ZrN Systems Research Articles

Features of the Application of Coatings Based on the ZrN System to Increase Resistance to Mechanical Wear and Corrosion of Titanium Alloy Products

The coatings of ZrN, (Zr,Ti)N, (Ti,Zr,Hf)N and (Ti,Zr,Nb)N deposited on the titanium alloy substrate were compared. The wear resistance in the pin-on-disk test together with the Al2O3 indenter and the corrosion resistance in 3.5% NaCl solution were studied. It was found that the (Zr,Nb,Ti)N coating has the best resistance to wear, but has low corrosion resistance. The (Ti,Zr,Hf)N coating, on the contrary, has the best corrosion resistance, but low resistance to wear. The ZrN coating has good corrosion resistance combined with good resistance to wear. This coating is best suited for use in friction conditions with a ceramic counterbody under the influence of seawater. An important resource for increasing the properties of coatings is increasing their adhesion to the substrate, which can be achieved in two combined ways: (1) complete removal of the original oxide layer from the surface of the substrate and (2) the use of optimal compositions of the adhesive sublayer, which have not only high adhesive properties in relation to both the substrate and the coating, but also high strength. While the introduction of Nb into the ZrN coating composition increases wear resistance and the introduction of Hf increases corrosion resistance, the ZrN coating without additives best resists wear and corrosion simultaneously.

Study of the Nature of the Destruction of Coatings Based on the ZrN System Deposited on a Titanium Alloy Substrate

The fracture strength was compared in a scratch test of coatings based on the ZrN system with the introduction of Ti, Nb and Hf, which were deposited on a titanium alloy substrate. The coatings were deposited using Controlled Accelerated Arc (CAA-PVD) technology. In coatings that simultaneously include Zr and Ti, a nanolayer structure is formed, while in coatings without Ti, the formation of a monolithic single-layer structure is observed. The comparison was carried out according to two parameters: adhesion strength to the substrate and overall coating strength. The (Zr,Hf)N coating showed better resistance to destruction, but had worse adhesion to the substrate. As a result, although the coating is retained directly in the scribing groove, a large area of delamination and destruction is formed around the groove. The (Ti,Zr,Nb)N coating, with its somewhat lower strength, has a high adhesion to the substrate; no noticeable delamination is observed along the groove boundary. In this paper, not only is the fracture resistance of various coatings deposited on a titanium alloy substrate compared, but the nature of this fracture is also investigated depending on the composition of the coatings.

Structural Color Materials with Color Mixing Effect Using Noble Metal‐Free Plasmonic Particles in SiO2–ZrN System (Advanced Optical Materials 19/2024)

Structural Color Materials with Color Mixing Effect Using Noble Metal‐Free Plasmonic Particles in SiO₂–ZrN System (Advanced Optical Materials 19/2024)

Ambient-Condition Recoverable Polymeric N10 Discovered from the Predicted Zr-N Compounds.

Polynitrogen has been widely studied recently as a rising star of high energy density materials. Here, we performed a systematic study of the Zr-N compounds in the N-rich region by the first-principles method. The high-pressure phase diagram of the Zr-N system is enriched by proposing five new compounds. ZrN10 with the infinitely extended band shaped structure is first reported. The band-like polynitrogen of ZrN10 decomposes into a more stable chain-like polynitrogen structure under the influence of temperature. Additionally, the novel honeycomb-like band-shaped N10 structure hcb-N10 has been discovered by removing the Zr atoms. The absence of the -4 oxidation state in the N10 unit prompts its further polymerization, which makes hcb-N10 possess dynamical and thermal stability in ambient conditions. hcb-N10 is a semiconductor with a bandgap of 2.97 eV due to highly localized electrons. Both chain-ZrN10 and hcb-N10 represent potential candidates for HEDMs with outstanding energy and explosive performance.

Structural Color Materials with Color Mixing Effect Using Noble Metal‐Free Plasmonic Particles in SiO2–ZrN System

AbstractStructurally colored materials with a color mixing effect are developed using SiO2–ZrN core–shell particles, where ZrN nanoparticles used as shells exhibited localized surface plasmon resonances (LSPRs). ZrN nanoparticles (10–30 nm) are attached to monodispersed SiO2 particles by modifying SiO2 particles with polymers. The attached ZrN nanoparticles exhibited a plasmon resonance absorption band at 700 nm. These SiO2–ZrN core–shell particles have a highly monodisperse particle size and assemble into a particle‐stacked film with Bragg diffraction light in the visible spectrum. The particle‐stacked film of the SiO2–ZrN core–shell particles exhibited the maximum reflection depending on the particle size of the SiO2 core. The ratio of the reflection intensity in the long‐wavelength region corresponding to the ZrN absorption to that in the short‐wavelength region of the particle‐stacked film containing the ZrN shell is less than that of the ratio in only SiO2 particle‐stacked film. The results reveal that these particle‐stacked films exhibit a “color mixing effect” that combines specific wavelength absorption through plasmon resonance and specific wavelength diffraction owing to the periodic structure without using precious metals.

Influence of niobium and hafnium doping on the wear and corrosion resistance of coatings based on ZrN

The properties of coatings based on the ZrN system with the introduction of hafnium and zirconium (ZrN, (Zr,Nb)N and (Zr,Hf)N), deposited on a Ti6Al–4V titanium alloy substrate are compared. Coatings are deposited by controlled accelerated arc-physical vapor deposition, and the structure of the coatings is studied using a transmission electron microscope. A comparison is made of both the mechanical (hardness, wear resistance, scratch strength) and anticorrosion (in a 3 % solution of NaCl) properties. The (Zr,Hf)N coating (22 at% Hf and 78 at% Zr) has the maximum hardness (HV, 3225 ± 73) and wear resistance. This coating also exhibits higher corrosion resistance. In contrast, introducing Nb into the coating composition reduces the corrosion resistance. This combination of beneficial properties makes the (Zr,Hf)N coating useful for conditions in which the surfaces of parts must simultaneously have high wear resistance, strength, and corrosion resistance.

Solid-state NMR applied to Si-based polymer derived ceramics: A review

In this contribution, a review of the use of solid state NMR in the field of Si-based Polymer Derived Ceramics is presented. This synthetic approach allows to prepare a large variety of precursors leading to a wide range of ceramics, both in terms of composition and microstructure: multinuclear solid state NMR is obviously a pertinent spectroscopic tool of investigation since its versatility provides a detailed description of the structure of the polymeric precursors and their pyrolysis products. In a first introductory section, the relevant nuclei that can be probed in such systems are presented with their advantages and drawbacks, as well as the main NMR sequences that have been used to obtain as much structural information as possible in terms of local environments and connectivities. All along this article, examples are then given to illustrate which solid state NMR techniques are currently available to characterise the structure of a large variety of PDCs screening Si-C, Si-C-O, Si-/Ti/B/Al-C-O, Si-C-N, and Si-B/Al/Ti/Zr-N systems.

Identification of concentration dependences of the electrical conductivity of composite materials of SiC‒TiN and SiC‒ZrN systems

An explanation of the physical nature of the experimentally established concentration dependences of the electrical conductivity of ceramic composite materials of the SiCTiN (ZrN) system is proposed. A model of the structure and a method for calculating the electrical conductivity of composite materials, as well as experimental dependences of the electrical conductivity of sintered ceramics of the SiC‒TiN (ZrN) system are presented.

Identification of Concentration Dependences of the Electrical Conductivity of Composite Materials of SiC–TiN and SiC–ZrN Systems

An explanation of the physical nature of the experimentally determined concentration dependences of the electrical conductivity of ceramic composite materials of the SiC–TiN (ZrN) system is proposed. A model of the structure and a method for calculating the electrical conductivity of composite materials, as well as experimental dependences of the electrical conductivity of sintered ceramics of the SiC–TiN(ZrN) system are presented.

Ab initio investigations of the phase stability in group IVB and VB transition metal nitrides

Using a combination of electronic structure density functional theory and an evolutionary algorithm, we predicted the thermodynamically stable structures of the group IVB and VB transition metal nitrides at 0K. Our results demonstrate that in the group IVB nitrides there is a competition between nitrogen interstitial ordered forms of the hexagonal close packed structure and nitrogen vacancy ordered forms of the B1 structure. The low metal vacancy formation energies in the B1 structure even allowed metal vacancy ordered forms of the B1 HfN structure to be thermodynamically stable. The work also revealed how bond distortion and bond angles allowed the predicted Ti2N and Zr2N P4/mnm phases to be stable as compared to the Pnnm structure for Hf2N. This work also predicted several metal-rich phases to be present in the Zr-N system, which have yet to be observed potentially owing to this system being the least experimentally studied of the group IVB nitrides. In the group VB nitrides, the low formation enthalpies of the ε-TaN prototype and Bh structures, as well as the C6 structure, suppress the dominance of the B1 phase at low temperatures. The collective results provide in-depth and inclusive examination of the similarities and differences for phase stability in these two classes of transitional metal nitrides at 0K.

Thermodynamic modelling of Ti-Zr-N system

Thermodynamic modelling of Ti-Zr-N system is performed using Calphad method coupled with ab initio calculations. The energies of formation of stable and metastable end-members of sublattice formulations of solid phases in Zr-N system and enthalpy of mixing of the mixed nitride (Ti, Zr)N (δ) are calculated using ab initio method. Phonon calculations are used to compute the Gibbs energies of stoichiometric ZrN and the mixed nitride δ. With the aid of experimental thermochemical and constitutional data from the literature along with the results of ab initio calculations, thermodynamic optimization is carried out to obtain the Gibbs energy model parameters.

Which Resolution can be Achieved in Practice in Neutron Imaging Experiments? – A General View and Application on the Zr - ZrH2 and ZrO2 - ZrN Systems

Current methodical developments improve the spatial resolution of neutron imaging facilities. Objects with dimensions down to several microns should be detectable. However, the minimum object size detectable depends not only on the facility hardware like detector resolution or neutron optics, but also on the attenuation contrast. In this paper the relation between illumination time needed, neutron contrast of the objects and their minimal size detectable is derived and an analysis of the minimal dimension of an object can be detected in neutron radiography and tomography is discussed at two examples: zirconium hydride ZrH2 in Zircaloy-4 as a high contrast system and zirconium nitride ZrN in zirconium oxide ZrO2 as a low contrast system. It is concluded which minimal sizes of the precipitates can be detected in realistic times.

First-principles quantum molecular dynamics study of TixZr1−xN(111)/SiNy heterostructures and comparison with experimental results

The heterostructures of five monolayers B1–TixZr1−xN(111), x = 1.0, 0.6, 0.4 and 0.0 (where B1 is a NaCl-type structure) with one monolayer of a Si3N4-like Si2N3 interfacial layer were investigated by means of first-principles quantum molecular dynamics and a structure optimization procedure using the Quantum ESPRESSO code. Slabs consisting of stoichiometric TiN and ZrN and random, as well as segregated, B1–TixZr1−xN(111) solutions were considered. The calculations of the B1–TixZr1−xN solid solutions, as well as of the heterostructures, showed that the pseudo-binary TiN–ZrN system exhibits a miscibility gap. The segregated heterostructures in which Zr atoms surround the SiyNz interface were found to be the most stable. For the Zr-rich heterostructures, the total energy of the random solid solution was lower compared to that of the segregated one, whereas for the Ti-rich heterostructures the opposite tendency was observed. Hard and super hard Zr–Ti–Si–N coatings with thicknesses from 2.8 to 3.5 μm were obtained using a vacuum arc source with high frequency stimulation. The samples were annealed in a vacuum and in air at 1200 °C. Experimental investigations of Zr–Ti–N, Zr–Ti–Si–N and Ti–Si–N coatings with different Zr, Ti and Si concentrations were carried out for comparison with results obtained from TixZr1−xN(111)/SiNy systems. During annealing, the hardness of the best series samples was increased from (39.6 ± 1.4) to 53.6 GPa, which seemed to indicate that a spinodal segregation along grain interfaces was finished. A maximum hardness of 40.8 GPa before and 55 GPa after annealing in air at 500 °C was observed for coatings with a concentration of elements of Si  (7–8) at.%, Ti  22 at.% and Zr  70 at.%.

Thermal stability, microstructure and mechanical properties of Ti 1 − xZr xN thin films

Single-phase [NaCl]-structure Ti 1 − x Zr x N thin films (0 < x < 1) have been deposited using cathodic arc plasma deposition. The films were investigated using X-ray diffraction (XRD), transmission electron microscopy, differential scanning calorimetry (DSC), and nanoindentation. Density functional theory calculations on phase stabilities show that the pseudo-binary TiN–ZrN system exhibits a miscibility gap, extending over 0 ≤ x ≤ 0.99 at 1000 °C, with respect to phase transformation from a solid solution into a two-phase mixture of [NaCl]-structure TiN and ZrN components. The films were found to retain their as-deposited single-phase structure during post-deposition annealing at 600 °C (18 h), 700 °C (12 h), 1100 and 1200 °C (2 h), and for as long as 195 h at 600 °C. DSC revealed no heat flow during annealing, similar to TiN, and only the x = 0.53 film exhibited a slight increase in XRD peak broadening after annealing at 1200 °C, consistent with spinodal decomposition. This effective thermal stability of the alloys is explained by the combination of a limited driving force for phase transformation and an insufficient atom diffusivity. In terms of mechanical properties, films with composition deepest within the miscibility gap showed a hardness of ∼ 30 GPa after annealing at 1100–1200 °C; a value only moderately lower than in the as-deposited condition. The principal hardening mechanism for the Ti 1 − x Zr x N films is proposed to be solid-solution hardening through local lattice strain fields originating from difference in atomic radius of Ti and Zr. The material system is thus promising for cutting tool applications.

Crystallography of a new metastable phase in Zr-N alloy.

Selected-area and convergent-beam electron diffraction were used to determine the lattice, point and space groups of a new metastable phase (designated the pi phase) in the Zr-N system. The pi phase has a body-centered tetragonal lattice with a approximately 0.66 nm and a c/a ratio of 0.81. The point-group symmetry of the phase is 4/mmm and the space group is I4/mmm.

Adhesion and hardness of compositionally gradient TiO2/Ti/TiN, ZrO2/Zr/ZrN, and TiO2/Ti/Zr/ZrN coatings

A technique using compositionally gradient interlayers has been applied to TiO2/Ti/TiN, ZrO2/Zr/ZrN, and TiO2/Ti/Zr/ZrN multi-compositional coatings to enhance the adhesion of hard coatings to substrate. The coatings were prepared by dc reactive magnetron sputtering using a combination of a Zr or a Ti metal target and a pure Ar, an Ar-O2 mixture, or an Ar-N2 mixture discharge gas, onto a borosilicate glass substrate. Adhesion of coatings to the substrate was estimated by a scratch method. The hardness of coatings was measured by a nano-indentation method. Without an interface, ZrN coatings showed a very poor adhesion. By using glass/ZrO2/Zr or glass/TiO2/Ti compositionally gradient interface layers, the adhesion strength of ZrN coatings was enhanced to the adhesion strength almost equal to or higher than those of TiO2 or ZrO2 single layer coatings. From the results of internal stress evaluation, it was found that a high internal stress causes a poor adhesion of ZrN coatings. Hardness of coatings with a ZrN overlayer were 20 to 35 GPa and larger than those of coatings with a TiN overlayer. The increase in the hardness by inserting a compositionally gradient interface was observed in ZrO2/Zr/ZrN and TiO2/Ti/Zr/ZrN systems.

メカニカルアロイング法によるＺｒＯ２‐ＺｒＮ固溶体の作成

Mechanical alloying (MA) of ZrO2-8mol%ZrN system is exmained. XRD peaks from the mixed powders in ZrO2-8mol%ZrN consist of m-ZrO2 and ZrN with NaCl strucrure. After MA for 80h of the powders, the peak intensity from m-ZrO2 and ZrN was reduced and new peaks appeared. The new peaks can be indexed to be cubic fluorite structure or pseudofluorite structure. Nitrogen must be in solution during mechanical alloying, and a high-temperature form of ZrO2 is stabilized.

A new face-centered cubic phase in the ZrO 2ZrN system

A face-centered cubic (fcc) phase with quadrupled cell dimension of the rock salt-type ZrN has been found in the ZrO 2ZrN system by the powder X-ray diffraction method and electron microscopy. The fcc phase coexists with Zr 7O 11N 2, ZrN, and ZrO 2 in the ZrO 2ZrN system with ZrN fraction ranging from 30 to 90 mole%. The cell dimension of the fcc phase has been refined to a = 18.334(2) Å in the 70 mole% ZrO 2-30 mole% ZrN compound and a = 18.329(3) Å in the 30 mole% ZrO 2-70 mole% ZrN compound. The fcc phase is supposed to be chemically denoted as ZrN(O), substituting a small amount of nitrogen atoms with oxygen atoms in the ZrN host lattice in an ordered form.

Determination of the Compositions of thin Film Compounds by using the Electron-Probe X-ray Microanalyzer. Analyses of Nitride Thin Films

Several refractory nitrides of transition metals, e. g. Ta2N, TaN, TiN, ZrN etc, have been considered for use in thin film resistors, because of their excellent stability. But, in these binary systems, the relationships between the electrical characteristics and the chemical composition have been not clarified, owing to the lack of the proper means capable to detect exactly the compositions of films. In this report, the convenient method using the electron-probe X-ray microanalyzer is explained in the case of determining the compositions of thin films of both system Ti-N and Zr-N, prepared by evaporation synthesis and or reactive sputtering. The error in this analysis is several per cent or less. Data of the film composition determined by this process have been adopted to feature each resistivity and temperature coefficient of resistivity-composition curves of Zr-N system and Ti-N system, respectively.