin films can be deposited well.
Fabrication of diamond-like carbon films using short-pulse HiPIMS
Surface and Coatings Technology, Volume 286, 2016, pp. 239-245
Diamond-like carbon (DLC) films were fabricated by sputtering a graphite target using a high-power pulsed magnetron sputtering (HiPIMS) technology operating with short pulses. The pulse duration was 7μs with a maximum source voltage of −2400V, which effectively facilitated the ionization of the sputtered carbon species. In order to show the effectiveness of short-pulse operation, the fabricated DLC films were investigated by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and spectroscopic ellipsometry. The XPS spectra were curve fitted using three Gaussian functions of the sp3-C, sp2-C and C–O bonding. Information from Raman and XPS spectra showed that the sp3fraction in DLC films fabricated using a 7μs pulse duration was greater than that obtained with a 50μs pulse duration. It was found that sp3/sp2ratio was greater than 40%, which was about 1.5 times compared to that obtained with a pulse duration of 50μs. A high sp3Fractionation was performed due to the application of high voltage without arcing carried by magnetron sputtering (MS) flash discharge. To get the high sp3fraction in the fabricated DLC films, a parametric investigation was performed, in which the background gas pressure, the bias voltage applied to the substrate, the power source voltage, and the target-to-substrate distance were varied. There were optimal deposition parameters to reduce the intensity ratio of D band and G band (IHey/IG) in the Raman spectra. The optimal source voltage was in the range of −1200 to −1600V. For voltages higher than -1600 V, the energetic carbon and argon ions may deteriorate the film properties. The hardness of the fabricated DLC films at 7 μs pulse width and -1200 V source voltage was obtained as 37 GPa measured by nano-indentation. The hardness decreased in a range from 20 to 27 GPa with increasing pulse width in the range from 40 to 60 μs.
Aluminum-rich HPMS (Cr1−xAlx)N coatings deposited with different target compositions and at different pulse lengths
Vacuum, Volume 122, Part A, 2015, pp. 201-207
Target properties and pulse shaping are important factors in high-power magnetron pulsed scattering. The present work deals with analyzes of the effects of pulse length, i.e. duty cycle on the HPMS process and the properties of Al-rich (Cr1−xAlX)N coatings deposited with plugged targets in an industrial-scale unit. The results showed that the maximum power density increased from 0.32 kW/cm2up to 0.86 kW/cm2as the pulse length decreased from ton=200µsto40µs. (Cr1−xAlX)N coatings with high aluminum content between x=68at% and x=76at% were produced. The deposition rate reveals a constant behavior using different Al-rich targets at the same pulse length. A mixture of cubic and hexagonal (Cr1−xAlX)N phases were found for each coating. Additionally, a thinner and denser morphology as well as a smoother surface were observed at reduced pulse length compared to long pulse modulation due to the high peak current and power density. The maximum hardness of HU=30.0GPa and moderate modulus of elasticity ETHE=421GPa were achieved for (Cr0,30Al0,70)N coating deposited at pulse length ton=40 μs, i.e. 2% duty cycle.
AlTiCrN coatings deposited by hybrid HIPIMS/DC magnetron co-plane
Vacuum, Volume 136, 2017, pp. 129-136
In this study, AlTiCrN coatings with different Cr contents were deposited from AlTi and Cr targets using a hybrid coating process that combines high-power pulsed magnetron sputtering with DC magnetron sputtering. The microstructure and mechanical properties of the AlTiCrN coatings were investigated using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and nano-indentation. The tribological behaviors of the AlTiCrN coatings were evaluated by pin-on-disk friction tests at 400°C, 600°C and 800°C, respectively. The results showed that all AlTiCrN coatings exhibited (Al,Ti,Cr)N solid solution phases with an FCC NaCl type structure. With increasing Cr target strength, the Cr content increased from 0 to 25 at. %, adjusting for changes in coating microstructure and properties. First, the preferred orientation shifted from (111) to (200). Second, the hardness and elastic modulus of AlTiCrN coatings increased from 31.4±1.4GPa and 448.8±9.3GPaat 0at.% Cr to 33.7±1.4GPa and 469.5±8.2GPaat 8, 9at.% Cr and then decreased with further increase in Cr content. Third, the coefficient of friction and wear rates of the coatings against Al2THE3The balls also showed some relationship with coating compositions and test temperatures. The intrinsic mechanism was analyzed and discussed.
The effect of positive pulses on HiPIMS deposition of DLC hard coatings
Surface and Coating Technology, Volume 358, 2019, pp. 43-49
Diamond-like carbon (DLC) coatings were deposited by a novel HiPIMS method that incorporates positive voltage pulses at the end of the conventional HiPIMS discharge. Different positive voltage amplitudes (100, 200, 300, 400 and 500 V) were used to evaluate the effect of this mode on the discharge process and mechanical properties of the deposited DLC coatings. The application of positive pulses was observed to enhance the ionization of both sputtered carbon and argon. Mass spectroscopy measurements showed that a larger amount of high-energy C+ions are produced, with ion energies proportional to the amplitude of the overvoltage. The ion bombardment induced by the positive pulses led to higher compressive residual stresses and densification of the deposited DLC coatings. In addition, the Raman spectra showed lower D and G band intensity ratios (IHey/IG) as the pulse voltage increased, which is indicative of a higher sp3content. The mechanical properties were evaluated by nanocharacterization test and the hardness of the deposited DLC films was observed to increase from 9.6 GPa (for no applied voltage pulse) to 22.5 GPa (for applied positive pulse voltage of 500 V).
Structure, mechanical and corrosion properties of TiN films deposited on stainless steel substrates at different tilt angles by DCMS and HPPMS
Surface and Coatings Technology, Volume 292, 2016, pp. 54-62
To modify the physical surface of a composite workpiece, incoming particles are difficult to reach the inclined surface of the composite workpiece due to the self-shadowing effect. This will result in non-uniform distribution of the structure and properties of the films on different surfaces of the composite workpiece. In order to mitigate the self-shadowing effect and improve the uniformity of the film structure and properties, high-power pulsed magnetron sputtering (HPPMS) was used to fabricate TiN films on a 316L stainless steel substrate with different tilt angles. During deposition, the electrical characteristics of the HPMS were recorded with an oscilloscope and the plasma component was diagnosed with optical emission spectroscopy. The structure, mechanical and corrosion properties of TiN films deposited on substrate with different tilt angles by DC magnetron sputtering (DCMS) and HPMS respectively were also studied. Compared with DCMS, the results showed that the high ion/atom ratio and large ion flux in HPMS led to stronger ion bombardment and atom mobility, which caused densification of TiN films. The uniformity of hardness and corrosion resistance of TiN films deposited on the substrate with different tilt angles were improved by HPMS. And for HPMS, longer pulses in the same duty cycle could effectively mitigate the self-shadowing effect and improve the hardness and corrosion resistance of TiN-coated stainless steel.
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