rss_2.0Materials Science-Poland FeedSciendo RSS Feed for Materials Science-Polandhttps://sciendo.com/journal/MSPhttps://www.sciendo.comMaterials Science-Poland 's Coverhttps://sciendo-parsed-data-feed.s3.eu-central-1.amazonaws.com/61009f9cf4b0eb6bda0f2a29/cover-image.jpg?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Date=20211023T110319Z&X-Amz-SignedHeaders=host&X-Amz-Expires=604800&X-Amz-Credential=AKIA6AP2G7AKDOZOEZ7H%2F20211023%2Feu-central-1%2Fs3%2Faws4_request&X-Amz-Signature=650f09d1dc8b482c09de9fad2c335054f94c399f72994ff58a280afd3cb52c5a200300Experimental investigation of the electrochemical micromachining process of Ti-6Al-4V titanium alloy under the influence of magnetic fieldhttps://sciendo.com/article/10.2478/msp-2021-0013<abstract> <title style='display:none'>Abstract</title> <p>An attempt has been made to study the influence of magnetic field on the micro hole machining of Ti-6Al-4V titanium alloy using electrochemical micromachining (ECMM) process. The presence of magneto hydro dynamics (MHD) is accomplished with the aid of external magnetic field (neodymium magnets) in order to improve the machining accuracy and the performance characteristics of ECMM. Close to ideal solution for magnetic and nonmagnetic field ECMM process, the parameters used are as follows: concentration electrolyte of 15 g/l; peak current of 1.35 A; pulse on time of 400 s; and duty factor of 0.5. An improvement of 11.91–52.43% and 23.51–129.68% in material removal rate (MRR) and 6.03–21.47% and 18.32–33.09% in overcut (OC) is observed in ECMM of titanium alloy under the influence of attraction and repulsion magnetic field, respectively, in correlation with nonmagnetic field ECMM process. A 55.34% surface roughness factor reduction is ascertained in the hole profile in magnetic field-ECMM in correlation with electrochemical machined titanium alloy under nonmagnetic field environment. No machining related stress is induced in the titanium alloy, even though environment of electrochemical machining process has been enhanced with the presence of magnetic field. A slight surge in the compressive residual factor, aids in surge of passivation potential of titanium alloy, resulting in higher resistance to outside environment.</p> </abstract>ARTICLE2021-07-09T00:00:00.000+00:00Transport and magnetic properties of Bi(Pb)2212 superconducting ceramics doped by low rate of potassiumhttps://sciendo.com/article/10.2478/msp-2021-0005<abstract> <title style='display:none'>Abstract</title> <p>Samples of Bi<sub>1.5</sub>Pb<sub>0.5</sub>(Sr<sub>1.8−x</sub>K<sub>x</sub>)CaCu<sub>2</sub>O<sub>8+d</sub> and Bi<sub>1.5</sub>Pb<sub>0.5</sub>Sr<sub>1.8</sub>CaCu<sub>2</sub>O<sub>8+d</sub>K<sub>x</sub> have been prepared from powders of carbonates and primary oxides using the solid state reaction method and compared in this study. In the first case, potassium (K) is substituted in the strontium (Sr) site. In the second one, K is added. A part of the paper is devoted to discuss the results obtained by X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) observations of (Bi,Pb)<sub>2</sub>Sr<sub>1.8</sub>CaCu<sub>2</sub>O<sub>8+d</sub> samples doped by potassium to provide additional microstructural information related to the doping method. These analyses are supplemented by resistivity and magnetic measurements. Results show how the rate of doping by potassium affects transport and magnetic properties of Bi(Pb)2212 phase. The critical current density (J<sub>c</sub>) is improved using the two methods and it reaches a double value by the addition of K as compared to the undoped sample.</p> </abstract>ARTICLE2021-06-01T00:00:00.000+00:00Stimulated autogenous-healing capacity of fiber-reinforced mortar incorporating healing agents for recovery against fracture and mechanical propertieshttps://sciendo.com/article/10.2478/msp-2021-0009<abstract> <title style='display:none'>Abstract</title> <p>This study aimed to investigate the effect of autogenous healing capacity with the addition of expansive and crystalline agents on mechanical and fracture behaviors of fiber-reinforced (FR) mortar specimens with crack mouth opening displacement (CMOD) controlled test set-up. The experimental results of a self-healing approach of FR mortar were analyzed in terms of first cracking peak load (FCPL) increase, index of fracture toughness recovery (IFTR), and index of fracture energy recovery (IFER). Initially, the specimens were pre-cracked at different crack widths ranging from 30 μm to 200 μm after 28-days of curing. After pre-cracking, the specimens were kept in water for 56- and 120-day healing. A controlled three-point bending test (PBT) was applied on prism specimen having a central notch of 40 mm depth for pre-cracking as well as the post-conditioning stage for determining the FCPL. However, the crack surfaces were monitored by a high-range digital microscope and scanning electron microscope (SEM) to examine the nature of healed products near the damaged area. Test results revealed that a significant recovery of small cracks (≤50 μm) could be achieved for self-healing specimens by using healing agents (HA), while for large cracks (≥100 μm) partial recovery could be achieved after the 120-day healing period.</p> </abstract>ARTICLE2021-06-26T00:00:00.000+00:00Influence of zinc substitution on structural, elastic, magnetic and optical properties of cobalt chromium ferriteshttps://sciendo.com/article/10.2478/msp-2021-0008<abstract> <title style='display:none'>Abstract</title> <p>The polycrystalline Co<sub>1−x</sub>Zn<sub>x</sub>Cr<sub>0.5</sub>Fe<sub>1.5</sub>O<sub>4</sub> series with (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0) has been synthesized by conventional ceramic rout method. The structural and elastic properties have been investigated by X-ray diffractometer and Fourier transform spectroscopy. Both XRD and FTIR confirm the formation of single phase cubic spinel ferrites. The cationic distribution for all samples has been proposed. The lattice parameter, X-ray density, hoping length, bond length, and packing factors–in accompaniment with variations in the zinc concentration–have been studied. The IR band position has been explained by the cations involved in the structure. The elastic moduli such as Young's modulus, bulk modulus, rigidity modulus and Poison's ratio have bee calculated using force constants. Scanning electron microscope (SEM) observation conveys information about the agglomeration of particles. The hysteresis curve obtained from vibrating sample magneto meter (VSM) conveys information about the soft nature of prepared compositions. The saturation magnetization decreases with addition of zinc ions and coercivity is almost zero. An increase in band gap energy has been observed with addition of zinc by Ultraviolet Visible Spectroscopy (UV-VIS), which is due to small crystallite size.</p> </abstract>ARTICLE2021-07-16T00:00:00.000+00:00Finite element modeling of continuous drive friction welding of Al6061 alloyhttps://sciendo.com/article/10.2478/msp-2021-0001<abstract> <title style='display:none'>Abstract</title> <p>Continuous drive friction welding process is widely used in various industrial applications to assemble shafts, tubes, and many other components. This paper's motivation was developing a CDFW model using the Finite Element Method (FEM). The coupling of the process's thermal and mechanical behaviors was considered during the simulation by COMSOL Multiphysics®. The construction of phase transition curves for Al6061 allowed determining several temperature-dependent thermophysical properties of the material. These properties are then injected in a second simulation to study the temperature evolution during welding. Subsequently, these results are compared and analyzed with the experimental outcomes. Excellent comparability between the model and experimental results was achieved. A unique phenomenon in the welding temperature profile was observed and explained through the model and experimental results interpretation.</p> </abstract>ARTICLE2021-05-30T00:00:00.000+00:00A study on the mixed properties of green controlled low strength cementitioushttps://sciendo.com/article/10.2478/msp-2021-0004<abstract> <title style='display:none'>Abstract</title> <p>In this study, two industrial wastes – circulating fluidized bed combustion co-fired fly ash (CFA) and ground granulated blast-furnace slag (GGBS) – were used as green materials instead of cementitious materials in controllable low strength material (CLSM). CLSM was used to backfill the pavement. CLSM should meet the compressive strength requirements of the CLSM specification (under 8.24 MPa), and it had the self-consolidating characteristics of fluidized concrete. In order to comply with the characteristics of self-consolidation, a mix design including superplasticizers, adhesives, and accelerators were used to ensure that the proportion could meet the requirements of both CLSM and the self-consolidating properties. The test methods included the slump flow test, ball drop test, strength activity index, compressive strength, mercury intrusion porosimetry, chlo-ride migration test, and scanning electron microscope. A water/cement ratio of 0.85 was used as the mix design for the CLSM requirements. The CFA and GGBS used in CLSM could replace 78 wt.% of the cement, and CLSM could effectively meet the requirements of the workability, strength and microscopic properties.</p> </abstract>ARTICLE2021-07-06T00:00:00.000+00:00Formability of laser welded steel/magnesium dissimilar metal with Sn powder-adhesive interlayerhttps://sciendo.com/article/10.2478/msp-2021-0014<abstract> <title style='display:none'>Abstract</title> <p>The exploratory experiments of laser fusion welding with Sn powder and the automotive adhesive addition were conducted for DP590 dual-phase steel and AZ31B magnesium alloy in an overlap steel-on-magnesium configuration. The characteristics of metal vapor/plasma were analyzed by collecting and analyzing plasma shape and welding spectra. The microstructure of the welded was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS). The temperature field distribution of the joint was simulated by COMSOL finite-element software. The results showed that the transfer of heat from steel to the magnesium alloy is hindered by the adhesive layer, which is conducive to the simultaneous melting of steel and magnesium with large differences in melting and boiling points. In addition, the width of the molten pool increases, but the depth is shallow on the magnesium side. Meanwhile, the recoil pressure induced by the splashing of the molten pool reduces, and the surface quality of the weld is improved. Some intermetallic compounds (IMCs), such as FeSn, Fe<sub>1.3</sub>Sn, and Fe<sub>3</sub>Sn, are formed inside the molten pool, while columnar dendrite Mg<sub>2</sub>Sn phase is also produced. The presence of these phases helps realize the bidirectional metallurgical bonding of steel/magnesium dissimilar metals.</p> </abstract>ARTICLE2021-07-09T00:00:00.000+00:00The impact of changes in pore structure on the compressive strength of sulphoaluminate cement concrete at high temperaturehttps://sciendo.com/article/10.2478/msp-2021-0006<abstract> <title style='display:none'>Abstract</title> <p>The internal pore structure of sulphoaluminate cement concrete (SACC) significantly affects its mechanical properties. The main purpose of this study was to establish the relationship between pore structure changes and compressive strength after exposure to elevated temperatures. SACC samples that had been cured for 12 months were dried to a constant weight and then exposed to different temperatures (100 °C, 200 °C and 300 °C), after which the compressive strength and pore structure were measured. The pore structure of SACC was quantitatively described by mercury intrusion porosimetry (MIP) and nitrogen adsorption results. The results showed that with increased temperature, the porosity of the SACC samples also increased and the pore structure was gradually destroyed. Moreover, the SACC’s compressive strength gradually decreased with increasing temperature. The relationship between compressive strength and porosity was in close agreement with the compressive strength–porosity equation proposed by Schiller. Therefore, after extensive exposure to elevated temperature, the changes in SACC’s compressive strength can be quantitatively described by the Schiller equation.</p> </abstract>ARTICLE2021-07-06T00:00:00.000+00:00Spinel zinc ferrite nanostructured thin-films for enhanced light-harvesting in polycrystalline solar cellshttps://sciendo.com/article/10.2478/msp-2021-0002<abstract> <title style='display:none'>Abstract</title> <p>Spinel zinc ferrite (ZnFe<sub>2</sub>O<sub>4</sub>) nanocrystallites are applied as an anti-reflection coating (ARC) for the enhanced light harvesting in polycrystalline silicon solar cells (PCSSC) and its effect were studied. Spinel zinc ferrite nanocrystallites were prepared using precursors of zinc and ferric chloride by co-precipitation method. The morphological, optical, electrical characterizations are comprehensively used to establish the performance of spinel ZnFe<sub>2</sub>O<sub>4</sub> Nanostructured Thin Films (NTF) covered and uncovered PCSSC. Further, X-ray diffraction and fluorescence analysis have been performed to demonstrate the crystallographic patterns and elemental compositions of ZnFe<sub>2</sub>O<sub>4</sub> nanocrystallites. The developed spinel ZnFe<sub>2</sub>O<sub>4</sub> NTF on PCSSC shows the reduction in reflectivity (20.3%), improvement in light trapping efficiency (17.5%) and transmittance of the fabricated spinel ZnFe<sub>2</sub>O<sub>4</sub> NTF was validated with optical and electrical observations.</p> </abstract>ARTICLE2021-06-08T00:00:00.000+00:00Study on factors of interface properties of axial braided C/C composite materialshttps://sciendo.com/article/10.2478/msp-2021-0010<abstract> <title style='display:none'>Abstract</title> <p>In order to study the influencing factors of the tensile properties of axial braided C/C composites, the interfacial shear strength of the fiber rod and matrix was studied and ejecting tests of the fiber rod were carried out. The ejecting test specimens were formed with different thicknesses to obtain the changing rule of the interface shear strength with the thickness of the sample, and the testing method for the interface shear strength of the axial braided C/C composite material. The results show that the recommended thickness of the ejecting test specimens for the interface shear strength of is four times the diameter of the fiber rod. The interface shear strength distribution law of two different batches of materials was obtained through the interface ejecting test. The mesoscopic structure characteristics and pore statistical distribution law of the hole surface after ejecting were analyzed by scanning electron microscopy (SEM), and the mechanism of the difference of the interface shear strength was obtained. The tensile properties of two different batches of materials were obtained by tensile tests. The results show that the tensile properties of the two batches of materials differ greatly. The analysis suggests that the reason for this difference is the differences in interfacial bonding strength between the fiber rod and matrix. The higher the interface shear strength, the better the tensile property of the material will be.</p> </abstract>ARTICLE2021-07-02T00:00:00.000+00:00Analysis of the static and dynamic properties of wear-resistant Hardox 600 steel in the context of its application in working elementshttps://sciendo.com/article/10.2478/msp-2021-0007<abstract> <title style='display:none'>Abstract</title> <p>The article discusses the static and dynamic properties of high-strength, boron-containing Hardox 600 steel that is resistant to abrasive wear, both in its delivery state and after normalization. Since the available published material in the literature does not have any real mechanical indicators of the abovementioned steel, a static tension test was carried out at an ambient temperature. The steel’s tensile strength, yield strength, Young’s modulus, elongation and reduction of area were determined from the test. The Charpy impact test at temperatures of −40 °C, −20 °C, 0 °C, and +20 °C and fractographic analysis were performed to determine the transition temperature of ductility to brittleness. In dynamic load conditions, the assigned values of impact energy do not always truly determine the material behavior. Thus, the aim of the fractography was to provide precision when determining the behavior. A significant difference in the impact energy of the tested steel with respect to its heat treatment and ductile-brittle transition temperature was observed and determined based on the impact test result, as well as the nature of the fracture. On the basis of the determined structural and strength characteristics, an analysis of the possibility of application of Hardox 600 steel on selected elements of working machines was performed.</p> </abstract>ARTICLE2021-07-06T00:00:00.000+00:00Effect of heat treatment on the microstructure and mechanical properties of a low-carbon X80 pipeline steelhttps://sciendo.com/article/10.2478/msp-2021-0012<abstract> <title style='display:none'>Abstract</title> <p>In this work, the effect of heat treatment conditions on the microstructure and mechanical properties of an American Petroleum Institute (API) X80 steel with a low carbon content of ~0.02% wt., destined for the manufacture of pipelines and pipeline transmission systems by welding, was investigated. Samples were heat treated under different conditions and then were characterized by scanning electron microscopy (SEM), orientation image microscopy (OIM), and electron backscattered diffraction (EBSD). The results showed that when the steel is fastly cooled from the austenitic field (990°C), the mechanical properties increase significantly [ultimate tensile strength (UTS) &gt;1,100 MPa, yield strength (YS) 900 MPa, and elongation 27%] due to the high percentage of martensite (M) present in the microstructure (95%). In contrast, when the cooling rate decreases and the treatment conditions remain at/or above the bainitic/martensitic transformation (from 990°C to 600°C and 450°C), the mechanical properties are decreased by almost 50% because of the decrease in the percentage of martensite (18%). However, the percentage of elongation increases significantly (38%) due to the presence of other micro-constituents resulting from the phase transformation. On the other hand, the best combination of mechanical properties (UTS above 800 MPa and YS between 610 MPa and 720 MPa) was obtained when the steel acquired a dual-phase microstructure [(martensite/austenite)-(ferrite/martensite)] since the amount of martensite is conserved between 45% and 82%, in combination with the other micro-constituent present in the steel that allows us to achieve elongation percentages close to 30%.</p> </abstract>ARTICLE2021-07-09T00:00:00.000+00:00Klein–Nishina formula and Monte Carlo method for evaluating the gamma attenuation properties of Zn, Ba, Te and Bi elementshttps://sciendo.com/article/10.2478/msp-2021-0019<abstract><title style='display:none'>Abstract</title><p>In this work, the Klein–Nishina (K–N) approach was used to evaluate the electronic, atomic, and energy-transfer cross sections of four elements, namely, zinc (Zn), tellurium (Te), barium (Ba), and bismuth (Bi), for different photon energies (0.662 MeV, 0.835 MeV, 1.170 MeV, 1.330 MeV, and 1.600 MeV). The obtained results were compared with the Monte Carlo method (Geant4 simulation) in terms of mass attenuation and mass energy-transfer coefficients. The results show that the K–N approach and Geant4 simulations are in good agreement for the entire energy range considered. As the photon energy increased from 0.662 MeV to 1.600 MeV, the values of the energy-transfer cross sections decreased from 81.135 cm<sup>2</sup> to 69.184 cm<sup>2</sup> in the case of Bi, from 50.832 cm<sup>2</sup> to 43.344 cm<sup>2</sup> for Te, from 54.742 cm<sup>2</sup> to 46.678 cm<sup>2</sup> for Ba, and from 29.326 cm<sup>2</sup> to 25.006 cm<sup>2</sup> for Zn. The obtained results and the detailed information of the attenuation properties for the studied elements would be helpful in developing a new generation of shielding materials against gamma rays.</p></abstract>ARTICLE2021-10-18T00:00:00.000+00:00Surface roughness analysis of prepolymerized CAD/CAM dental acrylic resins following combined surface treatmentshttps://sciendo.com/article/10.2478/msp-2021-0018<abstract><title style='display:none'>Abstract</title><p>Oral dentures are subjected to mechanical and chemical cleansing processes. However, these processes alter the physical and mechanical properties of denture acrylic resins. This study analyzes the surface roughness of conventional heat-cured (HC) polymethacrylate, light-cured (LC) urethane dimethacrylate, and prepolymerized computer-aided design/computer-aided manufacturing (CAD/CAM) dental acrylic resins. The materials were subjected to combined surface treatment of mechanical brushing, thermal cycling, and immersion in chemical disinfectants (corega, chlorhexidine gluconate [CHG], and sodium hypochlorite) to simulate 1 year of clinical use. The surface roughness of the resin specimens before and after surface treatment was evaluated using a noncontact profilometer. Statistical tests based on analysis of variance revealed significant interactions between resin type and disinfectants, indicating that the effects of these two factors were interdependent. The highest and lowest surface roughness was observed in HC resins immersed in CHG and CAD/CAM resins immersed in sodium hypochlorite. Among the materials, HC resins demonstrated the overall highest mean roughness, followed by LC and CAD/CAM resins. Regarding the disinfectant use, the highest mean roughness was observed in disks immersed in CHG, followed by those immersed in corega and sodium hypochlorite. The prepolymerized CAD/CAM acrylic resin demonstrated superior surface quality following combined surface treatments. The HC and LC resins exceeded the roughness threshold and the reported roughness values for acrylic resins following surface treatments. Among the disinfectants tested, sodium hypochlorite produced overall low roughness values.</p></abstract>ARTICLE2021-10-14T00:00:00.000+00:00Analysis of the production process of the forked forging used in the excavator drive system in order to improve the currently implemented technology by the use of numerical modelinghttps://sciendo.com/article/10.2478/msp-2021-0020<abstract><title style='display:none'>Abstract</title><p>The study concerns a comprehensive analysis of a multistage hot-die forging on hammers, in order to produce a yoke-type forging, used as a component of excavator power transmission systems. The investigations were conducted with the aim to analyze and identify the sensitive areas in the process and then improve the currently implemented forging technology by using finite element (FE) simulation. QuantorForm (the developer of the QForm program) has developed a thermomechanical numerical model for the production of forked forging. The software Computer-Aided Three-Dimensional Interactive Application (CATIA) was used to develop and build Computer-Aided Design (CAD) models of forging tools. As a result of the numerical simulations, the plastic deformations and temperature distributions for the forgings and tools were obtained, and the force courses during the forging process were analyzed. The obtained results enabled a thorough analysis of the forging process, including identification of potential forging defects (laps) as well as those tool areas that are the most loaded and exposed to damage. On this basis, changes were implemented in the production process, which allowed for the improvement of the currently implemented technology and obtaining the corrected forgings.</p></abstract>ARTICLE2021-10-13T00:00:00.000+00:00The qualitative–quantitative approach to microstructural characterization of nanostructured bainitic steels using electron microscopy methodshttps://sciendo.com/article/10.2478/msp-2021-0017<abstract><title style='display:none'>Abstract</title><p>Both qualitative and quantitative analyses play a key role in the microstructural characterization of nanobainitic steels focused on their mechanical properties. This research demonstrates various methods of microstructure analysis using transmission electron microscopy (TEM), scanning electron microscopy (SEM), and electron backscatter diffraction (EBSD) techniques, taking into account these two approaches. The structural constituents have been qualitatively characterized using TEM and selected area electron diffraction (SAED), together with quantitative analysis based on the misorientation angle (EBSD). Besides, quantitative measurement of austenite with both blocky and film-like morphologies has been carried out. Due to the scale of nanostructured bainite, it is also important to control the thickness of bainitic ferrite and film-like austenite; hence, a method for measuring their thickness is presented. Finally, the possibility of measuring the prior-austenite grain size by the EBSD method is also demonstrated and compared with the conventional grain boundary etching method. The presented methods of qualitative and quantitative analyses form a complementary procedure for the microstructural characterization of nanoscale bainitic steels.</p></abstract>ARTICLE2021-10-01T00:00:00.000+00:00The effect of varied types of steel fibers on the performance of self-compacting concrete modified with volcanic pumice powderhttps://sciendo.com/article/10.2478/msp-2021-0016<abstract><title style='display:none'>Abstract</title><p>The aim of this work involves studying the impact of varied types of steel fibers (SF) on the performance of self-compacting concrete (SCC), containing volcanic pumice powder (VPP). In this study, five types of steel fiber, which had a hooked end with two lengths of (SF1) and (SF3), flat end of length (SF2), in addition to the pointed end of (SF4) and (SF5) by 1% of volume fraction, were used. In addition, hybrid steel fiber (a mixture of all the steel fiber types) by 0.2% of volume fraction of concrete volume was used. Moreover, VPP was utilized by 30% cement mass as a substitute material for producing SCC. The impact of steel fiber properties in the shape of SF on the fresh concrete properties as slump flow and segregation were investigated. In addition to their influence on the compressive strength, split tensile strength, flexural strength, toughness, porosity, water absorption, and bulk density were examined. The results showed that SF led to decreasing the SCC fresh properties. Utilizing SF, on the other hand, improved the SCC hardened properties, as well as the toughness indices.</p></abstract>ARTICLE2021-10-01T00:00:00.000+00:00Optoelectronics applications of electrodeposited p- and n-type AlSe thin filmshttps://sciendo.com/article/10.2478/msp-2021-0011<abstract><title style='display:none'>Abstract</title><p>In this paper, energy band gaps and electrical conductivity based on aluminum selenide (Al<sub>2</sub>Se<sub>3</sub>) thin films are synthesized electrochemically using cathodic deposition technique, with graphite and carbon as cathode and anode, respectively. Synthesis is done at 353 K from an aqueous solution of analytical grade selenium dioxide (SeO<sub>2</sub>), and aluminum chloride (AlCl<sub>2</sub>·7H<sub>2</sub>O). Junctions-based Al<sub>2</sub>Se<sub>3</sub> thin films from a controlled medium of pH 2.0 are deposited on fluorine-doped tin oxide (FTO) substrate using potential voltages varying from 1,000 mV to 1,400 mV and 3 minutes −15 minutes respectively. The films were characterized for optical properties and electrical conductivity using UV-vis and photoelectrochemical cells (PEC) spectroscopy. The PEC reveals a transition in the conduction of the films from p-type to n-type as the potential voltage varies. The energy band gap reduces from 3.2 eV to 2.9 eV with an increase in voltage and 3.3 eV to 2.7 eV with increase in time. These variations indicate successful fabrication of junction-based Al<sub>2</sub>Se<sub>3</sub> thin films with noticeable transition in the conductivity type and energy band gap of the materials. Consequently, the fabricated Al<sub>2</sub>Se<sub>3</sub> can find useful applications in optoelectronic devices.</p></abstract>ARTICLE2021-09-02T00:00:00.000+00:00Thermo-magnetic stability of magnetic FeO nanoparticles for hyperthermiahttps://sciendo.com/article/10.2478/msp-2020-0081<abstract> <title style='display:none'>Abstract</title> <p>Monodispersed Fe<sub>3</sub>O<sub>4</sub> magnetic particles adsorbed by amylase (such as citric acid (CA), carboxymethyl chitosan (CMCH) and β-cyclodextrin (CD)) were prepared by means of co-precipitation method. The absorption character of the samples was investigated by FT-IR, TG and VSM. It was found that the carboxyl (COOH groups) of amylase reacted with the hydroxyl (OH groups) on the surface of Fe<sub>3</sub>O<sub>4</sub> particles, resulting in the formation of iron carboxylate that was adsorbed onto Fe<sub>3</sub>O<sub>4</sub>. The induction heating properties of the magnetic Fe<sub>3</sub>O<sub>4</sub> nanoparticles in an alternating current magnetic field were also investigated and the thermo-magnetic stability in induction heating was discussed.</p> </abstract>ARTICLE2021-04-13T00:00:00.000+00:00Investigation and optimization of friction stir welding process parameters of stir cast AA6082/ZrO/BC compositeshttps://sciendo.com/article/10.2478/msp-2020-0082<abstract> <title style='display:none'>Abstract</title> <p>In the present investigation, aluminium-based alloy (AA6082) is stir-casted with 3 % ZrO<sub>2</sub> and 5 % B<sub>4</sub>C reinforcement particulates to fabricate Aluminium Metal Matrix Hybrid Composites (AMMHCs) which are further friction-stir welded at different welding conditions to develop a welded joint with optimum ultimate tensile strength (UTS) and microhardness. This newly developed AMMHC will find its specific application as bulkhead partitions in the hull of a ship due to its excellent properties, such as lower weight, higher specific strength, superior resistance to wear, and lower thermal expansion coefficient than that of AA6061 and AA5083 composites. The friction-welded butt joints performance of AA6082/3%ZrO<sub>2</sub>/5%B<sub>4</sub>C is generally determined by varying the FSW process parameters such as tool rotational speed (TRS), welding speed (WS), axial load (AL), tool tilt angle (TTA), tool pin profile (TPP), shoulder diameter (SD), etc. In the present work, the empirical relationships are established between parameters highly influencing FSW process (TRS, WS, and AL) and their responses (UTS and weld nugget microhardness (WNH)). The desirability approach is employed for predicting the optimal UTS and WNH. The corresponding values of input process parameters are TRS of 1030.95 rpm, WS of 38.5 mm/min, and AL of 5.88 kN. The calculated UTS and WNH for the present investigation are 239.98 MPa and 94.2 HV, respectively, and these values are consistent with the results of validation experiments.</p> </abstract>ARTICLE2021-04-13T00:00:00.000+00:00en-us-1