Physical Vapor Deposition Method Research Articles

Fractal-like Hierarchical CuO Nano/Microstructures for Large-Surface-to-Volume-Ratio Dip Catalysts

Dip catalysts are attracting interest in both academia and industry for catalyzing important chemical reactions. These provide excellent stability, better recoverability, recyclability, and easy scale-up. Using the unique microstructures of leaf skeletons, we present a fractal-like hierarchical surface that can be used as a versatile and efficient dip catalyst. Copper oxide microcactuses with nanoscalar features were fabricated onto the Bauhinia racemosa leaf skeletons via a combination of physical vapor deposition, electroplating, and chemical oxidation methods. The coated leaf skeletons have a very high surface area, and the three-dimensional (3D) morphology allows the reactants to encounter the catalytic sites efficiently and move around the reaction mixture swiftly. The fabricated bioinspired leaf skeleton-based dip catalyst was characterized and demonstrated to be very efficient for alcohol dehydrogenation reaction, examined under different experimental conditions. A ceramic 3D-printed catalyst holder was designed to hold the catalysts to avoid any damage caused by the magnetic bars during the reactions. The performance is determined using the reaction yields, and the efficiencies are correlated with microcactus-like structures composed of CuO and the 3D fractal-like shape provided by the leaf skeleton. This strategy can be applied to fabricate other dip catalysts using different materials and designs, suitable for catalyzing numerous other chemical reactions.

Failure Mechanism of EB-PVD Thermal Barrier Coatings under the Synergistic Effect of Thermal Shock and CMAS Corrosion

Thermal barrier coatings (TBCs) suffer from the thermo-chemo-mechanical coupling action of thermal shock and calcium–magnesium–alumina–silicate (CMAS) corrosion. However, the failure mechanism of TBCs under the synergistic effect of thermal shock and CMAS corrosion is still unclear due to a lack of an environmental simulator. Herein, an 8YSZ ceramic coating is deposited on a PtAl bond coating/DD419 nickel-based single crystal superalloy substrate using the electron beam physical vapor deposition (EB-PVD) method. The thermo-chemo-mechanical coupling effect of TBCs is achieved in a self-developed environmental simulator. The interaction of volume expansion induced by the phase transition of ZrO2, structural degradation and thermal fatigue further increases the out-of-plane tensile stress and in-plane shear stress in the ceramic coating, which accelerates the initiation and propagation of surface vertical cracks and horizontal cracks. As multiple surface vertical cracks propagate to the interface and merge with interfacial cracks, the ceramic coating spalls from the substrate.

Corrosion Behavior of MoSi<sub>2</sub> Coated Hastelloy X Utilized in Iodine -Sulfur Cycle for Hydrogen Production Application

Molybdenum di silicide (MoSi2) has lower mismatch of coefficient of thermal expansion (CTE) with Hastelloy X as compare to silicon carbide. So, MoSi2 coatings can be a potential candidate to protect Hastelloy X against high temperature sulfuric acid. Herein, MoSi2 thin films were deposited via electron beam physical vapor deposition (EBPVD) method. Corrosion behavior of MoSi2 coated HX and bare HX was analyzed. Corrosion tests of bare Hastelloy X and coated samples was performed at different temperatures (60°C and 120°C) in 98% sulfuric acid using the weight-loss method. The morphology of pre and post corrosion test was also analyzed by using optical microscopy. Bare Hastelloy X showed a slight weight gain at 60°C and a weight loss at 120°C. The MoSi2 coated Hastelloy X showed slight weight gain at 60°C and a weight loss at 120 °C. The weight gain is the result of oxides formation whereas, weight loss may be attributed to corrosion due to H+ ions. These findings were also accompanied by optical microscopy as corroded and very rough patches were evident for bare HX, whereas, for MoSi2 coated samples, the coating was still intact.

Sb2S3/Sb2Se3 heterojunction for high-performance photodetection and hydrogen production

Photoelectrochemical (PEC)-type devices provide promising ways for harvesting solar energy and converting it to electric and chemical energy with a low-cost and simple manufacturing process. However, the high light absorption, fast carrier separation, and low carrier recombination are still great challenges in reaching high performance for PEC devices. As emergent two-dimensional (2D) materials, Sb2Se3 and Sb2S3 exhibit desirable photoelectric properties due to the narrow bandgap, large optical absorption, and high carrier mobility. Herein, Sb2S3/Sb2Se3 heterojunction is synthesized by a two-step physical vapor deposition method. The type-II Sb2S3/Sb2Se3 heterojunction displays excellentphotoelectric properties such as a high photocurrent density (Iph ∼ 162 µA cm−2), a high photoresponsivity (Rph ∼ 3700 µA W−1), and a fast time response speed (rising time ∼ 2 ms and falling time ∼ 4.5 ms) even in harsh environment (H2SO4 electrolyte). Especially, the Sb2S3/Sb2Se3 shows an excellent self-powered photoresponse (Iph ∼ 40 µA cm−2, Rph ∼ 850 µA W−1). This increment is attributed to the improvement in light absorption, charge separation, and charge transfer efficiency. Taking these advantages, the Sb2S3/Sb2Se3 heterojunction also exhibits higher PEC water splitting synergically, which is approximately 3 times larger than that of Sb2Se3 and Sb2S3. These results pave the way for high-performance PEC devices by integrating 2D narrow bandgap semiconductors.

SnS Nanoflakes/Graphene Hybrid: Towards Broadband Spectral Response and Fast Photoresponse.

High responsivity has been recently achieved in a graphene-based hybrid photogating mechanism photodetector using two-dimensional (2D) semiconductor nanosheets or quantum dots (QDs) sensitizers. However, there is a major challenge of obtaining photodetectors of fast photoresponse time and broad spectral photoresponse at room temperature due to the high trap density generated at the interface of nanostructure/graphene or the large band gap of QDs. The van der Waals interfacial coupling in small bandgap 2D/graphene heterostructures has enabled broadband photodetection. However, most of the photocarriers in the hybrid structure originate from the photoconductive effect, and it is still a challenge to achieve fast photodetection. Here, we directly grow SnS nanoflakes on graphene by the physical vapor deposition (PVD) method, which can avoid contamination between SnS absorbing layer and graphene and also ensures the high quality and low trap density of SnS. The results demonstrate the extended broad-spectrum photoresponse of the photodetector over a wide spectral range from 375 nm to 1550 nm. The broadband photodetecting mechanisms based on a photogating effect induced by the transferring of photo-induced carrier and photo-hot carrier are discussed in detail. More interestingly, the device also exhibits a large photoresponsivity of 41.3 AW−1 and a fast response time of around 19 ms at 1550 nm. This study reveals strategies for broadband response and sensitive photodetectors with SnS nanoflakes/graphene.

Thin-Film Coating Methods: A Successful Marriage of High-Quality and Cost-Effectiveness—A Brief Exploration

In this review, several cost-effective thin-film coating methods, which include dip-coating, spin-coating, spray-coating, blade-coating, and roll-coating, are presented. Each method has its own set of advantages and disadvantages depending on the proposed application. Not all of them are appropriate for large-scale production due to their certain limitations. That is why the coating method should be selected based on the type and size of the substrate, including the thickness and surface roughness of the required thin films. The sol–gel method offers several benefits, such as simplicity in fabrication, excellent film uniformity, the capacity to cover surfaces of any size and over vast areas, and a low processing temperature. Nevertheless, these coating methods are somewhat economical and well managed in low-budget laboratories. Moreover, these methods offer thin films with good homogeneity and low-surface roughness. Furthermore, some other thin-film deposition methods, for instance, physical vapor deposition (PVD) and chemical vapor deposition (CVD), are also discussed. Since CVD is not restricted to line-of-sight deposition, a characteristic shared by sputtering, evaporation, and other PVD methods, many manufacturing methods favor it. However, these techniques require sophisticated equipment and cleanroom facilities. We aim to provide the pros and cons of thin-film coating methods and let the readers decide the suitable coating technique for their specific application.

Flame coatings by CCVD (Pyrosil) for R2R applications

Flame coatings by CCVD (Pyrosil) for R2R applications

Characterization of physical vapor deposited coating on acrylonitrile‐butadiene‐styrene and polycarbonate substrates

AbstractIn this study, acrylonitrile‐butadiene‐styrene and polycarbonate substrates plastics were coated with aluminum by physical vapor deposition method in order to determine which one is a better choice for outdoor reflector technology. This investigation has been done by applying the coating on a reflector that is already been used in the lighting industry. Scraping test, caustic soda and caustic potash test, reflection efficiency performance test and surface roughness test methods were used to determine the selection. Coatings on acrylonitrile‐butadiene‐styrene and polycarbonate plastic materials were characterized by scanning electron microscopy and energy dispersive x‐ray spectrometry. Although acrylonitrile‐butadiene‐styrene plastic material is easier for injection molding and cheaper than polycarbonate material, the results showed that polycarbonate plastic material is more efficient than acrylonitrile‐butadiene‐styrene plastic material, especially in terms of surface roughness and reflection efficiency.

Effects of TiN/CrN, CrAlN, and TiN Coatings on the Performance of AISI M2 Tool Steel

The aim of this study is to investigate the effects of various ceramic-based coatings on the performance of AISI M2 high-speed steel punch used in the nut piercing process. AISI M2 punches were coated with TiN, TiN/CrN, and CrAlN utilizing a physical vapour deposition method. The total stroke number of the punches was used to evaluate the tool life of TiN, CrAlN, and TiN/CrN coated AISI M2 punches. AISI M2 punch coated with TiN/CrN was able to work up to greater stroke numbers than punches coated with TiN and CrAlN. Hardness and wear tests were performed to study the wear resistance of TiN/CrN and CrAlN coatings under relatively normal load conditions compared to actual working conditions (impact loading conditions) in the piercing process. The hardness and wear resistance of the CrAlN coating were greater than those of the TiN/CrN coating. The wear performance of the CrAlN coating was higher at normal loads and sliding speeds while the tool life of the TiN/CrN-coated punch was better under impact loading conditions.

Tunning the Activity of Silver Alloy Electrocatalysts for the Oxygen Reduction Reaction in Alkaline Media

A bottleneck to achieve efficient and stable electrocatalysts for Anion Exchange Membrane Fuel Cells (AEMFCs) is the relatively slow kinetics of the oxygen reduction reaction (ORR) taking place at the cathode. The rather mild alkaline conditions in the AEMFC enable the utilization of various PGM-free catalysts, which brings up new possibilities of finding abundant and inexpensive electrocatalysts without compromising the power density. From theory and previous experiments, it is known that Au and Ag bind oxygen weakly, whereas other transition metals (e.g., Pd, Cu, Fe, Ni) bind strongly to oxygenated species1. Therefore, a suitable geometric arrangement between Ag, an abundant metal with relatively high specific activity, and other metals may give rise to optimum binding of oxygen and thus a high activity. A good strategy to improve the activity of Ag-based catalysts could be a rational design of alloys that can enhance the intrinsic activity of Ag by both ensemble and electronic effects2–4. The former is based on the combination of active sites that facilitate the initial oxygen binding together with Ag active sites that help desorb hydroxide anions, whereas the latter is induced by the alloying metal (which binds oxygenated species strongly) on the electronic structure of the overlaying Ag that tunes its binding to oxygen5. Herein, we report the fabrication and characterization of Ag thin-films alloyed with Pd, Ni, Cu and Mo as a tool to investigate the ORR reaction in terms of ensemble and electronic effects and thus relate alloy composition and geometric arrangement with ORR activity. Ag thin-film model catalysts are fabricated by means of physical vapor deposition methods (PVD) with high control over the amount of material deposited. By varying alloy composition and evaluating electrochemical activity and stability, together with detailed physical characterization, the degree and extent of electronic effects are elucidated. In the same way, sputtering of the same amount of Ag on thin-films of different metals evidences the role of the alloying metal on tuning the activity of Ag through an adjustment of its d-band that changes the binding of oxygenated species, as well as through an ensemble effect that provides active sites for the first elementary steps of the reaction. These results provide insights for more tailored design of electrocatalysts in alkaline media by shedding new light on the mechanisms through which the ORR kinetics are improved in alkaline media. Nørskov, J. K. et al. Origin of the overpotential for oxygen reduction at a fuel-cell cathode. J. Phys. Chem. B 108, 17886–17892 (2004).Betancourt, L. E. et al. Enhancing ORR Performance of Bimetallic PdAg Electrocatalysts by Designing Interactions between Pd and Ag. ACS Appl. Energy Mater. 3, 2342–2349 (2020).Slanac, D. A., Hardin, W. G., Johnston, K. P. & Stevenson, K. J. Atomic ensemble and electronic effects in Ag-rich AgPd nanoalloy catalysts for oxygen reduction in alkaline media. J. Am. Chem. Soc. 134, 9812–9819 (2012).Zamora Zeledón, J. A. et al. Tuning the electronic structure of Ag-Pd alloys to enhance performance for alkaline oxygen reduction. Nat. Commun. 12, 1–9 (2021).Stamenkovic, V. et al. Changing the Activity of Electrocatalysts for Oxygen Reduction by Tuning the Surface Electronic Structure. Angew. Chemie 118, 2963–2967 (2006).

A Path to Significant Reduction of the Interfacial Contact Resistance of Sintered Titanium Porous Transport Layers in Advanced Proton Exchange Membrane Water Electrolyzers

Proton exchange membrane water electrolyzers (PEMWEs) are a leading industry solution to large scale production of green hydrogen, and as a form of energy storage [5]. The PEMWEs have the advantages of having greater energy efficiency, higher product purity, and are environmentally friendly. Within the construction of a PEMWE stack, there are many catalysts coated membranes (CCMs) sandwiched between anode porous transport layers (PTLs) and cathode Gas Diffusion Layers. The PTL is constructed of sintered titanium powder or fibers. The Ti-PTL is on the anode side of a PEMWE cell where the water diffuses towards the CCM. The anode half-cell reaction or oxygen evolution reaction (OER) occurs on this side of the cell. This is important as the PTL is in contact with the bipolar plate (BPP) and the anode catalyst layer [9].A key aspect plaguing the PEMWEs is the highly oxidative and corrosive environment that is typically observed on the anode side. This significantly affects the interfacial contact resistance (ICR) of the components as the corrosion can cause the ohmic resistance of the PTL to increase. In order to combat the corrosion in the PTLs, in this work we use two thin film deposition methods, Physical Vapor Deposition (PVD) and Vacuum Sputtering, to deposit protective metal layers on top of the state-of-the-art Ti PTLs [2]. The explored metal coatings of interest are Platinum (Pt) and Gold (Au) [9]. For the purposes of these experiments, Au and Pt coatings with various thicknesses are deposited on Ti-PTLs by using either PVD or vacuum spattering method. As deposited thin films are characterized by scanning electron microscopy (SEM), digital optical microscopy, and inductively coupled plasma (ICP) analysis. Also, the in-plane conductivity and the ICR of all samples of interest are measured before and after the electrochemical tests by using the 4-probe method and in-house build setup for ICR measurements. The optimal deposition parameters for fabrication of thin, continuous and smooth Pt and Au protective coatings that result in minimum ICR and improved in-plane conductivity of the PTLs of interest are identified, and the results will be reported at the ECS 241 meeting.

A Review of Coating Methods and Their Applications in Compression and Spark-Ignition Engines for Enhanced Performance

Coating of metallic surfaces such as cylinder heads, cylinder liners, piston heads and exhaust-valves in Internal Combustion Engines (ICEs) has improved engine performance in areas of brake-thermal-efficiency including brake-specific-fuel consumption, etc. This review showed different methods of coating in compression and spark-ignition engines for improved performance using different coating thicknesses on the metallic surfaces. These coating thicknesses may be either minimum or maximum depending on the coating method used. The coating methods discussed in this paper were Thermal Spraying (TS), Physical-Vapour Deposition (PVD), Chemical-Vapour Deposition (CVD) and Ion Implantation methods. Minimum thicknesses were achieved using the PVD, CVD and Ion-Implantation methods. In addition, Sol-Gel and Slurry coatings were also discussed. Having considered these methods of coating, thermal-spraying method was recommended for compression and spark-ignition engines because it produces temperature ranging from 8000 K-14000 K on surfaces with thick coating thicknesses.

Improving the mechanical, tribological, and electrochemical behavior of AISI 304 stainless steel by applying CrN single layer and Cr/CrN multilayer coatings

The purpose of this study was to assess the mechanical and tribological behavior of chromium nitride (CrN) single layer and multilayer nanostructured coatings of chromium/chromium nitride (Cr/CrN) applied on AISI 304 stainless steel to be used in a marine application. CrN and Cr/CrN coatings were performed using cathode arc evaporation a division of physical vapor deposition (CAE-PVD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM) and field emission scanning electron microscopy (FE-SEM) were utilized for phase identification of coatings and surface morphology, respectively. Nano-indentation method was used to investigate the mechanical behavior of coatings. The tribological behavior of the coatings was studied by the ball-on-disk method. The results indicate that the mechanical behavior of the Cr/CrN multilayer nanostructured coatings is better in comparison to the CrN single-layer coatings. The hardness values of CrN and Cr/CrN coatings were 21.5 and 23.3 GPa, respectively. The higher hardness of the nanolayered coating might be owing to blocking the movement of dislocations and microcracks by its layered structure. Furthermore, the tribological behavior of AISI 304 stainless steel was highly amended by applying the coatings. The coefficient of friction for CrN and Cr/CrN coatings in a dry condition decreased from 0.61 to 0.49 and 0.46, respectively. Also, the CoF value reduced from 0.57 to 0.38 and 0.37 in 3.5 wt% NaCl electrolyte. The lower friction coefficient of the Cr/CrN multilayer nanostructured coating is perhaps due to its higher hardness and lower roughness.

Metal-ceramic diffusion barrier nanocomposite coatings on nickel based superalloys for corrosion and high temperature oxidation resistance

Ceramic diffusion barrier coatings are inevitable in high temperature aerospace and nuclear applications to protect superalloys from oxidation and hot corrosion. Compositionally graded coating (CGC) of Ni-YSZ with five layers was deposited on an Inconel-690 substrate through electron beam physical vapor deposition (EBPVD) method. After heat treatment, the phase formation and crystallite determination in each layer of the CGC were studied by X-ray diffraction. Pulsed radio frequency glow discharge optical emission spectroscopy (RF-GDOES) showed outward diffusion of Ni towards the surface of the CGC. High resolution transmission electron microscopy (HRTEM) studies of the cross-sectional region of the heat-treated coating at 1273 K revealed no secondary phases within the coating as well as at substrate-coating interface. The corrosion behavior of Ni-YSZ coating under 3 M HNO3 medium showed that the heat-treated CGC of Ni-YSZ exhibited better corrosion resistance due to the formation of NiO than as-deposited Ni-YSZ coating.

Investigation of vermiculite infiltration effect on microstructural properties of thermal barrier coatings (TBCs) produced by electron beam physical vapor deposition method (EB-PVD)

Thermal barrier coatings (TBCs) are protective coating systems that are mostly utilized to improve the thermal insulation and functional performance of gas turbine engines and other aircraft components that are both stable and movable. These coatings protect materials operating in harsh conditions from structural damage caused by corrosion, oxidation, the CaO-MgO-Al2O3-SiO2 effect (CMAS), thermal shock, volcanic ash, and vermiculite deposits at high temperatures. In this study, CoNiCrAIY metallic bond coatings were coated on Inconel 718 super alloy using a high velocity oxygen-fuel (HVOF) deposition technique. Then, single YSZ, Gd2Zr2O7 (GZ), and double YSZ/GZ based ceramic topcoats were applied to the bond coats by using the electron beam physical vapor deposition (EB-PVD) method. The produced TBC samples and the uncoated Inconel 718 superalloy substrate were subjected to vermiculite (VM) deposition at 1250 °C for 4 h, and then the coatings were characterized. To determine the phase structures, microstructural and mechanical properties of the TBCs, X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer elemental mapping analysis (EDS), stereo microscopy analyses, porosity, and hardness measurements were used. The obtained results were comparatively evaluated with the recent related studies in the literature.

Broadband photodetector based on vapor-deposited selenium self-supporting films

As a high-quality p-type semiconductor, Selenium (Se) has become an important potential candidate for photoelectric devices due to its high photoconductivity, non-linear optical response, and large piezoelectricity. However, the intrinsic Se has a wide bandgap (about 1.77 eV), so it is usually used for photodetection in the visible region. In this work, the Se self-supporting films have been successfully fabricated by an improved physical vapor deposition (PVD) method, and a metal-semiconductor-Metal (MSM) photodetector based on the Se self-supporting films has been designed for the first time. The photodetector shows broadband photoresponse from visible light to near-infrared (450–1550 nm), which is consistent with the experimental absorption spectrum of the obtained film. Besides, photodetection results indicate that the device exhibits a fast response speed (Tr = 4.5 ms, Td = 63.8 ms) with perfect responsivity (8.1 μA/W) and detectivity (1.3 × 105) under 3 V bias voltage and 450 nm (0.971 mW) light irradiation. The research of this paper will further enrich the application and development of traditional Se semiconductors in the field of optoelectronics.

Optical and electrical properties of ITO/Metal/NiO triple-layer grown by PVD method: An experimental study

In this work, transparent conducting oxides (TCOs) comprising an ITO/Metal/NiO sandwich structure grown by sputtering and thermal evaporation in a vacuum are investigated. By exploiting the four-point probe measurements and optical spectrometry both optical and electrical characteristics of the fabricated ITO/Metal/NiO trilayers for diverse metals such as Au, Ag, and Cu are studied. Moreover, through X-ray diffraction and high-resolution scanning electron microscopy method the structural characteristics are fully examined. The results reveal that the type of innermost metal plays the main role in the optical and electrical behavior of the trilayers structure. An average transmittance of 73-62% range at visible wavelength and small resistivity of 2 × 10−4 Ω cm are achieved for a 10 nm thick Au interlayer. The sheet resistivity (Rs) of NiO drops drastically from 200 Ω (single NiO layer) to 1.2Ω for ITO/Cu/NiO structure. Moreover, an increase in sputtering power and film thickness increases the optical bandgap. The obtained results prove that physical vapor deposition (PVD) is a good method for producing par excellence TCO films with beneficial characteristics such as high transmittance and low resistivity.

The Effect of Molecular Orientation in Disperse Red-1 Film on Its Refractive Index

The refractive index of materials is an important physical quantity in the design of various photonic devices. For thin-film based devices, the fabrication method should be compatible with existing processes in microelectronic fabrication and allow for controlling the refractive index. In this research, the material used is a polar Disperse Red 1 (DR1) molecule. The film fabrication was carried out using the physical vapor deposition method which had been equipped with an electric poling installation. The poling of the electric field during the deposition process was applied perpendicular to the substrate. The thickness measurement and the refractive index of the films were carried out using a reflectometer where the light was incident perpendicular to the substrate. The refractive index was determined by the multiple beam interference method. As a result, it was found that the application of an electric field causes a change in the orientation of the molecules, which were initially parallel to the substrate to become perpendicular. Increasing the field strength further reduces the number of molecules parallel to the substrate. This correlates with a decrease in the refractive index of the film.

Improved Corrosion Protection of Stainless Steel by Two Dimensional BN Nanomaterial Coating

Boron nitride (BN) nano coating was deposited on 304 type stainless steel sheets by standard thermionic vacuum arc (TVA) as a physical vapour deposition method. Deposited BN nano coating was characterized by attenuated total reflectance Fourier transform infrared spectroscopy, Raman spectroscopy, field emission scanning electron microscopy and X-ray diffraction analyses tools. Corrosion performances of un-coated and BN nano material coated steel samples were investigated in 1 M H2SO4 solution using Eocp-time curves, potentiodynamic polarization and electrochemical impedance spectroscopy techniques. BN nano coating was found to provide anodic protection to the steel and reduced significantly corrosion rate of 304 steel in acidic medium. Long term corrosion tests results demonstrated that the BN nano coating has ability to protect the 304 stainless steel in sulfuric acid corrosive media during 10 d and the protective behavior of the BN nano coating results from passivation effect of the coating against the attack of corrosive environment. Finally, BN nano coating is a promising two dimensional coating material for corrosion protection of stainless steel.

Microstructural and nanomechanical studies of PVD Cr coatings on SiC for LWR fuel cladding applications

The microstructure and nanomechanical properties of pure Cr coatings deposited on SiC with various physical vapor deposition (PVD) methods have been investigated for the mitigation of hydrothermal corrosion of SiC-SiCf (SiC fiber-reinforced SiC matrix) composite fuel cladding in light water reactors (LWR). Cr coatings (4–7 μm thick) were deposited on unbiased SiC substrates using six variants of magnetron sputtering processes: (i) standard (S-DCMS), (ii) pulsed (P-DCMS), (iii) ion-assisted (I-DCMS), and (iv) pulsed ion-assisted direct current magnetron sputtering (PI-DCMS), (v) high-power impulse magnetron sputtering (HiPIMS), and (vi) bipolar HiPIMS (B-HiPIMS). Microstructural characterization and nanoindentation testing were used to evaluate effects of deposition technique on coating microstructure and nanomechanical properties. The application of positive reverse pulses to the sputter target induced coarsening of the columnar grain structure, while ion bombardment of substrates during deposition promoted densification of the coating microstructure. Both effects are exemplified in B-HiPIMS deposition, resulting in a high-density microstructure with compressive residual stress. Material pile-up around nano-indents and plastic work during nanoindentation were analyzed to understand deformation behavior of the coatings. The results suggest the B-HiPIMS process to be among the promising methods for the deposition of Cr coatings on SiC-SiCf for LWR cladding application.