Iranian Journal of Materials Science and Engineering

Evaluating Corrosion and Wear Resistance of Ni-Fe(Si-Ti)C Nanocomposite Coating

Fatemehsadat Sayyedan

The aim of this study was to optimize the values of current density and carbide concentration in electrodeposition process of Ni-Fe(Si-Ti)C nanocomposite coating on the AISI 304 stainless steel. The optimal current density in each electrolyte was determined using scanning electron microscope (SEM) images and energy-dispersive spectroscopy (EDS) analysis. Corrosion behavior and wear resistance of the optimized coatings were examined by TOEFL polarization test in 3.5 wt.% NaCl solution and ball-on-disk apparatus, respectively. The values of 30 mA/cm² and 10 mA/cm² were obtained to be the optimal current densities for electrolytes containing 6 g/L and 12-18 g/L double carbide, respectively. Electrochemical measurements declared that the corrosion rate decreased from 0.0829×10^-5 mA/cm² to 0.0208×10^-5mA/cm² with increasing the concentration of carbide in the electrolyte from 6 g/L to 18 g/L. Moreover, the friction coefficient of the substrate was found to be significantly greater than that of the coated samples.

Low-Cost Fabrication and Surface Engineering of Insulating KBr Crystals: An AFM Study on the Effects of Thermal Annealing

Mohammad Mohammadnezhad

Potassium bromide (KBr) crystal structure attracts attention due to its various applications in electronic and optical devices as well as its potential in inducing local electrostatic fields. Fabricating this crystal via the conventional Czochralski method or more novel epitaxial methods is very costly. Here, with the focus on surface properties, a simple low-cost technique is employed based on the usage of KBr powder, pellet making, and pressure appliance for the fabrication of pellet crystals. These pellets have been annealed at various temperatures and studied via atomic force microscopy; morphologically and structurally. Our results demonstrate that increasing the temperature before the KBr melting point significantly reduces different roughness parameters, the height of the atomic steps, and the distance between them. At 500 °C, the atomic steps are more regular than at other temperatures, surface flatness and crystallinity are enhanced, approaching the quality of commercial single crystals. These modifications improve the quality of the crystals significantly, for various applications. Force spectroscopic measurements across atomic step edges of KBr, demonstrates higher forces with respect to flat regions. These engineered steps could serve as nanoscale templates for directing the self-assembly of molecules or for creating spatially varying electrostatic potentials in 2D material heterostructures.

Synthesis of Nanocrystalline SiC via Sol–Gel Method: Effect of Low-Temperature Heat Treatment on Phase Formation and Nanostructures

hamid Haratizadeh

Silicon carbide (SiC) is one of the most important silicon-based compounds, owing to its favorable physical, chemical, and biological properties, and is widely employed in various fields such as electronics, chemical industries, and quantum computing. Several methods have been reported for synthesizing SiC nanoparticles, including chemical vapor deposition (CVD), hydrothermal synthesis, carbothermal reduction, and sol–gel processing. Among these, the sol–gel method has attracted significant attention due to its high yield, process controllability, biocompatibility, accessibility of precursors, and ability to produce nanoparticles. In this study, SiC nanosized powders were synthesized through the sol–gel route combined with carbothermal reduction, using tetraethyl orthosilicate (C₂H₅)₄SiO₄) and sucrose (C₁₁H₂₂O₁₁) as the silicon and carbon sources, respectively. The silica/sucrose composite was subjected to carbothermal reduction under an argon atmosphere at a pressure of 10 mTorr in a vacuum furnace at 1350°C for 3 h. The structural properties of the synthesized SiC nanopowders were analyzed using X-ray diffraction (XRD), while their optical characteristics were investigated through FTIR, diffuse reflectance spectroscopy (DRS), and photoluminescence (PL). This work demonstrates a greener, lower-temperature route to phase-controlled SiC nanoparticles with optically active vacancy centers.

Effect of Ti and Nb Addition on Hot Deformation and Dynamic Recrystallization Modeling of Boron-Bearing Low-Carbon Steel: A Comparative Study Using Hot Compression Flow Curves

Ehsan Mohammad Sharifi

The hot deformation behavior modeling and microstructural evolution of low-carbon boron steels with Ti (FBT) and Nb (FBN) additions were investigated and compared with a baseline boron-treated steel (FB) in our previous work. Hot compression tests were conducted at temperatures of 850–1150 °C and strain rates of 0.01–10 s⁻¹. Flow curve analysis revealed that both Ti and Nb increased flow stress and delayed the onset of dynamic recrystallization (DRX), with the effect more pronounced in FBN. Constitutive analysis based on the Arrhenius model showed that the activation energy of deformation increased from 293.37 kJ/mol in FB to 314.15 kJ/mol in FBT and 353.04 kJ/mol in FBN, highlighting the strong pinning effect of precipitates. Critical stresses and strains (σ_c, σ_p, ε_c, ε_p) followed the order FB < FBT < FBN, indicating higher resistance to recrystallization in the microalloyed steels. DRX kinetics, modeled using the Avrami equation, yielded exponents of 2.09, 1.65, and 1.88 for FB, FBT, and FBN, respectively, confirming that Ti suppressed nucleation more strongly than Nb. Microstructural analysis demonstrated that Ti inhibited BN formation and promoted TiN/Ti(C,N), whereas Nb retained BN and generated Nb(C,N), mainly at MnS interfaces. Grain size distribution analysis revealed that both FBT and FBN exhibited significantly finer and more homogeneous grains compared to FB, with average grain sizes at 1150 °C (0.1 s⁻¹) of 17.3 μm in FBT and 17.0 μm in FBN, nearly half that of FB (33.6 μm). Overall, Ti and Nb additions distinctly altered the high-temperature deformation and recrystallization mechanisms of boron steels, enhancing grain refinement while suppressing DRX, thereby extending the findings of our previous study on FB.

Synthesis, and Morphological Characterization of TiO2 Based Nanocomposite for Antimicrobial Applications

Sabah Hasan jumaah

In the current study, titanium dioxide (TiO₂) nanoparticles were synthesized and subsequently combined with chitosan (CS) and silver (Ag) to augment their antimicrobial effectiveness. The synthesized TiO₂, TiO₂-CS, and TiO₂-CS-Ag nanocomposites were subjected to various characterization analyses in order to thoroughly assess their structural, morphological, and compositional attributes. XRD analysis substantiated the phase transition from anatase to rutile consequent to incorporation of chitosan and silver, accompanied by a diminution in nanoparticle dimensions. FTIR spectra corroborated the existence of functional groups linked to chitosan and silver, while FESEM illustrated morphological modifications, notably the emergence of polygonal nanostructures within the TiO₂-CS-Ag composite. The antibacterial efficacy of the synthesized nanocomposites was evaluated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Although pure TiO₂ demonstrated minimal antibacterial properties, the TiO₂-CS and TiO₂-CS-Ag composites exhibited substantial inhibition zones, with the most pronounced efficacy recorded for the TiO₂-CS-Ag composite attributable to the synergistic interaction between chitosan and silver nanoparticles. BET analysis revealed that the augmented antimicrobial activity was associated with the increased surface area of the TiO₂-CS-Ag nanocomposite.

Development and Performance Analysis of Polymer Composite Gears: A Comprehensive Review of Material Innovations and Key Parameters

Pravin Jadhav

The development of polymer composite materials for gear applications has gained significant attention due to the growing need for lightweight, corrosion-resistant, and high-performance alternatives to traditional metallic gears. This literature review consolidates key findings and insights from numerous studies, highlighting the advancements, challenges, and potential of polymer composites in gear applications. High-performance polymers such as poly ether ether ketone (PEEK), poly ether ketone(PEK), poly ether ketone ketone (PEKK) and poly aryl ether ketone (PAEK) especially when reinforced with multi-walled carbon nanotubes (MWCNTs) and functionalized MWCNTs, exhibit superior mechanical, thermal, and tribological properties. These enhancements include improved strength-to-weight ratios, wear resistance and load transfer capabilities. The review also examines the influence of various parameters on gear performance. The necessity for standardized testing methods and benchmarks to evaluate wear, surface temperature, roughness and environmental exposure is emphasized to ensure reliability and consistency. This study focuses on study of development of high performance polymer composite materials for gear applications and performance analysis of these gears.

Synthesis of Fe3O4/ ZnO/CuO Nanocomposite and their Sono-photocatalyst Property for Removal of Methylene Blue from Wastewater

Mohammadtaghi Hamedani

Fe₃O₄/ZnO/CuO nanocomposites with various molar ratios of CuO were successfully synthesized. Sol-gel method was used to syntehesize nanocomposite materials at a low temperature. A set of experiments, including X-ray diffraction (XRD), Dynamic Light Scattering (DLS), scanning electron microscopy (SEM), and UV-Vis spectroscopy, was used to confirm the successful synthesis of Fe₃O₄/ZnO/CuO nanocomposites in crystalline form.
The photocatalytic activity of the samples was investigated via the degradation of methylene blue (MB) dye
from synthetic wastewater under three distinct conditions: visible light, ultraviolet light, and a combination of visible light with ultrasonic treatment. Fe₃O₄/ZnO/CuO nanocomposite with a molar ratio of 1:1:0.5 showed the highest photocatalytic activity when irradiated with either visible or ultraviolet light. Furthermore, when visible light was combined with ultrasonic treatment, complete (100%) removal of methylene blue was achieved within 120 minutes. The results demonstrate that these nanocomposites are efficient catalysts for wastewater treatment through the removal of organic pollutants Fe₃O₄/ZnO/CuO nanocomposites with various molar ratios of CuO were successfully synthesized. Sol-gel method was used to syntehesize nanocomposite materials at a low temperature. A set of experiments, including X-ray diffraction (XRD), Dynamic Light Scattering (DLS), scanning electron microscopy (SEM), and UV-Vis spectroscopy, was used to confirm the successful synthesis of Fe₃O₄/ZnO/CuO nanocomposites in crystalline form.
The photocatalytic activity of the samples was investigated via the degradation of methylene blue (MB) dye
from synthetic wastewater under three distinct conditions: visible light, ultraviolet light, and a combination of visible light with ultrasonic treatment. Fe₃O₄/ZnO/CuO nanocomposite with a molar ratio of 1:1:0.5 showed the highest photocatalytic activity when irradiated with either visible or ultraviolet light. Furthermore, when visible light was combined with ultrasonic treatment, complete (100%) removal of methylene blue was achieved within 120 minutes. The results demonstrate that these nanocomposites are efficient catalysts for wastewater treatment through the removal of organic pollutants

Synergistic Impact of Mechanical Alloying Duration and Spark Plasma Sintering Temperature on Microstructure and Properties of CoCrFeNiMn High-Entropy Alloys

ALireza hajialimohammadi

This study successfully synthesized the CoCrFeNiMn high-entropy alloy (HEA) using a two-step powder metallurgy approach: mechanical alloying (MA) followed by spark plasma sintering (SPS). The research investigated the effects of processing parameters, specifically MA duration and SPS temperature, on the alloy's microstructure, densification, and mechanical properties. X-ray diffraction (XRD) analysis after 25 hours of MA (ball-to-powder ratio of 10:1) confirmed the formation of a single-phase face-centered cubic (FCC) solid solution. Scanning electron microscopy (SEM) images revealed significant powder particle refinement, with average particle sizes decreasing from initial micrometers to sub-micrometer ranges. The alloyed powders were then consolidated via SPS at temperatures of 800°C, 900°C, and 1000°C (40 MPa, 10 min in argon). Detailed analysis of the sintered samples showed relative densities ranging from 95.78% to 96.77%, with the highest density (96.77%) achieved at 1000°C. Vickers microhardness measurements exhibited a peak hardness of 446 HV at 900°C, with a decrease to 420 HV at 1000°C, primarily due to grain growth. This research establishes the combined MA and SPS approach as effective for producing high-density, high-hardness HEAs, underscoring the critical role of processing parameters in tailoring their final properties.

Effect of ZrO2 Doping on the Properties of TiO2 Thin Films as an Ethanol Vapor Gas Sensor

farqad saeed

In this study, RF magnetron sputtering was employed to create titanium dioxide (TiO₂) thin films doped with zirconium oxide (ZrO₂) (TZO) onto quartz and silicon substrates at 100^oC for the purpose of evaluating the effect of ZrO₂ doping on the microstructural, electrical, optical and gas sensing properties of the TiO₂ films. Different doping concentrations (0.0, 2.0 and 4.0 wt.%) were used to compare performances of the films with a thickness ranging between 147 nm to 178 nm. Structural and surface morphology characterizations of the prepared films were carried out by X-ray diffraction (XRD) and atomic force microscopy (AFM) techniques. The surface morphology of the prepared TZO films showed a gradual reduction in the grain size while the doping concentration increased. The optical characteristics of the films also exhibited an increasing trend in the optical band gap with the rising ZrO₂ concentration. TiO₂ films showed an n-type conductivity as confirmed by Hall's measurement. The results of the gas sensing experiments revealed that the sensitivity of the TZO films for the detection of ethanol vapor increased with an increase in the concentration of ZrO₂ dopant. Therefore, TZO film with 4.0 wt.% of ZrO₂ could be used as an effective sensor for detecting ethanol vapor.

The Potential of Lithium Metasilicate Glass in Bioinspired Zirconia Infiltration Technology( An Experimental Study)

Sara Banijamali

This study investigates the crystallization behavior and microstructural evolution of lithium metasilicate (Li₂SiO₃) glass subjected to thermal histories designed to emulate the cooling stage of zirconia infiltration in dental restorations. Three thermal routes were examined: (i) a non-isothermal schedule to identify crystallization and melting events, (ii) a controlled isothermal schedule to obtain homogeneous glass–ceramic microstructures, and (iii) a quasi-isothermal natural cooling schedule from the molten state to mimic the thermal profile during infiltration without reproducing actual capillary flow or interfacial reactions. Phase identification and quantitative analysis were performed by X-ray diffraction with Rietveld refinement, and the resulting microstructures were characterized by field-emission scanning electron microscopy. Under isothermal conditions, lithium metasilicate (Li₂SiO₃), lithium disilicate (Li₂Si₂O₅), γ-spodumene (γ-LiAlSi₂O₆), β-lithium phosphate (β-Li₃PO₄), and quartz crystallized with an overall crystallized fraction of approximately 62±0.9 wt.%. In contrast, quasi-isothermal cooling produced a crystallized fraction exceeding 87±1 wt.%, dominated by lithium metasilicate (Li₂SiO₃), β-lithium phosphate, quartz, and cristobalite, with neither lithium disilicate (Li₂Si₂O₅) nor γ-spodumene (γ-LiAlSi₂O₆) detected under the present XRD conditions. The quasi-isothermal route also generated significantly coarser morphologies: average crystal length and thickness were roughly 10-fold and 31-fold larger, respectively, than those in the isothermally treated sample. These results demonstrate that the thermal path strongly governs phase assemblage, crystallized volume fraction, and crystal morphology in lithium silicate glass–ceramics. By clarifying how controlled versus quasi-isothermal cooling histories shape the final microstructure, this work provides a structural basis for optimizing lithium silicate glasses used in zirconia infiltration technology and for guiding future studies on the mechanical and functional performance of these materials.

Microstructural and Mechanical Comparison of Metakaolin Geopolymer vs Cement Composites with Quartz and Polypropylene

Azam Moosavi

This study evaluates the mechanical performance of a metakaolin-based geopolymer matrix reinforced with quartz particles and polypropylene fibers, in comparison with a Portland cement-based matrix. Compressive strength, shrinkage, and flexural strength tests reveal that incorporating 20 wt% quartz particles significantly improves the mechanical properties of both matrices. The combined use of quartz particles and fibers contributes to shrinkage crack control and dimensional stability through synergistic effects involving particle–matrix interactions, fiber–matrix bonding, fiber surface characteristics, and toughening mechanisms. In the geopolymer matrix, the reinforcement effect of quartz particles is more pronounced due to the formation of a strong and chemically active interfacial bond. Compared with Portland cement composites, quartz particles increase the flexural and compressive strengths of geopolymer composites by approximately 2.5 and 1.3 times, respectively. The addition of 0.5 wt% polypropylene fibers slightly reduces strength but enhances energy absorption and alters the failure mode from brittle to more ductile. Overall, the results highlight the role of fibers in suppressing or arresting brittle fracture in cementitious and geopolymeric composites.