TiAlN Layers Research Articles

Influence of Multilayer Structure on the Structural and Mechanical Properties of TiAlN/CrN Coatings for Advanced Machining Applications

This study investigates single and multilayer TiAlN/CrN nanocomposite thin films developed using an RF magnetron sputtering system. The TiAlN and CrN layers showed a high degree of orientation, with the (200) peak being the strongest peak in both layers, and a multilayer structure was clearly observed. The surface roughness analysis using atomic force microscopy (AFM) and cross-sectional transmission electron microscopy (TEM) revealed that the TiAlN/CrN coatings had a smoother surface than the single-layer coatings and minimal intermixing between the two layers. Depth-sensing indentation measurements were used to measure the hardness and Young’s modulus of the coatings, demonstrating that TiAlN/CrN coating had the highest hardness (~16.38 GPa) and elastic modulus (~3.82 GPa) among all the coatings studied. This indicates that the TiAlN/CrN multilayer coating possesses superior mechanical properties due to its interface strength. Our findings suggest that these multilayer coatings have potential applications in tribological and decorative coatings.

Annealing enhanced optical performances of nano-multilayered TiAlN/AlCrSiN-based solar selective absorber

Solar selective absorber is an important component to improve the solar thermal conversion efficiency of next-generation concentrated solar power with working temperature higher than 700 °C. However, the selective absorbers with thermal stability up to 700 °C are still lacking. Here, we designed a solar selective absorber based on nano-multilayered TiAlN/AlCrSiN films via thermal annealing, which could induce spinodal decomposition in TiAlN layer and form dual phase structure of Ti-rich and Al-rich cubic-TiAlN, to enhance the optical performances and thermal stability of the absorber. The obtained absorber after annealed at 900 °C exhibited a solar absorptance of 0.923 and a thermal emittance of 0.192, as well as small variation (0.935/0.232) after annealing at 700 °C for 100 h. However, after annealing the absorber at temperatures higher than 1000 °C, the N-loss induced the formation of metal CrSi2 phase and obviously decreased the absorption in near-infrared region. These results indicated the potential of the implement of spinodal decomposition to construct solar selective absorbers with high performances.

Effect of modulation period and thickness ratio on the growth and mechanical properties of heteroepitaxial c-Ti0.4Al0.6N/h-Cr2N multilayer films

c-TiAlN/h-Cr2N multilayer thin films, with modulation period λ of 10 nm, 20 nm, and 30 nm and different Cr2N/ λ thickness ratios (25 %, 50 % and 75 %), were deposited on c-plane sapphire using reactive DC magnetron sputtering. All multilayers exhibited preferred orientation [Cr2N(0001)/ TiAlN(111)]x, regardless of the modulation period and thickness ratios. X-ray diffraction φ-scans revealed an influence of the Cr2N layer thickness on the overall orientation quality of the multilayer, where the thicker the Cr2N layer the higher orientation quality. Atomically resolved high-angle annular dark-field scanning transmission electron microscopy revealed well defined and homogeneous atom stacking in the Cr2N layers. In contrast, the cubic TiAlN layer was found to be composed of coherent cubic AlN-rich and TiN-rich regions. Additionally, the TiAlN layers were found with a higher density of grain boundaries compared to the Cr2N layers. Mechanical properties evaluation revealed that the film with a 20 nm period and 75 % Cr2N thickness ratio exhibited the highest hardness of 27.11 ± 0.72 GPa and an reduced elastic modulus of 349.1 ± 6.84 GPa. The hardness increased as the thickness of Cr2N increased, until reaching 10 nm, after which it remained at a high level (∼ 25 GPa).

Effect of the auxiliary cathode on the thickness of the HiPIMS TiAlN coating deposited on the inner surface of the tube

The paper is focused on influencing the thickness of the TiAlN layer deposited using the high power pulse magnetron sputtering (HiPIMS) method on the inner surface of the tube. The HiPIMS method makes it possible to deposit layers at temperatures up to 400°C. An auxiliary cathode placed in the axis of the coated tube was used. The auxiliary cathode made it possible to deposit an AlTiN layer with a thickness in the center of the coated tube up to 45% higher compared to the thickness of the layer deposited without an auxiliary cathode.The layer thickness was measured to be from 1.5 µm to 2.2 µm for the layer deposited without an auxiliary cathode and 1.05 µm to 1.95 µm for the layer deposited with the wire as the cathode in the axis of the coated tube. Adhesion of the evaluated layers showed the degree of HF2 at the measured thickness points.

High-speed laser writing of structural colors for full-color inkless printing

It is a formidable challenge to simultaneously achieve wide-gamut, high-resolution, high-speed while low-cost manufacturability, long-term stability, and viewing-angle independence in structural colors for practical applications. The conventional nanofabrication techniques fail to match the requirement in low-cost, large-scale and flexible manufacturing. Processing by pulsed lasers can achieve high throughput while suffering from a narrow gamut of ~15% sRGB or angle-dependent colors. Here, we demonstrate an all-in-one solution for ultrafast laser-produced structural colors on ultrathin hybrid films that comprise an absorbent dielectric TiAlN layer coating on a metallic TiN layer. Under laser irradiation, the absorption behaviours of the TiAlN-TiN hybrid films are tailored by photothermal-induced oxidation on the topmost TiAlN. The oxidized films exhibit double-resonance absorption, which is due to the non-trivial phase shifts both at the oxide-TiAlN interface, and at the TiAlN-TiN interface. By varying the accumulated laser fluence to modulate the oxidation depth, angle-robust structural colors with unprecedented large-gamut of ~90% sRGB are obtained. The highest printing speed reaches 10 cm2/s and the highest resolution exceeds 10000 dpi. The durability of the laser-printed colors is confirmed by fastness examination, including salt spray, double-85, light bleaching, and adhesion tests. These features render our technique to be competitive for industrial applications.

NaCl-induced hot-corrosion behavior of TiAlN single-layer and TiAlN/Ti multilayer coatings at 500 °C

The microstructure and corrosion behavior of the TiAlN and the TiAlN/Ti coatings were studied under the synergistic effects of salt spray and high temperature at 500 °C. The results showed that the salt spray test accelerated the hot corrosion process of the coatings. The columnar grain boundaries of TiAlN coatings provide a preferred position for internal corrosion, where the corrosion product was mainly composed of TiO 2 . The TiAlN/Ti multilayer interface and Ti interlayer have double effects on the hot corrosion resistance of the coating. The Ti metal layer restrained the corrosion zone propagation to TiAlN layer and also aggravated the local corrosion inside the coating. The corrosion mechanisms of TiAlN and TiAlN/Ti coatings were discussed in detail. • The hot corrosion behaviors of TiAlN single-layer and TiAlN/Ti multilayer coatings were investigated. • During the hot corrosion process, the Ti and Al elements were consumed greatly, and no complete and protective oxide layer was formed. • The columnar grain boundaries of TiAlN coating provide favorable position for internal corrosion. • Ti metal layer was preferentially corroded in TiAlN/Ti coating. It provides a reference for the development of new nitride coatings.

Effect of bias voltage on microstructure, mechanical and tribological properties of TiAlN coatings

TiAlN multilayer coatings composed of TiAl and TiAlN layers were deposited on ZL109 alloys using filtered cathodic vacuum arc (FCVA) technology. The effect of bias voltage on the microstructure and properties of the coating was systematically studied. The results show that the coating exhibits a multi-phase structure dominated by TiAlN phase. As the bias voltage increases, the orientation of TiAlN changes from (200) plane to (111) plane due to the increase of atomic mobility and lattice distortion. The hardness, elastic modulus and adhesion of the coating show the same trend of change, that is, first increase and then decrease. When the bias voltage is 75 V, the coating exhibits the highest hardness (~30.3 GPa), elastic modulus (~229.1 GPa), adhesion (HF 2) and the lowest wear rate (~4.44×10−5 mm3/(N·m)). Compared with bare ZL109 alloy, the mechanical and tribological properties of TiAlN coated alloy surface can effectively be improved.

Surface protection of a V-4Cr-4Ti alloy through a multilayered TiAl/TiAlN composite coating

The vanadium alloys are attractive structural materials for applications in Generation IV reactors and fusion reactors. Surface protections of the alloy are required due to its high affinity to H, O etc. impurity atoms. The previous coating designs on the vanadium alloys have been focused on monolithic coatings and may have low coating-substrate bonding strengths. The TiAlN-based composite coatings which show remarkable surface protection effects, are yet to be applied to the vanadium alloy substrates. In the current work, a TiAl/TiAlN composite coating with intermediate TiAl layers was deposited on a V-4Cr-4Ti alloy substrate using the filtered-cathodic vacuum-arc-deposition (FCVAD) method. The coating with a total thickness of ∼18 μm was compact and free of any voids or inclusions. A high adherence strength of ∼82 N was measured for the coating. The ultrafine equi-axed γ-TiAl grains in the TiAl layer, and the columnar grains in the TiAlN layer which are composed of a mixture of TiN/AlN/Ti3AlN phases were characterized in detail with the transmission electron microscopy (TEM). The surface hardness and surface roughness were significantly improved for the coating compared with the substrate. The electrochemical corrosion results also show that the composite coating offers improved corrosion resistance against aqueous corrosion at room temperature.

Study on bonding strength and layer structure design of TiAlSiN multilayer gradient coating

Compared with TiN coating and TiAlN coating, the TiAlSiN superhard coating has more outstanding comprehensive properties. However, the TiAlSiN superhard coating has different physical properties from the substrate, which causes large internal stress at the interface, and reduces the bonding strength of the coating and the substrate. In this paper, according to the design criteria of nano-micron multilayer structure coating, a multilayer gradient TiAlSiN coating is designed to improve the bonding strength of TiAlSiN superhard coating, and studying the bonding strength and mechanical properties after high temperature oxidation of TiAlSiN multilayer gradient coatings prepared by cathodic arc ion plating. The results show that the designed multilayer gradient structure TiAlSiN coating has four layers: TiN layer, TiAlN layer, TiAlSiN layer and TiSiN layer. The bonding strength of the TiAlSiN multilayer gradient coating conforms to the industrial grade HF1 and it maintains good bonding properties and mechanical properties in a high temperature environment below 1000°C. It is expected to provide reference for the study and design of improving the bonding strength of the coating.

Contamination of Substrate-Coating Interface Caused by Ion Etching

In–situ cleaning of the substrate surface by ion etching is an integral part of all physical vapor deposition (PVD) processes. However, in industrial deposition systems, some side effects occur during the ion etching process that can cause re-contamination. For example, in a magnetron sputtering system with several sputter sources and with a substrate holder located centered between them, the ion etching causes the contamination of the unshielded target surfaces with the batching material. In the initial stage of deposition, this material is redeposited back on the substrate surface. The identification of the contamination layer at the substrate–coating interface is difficult because it contains both substrate and coating elements. To avoid this problem, we prepared a TiAlN double coating in two separate production batches on the same substrate. In such a double-layer TiAlN hard coating, the contamination layer, formed during the ion etching before the second deposition, is readily identifiable, and analysis of its chemical composition is easy. Contamination of the batching material was observed also on seed particles that caused the formation of nodular defects. We explain the origin of these particles and the mechanism of their transfer from the target surface to the substrate surface. By comparison of the same coating surface area after deposition of the first and second TiAlN layers, the changes in coating topography were analyzed. We also found that after the deposition of the second TiAlN coating, the surface roughness slightly decreased, which we explain by the planarization effect.

Designed Ti/TiN sub-layers suppressing the crack and erosion of TiAlN coatings

Solid particle erosion damage seriously affects the service life and operational safety of engine blades, while the erosion resistant coating is one of the effective measures to effectively improve the erosion resistance of the blade material and extend its service life. Here, we deposited the Ti/TiN/TiAlN multilayer coatings with different thickness ratio of the Ti to TiN layer on Ti-6Al-4V substrates by a home-made hybrid multisource cathodic arc system. The relationship between coating structure and coating properties including adhesion strength, residual stress, load-bearing capacity, crack resistance and erosion resistance was focused. Results showed that the Ti layer was beneficial in improving adhesion strength and reducing residual stress of the multilayer coatings, which was benefited from coordinating the deformation and absorbing strain energy induced by plastic deformation. The TiN layer was important in maintaining load-bearing capacity. Radial cracks initiation and propagation from the Ti/TiN interface occurred at most cases, while wide lateral cracks were formed only in the TiAlN layer for its high brittleness and internal stress during scratching. When the thickness ratio of the Ti to TiN layer was 1:2, the coating exhibited the best combination of hardness, adhesion strength, crack resistance, and load-bearing capacity. As a consequence, the coating behaved the lowest erosion rate of 0.060 ± 0.0002 mg/g and 0.024 ± 0.0068 mg/g at the erosion angle of 90° and 30°, respectively.

Microstructure, mechanical and tribological properties of multilayer TiAl/TiAlN coatings on Al alloys by FCVA technology

In order to improve the surface properties of Al alloy, TiAlN ceramic coatings composed of alternating TiAl layer and TiAlN layer were prepared by FCVA technology. The influence of N 2 flow rate on the microstructure, mechanical and tribological performance of multilayer TiAlN coatings was systematically studied. The results showed that the coating exhibited a multi-phase structure with mainly fcc TiAlN phase and a small amount of TiN and AlN phases. As the N 2 flow rate increased from 50 to 80 sccm, the preferred orientation varied from TiAlN (220) plane to (111) plane due to lattice distortion. The hardness and elastic modulus of multilayer TiAlN coatings first increased and then decreased with the increase of N 2 flow rate. However, the average friction coefficient and wear rate of multilayer TiAlN coatings exhibited an opposite trend to the hardness, H/E and H 3 /E 2 values. The adhesion gradually decreased from 27.3 to 14.9 N due to the continuous increase of the compressive stress in the coating with the increase of N 2 flow rate. When the N 2 flow rate was 70 sccm, the coating showed the lowest average friction coefficient and wear rate, which was attributed to the highest hardness and the best resistance to cracking and plastic deformation.

Smart PVD hard coatings with temperature sensor function

In manufacturing technology, the performance of the tools have to conform to increasingly higher standards. Aditionally, recording process data during production is becoming more and more important in the Industrie 4.0. Thin hard tool coatings deposited by physical vapor deposition (PVD) and serving as protection from wear and corrosion are state of the art in manufacturing technology since decades. Integrating additional functions into the coatings will help extend the process limits faced by the load collective in manufacturing technology. One approach here is to exploit the electrical properties of thin coatings to design sensors for temperature measurement. The overall objective of this study is therefore the design PVD sensor coatings. These coatings should facilitate an online measurement of the surface temperature and offer a thermal resistance up to a few hundred degrees centigrade that allows their application in different technical applications. The hard coatings are selected for the two multilayer sensor coatings presented, because they are state of the art as wear protection for numerous manufacturing technology tools. Their temperature sensor function is based on the thermoelectric effect, expected because of the metallic bonding parts of the single coatings. Electrically insulated by Al 2 O 3 , the one material pair consists of CrN/AlN and TiAlN layers. The other material pair consists of a CrAlN and a TiAlN layer. Both sensor coatings show a dense and fine crystalline morphology as well as interlayer without cracks or damages in the SEM crosssection, even between the oxide insulation layer and the nitride sensor layers. Phase stability and oxidation resistance up to at least T ≤ 700 °C are demonstrated for all coating materials. For both sensor coatings, the ability to measure potential differences as a function of the applied temperature is demonstrated. The sensor coating, which in addition to TiAlN consists of a second sensor layer CrN/AlN with nanolaminate architecture, shows a better response behavior and a lower scattering of the measuring values. • Combination of wear protection coatings for multilayer sensor coatings • Temperature measurement by nitridic hard coatings is possible. • Higher temperature measuring accuracy for sensor coating CrN/AlN+TiAlN • Thermal resistivity up to T ≤ 700 °C for developed nitride sensor coatings

Arc Ion Plating 법으로 형성된 TiAlN 박막의 버퍼층에 따른 특성 연구

In this study, using the AIP method, a TiAlN thin film was grown on a WC-5Co alloy using the buffer layer as TiAl, TiN, and CrN. The preferred orientation according to the XRD analysis showed a pattern with the growth directions of (111) and (110) in almost coating conditions. In the case of the thin film using TiN and CrN as buffer layers, (220) was more prominent than that of other specimens. The adhesion of the TiAlN layer showed a tendency to be affected by the buffer layer and surface roughness. The TiN buffer layer showed the highest adhesion of 130 [N], while the TiAl buffer layer showed a low adhesion of 20[N]. And to examine the high-temperature oxidation resistance, heat treatment was performed. In the case of the specimen using TiN and CrN as buffer layers and coating the TiAlN upper layer for 60 minutes, nitrogen was not replaced with oxygen even at 900[℃] and the nitride thin film was maintained as it is.

Structural, interface texture and toughness of TiAlN/CN multilayer films

Microstructure evolution study of TiAlN/CN x multilayer films with similar single layer thickness (the thickness of individual TiAlN layer: L TiAlN , L TiAlN /L CN x = 1) in the range of 0.9 nm to 13.7 nm shows that the structure of the TiAlN/CN x -MFs changes with the change of L TiAlN . TiAlN/CN x -MFs with L TiAlN of 0.9 nm exhibit a nanocomposite structure with embedded nano-sized crystalline TiAlN particles in the matrix. Due to the template effect of the TiAlN layers when L TiAlN is 2.6 nm, the CN x layers will partially crystallize and grow coherently with the TiAlN layers. Analysis of the different relationships between the TiAlN/CN x interface reveals one type of orientation relationship between the fcc TiAlN and crystalline CN x layers: (111) TiAlN‖(111) C 3 N 4 . Interfaces of the TiAlN/CN x are sharp but with the expansion of the TiAIN lattice spacing and the shrinking of CN X relative to itself, the lattice spacing will vary near the interface region. Further increasing L TiAlN , the CN x layers will exhibit completely amorphous structures and slowly lose their coherent interfaces, triggering a rapid decline in hardness and toughness. Maximum hardness of the MFs is 27.2 GPa when the L TiAlN is 0.9 nm, while the fracture toughness of the MFs with L TiAlN of 2.6 nm is almost 1.5 times that of the other MFs. To obtain high hardness and enhanced toughness in MFs, crystallization of CN x layers and coherent growth are required. • TiAlN/CNx-MFs with LTiAlN of 0.9 nm exhibit nanocomposite structure • Extremely fine TiAlN crystals were formed • The atomic mixing or the bond energy lead to the change of lattice spacing • TiAlN nc grains are separated by a matrix phase

Comprehensive Research and Analysis of a Coated Machining Tool with a New TiAlN Composite Microlayer Using Magnetron Sputtering.

The application of thin monolayers helps to increase the endurance of a cutting tool during the drilling process. One such trendy coating is TiAlN, which guarantees high wear resistance and helps to “smooth out” surface defects. For this reason, a new type of weak TiAlN microlayer with a new composition has been developed and applied using the HIPIMs magnetron sputtering method. The aim of this study was to analyze surface-applied micro coatings, including chemical composition (EDX) and microstructure in the area of the coatings. Microstructural characterization and visualization of the surface structures of the TiAlN layer were performed using atomic force microscopy. To study the surface layer of the coatings, metallographic cross-sectional samples were prepared and monitored using light and electron microscopy methods. The microhardness of the test layer was also determined. Analyses have shown that a 2-to-4-micron thick monolayer has a microhardness of about 2500 HV, which can help increase the life of cutting tools.

Growth model for high-Al containing CVD TiAlN coatings on cemented carbides using intermediate layers of TiN

This work concerns high Al-containing TixAl1-xN coatings prepared using low pressure-chemical vapour deposition (LP-CVD). The coatings were examined using electron microscopy techniques, such as scanning transmission electron microscopy (STEM), energy dispersive X-ray analysis (EDX) and transmission Kikuchi diffraction (TKD). An intermediate TiN-layer with a 〈211〉 texture consisting of twinned, needle-shaped grains influences the subsequent growth of the TiAlN layer. The TiAlN grains were columnar with a texture of 〈211〉. As the grains grow along 〈111〉, with {001} facets, this led to a tilted pyramid surface morphology. The grains developed an internal periodic epitaxial nanolamella structure. The thicknesses were 2 nm for the low (x = 0.6) and 6 nm for the high (x = 0.9) Al-containing lamellae. The TiAlN layer growth could be described by a “two-wing” model, where two TiAlN grains with a twin-related orientation grow on a twinned TiN grain, where the two TiAlN grains gradually switch sides, making the appearance of two wings of columnar grains. In general, this work shows that it should be possible to control the growth of TiAlN layers by controlling the texture and morphology of an intermediate layer, such as TiN.

Erosion behavior and failure mechanism of Ti/TiAlN multilayer coatings eroded by silica sand and glass beads

Severe erosion by hard particles is a crucial problem to engine blades when aircraft take off and land in harsh environments, especially for the developed lightweight titanium alloy components. Here, we deposited the Ti/TiAlN multilayer coatings with various cycles on Ti–6Al–4V substrates by a home-made hybrid multisource cathodic arc system. The effects of the silica sand and glass beads on erosion behavior of the coatings were focused. Results showed that the Ti/TiAlN multilayer coatings eroded by the silica sand exhibited the predominant “layer by layer” failure mechanism. In particular, increasing the number of cycles led to the dramatic increase in erosion rate for Ti/TiAlN multilayer coatings, due to the deterioration of their mechanical properties. Different from the silica sand case, however, the erosion rate of the coatings treated by glass beads indicated faint dependence upon the number of cycles, where the coating failure was dominated by the “piece by piece” failure mechanism. Noted that the Ti layers along with the formed interfaces enhanced the erosion resistance of the coatings, although the failure mechanisms were differently eroded by silica sand and glass beads. Meanwhile, the Ti layers and interfaces hindered the propagation of radial cracks and restrained the lateral cracks within one single TiAlN layer.

Corrosion mechanism investigation of TiAlN/CrN superlattice coating by multi-arc ion plating in 3.5 wt% NaCl solution

This study focuses on effects of layered design method on the corrosion resistance of the coatings. The different corrosion behaviors could be extracted from the microstructure and electrochemical properties for nanoscale multilayer coating (TiAlN/CrN) and single layer coatings (TiAlN and CrN). Based on the analysis of microstructure characterization, electrochemical response and corrosion morphology, it may provide a reference for the development of new anti-corrosive films. The three different coatings were prepared by the process of multi-arc ion plating on 316 stainless steel. In the deposition of TiAlN/CrN multilayer coating, the almost 150 nm Cr film was first deposited as a transition layer, and then CrN and TiAlN individual layers were alternately deposited with a single layer thickness of 10 nm. The influences of the layered construction on the electrochemical performance of the multilayer and single layer coatings were investigated in a neutral saline solution (3.5 wt% NaCl), for which potentiodynamic polarization and electrochemical impedance spectroscopy were employed. The 316 stainless steel was regarded as comparative group. The surface and cross-sectional morphology of the as-deposited coatings were investigated by scanning electron microscope (SEM). The crystal structure and preferred orientation were analyzed by X-ray diffraction (XRD). The interface characteristic of the multilayer TiAlN/CrN coating was detected by transmission electron microscope (TEM). After the 15 days immersion corrosion test, the surface morphology of the samples were observed by the means of SEM and laser scanning confocal microscope (LSCM). The results showed that all the coatings exhibited a face centered cubic structure (fcc) and the multilayer coating presented (200) preferred orientation and coherent interface. In comparison with polarization curves of the substrate and the TiAlN and CrN single layer coatings, the corrosion potential of the TiAlN/CrN multilayer coating shifted positively to −0.36 V, the corrosion current density decreased to 0.047 μAcm−2 and the polarization resistance is 124.69 kΩ cm2. In terms of EIS, the TiAlN/CrN multilayer coating possessed the low value of CPE (10.9 × 10−6 Ω−1 cm−2 sn) and high value of n (0.9) in all samples. Furthermore, the corrosion morphology of the TiAlN/CrN multilayer coating was more close to the morphology of as-deposited coating. Therefore, the TiAlN/CrN multilayer coating exhibited superior corrosion resistance compared with 316 stainless steel and the single coatings. The roles of the layered design in enhancing the corrosion resistance can be summarized as: multilayer design can change the original growing mode of the coating, block the pinholes, reduce the inherent defects and form passive coating with compactness.

Growth of dense, hard yet low-stress Ti0.40Al0.27W0.33N nanocomposite films with rotating substrate and no external substrate heating

W+ irradiation of TiAlN is used to demonstrate growth of dense, hard, and stress-free refractory nitride coatings with no external heating during reactive magnetron sputtering. Ti0.40Al0.27W0.33N nanocomposite films are deposited on Si(001) substrates using hybrid high-power impulse and dc magnetron cosputtering (HiPIMS and DCMS) in an industrial sputtering system employing substrate rotation during film growth from six cathodes. Two W targets powered by HiPIMS serve as a pulsed source of energetic W+ ions with incident fluxes analyzed by in situ time- and energy-resolved mass spectroscopy, while the remaining four targets (two elemental Ti targets and two Ti plates with Al plugs) are operated in the DCMS mode (W-HiPIMS/TiAl-DCMS) to provide a continuous flux of metal atoms and sustain a high deposition rate. A negative substrate bias Vs is applied only in synchronous with the W+-ion-rich portion of each HiPIMS pulse in order to provide film densification by heavy-ion irradiation of the TiAlN layers deposited between W+-ion exposures. W is selected for densification due to its high mass and relatively low reactivity with N2, thus minimizing target poisoning while enhancing gas rarefaction. Dense Ti0.40Al0.27W0.33N alloy films, grown with no external substrate heating (substrate temperature Ts lower than 150 °C due to heat load from the plasma) and Vs = 500 V, exhibit a nanoindentation hardness of H = 23.1 GPa and an elastic modulus of E = 378 GPa, which are, respectively, 210% and 40% higher than for reference underdense DCMS Ti0.58Al0.42N films grown under the same conditions, but without W+ irradiation. The W ion bombardment does not affect the film stress state, which is compressive and low at 1.2 GPa.