Multilayer Nitride Research Articles

Comparative Study of Zirconium Nitride Multilayer Coatings: Crystallinity, In Vitro Oxidation Behaviour and Tribological Properties Deposited via Sputtering and Arc Deposition.

This study aims to evaluate and compare the properties of a biomedical clinically established zirconium nitride (ZrN) multilayer coating prepared using two different techniques: pulsed magnetron sputtering and cathodic arc deposition. The investigation focuses on the crystalline structure, grain size, in-vitro oxidation behaviour and tribological performance of these two coating techniques. Experimental findings demonstrate that the sputter deposition process resulted in a distinct crystalline structure and smaller grain size compared to the arc deposition process. Furthermore, in vitro oxidation caused oxygen to penetrate the surface of the sputtered ZrN top layer to a depth of 700 nm compared to 280 nm in the case of the arc-deposited coating. Finally, tribological testing revealed the improved wear rate of the ZrN multilayer coating applied by sputter deposition.

Tunnel transport problem for open multilayer nitride nanostructures with an applied constant magnetic field and time-dependent potential: An exact solution

A quantum mechanical theory for description of electronic quasistationary states in two-dimensional (2D) layered semiconductor nanostructure was developed. A constant external magnetic field B was directed along semiconductor layers. The presence of internal electric fields F originated from the potential barriers and wells in semiconductor layers was taken into account. The vector of F was directed perpendicularly to semiconductor layers. The interaction of tunneled electrons with a time-dependent electromagnetic fields was analyzed in detail. An approach to obtain an exact solution to the problem based on a combination of the Lewis-Riesenfeld method for complete Schrödinger equation and scattering theory was developed. Application of the scattering theory in combination with the -matrix and transfer-matrix methods allowed us to calculate the electron quasistationary spectra. Effects of magnetic field on the resonant energy and width of electronic quasistationary states as well as on the electronic conductivity were also discussed. Published by the American Physical Society 2024

Unraveling interfacial thermal transport in β-Ga2O3/h-BN van der Waals heterostructures

As global power consumption rapidly increases with generation of significant amount of heat, efficient thermal management in electronic equipments becomes an urgent task, which requires a comprehensive understanding on thermal transport in heterostructures within devices. Here, we present detailed examination on the interfacial thermal transport of van der Waals (vdW) heterostructures, composed of β-Ga2O3 and hexagonal boron nitride (h-BN) multilayers. Through extensive molecular dynamics simulations, we show that the interfacial thermal conductance (ITC) of β-Ga2O3/h-BN system becomes as high as 136.8MWm−2K−1, and the high ITC value results from substantial phonon interaction across the interface. In addition to the pristine interface, the effect of structural modulation including strain, vacancies and substitutional defects in h-BN multilayers on the ITC is also analyzed, and it is demonstrated that there exists ranges of strain values and defect concentrations which increase the ITC, and that the enhanced ITC is the result of the interplay among the interfacial distance, the overlap in the phonon density of states and elastic mismatch between β-Ga2O3 and h-BN multilayers. These results not only provide insights into understanding interfacial phonon transport in vdW systems but also offer guiding principles for designing efficient heat dissipators in device applications.

Fatigue and tensile behaviour of Ti+TiN+Ti+TiVN multilayer nitride films coated on AZ91 magnesium alloy by closed field unbalanced magnetron sputtering

Despite their extensive use in the automotive and aerospace industries, Mg and Mg alloys, which are light metals, exhibit low fatigue and tensile strength. In this study, transition metal-nitride (TMN) multilayer coatings (Ti+TiN+Ti+TiVN) were coated twice on AZ91 Mg alloy using a Confined Field Unbalanced Magnetron Sputtering (CFUBMS) system to increase fatigue and tensile strength. The structural properties of the films were analyzed by using X-ray diffraction (XRD), scanning electron microscope (SEM), and energy dispersive spectrometry (EDS) methods, and the mechanical properties were analyzed by rotating bending fatigue and tensile testing machines. Ti+TiN+Ti+TiVN multilayer nitride surface coatings on AZ91 Mg alloys showed a dense and columnar microstructure and according to XRD results (111) was the preferred orientation with the dominant peak. The fatigue limit value of the AZ91 base material was fixed at 60.46 MPa, while it increased to 68.48 MPa after being coated with multilayer nitride. Along with the multilayer nitride coating, the tensile strength increased from 169.98 MPa to 175.43 MPa. As a result, the multilayer hard nitride coating with low surface roughness, which fills the defects, notches, and voids on the surface of the AZ91 base material, increased the fatigue and tensile strength in parallel. Based on the outcomes of the research, the literature has been enriched with an innovative approach through the enhancement of fatigue and tensile strengths by applying a CFUBMS coating to lightweight metals and alloys, such as AZ91, especially in the transportation industry where lightness and dynamic load resistance are essential.

Preparation and tribologic properties of Ti and Zr nitride multilayer coatings

This paper focuses on synthesis and characterization of Zr/Ti and Ti/Zr nitride multilayer coatings by magnetron plasma sputtering to enhance the tribologic properties. The synthesis of nitrides was achieved by non-reactive deposition using Ti or Zr nitride targets or by reactive deposition using Ti or Zr targets in the presence of nitrogen. The formation of nitride layers was highlighted by XRD, EDX and XPS investigations, while the tribologic properties were made with HFRR equipment. The tribological study showed that the coefficient of friction and wear scar diameter decrease in multilayer films with zirconium nitride as the upper layer.

Influence of Technological Parameters of Deposition on Physical and Mechanical Properties of Vacuum-Arc Multilayer Nitride Coatings Based on Chromium and Niobium

Influence of Technological Parameters of Deposition on Physical and Mechanical Properties of Vacuum-Arc Multilayer Nitride Coatings Based on Chromium and Niobium

Effect of titanium interlayer configurations on residual stresses and performance of titanium/titanium nitride multilayer coatings

Multilayer coatings provide an effective measure to control and optimise of residual stresses, enhance coating adhesion, fracture toughness, wear and corrosion resistance of coating system. In this study, we designed and produced bi-layer and four-layer titanium/titanium nitride magnetron sputtered coating configurations by altering the position of the interlayer. The in-plane residual stresses in different coating configurations are measured by multiple peak grazing incidence X-ray diffraction techniques. Subsequently, the effect of different compressive residual stresses on adhesion, mechanical properties, wear and corrosion resistance of coatings are investigated. Results show that the position of interlayer in multilayer coating configuration has a great impact on relaxation of residual stresses. The residual stresses are relieved by 26% and 46% by lowering the position of titanium interlayer from 800 nm at the top to 1000 nm and 1200 nm, respectively. The nanoindentation hardness is decreased by 11% and 13%, respectively. The wear rate of multilayer coating having interlayer position at 800 and 1000 nm from the top is ≈ 23% lower compared to bilayer however it is increased by ≈ 50% when interlayer coatings position changed to 1200 nm from the top. The interposition of interlayer in multilayer coating configurations decreased the corrosion current density by ≈ 50%. All multilayer coatings including higher residual stresses show better adhesion to the substrate compared to bilayer coatings which shows severe delamination.

Mechanical properties of Xe-ion-irradiated high-entropy-alloy-based multilayers

In this Letter, we investigate the mechanical stability of HEA-based multilayers after Xe-ion irradiation. CrFeCoNi/TiNbZrTa metallic and nitride thin films with a bilayer thickness of 30 nm were grown by reactive dc-magnetron sputtering on Al2O3(0001) substrates for irradiation studies and on Si(100) substrates for other characterizations. The films were subjected to 3-MeV Xe-ion irradiation at room temperature (RT) and at 500 °C. The crystal structure and mechanical properties of the films before and after irradiation were studied by x-ray diffraction and nanoindentation. Before irradiation, both the metallic and nitride multilayers displayed a lower hardness (7 and 20 GPa, respectively). Annealing at 500 °C for 150 min increased the hardness of the multilayer samples, but it also induced intermixing of elements between the sublayers of the metallic multilayer. Irradiation hardening was observed only in the metallic multilayer at room temperature. When comparing the effects of irradiation damage vs the effects of annealing on the mechanical properties, it was observed that annealing the multilayers had a more pronounced effect.

A mechanism for thickness-controllable single crystalline 2D materials growth

Recent efforts in growing two-dimensional (2D) multilayers have enabled the synthesis of single crystalline 2D multilayers in a wafer scale through the seamless stitching of multiple epitaxial 2D islands. Unlike previously observed wedding-cake or inverted-wedding-cake structures, these multilayer islands have the same size and shape in each layer with aligned edges. In this study, we investigated the underlying growth mechanisms of synchronic 2D multilayers growth and have showed that a heterogenous layer on a crystalline substrate is critical for maintaining the synchronic growth of 2D multilayers. During growth, the heterogenous layer passivates the edges of multilayer 2D island and thus prevents the coalescence of these active edges, while the high interfacial energy between the heterogenous surface layer and the substrate stabilizes the synchronic structure. Based on this model, we have successfully explained the previously observed synchronic growth of graphene and hexagonal boron nitride multilayers (Nat Nanotech 2020, 15: 861; Nature 2022, 606: 88). The deep understanding on the mechanism paves a way towards the synthesis of wafer-scale single-crystal 2D multilayers with a uniform thickness.

Preparation and properties of nitride multilayer coating modified stainless steel as bipolar plates for proton exchange membrane fuel cells

Nitride multilayer coating is prepared on 316L stainless steel (SS) by employing multi-arc ion planting to enhance the corrosion resistance, interfacial electrical conductivity, and hydrophobicity. The electrochemical results show that the coating can effectively inhibit the interface reactions. The icorr of the coated 316L SS was 0.04 μA cm−2, which was significantly lower than that of the substrate (54.7 μA cm−2). The protection efficiency (Pi) of the multilayer nitride coating was 99.93%. After 9 hours of PP, the current density of the coated 316L SS stabilized at 0.085 μA cm−2. The typical ICR value of the coated 316L SS slightly increased from 8.6 mΩ cm2 to 12.6 mΩ cm2. The XPS results demonstrated that the significantly increased ICRs (114.7–200.4 mΩ cm2) of the 316L SS substrate were mainly attributed to the increased proportion of Cr oxide, while the oxide content of the coating was still relatively small. The change in surface morphology and current transient events are further discussed.

Effect of substitutional oxygen on the cohesion of transition-metal nitride multilayers

Using a first-principles approach, we investigated the effect of oxygen as a substitutional impurity on cohesion of three transition metal nitride multilayers. Namely, we studied AlN/VN, AlN/TiN, and VN/TiN systems in a rock salt structure (B1) with (001) interfaces. The preferred oxygen positions were determined with the help of calculations of free energy that also included contribution from the vibrational entropy. Subsequent calculations of the cleavage energy for all possible cleavage planes enabled us to identify the weakest link and assess the impact of the oxygen impurity on a cohesion of each of the studied multilayers. Supercells of different sizes were used to estimate the effect of oxygen concentration. Our results indicate that oxygen prefers to replace nitrogen atoms in interfacial planes and that these impurities do not reduce the multilayer cohesion. Moreover, in the case of the AlN/TiN system, their presence was found to increase cohesion of the interface.

Micro structure and wear analysis of multi-layer nitride coating deposited on the austenitic steel

Utilizing the appropriate technology, the surface property must be improved to offset wear loss caused by friction. Hard ceramic coating compounds include titanium nitride (TiN) and titanium aluminium nitride (TiAlN). The cathodic arc deposition method's effects on the stainless steel (SS304) mechanical and wear properties (CAD) Measurements and comparisons are made for the coated samples of the wear rate microstructural study. In the ball-on-disc wear test, the tribological parameters are altered. Compared to different kinds of coatings, The TiN coating offers remarkable mechanical and tribological qualities on the SS316L surface. the microstructure of the wear areas of materials coated with titanium nitrate and aluminium titanium nitride under various loads. Compared to non-coated material, the titanium nitride and aluminium titanium nitride coated materials have high wear resistance.

Interface-independent sound speed and thermal conductivity of atomic-layer-deposition-grown amorphous AlN/Al2O3 multilayers with varying oxygen composition

Dielectric amorphous multilayers (AMLs) play a critical role in a wide array of technologies such as optical coatings, nanoelectronics, energy harvesting, and recovery devices. However, despite their wide applications, a robust understanding of the effect of the interplay between chemical and structural disorder on the thermal properties of AMLs is still lacking. Therefore, in this paper, we experimentally and numerically investigate the effects of composition and interface density on the sound speed and thermal conductivity of a series of amorphous aluminum nitride and aluminum oxide multilayers grown via plasma-enhanced atomic layer deposition. To systematically change the composition, the oxygen content of the AMLs is proportionally varied with interface density during growth. We find that the longitudinal sound speed of these AMLs is dictated by the oxygen content instead of the number of interfaces. The thermal conductivity, in contrast, is dictated by both interface density and oxygen content. The interfaces act to decrease the thermal conductivity, whereas the oxygen content increases the thermal conductivity. Due to the competing influence of the interfaces and oxygen content, the thermal conductivity of the AMLs remains nearly constant as a function of interface density. Our study provides crucial insights into the effect of the interplay of composition and interfaces on the sound speed and thermal conductivity of AMLs.

Experimental investigation of a multilayer nitride coating deposited on austenitic coating steel

Friction is the drawback in automotive and industrial machining parts and assembly. To overcome the wear loss due to friction the surface property must be enhanced using suitable technology. Arc deposition is a PVD type of coating which improves the property such as hardness, roughness, corrosion, and tribological on a server work environment. Titanium nitride (TiN) and titanium aluminum nitride (TiAlN) are hard ceramic coating materials. The mechanical and wear properties of stainless steel (SS304) coated with Method of cathodic arc deposition (CAD) The ability to slide against Ti–6Al–4 V alloy has improved significantly. The three coated samples' surface hardness, roughness, and wear rate are measured and compared. The applied tension (2–6 N), sliding velocity (0.32–0.75 m/s), and sliding distance (580–1500 m) tribological parameters are modified during the wear test with the ball-on-disc. In comparison to other types of coatings, On the SS316L surface, the TiN coating provides exceptional mechanical and tribological properties.

Microstructure and high-temperature tribological characteristics of self-lubricating TiAlSiN/VSiN multilayer nitride coatings

In recent years, self-lubricating hard protective coatings operated at elevated temperature have drawn great amount of attentions. It has been found that alloying certain elements such as vanadium is an effective method to reduce the friction coefficient, since the Magnéli phase formed at elevated temperature provides a self-lubricious surface during the wear process. However, the formation kinetics of the Magnéli phase should be appropriately controlled. Insufficient or excessive amount of Magnéli phase formation may result in high friction coefficient or severe oxidation of coatings. This study reports an architectural design strategy to engineer the mechanical and high temperature tribological properties of TiAlSiN/VSiN multilayer.In this study, the multilayer system exhibited a low friction coefficient of 0.28 and the lowest wear rate of 7.01 × 10−6mm3N−1m−1 was revealed at multilayer with bilayer period of 16 nm during the wear test at 700 °C. The existence of the Magnéli phase, V2O5, was observed by XPS and its high-temperature lubricating effect was revealed as compared to the wear test at room temperature. It is demonstrated that a particular architectural design of TiAlSiN/VSiN multilayer coating provides a potential candidate for high-speed cutting tools due to their mechanical and lubricious properties.

High-Temperature Oxidation of CrN/ZrN Multilayer Coatings

Multilayer nitride coatings provide some of the best performance when in their use for the production of metalworking tools. In this work, vacuum-arc plasma-assisted deposited multilayer ZrN/CrN coatings with different numbers of constituent layers were characterized for high-temperature oxidization in air using weighing, confocal and scanning electron microscopy and synchrotron XRD. Oxidizing at 300 °C did not deteriorate the coating surfaces, while higher temperatures caused surface deterioration and oxidation accompanied by cracking, delamination and considerable mass gains. The coating with higher number of thinner layers showed higher oxidation resistance due to more prominent oxygen barrier effect.

Effect of Negative Bias of HiPIMS and AIP Hybrid Deposition on Microstructure, Mechanical and Anti-Corrosive Properties of Cr2N/TiN Multilayer Coatings

Multi-layered nitride coatings have been widely applied to improve the mechanical and anti-corrosive of metals and/or alloys. Cr2N/TiN multilayer coatings were prepared by the combination of high-power pulsed magnetron sputtering (HiPIMS) and arc ion plating (AIP). The Cr2N layer was co-deposited by HiPIMS and AIP, while the TiN layer was deposited by a single HiPIMS. With increasing the negative bias voltage (Vs) on substrate up to −100 V, the number and size of the droplets decreased; the average grain size of the coatings decreased from 9.4 to 7.5 nm and the hardness increased from 21.5 to 25.1 GPa, and the level of the adhesion of the coatings has reached HF1. The coatings obtained at Vs = −100 V present the best corrosion resistance in NaCl aqueous solution based on the anodic polarization curves and EIS spectroscopy.

Xe-ion-irradiation-induced structural transitions and elemental diffusion in high-entropy alloy and nitride thin-film multilayers

The study aims to understand the irradiation behavior of multilayer coatings composed of high-entropy materials. Here, we report the structural stability and elemental segregation of high-entropy TiNbZrTa/CrFeCoNi metallic and nitride multilayer coatings under 3-MeV Xe20+ ion-irradiation at room temperature and 500 °C, respectively. Transmission electron microscopy analysis shows that the microstructure of nanocrystalline CrFeCoNi high-entropy-alloy sublayers are not stable and readily transforms into amorphous state at 500 °C and/or under irradiation conditions. The elemental distribution, acquired by energy-dispersive X-ray spectroscopy under scanning transmission electron microscopy mode, shows preferential diffusion of Co and Ni into TiNbZrTa sublayers, while Fe and Cr preferentially remain within the previous CrFeCoNi sublayers. TiNbZrTaN/CrFeCoNiNx nitride multilayers exhibit a higher crystallinity and structural stability as well as resistance to diffusion at high-temperature and/or irradiation conditions than their TiNbZrTa/CrFeCoNi metallic multilayer counterparts. These findings are explained by atomic size differences, the difference in Gibbs free energy of the mixing system, and interstitial-solute-induced chemical heterogeneity. Our findings thus provide a design strategy of high entropy nitride for nuclear fuel cladding.

Deposition, microstructure and nanoindentation of multilayer Zr nitride and carbonitride nanostructured coatings

Nitrides, carbides, and carbonitrides of transition metal elements like Zr, W, Ti, etc. are generally employed to produce hard coatings. Zirconium-based hard coatings have shown useful applications in the areas of tribology, biomedicine and electrical due to their high thermal stability, hardness, biocompatibility, good erosion, wear, and corrosion resistance. In this study, we created homogeneous and tenacious nanostructured hard coatings based on Zr with good mechanical properties. The magnetron sputter deposition technique was utilized to coat stainless steel 316L substrates with multilayers of Zr/ZrN and ZrN/ZrCN with individual layer thicknesses of 250 and 500 nm for each coating composition. The deposition conditions were adjusted to create two different coating thicknesses of 2 and 3 µm. The thickness of the coating was confirmed using Calotest and the coatings’ morphology and elemental composition were determined utilizing the atomic force microscope and scanning electron microscope equipped with energy dispersive x-ray spectrometer. Coating thickness and adhesion were measured using cross-sectional samples and XRD was utilized to analyze the coatings structure. Nanoindenter was employed to determine the instrumental nanoindentation hardness and elastic modulus. The influence of coating thickness on tribological behavior was further investigated using the ratio of nanohardness-to-elastic modulus (H/E). No evidence of decohesion was observed at the substrate/coatings interface, and the grains of all the coatings were observed to show columnar growth which were homogeneous, compact and dense. The grains of the ZrN/ZrCN coatings were observed to be denser, finer and more compact compared to those of the Zr/ZrN coatings. Correspondingly, higher hardness, modulus and H/E values were exhibited by ZrN/ZrCN than Zr/ZrN coatings. This suggests that the ZrN/ZrCN coatings are capable of exhibiting better wear resistance and fracture toughness. The coatings developed in this investigation are anticipated to be suitable for applications in tribology due to their excellent hardness and H/E properties.

Nanostructured AlTiSiN/CrVN/ZrN coatings synthesized by cathodic arc deposition- mechanical properties and cutting performance

Multicomponent and multilayer coatings have been attracting significant research interest, and these coatings allow the deposition of graded layers with a continuous variation of the concentration of the components to fulfill specific requirements at the substrate interface or that at the surface. On the basis of the binary compounds TiN, CrN and ZrN, various deposition strategies were developed to improve or adapt the hard coatings to a specific tribological problem. In this study, a cathodic arc deposition technology was used to deposit the AlTiSi/CrV/Zr and multilayer nitride coatings of AlTiSiN/CrVN/ZrN. By controlling the rotation speed of the substrate, hierarchical gradient and multilayered structures containing periodic AlTiSiN, CrVN and ZrN layers were found in the multilayer nitride coatings. Microstructure, mechanical properties and cutting applications were discussed. The highest hardness was obtained for the multilayered AlTiSiN/CrVN/ZrN coating with modulation period of 13.5 nm. The presence of multicomponent AlTiSiN/CrVN/ZrN with nanolayer structure mainly attributed to the formation of strong metal‑nitrogen bonding enhanced the hardness of the coatings. For the field test of cutting, a glass-reinforced epoxy laminate material was machined by the coated WC-Co end mills using a milling machine at high cutting spindle rotational speed of 40,000 rpm. The obtained results showed that the periodic thickness of the multilayer structure had a direct effect on the mechanical properties and cutting performance of the coatings. The design of nanostructured AlTiSiN/CrVN/ZrN hard coatings improved the overall tribological performance and showed applicability of these coatings in high speed cutting of glass-reinforced epoxy laminate materials.