نشریه علم و مهندسی سرامیک
سال دوازدهم شماره 2 (پیاپی 45، تابستان 1402)

The structures used in the military and aerospace industries require properties such as melting points, thermal shock resistance, and high erosion/oxidation resistance, and ZrB2-ZrC-SiC composites are the best choice due to their physical, mechanical, and oxidation properties. They are a suitable option for the protection of re-entry and supersonic structures.The strength of this research is the use of SiC in nano dimensions, the amount of its addition on the physical, mechanical properties and resistance to oxidation of ZrB2-ZrC-SiC nanocomposite has been investigated. For this purpose, SiC nanoparticles were added as reinforcement with amounts of 0, 5, 10, 15 and 20 wt% to the ZrB2 ‒10 wt % ZrC matrix and were sintered by PLS method. Also, B4C was used as a sintering aid in the amount of 3% by weight. The sintering process was carried out at a temperature of 2100°C for 1 hour with an approximate heating rate of 10°C/min. The results indicate that by adding 5% by weight of SiC in nano dimensions, the relative density reaches its highest value (98.5%). Also, by adding the same amount of nano SiC, the hardness of the samples reaches 13.8 Gpa. By examining the oxidation rate of the samples, it was proved that the sample containing 5% by weight of Nano SiC has the highest resistance to oxidation. The mass erosion rate in the sample containing 5% by weight of nano SiC is equal to 0.18 mg/s. However, increasing the amount of SiC nano has decreased the toughness so that the highest toughness is related to the sample without SiC.

Tantalum nitride (TaN) is widely used in mechanical and microelectronic industries due to its unique properties such as high hardness and high we are resistance as well as stable electrical resistance. Considering the its importance in this paper, taking into account the reliable references, a comprehensive review of research developments in the field of layer identification methods, characterization methods, properties and applications of TaN thin films has been carried out. For this purpose, firstly, the production and deposition of these thin layers have been studied by methods such as physical deposition (PVD), DC and RF magnetron sputtering. In addition, the structural, microscopic, electrical, optical, mechanical and tribological properties of thin layers of tantalum nitride have been comprehensively discussed. For this purpose, by analyzing X-ray diffraction patterns, atomic force microscope, scanning electron microscope, calculating the we arrate of the layers, the effect of changing the nitrogen content of the substrate bias voltage on the residual stress of the layers, changing the hardness and elastic modulus of the tantalum nitride layers with the current ratio Nitrogen, refractive index and extinction coefficient of layers, optical transmission spectrum of layers, electric resistance of layer in different nitrogen flow, surface resistance normalized according to temperature and changes of surface resistance of layers kept at different temperatures have been investigated in detail. The reviewed results show that the produced thin layers have a high potential for application in various fields, especially in harsh environments with high temperature and pressure. This review Article can be a suitable and comprehensive reference for the research that will be done in the field of TaN thin films and related technologies.

In this research, the cement base composite reinforced with sand was produced by water and poly-polyurethane. In order to investigate the destructive effect of corrosive environments, the samples produced in different amounts of water, polyurethane polymer and sand were immersed in 10% caustic soda and 10% sulfuric acid electrolytes for 70 days. Next, in order to characterize the samples after immersion, the samples were examined by mechanical and physical evaluations including densitometry test and pressure test. The results of the densitometry test showed that the density of the samples immersed in sulfuric acid is about 10-20% lower than the samples immersed in caustic soda. The results of the pressure test showed that the strength of water produced samples is higher than the samples produced with polyurethane polymer. On the other hand, it was found that if sand is used and composite concrete samples are produced, the strength of the samples increases by 75%. The results of the compressive strength test showed that the strength of samples immersed in sulfuric acid electrolyte is generally 20-30% weaker than the strength of samples immersed in caustic soda electrolyte.

In this paper, nickel oxide nanoparticles were synthesized and studied for the first time in the presence and absence of Deep Eutectic Solvents (DES) using a simple and economical solvothermal method. The purpose of this study is to investigate the effect of DES on the structure, morphology and sonophotocatalytic activity of synthesized nanoparticles. The synthesized nanostructures were characterized by XRD, BET and SEM to evaluate their crystallinity, morphology, size and composition. The results show that the nickel oxide nanoparticles synthesized with DES have higher porosity and specific surface area than nickel oxide nanoparticles synthesized without DES. This caused better sonophotocatalytic performance for the degradation of organic pollutant. A comparison of the sonophotocatalytic activity of nanoparticles for the degradation of the organic pollutant methylene blue was studied to compare the effect of DES. The sonophotocatalyst is stimulated by ultraviolet light and ultrasonic radiation to form more active radicals during the sonophotocatalytic performance. According to the data from the sonophotocatalytic degradation study, the removal efficiency of the nickel oxide nanoparticles synthesized with DES was 94% at a constant rate of 1.706 (min-1), while the removal efficiency of the nickel oxide nanoparticles synthesized without DES was 85% at a constant rate of 1.475 (min-1).

In this research, NiO/Fe3O4 magnetic composite supported onto clinoptilolite zeolite (NiO/Fe3O4/CP) was synthesized and characterized by different techniques such as X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectrometer (EDS) and vibrating-sample magnetometer (VSM). The feasibility of employing NiO/Fe3O4/CP as a catalyst in the catalytic ozonation of dairy effluent was investigated. The effect of four effective operational parameters (catalyst dosage, pH, ozone dosage and time) was investigated. Based on the obtained results, increasing the catalyst and ozone dosage play a vital role in increasing the COD removal efficiency of effluent. The effect of solution pH also showed that the COD removal efficiency of dairy effluent in alkaline solutions is higher than acidic solutions, which can be attributed to the presence of hydroxyl radicals in alkaline environments and their high oxidizing power. The kinetic studies demonstrated that the presence of the NiO/Fe3O4/CP ternary composite in the catalytic ozonation process leads to a doubling of the reaction rate compared to the ozonation process.

This research investigates the effects of ball milling on microstructure, mechanical properties and tribological behavior of Al2O3/30wt%Ni cermet. For this purpose, the primary powders of alumina and pure nickel were either mixed using a turbula mixer or milled using a planetary ball mill. The mixed or milled powders were consolidated by spark plasma sintering at 1250 °C and 30 MPa, and the properties of the produced composites were investigated. The results showed that the milling process caused the formation of a layer of nickel particles on the surface of the alumina particles, which improved the sintering process. As a result of the milling, the distribution of nickel particles in the alumina matrix and the bonding quality between them improved and the microstructural porosity was also reduced. The hardness of the mixed or milled composites was measured as 576 and 858 Vickers, respectively. In addition, the friction conditions in the milled composite became more stable and its friction coefficient decreased compared to the mixed sample. The wear rate for mixed and milled composites was calculated to be 0.00414 and 0.00081 mm3/m, respectively. The results of the wear surface analysis showed that the formation of the tribo-layer plays an essential role in the wear behavior of alumina-nickel cermets.

Lithium-oxygen (Li-O2) battery is considered the system with the highest theoretical specific energy density among all other energy storage devices. Therefore, it can be a suitable response to the increasing demand for the energy. Due to the fact that the cathode is one the of key components, this research represents a practical investigation on the impact of utilizing molybdenum disulfide as an electrocatalyst in the cathode on specific capacitance of Li-O2 battery.To do so, at the first step, graphite/MoS2 composite was synthesized via one-pot hydrothermal approach. Then, different analysis of X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectrometer (FTIR), N2 adsorption-desorption, and scanning electron microscopy (SEM) were applied to study phase characteristics, covalent bonds, porous structure, and to observe the surface morphology of the synthesized composite. Finally, it was employed as the cathode of the Li-O2 battery and could exhibit the specific capacitance of 912 mA h g-1, which illustrates the significant effect of using MoS2 on increasing the specific capacitance by about 17.5 times than the sample without it.