A Si3N4–ZrN wear-resistant self-healing composite material was developed. Si3N4–ZrN composite ultrafine powders were synthesized at a temperature of 1200 °С via solid-state reactions without milling ...and densified by spark plasma sintering at 1650 °C to a relative density of 97 ± 0.5%. Balls 13.494 mm in diameter for ball bearings manufactured by spark plasma sintering had a fine-grained structure with a grain size of 200–500 nm, Vickers hardness of 22.5 ± 1.8 GPa, and indentation fracture toughness of 6.2 ± 0.4 MPa. The tribological properties of the composite were investigated under static and dynamic loading. The self-healing capability of the Si3N4–ZrN composite was evaluated in the temperature range 500–550 °С. High-temperature three-point bending tests of notched specimens showed a bending strength of 383 ± 21 MPa at room temperature and 413 ± 30 MPa at 500 °С, which confirmed the self-healing of the composite.
Dense silicon carbide (SiC) composites with 0–30 vol% (ZrN-TiB2) were fabricated by using liquid phase spark plasma sintering at a relatively lower sintering temperature (1800 °C) and shorter holding ...time (5 min). The effects of co-addition of ZrN and TiB2 on densification, mechanical properties, and electrical conductivity of SiC ceramics were investigated. The reinforcement significantly enhanced density of sintered composites, while the phase analysis and microstructure confirm the suppression of β→α phase transformation in the SiC matrix. The fracture toughness ranged from 4.1 to 4.6 MPa·m0.5, hardness from 19.5 to 20.3 GPa, and electrical conductivity from 4.85 ×101 to 1.25 ×103 (Ω·cm)−1. Incorporating conductive reinforcements and nitrogen additives enhanced electrical conductivity. Successful wire-EDM cutting of SiC-ZrN-TiB2 composites demonstrate the feasible alternative to conventional machining of non-oxide ceramics with a maximum material removal rate of 8.54 mm2/min.
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Most microwave absorbers lose their function under harsh working conditions, such as a high temperature and an oxidative environment. Here, we developed a heterogeneous ZrN
B
/SiC nanohybrid via ...combined catalytic chemical vapor deposition (CCVD) and chemical vapor infiltration (CVI) processes using ZrB
as the starting material. The composition and structure of the ZrN
B
/SiC nanohybrid were controlled by tuning the CCVD and CVI parameters, such as reaction temperature, time, and reactant concentration. The optimal heterogeneous ZrN
B
/SiC nanohybrids were obtained initially by preparing ZrB
@C via the CCVD process at 650 °C for 30 min and the subsequent CVI at 1500 °C, where the ZrB
@C reacted with Si under N
. The ZrN
B
/SiC nanohybrid exhibited enhanced microwave absorption ability with a minimum reflection loss value of approximately -50.8 dB at 7.7 GHz, a thickness of ∼3.05 mm, and antioxidation features at a high temperature of 600 °C. The heterogeneous ZrN
B
/SiC nanohybrid possessed reasonable conductivity, leading to dielectric loss, whereas SiC nanofibers formed a three-dimensional network that brought higher dipole moments, whereas a small part of the ZrN
B
/SiC nanohybrid structure generated an effective interface for higher attenuation of microwaves. Therefore, these material features synergistically resulted in a well-defined Debye relaxation, Maxwell-Wagner relaxation, dipole polarization, and the quarter-wavelength cancellation, which accounted for the enhanced microwave absorption.
•ZrN was prepared and introduced into low-carbon MgO–C refractory for the first time.•ZrN significantly affected the microstructure and properties of refractories.•Pore structure and distribution of ...refractory were studied based on industrial CT.•The mechanism of ZrN in the low-carbon MgO–C refractories was clarified.
To solve the problem of the high cost of ZrN as a raw material, nanoscale c-ZrN powders were synthesized by molten-salt nitridation at 1100 °C and introduced into low-carbon MgO–C refractories. The effect of ZrN content on the microstructure and properties of the refractories was investigated. The results indicated that the addition of ZrN significantly promoted the reaction, and there was a certain degree of chemical bonding between ZrN and the formed ceramic phases. As the content of ZrN increased, the formation of more ceramic phases was promoted, especially the formation of a larger amount and larger size of flake-like Mg2SiO4, which greatly improved the mechanical properties of the MgO–C refractories. Finally, the mechanism of ZrN in the MgO–C refractories was clarified.
SiBCN/ZrB2–ZrN ceramics were prepared by mechanical alloying followed by reactive hot pressing. The preparation, microstructures, mechanical properties and oxidation resistance were evaluated. Air ...exposure immediate before cooling leads to the formation of ZrB2, ZrN, ZrO2 and SiC. Reactive hot pressing provides composite materials with similar structures consisting of ZrB2, ZrN, SiC and a BNC phase. The mechanical properties of the as-obtained ceramics depend on the volume fractions of the individual phases. High volume ratios of SiC/ZrB2–ZrN in ceramics provide better oxidation resistance but reduce overall mechanical properties. The oxide surface of all investigated ceramics composes of SiO2, ZrSiO4 and ZrO2 with a layered structure. The oxidation behavior of SiBCN/ZrB2–ZrN ceramics in structure changes is similar, but the oxidation kinetics is different. The oxide layer can be divided into three layers: (1) outermost layer consists of SiO2 glass with uniform distribution of ZrSiO4, (2) porous ZrO2–SiO2 layer, (3) unreacted matrix.
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•ZrN coatings were grown on the polished steel substrates at the different N flow rate.•Nanocrystalline microstructure of the surface are explored by AFM analysis.•The main texture of ...ZrN phase changes from (111) to (200) with the increase of N.•E and H were analyzed by nanoindentation.
ZrN coatings with the thickness of about 3 μm were deposited on hardened steel substrates by reactive magnetron sputtering at the constant magnetron power of 700 W and at the substrate bias voltage about − 10 V with different nitrogen flow rate from 3 to 6 sccm. The surface investigations were carried out using scanning electron microscopy, atomic-force microscopy, nanoindentation and glancing-angle X-ray diffraction. It was found that the texture of ZrN phase, the mechanical properties and the size of grains in the polycrystalline ZrN coatings can be controlled using different nitrogen flows.
Maritime transportation represents one of the biggest industries worldwide. The functionality improvement of critical ship parts such as sea chest gratings could mean substantial impacts in fuel ...consumption reduction, larger lifetime span or reduction of non-indigenous sea species transportation. Since 2008, the ban imposed by the international maritime organization over polluting products, especially tributyltin, created the need to explore new sustainable and environmentally friendly alternatives. Multifunctional coatings have the potential to overcome this situation, creating highly tuneable materials able to combine properties according to the naval industry's needs. Zirconium nitride is known for its reliable mechanical and anti-corrosion properties, critical in a multifunctional coating used in the sea. In the present study, this material was obtained through high-power impulse magnetron sputtering technology in a reactive atmosphere (R-HiPIMS). SEM, EDS, AFM and XRD were used to assess the coatings. Also, the films’ mechanical properties and adhesion were assessed via nanoindentation and progressive load scratch tests, respectively. The pin-on-disk test was used to assess the coatings' tribological properties under dry and wet (3.5% wt. NaCl solution) conditions. The results demonstrate that the increase in hardness was directly influenced by the changes in the structure promoted by the nitrogen rise, from 16 GPa to 25 GPa, with a nitrogen increase in film composition from 47% to 54%. Besides, the tribological tests revealed the key role of an oxygen-rich tribolayer and surface roughness features (skewness and kurtosis) in keeping the film’s integrity. The ZrxNy films obtained by HiPIMS improved the mechanical and tribological properties compared to ZrN obtained by DCMS, opening new possibilities to be explored as a solution inside a multifunctional coating system.
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•ZrxNy coatings system was deposited by Reactive High Impulse Magnetron Sputtering.•Film structures turned from ZrN to Zr3N4 as the nitrogen increased.•Hardness was influenced by the coating’s microstructure and nitrogen content.•Tribolayer was formed during the wear process despite the condition (wet or dry).•The tribolayer attaching was influenced by the roughness features (Ssk < 0).
The development of innovative ceramic tiles looks for materials with improved mechanical and tribological properties as well as a higher corrosion resistance (high relative humidity, daily watering, ...household chemical cleaners). In addition, a greater durability leads to lower environmental impact. Along with their improved functionality and recyclability, ceramic tiles should also provide aesthetic properties. Ceramic tiles can be treated to modify the physico-chemical properties of the surface by metal coatings or metallic compounds, also providing an attractive metallic sheen appearance. In the present paper, titanium nitride (TiN) and zirconium nitride (ZrN) coatings were deposited on glazed porcelain stoneware by an industrial PVD multicathode arc deposition system under a reactive nitrogen atmosphere. After the process, the tiles showed a gold-like colour, a smooth surface and a coating thickness between 0.7 and 1.6 μm. The coating composition, scratch resistance and corrosion behaviour have been evaluated. It can be concluded that both coatings are suitable for use in domestic environments due to their stability and resistance to aggressive conditions. Few references have been found regarding these coatings on ceramic tiles for domestic and industrial applications, but it has been proved that they bring added value to traditional ceramics, giving new functional properties of ceramics both decorative and highly corrosion and mechanical resistance.
