Mechanical properties of metals are substantially dependent on the microstructure, which can be controlled by thermo-mechanical parameters such as temperature, strain, and strain rate. Hence, understanding the microstructural evolution of alloys during the hot deformation is crucial to engineer the metal forming processes. The main objective of this work is to present an overview of cellular automaton (CA) modeling to predictthe microstructure of alloys experienced the dynamic recrystallization (DRX) phenomenon. In this review paper, first, overall descriptions about the DRX phenomenon and the CA modeling are presented. Then, the CA modeling procedure is compared with similar methods. Meanwhile, related studies in the field of the DRX simulation by using the CA modeling are evaluated. Four main stages of the CA modeling are analyzed in terms of the “nucleation”, “growth”, “topological changes” and “texture evaluation” steps. Most important limitations including the calibration sensitivity, limitations in modeling the continuous DRX, ignoring microstructural effects on the deformation behavior, limited applications, and limited database as well as the saturation in published works are discussed and then objective suggestions are presented to overcome these limitations. Finally, prospects in the CA modeling of DRX are provided in the last section.
{"title":"Modeling the Dynamic Recrystallization by Using Cellular Automaton: The Current Status, Challenges and Future Prospects, a Review","authors":"M. Azarbarmas","doi":"10.22068/IJMSE.17.4.103","DOIUrl":"https://doi.org/10.22068/IJMSE.17.4.103","url":null,"abstract":"Mechanical properties of metals are substantially dependent on the microstructure, which can be controlled by thermo-mechanical parameters such as temperature, strain, and strain rate. Hence, understanding the microstructural evolution of alloys during the hot deformation is crucial to engineer the metal forming processes. The main objective of this work is to present an overview of cellular automaton (CA) modeling to predictthe microstructure of alloys experienced the dynamic recrystallization (DRX) phenomenon. In this review paper, first, overall descriptions about the DRX phenomenon and the CA modeling are presented. Then, the CA modeling procedure is compared with similar methods. Meanwhile, related studies in the field of the DRX simulation by using the CA modeling are evaluated. Four main stages of the CA modeling are analyzed in terms of the “nucleation”, “growth”, “topological changes” and “texture evaluation” steps. Most important limitations including the calibration sensitivity, limitations in modeling the continuous DRX, ignoring microstructural effects on the deformation behavior, limited applications, and limited database as well as the saturation in published works are discussed and then objective suggestions are presented to overcome these limitations. Finally, prospects in the CA modeling of DRX are provided in the last section.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44765572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The construction sector is responsible for relevant environmental impacts and one of its most crucial points is the use of concrete. Geopolymers represent the most promising green and ecological alternative for common Portland cement and cementitious materials, due to its proven durability, mechanical and thermal properties. This work presents an experimental and comparative study of adhesion at the fiber-matrix interface between glass fibers and carbon fibers added to the geopolymer matrix. This analysis was performed by pull-out test, whereby it was found that the greatest efficiency was obtained by reinforcing with the glass fibers, incorporated at 2 mm in the geopolymer matrix. As a result, the adhesion between the fibers and the geopolymer structure can be assessed, as well as the optimum length of application.
{"title":"Fiber-matrix Adhesion on Industrial Geopolymer","authors":"Arissa Nogueira, S. Barros, L. Alves","doi":"10.22068/IJMSE.17.3.85","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.85","url":null,"abstract":"The construction sector is responsible for relevant environmental impacts and one of its most crucial points is the use of concrete. Geopolymers represent the most promising green and ecological alternative for common Portland cement and cementitious materials, due to its proven durability, mechanical and thermal properties. This work presents an experimental and comparative study of adhesion at the fiber-matrix interface between glass fibers and carbon fibers added to the geopolymer matrix. This analysis was performed by pull-out test, whereby it was found that the greatest efficiency was obtained by reinforcing with the glass fibers, incorporated at 2 mm in the geopolymer matrix. As a result, the adhesion between the fibers and the geopolymer structure can be assessed, as well as the optimum length of application.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42554983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Mortezaei, H. Arabi, H. Seyedein, A. Momeny, M. Soltanalinezhad
: Dynamic Recrystallization (DRX) is one of the likely mechanisms for fine-graining in metals and alloys. The dynamic recrystallization (DRX) phenomena occur in different thermo-mechanical processing (TMP) conditions for various metallic materials. DRX depends on various materials and thermo-mechanical parameters such as temperature, strain rate, strain, stress, and initial microstructure. in the present study, the restoration mechanism of the 17-7PH stainless steel has been investigated using a hot compression test under different conditions of thermo-mechanical treatment. The microstructural characteristics and the behavior of the hot deformation of the understudy steel are investigated using flow curves and microstructure images obtained from optical microscopy. The results show that the maximum and steady-state stresses are significantly affected by the strain rate and the deformation temperature. So, the flow stress increases with a decrease in the deformation temperature and an increase in the strain rate. Microstructural studies confirm the occurrence of DRX as a restoration mechanism in the microstructure for the two phases of austenite and ferrite.
{"title":"Investigation on Microstructure Evolution of a Semi-Austenitic Stainless Steel Through Hot Deformation","authors":"S. Mortezaei, H. Arabi, H. Seyedein, A. Momeny, M. Soltanalinezhad","doi":"10.22068/IJMSE.17.3.60","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.60","url":null,"abstract":": Dynamic Recrystallization (DRX) is one of the likely mechanisms for fine-graining in metals and alloys. The dynamic recrystallization (DRX) phenomena occur in different thermo-mechanical processing (TMP) conditions for various metallic materials. DRX depends on various materials and thermo-mechanical parameters such as temperature, strain rate, strain, stress, and initial microstructure. in the present study, the restoration mechanism of the 17-7PH stainless steel has been investigated using a hot compression test under different conditions of thermo-mechanical treatment. The microstructural characteristics and the behavior of the hot deformation of the understudy steel are investigated using flow curves and microstructure images obtained from optical microscopy. The results show that the maximum and steady-state stresses are significantly affected by the strain rate and the deformation temperature. So, the flow stress increases with a decrease in the deformation temperature and an increase in the strain rate. Microstructural studies confirm the occurrence of DRX as a restoration mechanism in the microstructure for the two phases of austenite and ferrite.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46354758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Effect of Minor Amounts of Scandium on Recrystallization Behavior of 7000 series Aluminium","authors":"A. Kheradmand, S. Mirdamadi, S. Nategh","doi":"10.22068/IJMSE.17.3.70","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.70","url":null,"abstract":"","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46207252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, the effect of two-step precipitation hardening on the mechanical properties of Al-3.7Cu-1Mg was investigated. For this meaning, some specimens were subjected to the first step aging at 175, 190 and 205 °C for 2 h, once the samples solution treated at 500 °C. To have stable precipitates uniformly distributed in the microstructure and to reduce the heat treatment time, the second step was implied at 65 °C. The tensile and hardness tests were performed at ambient temperature immediately after aging. The results indicated that depending on the first step temperature, the second aging time affects the mechanical behavior of the alloy in different aspects. A factor named SNMP introduced to determine the cycle giving the best mechanical properties. The strength and elongation increase 1.5 and 2 times, respectively; compared to the values reported in the DIN EN 755-2 standard by performing the two-step aging cycle, consisting of the first-stage at 175 °C and the second step at 65 °C for 10 hours. Moreover, using the proposed two-step aging, the heat treatment time was reduced considerably compared to the conventional precipitation-hardening process.
研究了两步沉淀硬化对Al-3.7Cu-1Mg合金力学性能的影响。为此，一些样品在175、190和205℃下进行第一步时效2小时，然后在500℃下进行固溶处理。为使析出相在组织中均匀稳定分布，缩短热处理时间，在65℃下进行第二步。时效后立即在常温下进行拉伸和硬度试验。结果表明，根据第一步时效温度的不同，第二次时效时间对合金的力学行为有不同的影响。引入一个名为SNMP的因素来确定产生最佳机械性能的循环。强度和伸长率分别提高1.5倍和2倍;与DIN EN 755-2标准中报告的值进行比较，通过执行两步老化循环，包括第一步在175°C下，第二步在65°C下持续10小时。此外，与传统的沉淀硬化工艺相比，采用所提出的两步时效，热处理时间大大缩短。
{"title":"Significant Increase in Strength and Elongation of Al-3.7 Cu-1Mg Alloy Via Short Age Treatment Cycle","authors":"B. Mirzakhani, Y. Payandeh, H. Talebi, M. Maleki","doi":"10.22068/IJMSE.17.3.30","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.30","url":null,"abstract":"In this paper, the effect of two-step precipitation hardening on the mechanical properties of Al-3.7Cu-1Mg was investigated. For this meaning, some specimens were subjected to the first step aging at 175, 190 and 205 °C for 2 h, once the samples solution treated at 500 °C. To have stable precipitates uniformly distributed in the microstructure and to reduce the heat treatment time, the second step was implied at 65 °C. The tensile and hardness tests were performed at ambient temperature immediately after aging. The results indicated that depending on the first step temperature, the second aging time affects the mechanical behavior of the alloy in different aspects. A factor named SNMP introduced to determine the cycle giving the best mechanical properties. The strength and elongation increase 1.5 and 2 times, respectively; compared to the values reported in the DIN EN 755-2 standard by performing the two-step aging cycle, consisting of the first-stage at 175 °C and the second step at 65 °C for 10 hours. Moreover, using the proposed two-step aging, the heat treatment time was reduced considerably compared to the conventional precipitation-hardening process.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45393671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Hamdi, H. S. Larijani, S. Shabestari, N. Rahbari
: Aluminum matrix composites are candidate materials for aerospace and automotive industries owing to their specific properties such as high elastic modulus (E), suitable strength and low wear rate. The effect of thixoforming process on the wear behavior of an Al-Mg 2 Si composite sample was studied in this paper. In thixoforming process, casting defects such as macrosegration, shrinkage and porosity are reduced significantly. These advantages are sufficient to attract further studies on thixoforming operation. Thermal analysis of the composite sample, as-cast microstructure, wear surface and subsurface area of the thixoformed alloy were investigated. Wear behavior of the specimens were examined using a pin-on-disk machine based on ASTM-G99, at the applied loads of 25, 50 and 75 N and the constant sliding velocity of 0.25m/s. The worn surfaces and subsurfaces were examined by scanning electron microscopy (SEM). The experimental results indicated that the thixoformed specimens exhibited superior wear resistance than the as-cast alloy. Moreover, the dominant wear mechanism is an adhesive wear followed by the formation of a mechanical mixed layer (MML). However, a severe wear regime occurs in the as cast specimens compared to the thixoformed counterparts.
{"title":"The Wear Behavior of a Cast Al-20wt%Mg2Si Composite Thixoformed Via SIMA","authors":"M. Hamdi, H. S. Larijani, S. Shabestari, N. Rahbari","doi":"10.22068/IJMSE.17.3.49","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.49","url":null,"abstract":": Aluminum matrix composites are candidate materials for aerospace and automotive industries owing to their specific properties such as high elastic modulus (E), suitable strength and low wear rate. The effect of thixoforming process on the wear behavior of an Al-Mg 2 Si composite sample was studied in this paper. In thixoforming process, casting defects such as macrosegration, shrinkage and porosity are reduced significantly. These advantages are sufficient to attract further studies on thixoforming operation. Thermal analysis of the composite sample, as-cast microstructure, wear surface and subsurface area of the thixoformed alloy were investigated. Wear behavior of the specimens were examined using a pin-on-disk machine based on ASTM-G99, at the applied loads of 25, 50 and 75 N and the constant sliding velocity of 0.25m/s. The worn surfaces and subsurfaces were examined by scanning electron microscopy (SEM). The experimental results indicated that the thixoformed specimens exhibited superior wear resistance than the as-cast alloy. Moreover, the dominant wear mechanism is an adhesive wear followed by the formation of a mechanical mixed layer (MML). However, a severe wear regime occurs in the as cast specimens compared to the thixoformed counterparts.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47644438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Low-grade iron ores contain many impurities and are difficult to upgrade to make appropriate concentrates for the blast furnace (BF) or direct reduction (DR) technologies. In this study, the beneficiation of an Oolitic-iron ore (containing 45.46wt% Fe2O3) with magnetization roasting by non-coking coal (containing 62.1wt% fixed carbon) under a stream of argon gas was investigated. Then, a 2500 Gaussian magnet was used for dry magnetic separation method. The effects of roasting time, ore particle size and reaction temperature on the amount of separated part and grade of the product were examined. It was found out that the hematite inside the ore could almost be completely converted into magnetite with stoichiometric ratio of coal to ore at the roasting temperature of 625 °C for 25 min. Under the optimum condition, a high amount of magnetic part of the product (72.22 wt.%) with a grade of 92.7% was separated. The most important point in this process was the prevention of reduced ore from re-oxidation reaction by controlling roasting atmosphere, time and temperature. In addition, different analytical methods such as X-ray fluorescence (XRF), X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis (TG) and scanning electron microscopy (SEM) were applied to investigate and expound the results..
{"title":"BenefIciation of an Oolitic-Iron ORE by Magnetization Roasting and Magnetic Separation","authors":"M. Monzavi, S. Raygan","doi":"10.22068/IJMSE.17.3.17","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.17","url":null,"abstract":"Low-grade iron ores contain many impurities and are difficult to upgrade to make appropriate concentrates for the blast furnace (BF) or direct reduction (DR) technologies. In this study, the beneficiation of an Oolitic-iron ore (containing 45.46wt% Fe2O3) with magnetization roasting by non-coking coal (containing 62.1wt% fixed carbon) under a stream of argon gas was investigated. Then, a 2500 Gaussian magnet was used for dry magnetic separation method. The effects of roasting time, ore particle size and reaction temperature on the amount of separated part and grade of the product were examined. It was found out that the hematite inside the ore could almost be completely converted into magnetite with stoichiometric ratio of coal to ore at the roasting temperature of 625 °C for 25 min. Under the optimum condition, a high amount of magnetic part of the product (72.22 wt.%) with a grade of 92.7% was separated. The most important point in this process was the prevention of reduced ore from re-oxidation reaction by controlling roasting atmosphere, time and temperature. In addition, different analytical methods such as X-ray fluorescence (XRF), X-ray diffraction (XRD), differential thermal analysis (DTA), thermogravimetric analysis (TG) and scanning electron microscopy (SEM) were applied to investigate and expound the results..","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45761288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thin films of meta-cinnabar mercuric sulfide (β-HgS) nanoparticles (NPs) was prepared by pulsed laser ablation (PLA) utilizing a pellet of cinnabar mercuric sulfide (α-HgS) was immersed in distilled water (DW). Q-switched Nd:YAG laser of 1064 nm wavelengths with repetition rate (1 Hz) and fluency (1.5 J/ cm2) applied for ablation. Structural, morphological, and particle sizes of the β-HgS NPs are investigated by analyzing XRD, AFM, SEM, and TEM measurements. Their crystal structure is transformed from hexagonal (wurtzite) of the α-HgS target material to cubic (zinc blende) β-HgS NPs. The optical properties of the β-HgS NPs are measured by UV–visible spectrophotometer. The direct bandgap is calculated to be (2.45 eV) of small particles (4-6.2 nm) moreover, the bandgap value of smallest particles (1-4 nm) is (3.47 eV) according to the optical transmission spectra.
{"title":"Synthesis and Characterization of Mercuric Sulfide Nanoparticles Thin Films by Pulsed Laser Ablation (PLA) in Distilled Water (DW)","authors":"Nadheer Jassim Mohammed, H. Dagher","doi":"10.22068/IJMSE.17.3.11","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.11","url":null,"abstract":"Thin films of meta-cinnabar mercuric sulfide (β-HgS) nanoparticles (NPs) was prepared by pulsed laser ablation (PLA) utilizing a pellet of cinnabar mercuric sulfide (α-HgS) was immersed in distilled water (DW). Q-switched Nd:YAG laser of 1064 nm wavelengths with repetition rate (1 Hz) and fluency (1.5 J/ cm2) applied for ablation. Structural, morphological, and particle sizes of the β-HgS NPs are investigated by analyzing XRD, AFM, SEM, and TEM measurements. Their crystal structure is transformed from hexagonal (wurtzite) of the α-HgS target material to cubic (zinc blende) β-HgS NPs. The optical properties of the β-HgS NPs are measured by UV–visible spectrophotometer. The direct bandgap is calculated to be (2.45 eV) of small particles (4-6.2 nm) moreover, the bandgap value of smallest particles (1-4 nm) is (3.47 eV) according to the optical transmission spectra.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44515888","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mercury, one of the common pollutants in water, is known to affect human health adversely upon exposure. It is released in water not only by various natural processes but also by human activities. Methods developed so far for the detection of mercuric ions in water have limitations like sensitivity range, complex setup, skillful operation etc. Silver nanoparticles, due to unique properties, have been explored by researchers to develop better detection systems. Stable silver nanoparticles can be easily synthesized by methods of green chemistry, its reaction with mercuric ion can be easily observed by changes in color and UV-Vis spectra. The absorbance data from UV-Vis spectra can also be used in quantifying mercury concentration. In this paper, stable silver nanoparticles synthesized using silver nitrate as precursor, sodium lignosulphonate (LS) as reducing and stabilizing agent under microwave radiation are explored for detection of mercuric ions in water. Formation of Ag nanoparticles was confirmed by UV-Vis band at 403.5nm. The intensity of this band showed a proportional decrease with increasing Hg+2 concentration. Hg+2 ions were detected by a distinct color change at higher concentration of Hg+2 also. The limit of detection (LOD) calculated from the observed absorbance data to be 0.7 ppm.
{"title":"Spectrophotometric Detection of Mercury Using Lignosulphonic Stabilized Silver Nanoparticles (AgNP)","authors":"A. Thakur, Gantla Sai Kumar Reddy","doi":"10.22068/IJMSE.17.3.80","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.80","url":null,"abstract":"Mercury, one of the common pollutants in water, is known to affect human health adversely upon exposure. It is released in water not only by various natural processes but also by human activities. Methods developed so far for the detection of mercuric ions in water have limitations like sensitivity range, complex setup, skillful operation etc. Silver nanoparticles, due to unique properties, have been explored by researchers to develop better detection systems. Stable silver nanoparticles can be easily synthesized by methods of green chemistry, its reaction with mercuric ion can be easily observed by changes in color and UV-Vis spectra. The absorbance data from UV-Vis spectra can also be used in quantifying mercury concentration. In this paper, stable silver nanoparticles synthesized using silver nitrate as precursor, sodium lignosulphonate (LS) as reducing and stabilizing agent under microwave radiation are explored for detection of mercuric ions in water. Formation of Ag nanoparticles was confirmed by UV-Vis band at 403.5nm. The intensity of this band showed a proportional decrease with increasing Hg+2 concentration. Hg+2 ions were detected by a distinct color change at higher concentration of Hg+2 also. The limit of detection (LOD) calculated from the observed absorbance data to be 0.7 ppm.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45107058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The microstructural characteristics, mechanical properties and wear characterization of air plasma sprayed coatings obtained from Carbon nanotubes (CNTs) reinforced Al2O3-3wt%TiO2 powders were examined at different loading conditions and different percentage proportion of CNTs. The CNTs in the proportion of 2, 4, and 6 wt% were used as nanofillers to modify the properties of coatings. The uniform dispersion of CNTs throughout the powder particles can be observed from the SEM micrographs. The porosity of the microstructure of the coatings was measured by image analysis. Also, the mechanical properties such as microhardness and surface roughness were measured by microhardness tester and profilometer, respectively. The wear tribometer was used to analyze the tribology of the coatings by varying different parameters. The different loading conditions used were low load (0.5 kgf), moderate load (1.0 kgf), and elevated load (1.5 kgf), respectively. The microhardness showed a slight increase with an increase in the percentage of CNTs proportion. Similarly, the surface roughness value showed a decreasing trend, since the CNTs were filled in the pores. From wear tests, it was observed that the coefficient of friction and wear rate were very less at 6wt% CNTs and 1.5 kgf load. This was mainly due to the bridging of CNTs in between the splats. This implies that CNTs were one of the most suitable additives for improving the microstructural and tribological characteristics of the ceramic coatings.
{"title":"Impact of Carbon Nanotubes Reinforcement on Microstructural and Tribological Characteristics of Air Plasma Sprayed Conventional Alumina-Titania (Al2O3-3wt%TiO2) Coatings","authors":"V. Bolleddu","doi":"10.22068/IJMSE.17.3.92","DOIUrl":"https://doi.org/10.22068/IJMSE.17.3.92","url":null,"abstract":"The microstructural characteristics, mechanical properties and wear characterization of air plasma sprayed coatings obtained from Carbon nanotubes (CNTs) reinforced Al2O3-3wt%TiO2 powders were examined at different loading conditions and different percentage proportion of CNTs. The CNTs in the proportion of 2, 4, and 6 wt% were used as nanofillers to modify the properties of coatings. The uniform dispersion of CNTs throughout the powder particles can be observed from the SEM micrographs. The porosity of the microstructure of the coatings was measured by image analysis. Also, the mechanical properties such as microhardness and surface roughness were measured by microhardness tester and profilometer, respectively. The wear tribometer was used to analyze the tribology of the coatings by varying different parameters. The different loading conditions used were low load (0.5 kgf), moderate load (1.0 kgf), and elevated load (1.5 kgf), respectively. The microhardness showed a slight increase with an increase in the percentage of CNTs proportion. Similarly, the surface roughness value showed a decreasing trend, since the CNTs were filled in the pores. From wear tests, it was observed that the coefficient of friction and wear rate were very less at 6wt% CNTs and 1.5 kgf load. This was mainly due to the bridging of CNTs in between the splats. This implies that CNTs were one of the most suitable additives for improving the microstructural and tribological characteristics of the ceramic coatings.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2020-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48150181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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