Recent Developments in the Study of Recrystallization, 2013
Recent Developments in the Study of Recrystallization 118 Recent Developments in the Study of Rec... more Recent Developments in the Study of Recrystallization 118 Recent Developments in the Study of Recrystallization Recent Developments in the Study of Recrystallization Recent Developments in the Study of Recrystallization Recent Developments in the Study of Recrystallization 132 Recent Developments in the Study of Recrystallization 138
In this paper, the cladding of pure aluminum and a low-carbon steel alloy was performed through f... more In this paper, the cladding of pure aluminum and a low-carbon steel alloy was performed through friction stir processing with minimal intermetallic compound formation. A 3 mm thick aluminum plate was clamped on top of a steel plate. A thick, pure copper plate was used as a backing plate. The tool pin length was adjusted to be the same as the upper plate’s thickness (3 mm) and longer than 3.2 mm. The effect of the tool pin length and the rotation speed (500–1500 rpm) on the cladding’s quality, microstructure, and the mechanical properties of the steel/aluminum interface were investigated using optical and scanning electron microscopy, a hardness test, and a peel test. The results showed that the bonding of pure aluminum and a low-carbon steel alloy can be successfully performed at a more than 500 rpm rotation speed. At a tool pin length of 3 mm and a rotation speed of 1000 rpm, sound and free-intermetallic compound–cladding interfaces were formed, while some Fel2Al5 intermetallics we...
In this study, a multi-component FeMnNiCrAlSi high-entropy alloy, chosen through Thermo-Calc® sof... more In this study, a multi-component FeMnNiCrAlSi high-entropy alloy, chosen through Thermo-Calc® software (2021a, Stockholm, Sweden) calculation and produced by electric arc melting, was studied for phase continents and mechanical properties. The results elucidated that the cold rolled condition (area reduction ratio about 86%) was in the form of elongated grains with a dendritic structure. Also, small amounts of the BCC phase were precipitated at the grain boundaries. The annealed sample shows features of BCC phase and different sizes of intermetallics. These results coincided with the predictions of Thermo-Calc® software calculations. A cold rolled sample showed high compressive yield strength of about 950 MPa, and the annealed sample had only half the strength of the cold rolled condition. The cold rolled sample shows the highest micro-hardness. The wear resistance of the annealed condition was significantly improved at room temperature and at 200 °C. The brittle phases in the annea...
The International Journal of Oral & Maxillofacial Implants, 2022
The aim of this study was to coat titanium substrate with bioactive glass nanoparticles and chara... more The aim of this study was to coat titanium substrate with bioactive glass nanoparticles and characterize the deposited surface coat. Materials and Methods: Amorphous bioglass nanoparticles < 20 nm in diameter were prepared using a modified sol-gel technique followed by a ball-milling process. The prepared nanoparticles were used to coat airborne particle-abraded titanium disks. The in vitro bioactivity of the bioglass nanopowder was confirmed using simulated body fluid. Coated surfaces were characterized in terms of microstructure, composition, thickness, phase structure, surface roughness, wettability, and tissue behavior in a rabbit model. Results: Bioglass nanoparticles showed apatite formation under a scanning electron microscope (SEM) after 5 days, confirming that bioactivity was enhanced with increasing degradation rate for up to 2 weeks. An optimized deposition technique and heat-treatment process produced a homogenous coating with a uniform thickness of 32 to 39 μm. Chemical analysis confirmed the presence of silicon and calcium on the coated disks. Amorphous coated surfaces exhibited porous nano/microroughness with microcracks and super-hydrophilicity. The interface of the coated disks with subcutaneous tissue revealed good tissue adhesion, high cellular activity, and rich vascularization, with multinucleated cells in the microenvironment surrounding the coat, as confirmed using histomorphometric analysis. Conclusion: The results of this study show that it is feasible to coat titanium surfaces with bioactive glass nanoparticles with super-hydrophilicity and high biologic activity. These particles may promote the regenerative environment around dental implants.
New high entropy alloys with good corrosion resistance in severe environment are receiving increa... more New high entropy alloys with good corrosion resistance in severe environment are receiving increasing attention. This work reports upon the microstructure and the corrosion resistance of the non-equiatomic Fe36Mn20Ni20Cr16Al5Si3 alloy in different acidic solutions. This alloy was designed by thermodynamic calculations using CALPHAD SOFTWARE, fabricated through casting, subjected to cold-rolling and solution-treatment, and compared with SS304 stainless steel. The corrosion test was performed through electrochemical behavior in 0.6 M NaCl and 0.6 M NaCl with 0.5 M H2SO4 and 0.6 M NaCl with 1 M H2SO4 solutions. Experimental results indicate that the alloy is composed of FCC phase as the main constituent besides a small amount of other BCC/B2 phases and other intermetallics. The corrosion test measurements revealed that cold-rolled Fe36Mn20Ni20Cr16Al5Si3 alloy is more resistant to corrosion in 0.6 M NaCl, while it is more susceptible to localized pits in H2SO4 to 0.6 M NaCl. Experimenta...
The selection of high-entropy alloys (HEAs), which are relatively lightweight and have unique mec... more The selection of high-entropy alloys (HEAs), which are relatively lightweight and have unique mechanical properties, remains a substantial challenge. In this study, six new HEAs were designed from the relatively low-cost Fe–Mn–Ni–Cr–Al–Si system using Thermo-Calc software, and then manufactured using a casting process. The effects of the atomic ratio of the alloying elements on the microstructures and mechanical properties of these alloys in the as-cast condition were systematically investigated. Brittle body-centered cubic BCC/B2 and silicide phases were found in relatively large amounts in the form of dendritic structure within large equiaxed grains with fine needle-shaped phases in the Fe30Mn15Ni20Cr15Al10Si10 and Fe35Mn15Ni20Cr15Al10Si5 alloys, in addition to the face-centered cubic (FCC) phase. When the contents of Mn and Ni were increased in the Fe35Mn25Ni15Cr15Al5Si5 and Fe35Mn20Ni20Cr15Al5Si5 alloys, the amounts of brittle phases were reduced; however, the ductile FCC phase ...
Polyether-ether-ketone (PEEK) biomaterial has been increasingly employed for orthopedic, trauma, ... more Polyether-ether-ketone (PEEK) biomaterial has been increasingly employed for orthopedic, trauma, spinal, and dental implants due to its biocompatibility and in vivo stability. However, a lack of bioactivity and binding ability to natural bone tissue has significantly limited PEEK for many challenging dental implant applications. In this work, nanocomposites based on PEEK reinforced with bioactive silicate-based bioceramics (forsterite or bioglass) as nanofillers were prepared using high energy ball milling followed by melt blending and compression molding. The influence of nanofillers type and content (10, 20 and 30 wt.%) on the crystalline structure, morphology, surface roughness, hydrophilicity, microhardness, elastic compression modulus, and flexural strength of the nanocomposites was investigated. The scanning electron microscopy images of the nanocomposites with low nanofillers content showed a homogenous surface with uniform dispersion within the PEEK matrix with no agglomerat...
79 особливість у сприйманні художніх смислів музичних творів, що відображають культурну традицію ... more 79 особливість у сприйманні художніх смислів музичних творів, що відображають культурну традицію історичної епохи, у якій жив композитор, його внутрішній світ. У музичних творах художні смисли є непредметним і, водночас, поетичними. Уміння розкодувати художні смисли, з дотриманням певної об'єктивності, формуються тільки в контексті культурного досвіду тієї епохи, у якій творив композитор. Отже, аналіз науково-теоретичного досвіду надав змогу визначити сутність базових понять дослідження: культура, культурологія, культурологічний підхід, культурологічна підготовка, педагогічна культура. Застосування культурологічного підходу до професійної підготовки майбутніх учителів музичного мистецтва має свою специфіку, що полягає в: опануванні студентами культурним досвідом різних видів мистецтв; привласненні цінностей мистецтв, значною мірою, через почуттєву сферу; сприйманні художніх смислів музичних творів. Культурологічна підготовка надає змогу сформувати ціннісну сферу майбутніх фахівців та сприяти зростанню їх духовних потреб.
79 особливість у сприйманні художніх смислів музичних творів, що відображають культурну традицію ... more 79 особливість у сприйманні художніх смислів музичних творів, що відображають культурну традицію історичної епохи, у якій жив композитор, його внутрішній світ. У музичних творах художні смисли є непредметним і, водночас, поетичними. Уміння розкодувати художні смисли, з дотриманням певної об'єктивності, формуються тільки в контексті культурного досвіду тієї епохи, у якій творив композитор. Отже, аналіз науково-теоретичного досвіду надав змогу визначити сутність базових понять дослідження: культура, культурологія, культурологічний підхід, культурологічна підготовка, педагогічна культура. Застосування культурологічного підходу до професійної підготовки майбутніх учителів музичного мистецтва має свою специфіку, що полягає в: опануванні студентами культурним досвідом різних видів мистецтв; привласненні цінностей мистецтв, значною мірою, через почуттєву сферу; сприйманні художніх смислів музичних творів. Культурологічна підготовка надає змогу сформувати ціннісну сферу майбутніх фахівців та сприяти зростанню їх духовних потреб.
The Oxidation behavior of the Al5Cr12Fe35Mn28Ni20 high entropy alloy was investigated in air at t... more The Oxidation behavior of the Al5Cr12Fe35Mn28Ni20 high entropy alloy was investigated in air at temperatures 900 °C, 1000 °C and 1100 °C for 100 h isothermally. The oxidation kinetics at all temperatures obeys the parabolic rate law with an activation energy 100.6 kJ mol−1. The alloy was externally oxidized forming duplex layer consisted of manganese oxides that overlays Mn-Cr-Fe spinel oxides. While, it was observed that at 1000 °C and 1100 °C the samples were also oxidized internally forming Al2O3 deep in the alloy. The initial oxidation behavior of the alloy oxidized at 1000 °C for 1 and 24 h producing external scale of Mn3O4 overlaying Mn-Cr-Fe spinel oxide and Al2O3 precipitates.
High entropy alloys (HEAs) show demonstrated unique and attractive properties for various enginee... more High entropy alloys (HEAs) show demonstrated unique and attractive properties for various engineering applications. Significant advancements in HEAs have revealed promising properties as ductility, toughness, hardness, and resistance to corrosion. The HEAs corrosion behavior in aqueous solutions attracted the interest recently of researchers to explore the range of its possible applications. The new Al12Cr12Fe35Mn21Ni20 high entropy alloy (HEA) is investigated as a potential corrosion-resistant alloy in acidic media. Cast Al12Cr12Fe35Mn21Ni20 HEA was cold rolled up to 70% reduction then solution treatment. The micro-hardness, X-ray diffraction, and microstructure of the Al12Cr12Fe35Mn21Ni20 HEA were investigated after solution treatment. The electrochemical experiments were performed at room temperature with two concentrations, 0.5 M and 1 M, in both NaCl and H2SO4 solutions. The potentiodynamic response is used to calculate corrosion rates. In addition, for the various conditions, cyclic voltammetry was investigated. Surface characterization of corroded samples was provided using scanning electron microscopy and energy dispersive x-ray analyzer. The results demonstrate that the Al12Cr12Fe35Mn21Ni2 HEA in NaCl has a good corrosion resistance especially in 1 M concentrations.
Abstract Tempcore process is an environmental friendly, simple and energy efficient technology fo... more Abstract Tempcore process is an environmental friendly, simple and energy efficient technology for producing high strength reinforcing steel rebars without requiring costly alloying addition. The mechanical properties of Tempcore treated steel rebar have been previously investigated using various models, although they are still restricted to specific steel compositions, bar sizes, and/or process parameters. In this study, a methodology is developed to predict the internal microstructure and overall mechanical properties (i.e., hardness, ultimate tensile strength, and yield strength) of Tempcore treated bars for any steel compositions, bar sizes, process parameters, and simulation assumptions. Three sequential models are proposed: (1) thermal model to predict thermal profiles of bars using computational fluid dynamics CFD simulation, (2) metallurgical model to estimate the internal microstructure change across the bar section using both; the JMatPro ® and a derived equation that calculates the martensite volume fraction (V m %) of a functionally graded steel bar, and (3) Regression models based on the rule of mixture to predict mechanical properties. The validation results show a good agreement between calculated and experimental results; the mean absolute percentage errors are 2.8% for hardness, 2.8% for ultimate stress and 3.8% for yield stress. Eventually, the proposed methodology presented a sustainable, easy, fast, and cost-efficient solution to attain the required mechanical properties of a steel bar treated by Tempcore process. Graphic Abstract
IOP Conference Series: Materials Science and Engineering, 2019
The effect of Sn-addition (0, 1.5, and 3 Sn, at.%) to the biomedical Ti-17Nb-6Ta alloy has been i... more The effect of Sn-addition (0, 1.5, and 3 Sn, at.%) to the biomedical Ti-17Nb-6Ta alloy has been investigated in this study. The three alloys were proved using XRD analysis to be β-type alloys. Microstructural analysis using optical microscope showed martensite lathes in all alloys and proved that Sn addition stabilized β phase and suppresses the martensite formation during quenching. Micro-hardness results showed a slight increase with 1.5% Sn adding but superior addition of Sn with 3% at. has negligible effect on the hardness compared to Sn-free alloy. The compressive yield stress for the three alloys located between 400 to 500 MPa, and the stain values increased with the increasing of Sn percentages in the TNT alloy.
The effect of manganese content (Mn-content) on the beta phase (β-phase) stability, plastic defor... more The effect of manganese content (Mn-content) on the beta phase (β-phase) stability, plastic deformability and mechanical behavior of titanium and (8–18 wt.%) manganese low-cost alloys were investigated. The alloys were produced by electric-arc melting under inert argon atmosphere. Microstructure change during cold rolling was evaluated through x-ray diffraction, scanning electron microscope, transmission electron microscope and electron backscatter diffraction in solution-treated and cold-deformed conditions. The β-phase was predominant in all the alloys under study in addition to very fine ω-phase precipitates, especially in the lower Mn-content alloys. Cold workability of the alloys was initially increased in the low Mn-content alloys and then decreased dramatically in the higher Mn-content alloys. The deformation mechanisms were a combination between dislocation slipping and twinning, with a predominance of twinning in the low Mn-content and slipping in the high Mn-content alloys. Tensile test results showed that an ultra-high-strength alloy of about 1950 MPa was obtained in the high Mn-content alloys after cold deformation.
In this work, two new α + β titanium alloys with low contents of ubiquitous and low-cost alloying... more In this work, two new α + β titanium alloys with low contents of ubiquitous and low-cost alloying elements (i.e., Mo and Fe) were designed on the basis of the electronic parameters and molybdenum equivalent approaches. The designed Ti - 2Mo - 0.5Fe at. % (TMF6) and Ti - 3Mo - 0.5Fe at. % (TMF8) alloys were produced using arc melting process for studying their mechanical, electrochemical and cytotoxicity compatibilities and comparing these compatibilities to those of Ti-6Al-4V ELI alloy. The cost of the used raw materials for producing the TMF6 and TMF8 alloys are almost 1/6 of those for producing the Ti-6Al-4V ELI alloy. The hardness of the two alloys are higher than that of the Ti-6Al-4V ELI alloy, while their Young's moduli (in the range of 85-82 GPa) are lower than that of the Ti-6Al-4V ELI alloy (110 GPa). Increasing the Mo equivalent from 6 (in TMF6 alloy) to 8 (in TMF8 alloy) led to an increase in the plastic strain percent from 4% to 17%, respectively, and a decrease in the ultimate tensile strength from 949 MPa to 800 MPa, respectively. The microstructure of TMF6 alloy consists of α'/α″ phases, while TMF8 alloy substantially consists of α″ phase. The corrosion current densities and the film resistances of the new alloys are in the range of 0.70-1.07 nA/cm2 and on the order of 105 Ω·cm2, respectively. These values are more compatible with biomedical applications than those measured for the Ti-6Al-4V ELI alloy. Furthermore, the cell viabilities of the TMF6 and TMF8 alloys indicate their improved compatibility compared to that of the Ti-6Al-4V ELI alloy. The CCK-8 (Cell Counting Kit-8) assay was conducted to investigate the cytotoxicity, proliferation, and shape index of the cells of the candidate alloys. Overall, the measured compatibility of the new V-free low-cost alloys, particularly TMF8, makes them promising candidates for replacing the Ti-6Al-4V ELI alloy in biomedical applications.
Recently, studying the shape memory effect of the biocompatible Ti alloys takes much attention in... more Recently, studying the shape memory effect of the biocompatible Ti alloys takes much attention in the biomedical and healthcare applications. This study concerns about characterizing the superelasticity of the new biocompatible Ti-17Nb-6Ta (TNT) alloy. Microstructure of TNT was observed using optical and confocal microscopes. The alloy consists of two phases: β (predominant phase) and α″ martensite phase. The influence of cold rolling deformation on the microstructure was illustrated in which the martensitic-induced transformation appeared by cold rolling. The alloy is ductile as only the fracture dimples appeared in its fracture surface. Multicyclic loading and deloading tensile testing was applied to TNT specimens (flat and wire shapes) in order to evaluate the superelasticity. A superelastic strain as high as 3.5% was recorded for this TNT alloy. Therefore, TNT alloy has high potential for many biomedical and healthcare applications.
Recent Developments in the Study of Recrystallization, 2013
Recent Developments in the Study of Recrystallization 118 Recent Developments in the Study of Rec... more Recent Developments in the Study of Recrystallization 118 Recent Developments in the Study of Recrystallization Recent Developments in the Study of Recrystallization Recent Developments in the Study of Recrystallization Recent Developments in the Study of Recrystallization 132 Recent Developments in the Study of Recrystallization 138
In this paper, the cladding of pure aluminum and a low-carbon steel alloy was performed through f... more In this paper, the cladding of pure aluminum and a low-carbon steel alloy was performed through friction stir processing with minimal intermetallic compound formation. A 3 mm thick aluminum plate was clamped on top of a steel plate. A thick, pure copper plate was used as a backing plate. The tool pin length was adjusted to be the same as the upper plate’s thickness (3 mm) and longer than 3.2 mm. The effect of the tool pin length and the rotation speed (500–1500 rpm) on the cladding’s quality, microstructure, and the mechanical properties of the steel/aluminum interface were investigated using optical and scanning electron microscopy, a hardness test, and a peel test. The results showed that the bonding of pure aluminum and a low-carbon steel alloy can be successfully performed at a more than 500 rpm rotation speed. At a tool pin length of 3 mm and a rotation speed of 1000 rpm, sound and free-intermetallic compound–cladding interfaces were formed, while some Fel2Al5 intermetallics we...
In this study, a multi-component FeMnNiCrAlSi high-entropy alloy, chosen through Thermo-Calc® sof... more In this study, a multi-component FeMnNiCrAlSi high-entropy alloy, chosen through Thermo-Calc® software (2021a, Stockholm, Sweden) calculation and produced by electric arc melting, was studied for phase continents and mechanical properties. The results elucidated that the cold rolled condition (area reduction ratio about 86%) was in the form of elongated grains with a dendritic structure. Also, small amounts of the BCC phase were precipitated at the grain boundaries. The annealed sample shows features of BCC phase and different sizes of intermetallics. These results coincided with the predictions of Thermo-Calc® software calculations. A cold rolled sample showed high compressive yield strength of about 950 MPa, and the annealed sample had only half the strength of the cold rolled condition. The cold rolled sample shows the highest micro-hardness. The wear resistance of the annealed condition was significantly improved at room temperature and at 200 °C. The brittle phases in the annea...
The International Journal of Oral & Maxillofacial Implants, 2022
The aim of this study was to coat titanium substrate with bioactive glass nanoparticles and chara... more The aim of this study was to coat titanium substrate with bioactive glass nanoparticles and characterize the deposited surface coat. Materials and Methods: Amorphous bioglass nanoparticles < 20 nm in diameter were prepared using a modified sol-gel technique followed by a ball-milling process. The prepared nanoparticles were used to coat airborne particle-abraded titanium disks. The in vitro bioactivity of the bioglass nanopowder was confirmed using simulated body fluid. Coated surfaces were characterized in terms of microstructure, composition, thickness, phase structure, surface roughness, wettability, and tissue behavior in a rabbit model. Results: Bioglass nanoparticles showed apatite formation under a scanning electron microscope (SEM) after 5 days, confirming that bioactivity was enhanced with increasing degradation rate for up to 2 weeks. An optimized deposition technique and heat-treatment process produced a homogenous coating with a uniform thickness of 32 to 39 μm. Chemical analysis confirmed the presence of silicon and calcium on the coated disks. Amorphous coated surfaces exhibited porous nano/microroughness with microcracks and super-hydrophilicity. The interface of the coated disks with subcutaneous tissue revealed good tissue adhesion, high cellular activity, and rich vascularization, with multinucleated cells in the microenvironment surrounding the coat, as confirmed using histomorphometric analysis. Conclusion: The results of this study show that it is feasible to coat titanium surfaces with bioactive glass nanoparticles with super-hydrophilicity and high biologic activity. These particles may promote the regenerative environment around dental implants.
New high entropy alloys with good corrosion resistance in severe environment are receiving increa... more New high entropy alloys with good corrosion resistance in severe environment are receiving increasing attention. This work reports upon the microstructure and the corrosion resistance of the non-equiatomic Fe36Mn20Ni20Cr16Al5Si3 alloy in different acidic solutions. This alloy was designed by thermodynamic calculations using CALPHAD SOFTWARE, fabricated through casting, subjected to cold-rolling and solution-treatment, and compared with SS304 stainless steel. The corrosion test was performed through electrochemical behavior in 0.6 M NaCl and 0.6 M NaCl with 0.5 M H2SO4 and 0.6 M NaCl with 1 M H2SO4 solutions. Experimental results indicate that the alloy is composed of FCC phase as the main constituent besides a small amount of other BCC/B2 phases and other intermetallics. The corrosion test measurements revealed that cold-rolled Fe36Mn20Ni20Cr16Al5Si3 alloy is more resistant to corrosion in 0.6 M NaCl, while it is more susceptible to localized pits in H2SO4 to 0.6 M NaCl. Experimenta...
The selection of high-entropy alloys (HEAs), which are relatively lightweight and have unique mec... more The selection of high-entropy alloys (HEAs), which are relatively lightweight and have unique mechanical properties, remains a substantial challenge. In this study, six new HEAs were designed from the relatively low-cost Fe–Mn–Ni–Cr–Al–Si system using Thermo-Calc software, and then manufactured using a casting process. The effects of the atomic ratio of the alloying elements on the microstructures and mechanical properties of these alloys in the as-cast condition were systematically investigated. Brittle body-centered cubic BCC/B2 and silicide phases were found in relatively large amounts in the form of dendritic structure within large equiaxed grains with fine needle-shaped phases in the Fe30Mn15Ni20Cr15Al10Si10 and Fe35Mn15Ni20Cr15Al10Si5 alloys, in addition to the face-centered cubic (FCC) phase. When the contents of Mn and Ni were increased in the Fe35Mn25Ni15Cr15Al5Si5 and Fe35Mn20Ni20Cr15Al5Si5 alloys, the amounts of brittle phases were reduced; however, the ductile FCC phase ...
Polyether-ether-ketone (PEEK) biomaterial has been increasingly employed for orthopedic, trauma, ... more Polyether-ether-ketone (PEEK) biomaterial has been increasingly employed for orthopedic, trauma, spinal, and dental implants due to its biocompatibility and in vivo stability. However, a lack of bioactivity and binding ability to natural bone tissue has significantly limited PEEK for many challenging dental implant applications. In this work, nanocomposites based on PEEK reinforced with bioactive silicate-based bioceramics (forsterite or bioglass) as nanofillers were prepared using high energy ball milling followed by melt blending and compression molding. The influence of nanofillers type and content (10, 20 and 30 wt.%) on the crystalline structure, morphology, surface roughness, hydrophilicity, microhardness, elastic compression modulus, and flexural strength of the nanocomposites was investigated. The scanning electron microscopy images of the nanocomposites with low nanofillers content showed a homogenous surface with uniform dispersion within the PEEK matrix with no agglomerat...
79 особливість у сприйманні художніх смислів музичних творів, що відображають культурну традицію ... more 79 особливість у сприйманні художніх смислів музичних творів, що відображають культурну традицію історичної епохи, у якій жив композитор, його внутрішній світ. У музичних творах художні смисли є непредметним і, водночас, поетичними. Уміння розкодувати художні смисли, з дотриманням певної об'єктивності, формуються тільки в контексті культурного досвіду тієї епохи, у якій творив композитор. Отже, аналіз науково-теоретичного досвіду надав змогу визначити сутність базових понять дослідження: культура, культурологія, культурологічний підхід, культурологічна підготовка, педагогічна культура. Застосування культурологічного підходу до професійної підготовки майбутніх учителів музичного мистецтва має свою специфіку, що полягає в: опануванні студентами культурним досвідом різних видів мистецтв; привласненні цінностей мистецтв, значною мірою, через почуттєву сферу; сприйманні художніх смислів музичних творів. Культурологічна підготовка надає змогу сформувати ціннісну сферу майбутніх фахівців та сприяти зростанню їх духовних потреб.
79 особливість у сприйманні художніх смислів музичних творів, що відображають культурну традицію ... more 79 особливість у сприйманні художніх смислів музичних творів, що відображають культурну традицію історичної епохи, у якій жив композитор, його внутрішній світ. У музичних творах художні смисли є непредметним і, водночас, поетичними. Уміння розкодувати художні смисли, з дотриманням певної об'єктивності, формуються тільки в контексті культурного досвіду тієї епохи, у якій творив композитор. Отже, аналіз науково-теоретичного досвіду надав змогу визначити сутність базових понять дослідження: культура, культурологія, культурологічний підхід, культурологічна підготовка, педагогічна культура. Застосування культурологічного підходу до професійної підготовки майбутніх учителів музичного мистецтва має свою специфіку, що полягає в: опануванні студентами культурним досвідом різних видів мистецтв; привласненні цінностей мистецтв, значною мірою, через почуттєву сферу; сприйманні художніх смислів музичних творів. Культурологічна підготовка надає змогу сформувати ціннісну сферу майбутніх фахівців та сприяти зростанню їх духовних потреб.
The Oxidation behavior of the Al5Cr12Fe35Mn28Ni20 high entropy alloy was investigated in air at t... more The Oxidation behavior of the Al5Cr12Fe35Mn28Ni20 high entropy alloy was investigated in air at temperatures 900 °C, 1000 °C and 1100 °C for 100 h isothermally. The oxidation kinetics at all temperatures obeys the parabolic rate law with an activation energy 100.6 kJ mol−1. The alloy was externally oxidized forming duplex layer consisted of manganese oxides that overlays Mn-Cr-Fe spinel oxides. While, it was observed that at 1000 °C and 1100 °C the samples were also oxidized internally forming Al2O3 deep in the alloy. The initial oxidation behavior of the alloy oxidized at 1000 °C for 1 and 24 h producing external scale of Mn3O4 overlaying Mn-Cr-Fe spinel oxide and Al2O3 precipitates.
High entropy alloys (HEAs) show demonstrated unique and attractive properties for various enginee... more High entropy alloys (HEAs) show demonstrated unique and attractive properties for various engineering applications. Significant advancements in HEAs have revealed promising properties as ductility, toughness, hardness, and resistance to corrosion. The HEAs corrosion behavior in aqueous solutions attracted the interest recently of researchers to explore the range of its possible applications. The new Al12Cr12Fe35Mn21Ni20 high entropy alloy (HEA) is investigated as a potential corrosion-resistant alloy in acidic media. Cast Al12Cr12Fe35Mn21Ni20 HEA was cold rolled up to 70% reduction then solution treatment. The micro-hardness, X-ray diffraction, and microstructure of the Al12Cr12Fe35Mn21Ni20 HEA were investigated after solution treatment. The electrochemical experiments were performed at room temperature with two concentrations, 0.5 M and 1 M, in both NaCl and H2SO4 solutions. The potentiodynamic response is used to calculate corrosion rates. In addition, for the various conditions, cyclic voltammetry was investigated. Surface characterization of corroded samples was provided using scanning electron microscopy and energy dispersive x-ray analyzer. The results demonstrate that the Al12Cr12Fe35Mn21Ni2 HEA in NaCl has a good corrosion resistance especially in 1 M concentrations.
Abstract Tempcore process is an environmental friendly, simple and energy efficient technology fo... more Abstract Tempcore process is an environmental friendly, simple and energy efficient technology for producing high strength reinforcing steel rebars without requiring costly alloying addition. The mechanical properties of Tempcore treated steel rebar have been previously investigated using various models, although they are still restricted to specific steel compositions, bar sizes, and/or process parameters. In this study, a methodology is developed to predict the internal microstructure and overall mechanical properties (i.e., hardness, ultimate tensile strength, and yield strength) of Tempcore treated bars for any steel compositions, bar sizes, process parameters, and simulation assumptions. Three sequential models are proposed: (1) thermal model to predict thermal profiles of bars using computational fluid dynamics CFD simulation, (2) metallurgical model to estimate the internal microstructure change across the bar section using both; the JMatPro ® and a derived equation that calculates the martensite volume fraction (V m %) of a functionally graded steel bar, and (3) Regression models based on the rule of mixture to predict mechanical properties. The validation results show a good agreement between calculated and experimental results; the mean absolute percentage errors are 2.8% for hardness, 2.8% for ultimate stress and 3.8% for yield stress. Eventually, the proposed methodology presented a sustainable, easy, fast, and cost-efficient solution to attain the required mechanical properties of a steel bar treated by Tempcore process. Graphic Abstract
IOP Conference Series: Materials Science and Engineering, 2019
The effect of Sn-addition (0, 1.5, and 3 Sn, at.%) to the biomedical Ti-17Nb-6Ta alloy has been i... more The effect of Sn-addition (0, 1.5, and 3 Sn, at.%) to the biomedical Ti-17Nb-6Ta alloy has been investigated in this study. The three alloys were proved using XRD analysis to be β-type alloys. Microstructural analysis using optical microscope showed martensite lathes in all alloys and proved that Sn addition stabilized β phase and suppresses the martensite formation during quenching. Micro-hardness results showed a slight increase with 1.5% Sn adding but superior addition of Sn with 3% at. has negligible effect on the hardness compared to Sn-free alloy. The compressive yield stress for the three alloys located between 400 to 500 MPa, and the stain values increased with the increasing of Sn percentages in the TNT alloy.
The effect of manganese content (Mn-content) on the beta phase (β-phase) stability, plastic defor... more The effect of manganese content (Mn-content) on the beta phase (β-phase) stability, plastic deformability and mechanical behavior of titanium and (8–18 wt.%) manganese low-cost alloys were investigated. The alloys were produced by electric-arc melting under inert argon atmosphere. Microstructure change during cold rolling was evaluated through x-ray diffraction, scanning electron microscope, transmission electron microscope and electron backscatter diffraction in solution-treated and cold-deformed conditions. The β-phase was predominant in all the alloys under study in addition to very fine ω-phase precipitates, especially in the lower Mn-content alloys. Cold workability of the alloys was initially increased in the low Mn-content alloys and then decreased dramatically in the higher Mn-content alloys. The deformation mechanisms were a combination between dislocation slipping and twinning, with a predominance of twinning in the low Mn-content and slipping in the high Mn-content alloys. Tensile test results showed that an ultra-high-strength alloy of about 1950 MPa was obtained in the high Mn-content alloys after cold deformation.
In this work, two new α + β titanium alloys with low contents of ubiquitous and low-cost alloying... more In this work, two new α + β titanium alloys with low contents of ubiquitous and low-cost alloying elements (i.e., Mo and Fe) were designed on the basis of the electronic parameters and molybdenum equivalent approaches. The designed Ti - 2Mo - 0.5Fe at. % (TMF6) and Ti - 3Mo - 0.5Fe at. % (TMF8) alloys were produced using arc melting process for studying their mechanical, electrochemical and cytotoxicity compatibilities and comparing these compatibilities to those of Ti-6Al-4V ELI alloy. The cost of the used raw materials for producing the TMF6 and TMF8 alloys are almost 1/6 of those for producing the Ti-6Al-4V ELI alloy. The hardness of the two alloys are higher than that of the Ti-6Al-4V ELI alloy, while their Young's moduli (in the range of 85-82 GPa) are lower than that of the Ti-6Al-4V ELI alloy (110 GPa). Increasing the Mo equivalent from 6 (in TMF6 alloy) to 8 (in TMF8 alloy) led to an increase in the plastic strain percent from 4% to 17%, respectively, and a decrease in the ultimate tensile strength from 949 MPa to 800 MPa, respectively. The microstructure of TMF6 alloy consists of α'/α″ phases, while TMF8 alloy substantially consists of α″ phase. The corrosion current densities and the film resistances of the new alloys are in the range of 0.70-1.07 nA/cm2 and on the order of 105 Ω·cm2, respectively. These values are more compatible with biomedical applications than those measured for the Ti-6Al-4V ELI alloy. Furthermore, the cell viabilities of the TMF6 and TMF8 alloys indicate their improved compatibility compared to that of the Ti-6Al-4V ELI alloy. The CCK-8 (Cell Counting Kit-8) assay was conducted to investigate the cytotoxicity, proliferation, and shape index of the cells of the candidate alloys. Overall, the measured compatibility of the new V-free low-cost alloys, particularly TMF8, makes them promising candidates for replacing the Ti-6Al-4V ELI alloy in biomedical applications.
Recently, studying the shape memory effect of the biocompatible Ti alloys takes much attention in... more Recently, studying the shape memory effect of the biocompatible Ti alloys takes much attention in the biomedical and healthcare applications. This study concerns about characterizing the superelasticity of the new biocompatible Ti-17Nb-6Ta (TNT) alloy. Microstructure of TNT was observed using optical and confocal microscopes. The alloy consists of two phases: β (predominant phase) and α″ martensite phase. The influence of cold rolling deformation on the microstructure was illustrated in which the martensitic-induced transformation appeared by cold rolling. The alloy is ductile as only the fracture dimples appeared in its fracture surface. Multicyclic loading and deloading tensile testing was applied to TNT specimens (flat and wire shapes) in order to evaluate the superelasticity. A superelastic strain as high as 3.5% was recorded for this TNT alloy. Therefore, TNT alloy has high potential for many biomedical and healthcare applications.
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