Iranian Journal of Materials Science and Engineering

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In this study, CrN/ZrN multilayer nanostructured coatings with different bilayers (10, 20, and 30) were created by the cathodic arc evaporation. The electrochemical behavior of samples was evaluated by polarization and impedance spectroscopy tests in the Ringer medium and the pin on disk test was used to investigate the tribological behavior of the samples. The results of measurements showed that the electrochemical and tribological behavior of the coatings depends on the number of bilayers and by rising the number of bilayers, the coating shows higher corrosion resistance and better tribological performance. Field emission scanning electron microscopy (FE-SEM) images of the specimens after exposure to the corrosion medium showed that the number of surface cavities were formed by the coating that had the highest number of bilayers comparing with other coatings were quite fewer in number and smaller in diameter. The results of the pin on disk test showed that by increasing the number of bilayers from 10 to 30, the coefficient of friction and wear rate decreased and the 30L coating ‌showed better wear resistance.

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Biocompatible ceramics, commonly known as “bioceramics”, are an extremely versatile class of materials with a wide range of applications in modern medicine. Given the inorganic nature and physico-mechanical properties of most bioceramics, which are relatively close to the mineral phase of bone, orthopedics and dentistry are the preferred areas of usage for such biomaterials. Another clinical field where bioceramics play an important role is oculo-orbital surgery, a highly cross- and interdisciplinary medical specialty addressing to the management of injured eye orbit, with particular focus on the repair of orbital bone fractures and/or the placement of orbital implants following removal of a diseased eye. In the latter case, orbital implants are not intended for bone repair but, being placed inside the ocular cavity, have to be biointegrated in soft ocular tissues. This article reviews the state of the art of currently-used bioceramics in orbital surgery, highlighting the current limitations and the promises for the future in this field.

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This study investigates the synthesis of Al/MoS₂ nanocomposite coating by the electro spark deposition (ESD) method for its lubricating properties. ESD method was selected because it is a very easy, rapid, and cost-saving method and the resulting coating has a strong bonding with the substrate. As a substrate, a Ti-6Al-4V alloy sheet containing 6.12 % Al, 4.06 % V, 0.19% Fe, and 0.05 % Ni was used. For coating, an aluminum-molybdenum disulfide composite electrode in the form of a cylindrical rod was employed. Three frequencies of 5, 8, and 11 kHz, three current limits of 15, 25, and 35 amps, and three duty cycles of 50, 60, and 70% were used in the coating operation. AFM analysis was used to study the topography, morphology, and calculate roughness. The samples were then subjected to hardness tests. To determine the wear resistance of the samples, pin on disk tests were performed. XRD analysis was performed to identify the phases on the surface of the coated samples. SEM was used to examine the microstructure of the coating before and after wear testing, in order to determine the wear mechanism. The results indicated that the Al/MoS2 nanocomposite coating was synthesized on the substrate surface. The hardness of the reference sample is 353 Vickers, and that of the coated samples is about 200 Vickers. For the reference sample, the roughness was measured at 15.7 nm, and for the coated sample at 268.1 nm. As spark energy increased, the coefficient of friction increased by approximately 0.09. As spark energy increased, the wear rate increased by 27%. A significant increase in the Lancaster coefficient occurred around 5 joules of energy. According to the wear rate results, the sample with the lowest thickness wears 4% less than the sample with the highest thickness. The wear rate of sample 351170 is 78% lower than that of sample 150550.

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The present study used a hydrothermal technique to synthesize undoped and Mn2+ doped CdS/Zn3(PO4)2 semiconducting nanocomposite materials. Powder X-ray diffraction, scanning electron microscopy, UV-Vis diffuse reflectance spectrometer, Fourier transform-Infrared Spectroscopy-FT-IR, and photoluminescence techniques were employed to study structural, optical, and luminescence properties of produced nanocomposites. The hexagonal structure of CdS and the monoclinic structure of Zn3(PO4)2 are both reflected in the powder X-ray diffraction spectra. When Mn2+ ions are present in the host lattice, a lattice distortion occurs, causing a phase change from the phase of γ-Zn3(PO4)2 to the β-phase of Zn3(PO4)2, without affecting the hexagonal phase of CdS. The average crystallite size of produced nanocomposites was 22-25 nm, and also calculated the lattice strain and dislocation density to better understand internal deformation of the samples. The FT-IR spectra were used to investigate the molecular vibrations and functional groups in the samples. The surface morphology of the nanocomposites is hexagonal spheres on rectangular shaped nano-flakes, and the interatomic distance between the hexagonal spheres is decreased as the doping concentration increases, forming a rod-like structure on the flakes. EDAX results confirm the presence of various relevant elements in the prepared samples. The quantum confinement of produced samples reduces as the Mn2+ doping concentration in the host lattice increases. The photoluminescence results demonstrate shallow trapped states due to the transition: d-d (4T1 → 6A1) of the tetrahedrally coordinated Mn2+ states and the impact of Mn2+ ions exhibiting several peaks in the UV-Visible region (365-634 nm) generating RGB (Red, Green, Blue) luminescence. Color coordinates and CCT values were calculated using the CIE diagram, and color correlated temperatures in the range of 2513–7307 K were discovered, which might be used in solid state lighting applications.

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In the present research work physical, mechanical and tribological behavior of Aluminum (Al) alloy LM13 reinforced with Nano-sized Titanium Dioxide (TiO₂) particulates were fabricated, mechanical and tribological properties were investigated. The amount of nano TiO₂ particulates in the composite was added from 0.5% to 2% in 0.5 weight percent (wt %) increments. The Al-LM13-TiO₂ Metal Matrix Composites (MMCs) were prepared through the liquid metallurgical method by following the stir casting process. The different types of Al LM13-TiO₂ specimens were prepared for conduction of Physical, Mechanical, and Tribological characteristics by ASTM standards. Microstructural images, hardness, tensile, and wear test results were used to evaluate the effect of TiO₂ addition to Al LM13. Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS), and X-Ray Diffractometer (XRD) were used to examine the microstructure and distribution of particulates in the matrix alloy. In the Al LM13 matrix, microstructure analysis indicates a consistent distribution of reinforced nanoparticles. The attributes of the MMCs, including density, hardness, tensile strength, and wear resistance, were improved by adding up to 1 wt% TiO₂. Fractured surfaces of tensile test specimens were studied using SEM pictures.  The standard pin-on-disc tribometer device was used to conduct the wear experiments; the tribological characteristics of unreinforced matrix and TiO₂ reinforced composites were investigated. The composites’ wear resistance was increased by adding up to 1 wt% of TiO₂.  The wear height loss of Al LM13-TiO₂ composite increased when the sliding distance and applied load were increased. Overall, the Al LM13 with one wt% of TiO₂ MMCs showed excellent Physical, Mechanical and Tribological characteristics among all the percentages considered in the present study.

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Materials that are applied to combat vehicles require an innovation as the development of the military world advances. The material innovation in this research is a lightweight hybrid laminated Al7075 composites. The main materials used in this research are aluminum 7075 plate, kevlar 29, silicon carbide (SiC) nano powder, and epoxy resin. SiC nano powder is mixed with polyethylene glycol-400 (PEG-400), then ethanol is added so that it becomes a shear thickening fluid (STF) solution which is used to impregnate kevlar. Laminate composites were prepared using the hand lay-up method with epoxy resin as an additive between layers of kevlar and aluminum 7075 plates. The thickness of laminates is various due to the number of kevlar used different of each laminated that is 8, 16, and 24 layers. The results of this study show that the composite with impregnated kevlar has higher ballistic and impact resistance values than the composite with non-impregnated kevlar, which has good potential as a base material for combat vehicles such as tanks. This is also supported by the Fourier Transfer Infrared Spectrometry (FTIR) results to determine the level of absorbance of the functional groups identified in impregnated kevlar and Scanning Electron Microscopy (SEM) results of the distribution of nano SiC filler that infiltrated to the empty space in the kevlar fiber.

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Fossil fuels served as the main source of energy throughout the 1800s when the industrial revolution got underway. Countries started aiming for carbon-neutral footprints and lowered emissions as environmental degradation became more apparent. Numerous research projects have been undertaken to discover a photovoltaic device that can replace conventional silicon (Si)-based solar cells. Dye-sensitized solar cells (DSSCs) have undergone extensive research during the past three decades. Due to their straightforward preparation process, low cost, ease of production, and low toxicity, DSSCs have seen extensive use. The reader will be able to comprehend the numerous types of TCO layers, physical methods for depositing metal oxide on TCO thin films, materials for fabricating the various DSSC layers, and the various types of dyes included in DSSC as well as their components and structures. The reader's ability to construct the DSSC, gain a general understanding of how it operates, and increase the effectiveness of these devices' potential growth and development paths are all aided by this review. For these technologies to be debated and shown to be appropriate for a breakthrough in consumer electronics on the market, manufacturing, stability, and efficiency improvements must also be addressed in the future. An overview of current DSSC prototype development and products from major firms is presented.
 

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Considering the widespread use of aluminum composites in various industries and the emergence of nanomaterials such as graphene and boron nitrite (BN) with their unique properties, aluminum-based nanocomposite reinforced by the graphene-BN hybrid was fabricated at different percentages. For this purpose, the graphene-BN hybrid was prepared and subjected to wet milling along with the aluminum powder. The mechanical properties of the final nanocomposite which was consolidated using the spark plasma sintering (SPS) method were examined. Aluminum-based composite specimens containing 1 wt.% graphene–0 wt.% BN (AGB1), 0.95 wt.% graphene–0.05 wt.% BN (AGB2), 0.90 wt.% graphene–0.1 wt.% BN (AGB3), and 0.85 wt.% graphene–0.15 wt.% BN (AGB4) were fabricated and compared with non-reinforced aluminum (AGB0). The hardness values of 48.1, 51.1, 56.2, 54.1, and 43.6 Hv were obtained for AGB0, AGB1, AGB2, AGB3, and AGB4, respectively. Additionally, tensile strengths of these specimens were 67.2, 102.1, 129.5, 123.7, and 114.7 MPa, respectively. According to the results of the hardness and tensile tests, it was revealed that the AGB2 specimen had the highest tensile strength (93% higher than AGB0 and 27% higher than AGB1) and hardness (17% higher than AGB0 and 10% higher than AGB1).

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In the third generation of solar cells, cheaper absorbent layers such as Cu₂ZnSnS₄ (CZTS) have been developed with specifications similar to Cu₂InGaS₄ (CIGS). This CZTS material is known as a material with good structural and optical properties where the CZTS material has a series of atoms bonded to each other to form a kesterite or stannite crystal arrangement. In its use as an absorbent layer for solar cells, CZTS material is synthesized using the electrochemical deposition method. In this electrochemical deposition technique, an electrical circuit will be connected to the electrode and inserted into the electrolyte. Several voltage variations from 1 volt to 5 volts will be applied to the electrical circuit, which will then trigger ions from the precipitating material in the electrolyte to stick to one of the electrodes. Variation of deposition voltage was carried out to determine the effect of deposition stress on the electrochemical deposition method on the characteristics of the CZTS absorbent layer. The characterizations used are X-Ray Diffraction (XRD), UV-Vis Spectrometry, and I-V meter. XRD results show that the resulting crystal size is getting smaller with greater deposition voltage around 6.07 - 7.27 nm. The optical absorption results show that the CZTS absorber layer is sensitive at low wavelengths around 300 – 480 m,, with Light Harvesting Efficiency (LHE) ranging from 13.3 - 24.75%. The band gap energy values obtained ranged from 1.4 to 1.48 eV. The cell efficiency test results show an excellent efficiency value according to the reference ranges from 2.56-8.77%. These results indicate that the deposition voltage affects the characteristics of the CZTS absorbent layer for solar cell applications.

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Several extensive researches are being carried out in the field of 3D printing. Polymer matrices, such as High-Density Polyethylene (HDPE), are less explored in particular on the microstructure and mechanical properties of HDPE composites developed via Fused Deposition Modelling (FDM) process. Very scarce amount of works is devoted to study HDPE’s reinforced with carbon nano-tubes (CNT’s) . In the present work, we report on the mechanical properties of  HDPE composites prepared via FDM process. Varying proportions of CNTs ( 0.5, 1, 1.5 and 2%) are used as reinforcements. It is found that increasing CNT content enhances impact and tensile strength, with HDPE/2.0%CNT outperforming pure HDPE by approximately 71.6% and 25.4%, respectively. HDPE/2.0%CNT composite also showed Young's modulus approximately 49.2% higher than pure HDPE. According to fracture analysis, pure HDPE failed near ductile, whereas composites failed brittle. CNTs occupy the free positions in the polymeric chains, and their tendency to restrict chain mobility causes HDPE to lose ductility and begin to behave brittle. The use of CNTs as reinforcement successfully improved the mechanical properties of HDPE.

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In this study, zinc chloride (ZnCl) was used as a precursor chemical to form boron reinforced zinc oxide (ZnO:B) particles. The supercapacitor performance of the reduced graphene oxide/boron reinforced zinc oxide (RGO/ZnO:B) composite electrodes produced by hydrothermal methods, and the impact of different boron doping ratios on the capacitance, were both examined. The characterization of the RGO/ZnO:B composites containing 5%, 10%, 15% and 20% boron by weight were performed using X-Ray diffraction (XRD) and scanning electron microscopy (SEM). The capacitance measurements of the electrodes produced were conducted in a 6 M KOH aqueous solution with a typical three electrode setup using Iviumstat potentiostat/galvanostatic cyclic voltammetry. The specific capacitance value of the 20% reinforced RGO/ZnO:B composite electrode was 155.88 F/g, while that of the RGO/ZnO composite electrode was 36.37 F/g. According to this result, the capacitance increased four-fold with a 20% boron doping concentration. Moreover, a longer cycle performance was observed for the RGO/ZnO:B electrodes with higher boron doping concentrations.
 

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In this study, an epoxy-based nanocomposite reinforced with copper oxide-graphene oxide hybrid was investigated. Initially, the hybrid powder of CuO–GO with a weight ratio of 9:1 was prepared. The hybrid filler with different weight percentages ranging from 0.1–0.5 was used to reinforce the epoxy resin. The prepared samples were analyzed using XRD, FTIR, FESEM, TEM, and tensile testing. According to the XRD results and SEM images, the hybrid powder was successfully prepared, and the mechanical testing results showed an improvement in tensile strength in the composite samples. The best composite sample in terms of tensile strength was the one containing 0.3 wt% of hybrid reinforcement, which exhibited a 73% increase in strength compared to the neat resin sample.

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The present work deals with the effect of Multi-walled Carbon Nanotube (MWCNT) and functionalized (carboxyl and amine) MWCNT on the mechanical properties of the PAEK (Poly Aryl Ether Ketone) polymer composite. The MWCNT and functionalized (carboxyl and amine) MWCNT concentration varied as 0.25, 0.5 and 0.75 weight percentages. Compositeswere prepared by using a melt compounding method using a twin-screw extruder and all testing samples were prepared using an injection molding machine as per American Society for Testing and Materials (ASTM) standards. Samples were tested for tensile strength, impact strength, flexural strength, heat deflection temperature, hardness, and density. There is an increase in the tensile strength, impact strength, flexural strength, and heat deflection temperature, with percentage increase in filler loading up to 0.5 %, followed by decrease in it with higher filler loading. The increase is maximum for amine functionalized MWCNT.

 

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The sensitivity of lead dioxide coating properties to the deposition conditions and electrolyte composition has allowed the preparation of coatings with different properties for different applications. In this study, the effects of electrolyte additives on the electrodeposition process were investigated using electrochemical measurements such as cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The results showed that the presence of fluoride ions significantly reduce the possibility of TiO₂ formation. The addition of copper ions not only prevents lead loss at the cathode, but also leads to the formation of copper oxide on the surface at initial stages, which hinders nucleation of PbO₂. The presence of sodium dodecyl sulfate (SDS) also interferes with the nucleation process as it occupies active nucleation sites. The α-PbO₂ interlayer prevents copper oxidation and solves the problem of lead dioxide nucleation. Finally, it was found that the simultaneous use of all additives together with the α-PbO₂ interlayer has a positive effect on the coating process.

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The trimanganese tetraoxide (Mn₃O₄) nanostructured thin films doped with 2 mol % of nickel (Ni) and molybdenum (Mo) ions were deposited by a simple electrophoretic deposition technique. The structural, optical, and morphological studies of these doped thin films were compared with pure Mn₃O₄ thin films. X-ray diffraction (XRD) confirmed the tetragonal Hausmannite spinel structure. The Fourier transform infrared spectroscopy (FTIR) provided information about the molecular composition of the thin films and the presence of specific chemical bonds. The optical study and band gap energy values of all thin films were evaluated by the UV visible spectroscopy technique. The scanning electron microscopy (SEM) illustrated the morphological modifications of the Mn₃O₄ thin films due to doping of the nickel and molybdenum ions. The Brunauer Emmett Teller (BET) method has confirmed the mesoporous nanostructure and nanopores of the thin films. The supercapacitive performance of the thin films was studied by cyclic voltammetry (CV), and galvanostatic charge discharge (GCD) techniques using the three-electrode arrangement. An aqueous 1M Na₂SO₄ electrolyte was used for the electrochemical study. The 2 mol % Ni doped Mn₃O₄ thin film has shown maximum specific capacitance than pure and Mo doped Mn₃O₄ thin films. Hence, this study proved the validity of the strategy - metal ion doping of Mn₃O₄ thin films to develop it as a potential candidate for electrode material in the futuristic energy storage and transportation devices.