rss_2.0Advances in Materials Science FeedSciendo RSS Feed for Advances in Materials Science in Materials Science 's Cover of Transparent Electrodes Study<abstract> <title style='display:none'>Abstract</title> <p>This work reports a study of corrosion lifetime of transparent electrodes deposited on the microscopic glass substrate. A procedure was developed for obtaining the transparent electrode by spray method. The corrosion lifetime variation in the presence of 1.5 M NaOH medium chemically degraded at room temperature before and after gamma irradiation was determined by measuring the evolution of the structure, electrical and optical characteristics. The mean values of transmittance up to 25 month before and after irradiation were calculated 91% ±6% and 96±7%, respectively. The average value of resistivity after corrosion and age time after γ-irradiation was 0.016±9% Ω.cm and 0.017± 4% at 1.0 kHz. No significant changes observed for 27 hr corrosion and 25 month age time of the transparent electrodes in NaOH solution.</p> </abstract>ARTICLE2022-07-12T00:00:00.000+00:00Effect of Shop-Primer Coating on S235JR Steel on MAG Weldability<abstract> <title style='display:none'>Abstract</title> <p>In this study, S235JR structural steel samples in uncoated condition and coated (shop-primer) in different thicknesses were welded by MAG (Metal Active Gas) welding method, and the effects of these applications on the mechanical and microstructure properties of the material were investigated. In the experimental studies, the first specimen group were used without any sandblasting and coating application, the second group specimens were sandblasted at Sa 2 ½ degree, and 25 µm, 50 µm, and 75 µm coatings were applied to the specimens in the other group. Surface conditions and coating thicknesses were selected as the variable parameters. With the examination of the radiography films, it was observed that the surface conditions affected the welded joint. As a result of the study, it was observed that altered coating thicknesses caused defects in the welding zone. It was determined that the coating thickness partially affected the mechanical properties, and the highest hardness values occurred in the weld zone in all samples. Relatively low values were obtained in tensile, bending and Charpy impact tests performed on sample groups with 75 µm coating thickness. The results were verified by the surface fracture, SEM, and EDS studies.</p> </abstract>ARTICLE2022-07-12T00:00:00.000+00:00Electrical Characteristics of Dry Cement – Based Composites Modified with Coconut Husk Ash Nanomaterial<abstract> <title style='display:none'>Abstract</title> <p>Coconut husk is generated yearly as waste in large quantities but majorly under-utilized. Also, as a result of high embodied carbon, cement production is one of the largest contributors to construction sector carbon footprint. Since accumulation of unmanaged agro-waste like coconut husk has an increased environmental concern due to its pollution effect, recycling it into sustainable construction materials is a viable solution for future generation. In this study, experiments were performed to investigate the influence of coconut husk ash nanomaterial (CHAN) inclusion on electrical characteristics of plain cement paste (BCP) and mortar (CSM) samples at curing ages of 7 and 28 days. The results showed increase in electrical resistivity, thermal constant, and activation energy with curing duration for heating and cooling cycles of BCP and CSM. With inclusion of CHAN, the developed cement paste (CAP) and mortar (CASM) possessed lower values in all cases compared to their counterparts. Also, during heating at 28 days, both the CAP and CASM exhibited decrease in thermal constant. Though electrical resistance of all the samples varied inversely with temperature, CAP and CASM were found to possess greater potentials to make building structures intrinsically smart. Hence, in addition to solving disposal problems, utilization of coconut husks as described herein could enhance development of safe, inexpensive, and sustainable buildings that have large temperature sensing volume.</p> </abstract>ARTICLE2022-07-12T00:00:00.000+00:00Effects of B Addition on the Microstructure and Microhardness of Melt-Spun Al-7075 Alloy<abstract> <title style='display:none'>Abstract</title> <p>Main aim of this study is to examine change of microstructural and the mechanical properties of Al-7075 alloy depending on B content added with different proportions. Rapid solidification process used to produce the alloys was carried out with a single roll melt spinner via a wheel with a rotational speed of 25 m/s. For the microstructural characterization of the alloys, a scanning electron microscope and X-ray diffraction analyzes were used. According to obtained results, it can be said that B addition led to modification of dimensions and shapes of both α−Al and intermetallic phases occurred, it reduced average grain size from 0.45 μm to 0.34 μm in the microstructure. The B addition also led to dramatically increase in microhardness of the Al-7075 alloy. The microhardness of the alloy with 0.4 wt. % B is 0.19 GPa, this is clearly one times higher than that of the alloy without B addition. The microhardness of the alloy with 1 wt. % B is 0.21 GPa, this is also slightly higher than that of the alloy with 0.4 wt. % B.</p> </abstract>ARTICLE2022-07-12T00:00:00.000+00:00Enhancement Photocatalytic Activity of Mn Doped Cds/Zno Nanocomposites for the Degradation of Methylene Blue Under Solar Light Irradiation<abstract> <title style='display:none'>Abstract</title> <p>In this study, Mn doped CdS/ZnO nanocomposites synthesized by co-precipitation method and its photocatalytic activity was tested using methylene blue under solar light irradiation. The prepared hybrid nanocomposites are characterized by using different physicochemical techniques including XRD, FESEM, EDX, TEM, UV-vis DRS and PL analysis. From the XRD analysis, Mn doped ZnO/CdS nanocomposite diffraction peaks only reflect the binary crystalline structures of ZnO and CdS. However, there is no characteristic peak of Mn is found that may be because of low content of Mn doped on ZnO/CdS. But Mn (2.9 wt%) was detected in the Mn doped ZnO/CdS nanocomposite, which was measured by EDX analysis. The FESEM and TEM results exhibit the surface particle of Mn doped ZnO/CdS nanocomposite which have spherical nature and confirmed the formation of Mn doped ZnO/CdS nanocomposites. The photocatalytic degradation results have revealed that the Mn doped CdS/ZnO nanocomposites exhibit admirable activity toward the photocatalytic degradation of the MB. The reason for excellent photocatalytic activity of Mn doped CdS/ZnO nanocomposites indicates the absorbance band shifted to red region and reduction of recombination of photogenerated electron-hole, which is in good agreement with UV-visible DRS analysis and PL study results. The fitted kinetic plots showed a pseudo-first-order reaction model and the appropriate rate constants were found to be 0.0068 min<sup>−1</sup>, 0.00846 min<sup>−1</sup>, and 0.0188 min<sup>−1</sup>, for ZnO, 25 % CdS/ZnO, and 0.8 mol% Mn doped CdS/ZnO nanocomposites, respectively. The maximum photocatalytic activity was achieved by 0.8 mol% Mn doped CdS/ZnO nanocomposites with a 95% degradation efficiency of MB. Hydroxyl and superoxide radicals, having a vital role in the degradation of MB, confirmed scavenging experiments. In addition, the recycling tests displays that the Mn doped CdS/ZnO nanocomposites have shown good stability and long durability. The enhanced photodegradation activity of Mn doped CdS/ZnO nanocomposites indicates the potential of the nanocomposite for the treatment of organic pollutants from the textile wastewater.</p> </abstract>ARTICLE2022-07-12T00:00:00.000+00:00Mathematical Model for Friction Stir Lap Welded AA5052 and SS304 Joints and Process Parameters Optimization for High Joint Strength<abstract> <title style='display:none'>Abstract</title> <p>Due to the numerous challenges faced during the dissimilar welding, choosing the right process parameters and their optimization yields better results. In this context, the current investigation is focused on the optimization of process parameters. Taguchi’s L<sub>9</sub> orthogonal array was selected to carry out the experimental investigations. The welded samples were tested for shear strength, and the results were analysed using Taguchi’s S/N ratio analysis with “larger the better” criteria. Log-linear regression analysis was applied to formulate an empirical correlation between the process parameters and shear strength. According to S/N ratio analysis, the tool rotational speed of 800 rpm, welding speed of 20 mm/min and a penetration depth of 4.1 mm are the optimized parameters that achieve high joint strength. The achieved joint strength was 3.46 kN that is 70% of the base aluminium metal. It was noticed from the Analysis of variance of the regression model that penetration depth and tool rotational speed are the significant contributors with p-values less than 0.5. Confirmation tests show that the error between the predicted and calculated shear strength is 2.06% which is considered acceptable. R<sup>2</sup> and adjusted R<sup>2</sup> values of the model with a standard error of 0.076 show that the developed model is statistically significant.</p> </abstract>ARTICLE2022-04-05T00:00:00.000+00:00NiO/CuO/TiO Ternary Composites: Development, Physicochemical Characterization and Photocatalytic Degradation Study Over Reactive Orange 30 Solutions Under Solar Light Irradiation<abstract> <title style='display:none'>Abstract</title> <p>The photocatalytic degradation and mineralization of Reactive Orange 30 on NiO/CuO/TiO<sub>2</sub> ternary composites have been studied using solar light irradiation. The NiO/CuO/TiO<sub>2</sub> ternary composites were prepared by producing ethanolic dispersions containing varied amounts of NiO and CuO/TiO<sub>2</sub> (3wt% to 15wt.%), followed by annealing at 300 °C. SEM, UV- Vis DRS, PL, XRD and FTIR analysis have been used to characterize the unary (parent photocatalysts), binary and ternary composites. Under solar light irradiation, NiO/CuO/TiO<sub>2</sub> ternary composites exhibited an excellent photocatalytic activity in degradation of reactive orange 30 in aqueous solution, whereas the NiO/TiO<sub>2</sub>, CuO/TiO<sub>2</sub> and bare photocatalyst such as NiO, CuO, TiO<sub>2</sub> showed lower activities. It was deduced that the remarkable visible-light absorption phenomenon and band gap reduction of the NiO/CuO/TiO<sub>2</sub> ternary composites taking place. It paves way for the photogenerated electron transfer between CB of the NiO, CuO, TiO<sub>2</sub> semiconductors and also holes shifting between VB of above mentioned materials. The NiO/CuO/TiO<sub>2</sub> ternary composite shows good photostability and the photocatalyst retains 94% of its initial activity in the seventh cycle, respectively.</p> </abstract>ARTICLE2022-04-05T00:00:00.000+00:00Rubber Influence on the Performance of Thermal Insulating Quarry Sand Mortars-A Statistical Analysis<abstract> <title style='display:none'>Abstract</title> <p>The purpose of this paper is to develop a framework for managing wastes resulting from the tire rubber valorization waste of quarry sand mortar. A research methodology was developed to achieve the abovementioned main objective. To create a framework for use of crumb rubber in the production of quarry sand mortars, with adequate physical and mechanical properties to be used in a variety of construction applications. Testing included strength and thermal conductivity properties of the various mixture composition subjected to varying by 5%. 10%. 15% and 20% by quarry sand substitution. The internal microstructure, and phase composition of all mixture mortars, were investigated using scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM/EDS). The results show that increasing incorporation rate of additives significantly improves thermophysical properties of based materials, the hardened properties of the various mortars made are analyzed and compared, the experimental results revealed that; the addition of crumb rubber waste in the quarry sand mortar is beneficial for physical properties (Mv) mass loss, The results of mechanics strength of the rubber based quarry mortar studied are also significantly reduced.The addition of 5% to 20% rubber crumb in matrix and the replacement of sand by 20% of rubber in quarry mortar record the low thermal conductivity properties including that appropriate QS and CR levels may change the pattern of quarry sand mortar. witch explain by a Larger pore and higher porosity produce a less rigid and uniform matrix, meaning that the sonic pulses must travel through longer and more miscellaneous paths which improvement of insulation. The good performance of new materials encourages us to integrate them into the building envelope.</p> </abstract>ARTICLE2022-04-05T00:00:00.000+00:00Chemical characteristics of new nanopowder of titania doped with nitrogen atoms<abstract xml:lang="en"><title style='display:none'>Chemical characteristics of new nanopowder of titania doped with nitrogen atoms</title><p>Characteristics of new nitrogen doped TiO<sub>2</sub> prepared in an one-pot synthesis where titania (IV) complexes with ligands containing nitrogen atoms were used as a precursor are presented in this paper. The pale yellow nanopowder with crystallite size of 9 - 12 nm is obtained as a product of calcination at 310°C and repeated washing procedure. Elemental analysis shows that nitrogen (1.087 at. pct.) is present in obtained material. The morphology and microstructure of samples were examined by XRD, AFM, UV-VIS and FTIR-ATR techniques. These studies confirm that obtained powder demonstrates a significant decrease in the band gap energy value (<italic>E</italic><sub>g</sub> = 2.83 eV) comparing to pure TiO<sub>2</sub> (<italic>E</italic><sub>g</sub> 3.22 eV). Presence of N-Ti-O bonds was confirmed <italic>via</italic> FTIR ATR. Products of the powder thermal decomposition were detected using TG-DSC technique coupled with mass spectrometry (MS). The report presents electrochemical studies which allow estimation of a flatband potential <italic>E</italic><sub>fb</sub> on the basis of the Mott-Schottky relation.</p></abstract>ARTICLE2010-01-13T00:00:00.000+00:00Mathematical modelling of the thermal cycle in affected zone with three dimensional heat source models and pulsed power welding: Part II<abstract xml:lang="en"><title style='display:none'>Mathematical modelling of the thermal cycle in affected zone with three dimensional heat source models and pulsed power welding: Part II</title><p>In order to execute computer calculations with temperature dependent physical parameters: λ, c<sub>p</sub>, ρ, a and pulsed heat input q(t), the algebraic expression will be transformed. For this purpose we will use calculations in Mathcad programme [1]. This application is very useful for modelling and simulation of welding thermal process. Finally, the specifications of sub-procedures: Stab_time, last, calculation of roots r<sub>i</sub>, λ(T), a(T) and q(t) are presented.</p></abstract>ARTICLE2010-01-13T00:00:00.000+00:00Optoelectronic system for investigation of CVD diamond/DLC layers growth<abstract xml:lang="en"><title style='display:none'>Optoelectronic system for investigation of CVD diamond/DLC layers growth</title><p>Development of the optoelectronic system for non-invasive monitoring of diamond/DLC (Diamond-Like-Carbon) thin films growth during μPA ECR CVD (Microwave Plasma Assisted Electron Cyclotron Resonance Chemical Vapour Deposition) process is described. The system uses multi-point Optical Emission Spectroscopy (OES) and long-working-distance Raman spectroscopy. Dissociation of H<sub>2</sub> molecules, excitation and ionization of hydrogen atoms as well as spatial distribution of the molecules are subjects of the OES investigation. The most significant parameters of the deposited film like molecular composition of the film can be investigated by means of Raman spectroscopy. Results of optoelectronic investigation will enable improvement of CVD process parameters and synthesized DLC films quality.</p></abstract>ARTICLE2010-01-13T00:00:00.000+00:00Allergies to implant metal compounds<abstract xml:lang="en"><title style='display:none'>Allergies to implant metal compounds</title><p>The surgical implants are made of different materials, such as cobalt alloys, titanium alloys and stainless steels. These materials contain little amount of carbon and significant amount of Cr, Ni and Mo. The metallic implants introduced into the human body undergo degradation mainly as a result of corrosion after a long use, due to aggressive biological impact between the implant surface and human body. This phenomenon is accompanied by the release of metal ions from implant surface, which gather in tissues surrounding the implant as well as the soft tissues (for eg. the liver).</p></abstract>ARTICLE2010-01-13T00:00:00.000+00:00Microstructural Characterization of Borided Co-Cr-Mo Alloy<abstract> <title style='display:none'>Abstract</title> <p>This study involves the effect of boriding powder composition on the microstructure and hardness of a CoCrMo alloy borided in a solid medium using the powder pack method. To investigate the effect of boriding powder composition, two different commercial boriding agents, Ekabor-HM and Ekabor III, were thoroughly mixed with ferrosilicon powders to form the boriding media. The CoCrMo samples were tightly packed with the Ekabor-HM and Ekabor III boriding powders in stainless steel containers to minimize oxidation. The boriding process was carried out under atmospheric conditions for 9 h in an electrical resistance furnace preheated to 1223 K. X-ray diffraction (XRD) analyses revealed that the surfaces of the borided CoCrMo alloys consisted of a bilayer composed of CoB and Co<sub>2</sub>B phases and also contained minor amounts of CrB, Mo<sub>2</sub>B<sub>5</sub>, and Mo<sub>2</sub>B. The average thickness of the boride layer in the samples borided with Ekabor HM and Ekabor III powders was 28±4.1 μm and 21±2.3 μm, while the average hardness of the boride layer was 1752±5.3 HV<sub>0.1</sub> and 1364±3.8 HV<sub>0.1</sub>, respectively.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00Effect of Fe-Ni Substitution in FeNiSiB Soft Magnetic Alloys Produced by Melt Spinning<abstract> <title style='display:none'>Abstract</title> <p>Alloys of FeNiSiB soft magnetic materials containing variable Fe and Ni contents (wt.%) have been produced by melt spinning method, a kind of rapid solidification technique. The magnetic and structural properties of FeNiSiB alloys with soft magnetic properties were investigated by increasing the Fe ratio. X-ray diffraction analysis and SEM images shows that the produced alloy ribbons generally have an amorphous structure, together with also partially nanocrystalline regions. It was observed that the structure became much more amorphous together with increasing Fe content in the composition. Among the alloy ribbons, the highest saturation magnetization was obtained as 0.6 emu/g in the specimen with 50 wt.% Fe. In addition, the highest Curie temperature was observed in the sample containing 46 wt.% Fe.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00Microstructural Evaluation of the High-Frequency Induction Welded Joints of Low Carbon Steel Pipes<abstract> <title style='display:none'>Abstract</title> <p>The work presents the results of research on the structure of welded joints in the area of heat affected zone (HAZ). Based on precisely performed metallographic tests, the contribution of individual structural components in the area of welds of pipes welded with the induction method was assessed. The volume fraction of individual structural components in various areas of the heat affected zone, the size of the grain formed in the welding process, as well as its shape coefficients were determined. On the basis of metallographic observations, an attempt was made to describe the course of the pressure induction welding process, taking into account the structural changes, phase changes and the recovering and recrystallization processes taking place in this process.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00Assessment of Corrosive Behaviour and Microstructure Characterization of Hybrid Friction Stir Welded Martensitic Stainless Steel<abstract> <title style='display:none'>Abstract</title> <p>This study examined the effect of induction heating on the microstructure and corrosion characteristics of hybrid friction stir welded AISI 410 stainless steel. Five joints have been produced with different friction stir welding parameters like welding speed, spindle speed, plunge depth, and induction power. Their microstructures were evaluated using a scanning electron microscope, and chemical composition was examined using energy-dispersive X-ray spectroscopy (EDX). The rate of corrosion was found out via the weight loss method in a 1 M HCL solution. The hybrid friction stir welding method used for this work is induction assisted friction stir welding; the results show that this method could produce sound AISI 410 stainless steel Joints. The experiment results show that the joint made at a spindle speed of 1150 rpm, welding speed 40 mm/min, plunge depth 0.5 mm, and in-situ heat by induction 480°C show a better corrosion resistance property with a fine grain structure.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00Preparation and Evaluation of Conductive Polymeric Composite from Metals Alloys and Graphene to Be Future Flexible Antenna Device<abstract> <title style='display:none'>Abstract</title> <p>Every year hundreds of serious accidents and catastrophic are accompanied by mining sector services as disaster, flooding, and demolition. To reduce the severity of the results such as high death numbers, lost communication inner and out mining, we have to find an easy way to improve communication means during that problems. In this paper, we reach out to fabricate durable, flexible, and wearable chaps, in addition to an easier carrier with highly efficient receiving and sending a signal at 2.4 GHz broad wide band. By doping a bunch of unique conductive metals (silver, copper, and gallium indium alloy) assembled on Graphene, its integration inside Polydimethylsiloxane to be future applicable antenna. Furthermore, we studied the physical and electric properties of a composite including Electrochemical Impedance properties (EIS), cyclic voltammetry (CV), and its thermal stability chip (DSC), as well as, using Transmission electron microscopy (TEM), and, scanning electron microscopy (SEM) techniques to clarify the surface morphology of fabricated materials. In addition to various measurements had been carried out such as Ultraviolet-visible, inductively coupled plasma (ICP) spectroscopy, and Energy-dispersive X-ray spectroscopy (EDX) to reinforce and elucidate the solid-state of ions inside fabricated Antenna. On the other hand, throughout stress-strain for the stretchability of fabricated is expanded to 30% of its original length, in addition to thermal stability reached to 485°C compared to pure PDMS substrate, with enhancing electric conductivity of composite ship.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00Microstructure and Mechanical Properties of Laser Surface-Treated Ti13Nb13Zr Alloy with MWCNTs Coatings<abstract> <title style='display:none'>Abstract</title> <p>Laser surface modification of titanium alloys is one of the main methods of improving the properties of titanium alloys used in implantology. This study investigates the microstructural morphology of a laser-modified surface layer on a Ti13Nb13Zr alloy with and without a carbon nanotube coating deposited by electrophoretic deposition. Laser modification was performed for samples with and without carbon nanotube coating for two different laser powers of 800 W and 900 W and for different scan rates: 3 mm/s or 6 mm/s at 25 Hz, and the pulse duration was 2.25 ms or 3.25 ms. A scanning electron microscope SEM was used to evaluate the surface structure of the modified samples. To observe the heat-affected zones of the individual samples, metallographic samples were taken and observed under an optical microscope. Surface wettability tests were performed using a goniometer. A surface roughness test using a profilograph and a nanoindentation test by NanoTest™ Vantage was also performed. Observations of the microstructure allowed to state that for higher laser powers the surfaces of the samples are more homogeneous without defects, while for lower laser powers the path of the laser beam is clearer and more regular. Examination of the microstructure of the cross-sections indicated that the samples on which the carbon nanotube coating was deposited are characterized by a wider heat affected zone, and for the samples modified at 800 W and a feed rate of 3 mm/s the widest heat affected zone is observed. The wettability tests revealed that all the samples exhibit hydrophilic surfaces and the samples with deposited carbon nanotube coating increase it further. Surface roughness testing showed a significant increase in Ra for the laser-modified samples, and the presence of carbon nanotubes further increased this value. Nanoindentation studies showed that the laser modification and the presence of carbon coating improved the mechanical properties of the samples due to their strength.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00The Effect of Spray Distance on Porosity, Surface Roughness and Microhardness of WC-10Co-4Cr Coatings Deposited by HVOF<abstract> <title style='display:none'>Abstract</title> <p>The paper presents the computational studies on the microstructure of WC-Co-Cr coatings deposited by High Velocity Oxy Fuel spraying (HVOF). The study covers the porosity assessment according to ASTM E2109-01 standard, carried out in ImageJ software, in terms of volume porosity, size and shape of the pores. The evaluation was preceded by scanning electron microscope (SEM) observations at magnifications of 2000x and 5000x. Additionally, topography analysis has been performed by confocal laser scanning microscope (CLSM), and the surface roughness R<sub>a</sub> was evaluated by the contact method with use of a stylus profilometer. Finally, the influence of porosity was observed for coatings microhardness HV0.3. According to the results, the total closed porosity was found to be in the range of 5.01 vol.% and 5.38 vol.%. The dominated pores in the coatings were of size 0.1-1.0 μm. Studies showed that HVOF process enabled deposition of dense coatings, characterized by homogenous distribution of pores and low roughness.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00Effect of Holes in Overlap on the Load Capacity of the Single-Lap Adhesive Joints Made of EN AW-2024-T3 Aluminium Alloy<abstract> <title style='display:none'>Abstract</title> <p>The paper presents the results of experimental research aimed at determining the possibilities of strengthening structural adhesive joints. Techniques to improve the strength of adhesive joints was to make holes in the front part of the adherends in order to make the joint locally more flexible in the area of stress concentration at the joint edges. The tests were carried out for the lap joints of EN AW-2024-T3 aluminum alloy sheets, which were bonded with Loctite EA3430 epoxy adhesive. Static tests were carried out on the basis of the tensile/shear test. It has been shown that the applied structural modifications allow for an increase in the strength of the joint, in the best variant, an increase in strength of 14.5% was obtained. In addition, it has been shown that making holes in the adherends allows to reduce the spread of strength results.</p> </abstract>ARTICLE2021-12-30T00:00:00.000+00:00en-us-1