H. Tavakoli, M. Aboutalebi, H. Seyedein, S. N. Ashrafizadeh
Solvent extraction of samarium from aqueous solutions by two different types of extractants, namely D2EHPA and PC88A, in kerosene was investigated. Through identification of speciation diagrams, the chemically stable complex of samarium in different acidic solutions (H2SO4, HCl and HNO3) were studied. Regarding the various types of samarium species in sulfate medium in comparison with other acidic environments, H2SO4 and HNO3 media were chosen to examine the extraction behavior of samarium complexes. Thermodynamic parameters of samarium extraction reactions by D2EHPA and PC88A from aqueous solutions of HNO3 and H2SO4 were calculated as ∆G°D2EHPA-HNO3 , ∆G°D2EHPA-H2SO4 , ∆G°PC88A-HNO3 , ∆G°PC88A-H2SO4 equal to -5.58, 3.40, 6.70 and 14.26, and the corresponding ΔHo values were equal to -9.38, -2.75, 4.01 and 16.95 kJ/mol, respectively. According to the results, D2EHPA seemed to be a more efficient extractant than PC88A and nitric aqueous solution was a better media than the sulfuric type. The synergistic effect of binary extractants revealed that synergistic factors were 2.94 and 5.74 in sulfuric and nitric solutions, respectively, for a D2EHPA:PC88A ratio of 2:3. The compositions of extracted complexes by D2EHPA and PC88A in sulfuric and nitric solutions were SmH3A6 and SmH3B6, respectively. Thermodynamic parameters of extraction reactions were calculated as: Ke equal to 9.513, 0.254, 0.067, 0.003 and ∆S°D2EHPA-HNO3 , ∆S°D2EHPA-H2SO4 , ∆S°PC88A-HNO3 , ∆S°PC88A-H2SO4 values were equal to -12.75, -20.64, -9.03, and 9.03 (J mol-1) respectively.
{"title":"Implication of Thermodynamic Functions and Speciation Diagrams in Analysis of Solvent Extraction Behavior of Samarium from Acidic Solutions","authors":"H. Tavakoli, M. Aboutalebi, H. Seyedein, S. N. Ashrafizadeh","doi":"10.22068/IJMSE.2105","DOIUrl":"https://doi.org/10.22068/IJMSE.2105","url":null,"abstract":"Solvent extraction of samarium from aqueous solutions by two different types of extractants, namely D2EHPA and PC88A, in kerosene was investigated. Through identification of speciation diagrams, the chemically stable complex of samarium in different acidic solutions (H2SO4, HCl and HNO3) were studied. Regarding the various types of samarium species in sulfate medium in comparison with other acidic environments, H2SO4 and HNO3 media were chosen to examine the extraction behavior of samarium complexes. Thermodynamic parameters of samarium extraction reactions by D2EHPA and PC88A from aqueous solutions of HNO3 and H2SO4 were calculated as ∆G°D2EHPA-HNO3 , ∆G°D2EHPA-H2SO4 , ∆G°PC88A-HNO3 , ∆G°PC88A-H2SO4 equal to -5.58, 3.40, 6.70 and 14.26, and the corresponding ΔHo values were equal to -9.38, -2.75, 4.01 and 16.95 kJ/mol, respectively. According to the results, D2EHPA seemed to be a more efficient extractant than PC88A and nitric aqueous solution was a better media than the sulfuric type. The synergistic effect of binary extractants revealed that synergistic factors were 2.94 and 5.74 in sulfuric and nitric solutions, respectively, for a D2EHPA:PC88A ratio of 2:3. The compositions of extracted complexes by D2EHPA and PC88A in sulfuric and nitric solutions were SmH3A6 and SmH3B6, respectively. Thermodynamic parameters of extraction reactions were calculated as: Ke equal to 9.513, 0.254, 0.067, 0.003 and ∆S°D2EHPA-HNO3 , ∆S°D2EHPA-H2SO4 , ∆S°PC88A-HNO3 , ∆S°PC88A-H2SO4 values were equal to -12.75, -20.64, -9.03, and 9.03 (J mol-1) respectively.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44434060","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}
Amirhosein Paryab, Toktam Godary, S. Abdollahi, Mohsen Anousheh, A. M. Khachatourian
Silicon oxycarbide (SiOC) materials derived from silicone attracted great attention for their superior high-temperature behavior. In the present study, Si (Ti)OC and Si (Ti,Al)OC nanocomposites, in which alkoxide precursors were used with the main silicone precursor, have been compared with SiOC material. Although in SiOC, C was bonded with Si in a carbon-rich SiOC phase, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) showed that TiC was the preferred state for C atoms upon adding Ti into the system. This claim was also substantiated by Raman spectroscopy, where adding Ti into the system lowered the intensity of the D band, indicating the high affinity of C to form crystalline TiC. In the Si(Ti,Al)OC nanocomposites synthesized by adding AlCl3 into the Si(Ti)OC system, mullite nanocrystals formed a superlattice structure with TiC. UV-vis spectra of the nanocomposites showed Si (Ti,Al)OC with mullite-TiC superlattice had a larger bandgap compared with Si(Ti)OC with only TiC nanocrystals.
{"title":"Manufacturing and Structural Evaluation of Polymer Derived SiOC/TiC and SiOC/TiC/mullite Nanocomposites","authors":"Amirhosein Paryab, Toktam Godary, S. Abdollahi, Mohsen Anousheh, A. M. Khachatourian","doi":"10.22068/IJMSE.2093","DOIUrl":"https://doi.org/10.22068/IJMSE.2093","url":null,"abstract":"Silicon oxycarbide (SiOC) materials derived from silicone attracted great attention for their superior high-temperature behavior. In the present study, Si (Ti)OC and Si (Ti,Al)OC nanocomposites, in which alkoxide precursors were used with the main silicone precursor, have been compared with SiOC material. Although in SiOC, C was bonded with Si in a carbon-rich SiOC phase, X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) showed that TiC was the preferred state for C atoms upon adding Ti into the system. This claim was also substantiated by Raman spectroscopy, where adding Ti into the system lowered the intensity of the D band, indicating the high affinity of C to form crystalline TiC. In the Si(Ti,Al)OC nanocomposites synthesized by adding AlCl3 into the Si(Ti)OC system, mullite nanocrystals formed a superlattice structure with TiC. UV-vis spectra of the nanocomposites showed Si (Ti,Al)OC with mullite-TiC superlattice had a larger bandgap compared with Si(Ti)OC with only TiC nanocrystals.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44217325","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}
R. W. Sharudin, N. Azmi, Muhammad Shafiq Mat Shayuti, M. Ohshima
The control of silicone rubber’s viscoelastic properties such as loss factor, storage and loss moduli at crosslinking stage is crucial in their malleability. Hence, the objective in this study is to investigate the rheological behaviour of silicone rubber cured under different formulation using platinum catalysts and triethylamine, methanol & ethanolamine solvents. Measurements were conducted for the silicone rubber to cross-linker ratios of 2.5:7.5, 5:5, 7.5:2.5 and 10:1 at different temperatures, as well as for the silicone rubber with triethylamine, methanol and ethanolamine at different angular frequencies. The crossover of storage and modulus curve which signifies a gel point was not observed at higher ratios of platinum used across the temperature range of 25 – 100°C. However, the crossover was observed at 89 and 95°C with the formulation ratios of 10:1 and 7.5:2.5, respectively. On the other hand, the crossover point was observed for silicone rubber at 100 s-1 for triethylamine, 3 s-1 and 100 s-1 for methanol, and 70 s-1 alongside 290 s-1 for ethanolamine. The presence of gel point indicates that crosslinking of silicone rubber and this study proves the possibility of controlling the crosslinking behaviour..
{"title":"Rheological Comparison of Silicone Rubber Crosslinking with Platinum Catalysts and Triethylamine, Methanol & Ethanolamine Solvents","authors":"R. W. Sharudin, N. Azmi, Muhammad Shafiq Mat Shayuti, M. Ohshima","doi":"10.22068/IJMSE.2067","DOIUrl":"https://doi.org/10.22068/IJMSE.2067","url":null,"abstract":"The control of silicone rubber’s viscoelastic properties such as loss factor, storage and loss moduli at crosslinking stage is crucial in their malleability. Hence, the objective in this study is to investigate the rheological behaviour of silicone rubber cured under different formulation using platinum catalysts and triethylamine, methanol & ethanolamine solvents. Measurements were conducted for the silicone rubber to cross-linker ratios of 2.5:7.5, 5:5, 7.5:2.5 and 10:1 at different temperatures, as well as for the silicone rubber with triethylamine, methanol and ethanolamine at different angular frequencies. The crossover of storage and modulus curve which signifies a gel point was not observed at higher ratios of platinum used across the temperature range of 25 – 100°C. However, the crossover was observed at 89 and 95°C with the formulation ratios of 10:1 and 7.5:2.5, respectively. On the other hand, the crossover point was observed for silicone rubber at 100 s-1 for triethylamine, 3 s-1 and 100 s-1 for methanol, and 70 s-1 alongside 290 s-1 for ethanolamine. The presence of gel point indicates that crosslinking of silicone rubber and this study proves the possibility of controlling the crosslinking behaviour..","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48122449","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}
Phenomenological methods are more diagnostic tools than a predictor, so multi-crystalline material approaches based on their microstructures have been proposed during the last years. The purpose of this research is to review methods taking into account the effect of microstructures and texture deformation on predicting the behavior of sheet metals. These methods can be categorized into six general groups: Taylor-type models, crystal plasticity finite element methods, strain gradient methods, methods that consider dislocations, self-consistent methods, methods based on fast Fourier transform. This paper attempts to explain and compare these methods that have been used to forecasting forming limits or stress-strain curves.
{"title":"Multicrystalline Materials Analysis Based on Their Microstructure with Emphasis on Predicting Forming Limit Diagrams","authors":"Sedigeh Mohamadnejad Zanjani, A. Basti, R. Ansari","doi":"10.22068/IJMSE.1753","DOIUrl":"https://doi.org/10.22068/IJMSE.1753","url":null,"abstract":"Phenomenological methods are more diagnostic tools than a predictor, so multi-crystalline material approaches based on their microstructures have been proposed during the last years. The purpose of this research is to review methods taking into account the effect of microstructures and texture deformation on predicting the behavior of sheet metals. These methods can be categorized into six general groups: Taylor-type models, crystal plasticity finite element methods, strain gradient methods, methods that consider dislocations, self-consistent methods, methods based on fast Fourier transform. This paper attempts to explain and compare these methods that have been used to forecasting forming limits or stress-strain curves.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49404792","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 study, Ta powder was produced from Ta scarp via chemical processes using Mg and Ca powders. Initially, tantalum scraps were converted to tantalum oxide (Ta2O5) at 1100 ̊C in an oxygen atmosphere. Tantalum oxide was then reduced to Tantalum powder with Mg in a vacuum environment at 950 to 1200 ̊C for 3 hours. The obtained Ta powders further were reacted with Ca at 950 ̊C for 5 hours in a vacuum atmosphere. The powders were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), as well as conducting oxygen content measurement. The results showed that the average particle size of the produced Ta powders was around 58 nm with oxygen contents of 250 ppm.
{"title":"The Effect of Temperature on the Purity of Nano-Scale Tantalum Powder Produced from Its Scrap by Reaction with Magnesium and Calcium","authors":"G. Borhani, S. Bakhshi, Sadegh Soltani","doi":"10.22068/IJMSE.2006","DOIUrl":"https://doi.org/10.22068/IJMSE.2006","url":null,"abstract":"In this study, Ta powder was produced from Ta scarp via chemical processes using Mg and Ca powders. Initially, tantalum scraps were converted to tantalum oxide (Ta2O5) at 1100 ̊C in an oxygen atmosphere. Tantalum oxide was then reduced to Tantalum powder with Mg in a vacuum environment at 950 to 1200 ̊C for 3 hours. The obtained Ta powders further were reacted with Ca at 950 ̊C for 5 hours in a vacuum atmosphere. The powders were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), as well as conducting oxygen content measurement. The results showed that the average particle size of the produced Ta powders was around 58 nm with oxygen contents of 250 ppm.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44282936","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}
Friction-Stir Processing (FSP) was applied on AA1050 Aluminum Alloy (AA) to find the highest mechanical properties among 28 combinations of the rotational and traverse speed (800-2000 rpm and 50-200 mm.min-1) and four different tool probe shapes (threaded, columnar, square and triangle). To this aim, the AA standard sheet went through a single pass of FSP. The 1600 rpm and 100 mm.min-1 with threaded tool probe was chosen as the best combination of rotational and traverse speed. Grain size at the Stirred Zone (SZ) was studied using Optical Microscopy (OM). The results showed that the SZ’s grain size was refined from 30 μm down to about 12 μm due to dynamic recrystallization during FSP. The processed sample exhibited improved hardness, yield stress, ultimate tensile strength, elongation up to 65, 80, 66, and 14%, respectively, compared to the annealed AA sample. Studying fractographic features by OM and field emission scanning electron microscope (FESEM) revealed a dominantly ductile fracture behavior.
{"title":"Optimization of Parameters for the Friction Stir Processing and Welding of AA1050 Aluminum Alloy","authors":"Mahdi Alishavandi, M. Ebadi, A. Kokabi","doi":"10.22068/IJMSE.2016","DOIUrl":"https://doi.org/10.22068/IJMSE.2016","url":null,"abstract":"Friction-Stir Processing (FSP) was applied on AA1050 Aluminum Alloy (AA) to find the highest mechanical properties among 28 combinations of the rotational and traverse speed (800-2000 rpm and 50-200 mm.min-1) and four different tool probe shapes (threaded, columnar, square and triangle). To this aim, the AA standard sheet went through a single pass of FSP. The 1600 rpm and 100 mm.min-1 with threaded tool probe was chosen as the best combination of rotational and traverse speed. Grain size at the Stirred Zone (SZ) was studied using Optical Microscopy (OM). The results showed that the SZ’s grain size was refined from 30 μm down to about 12 μm due to dynamic recrystallization during FSP. The processed sample exhibited improved hardness, yield stress, ultimate tensile strength, elongation up to 65, 80, 66, and 14%, respectively, compared to the annealed AA sample. Studying fractographic features by OM and field emission scanning electron microscope (FESEM) revealed a dominantly ductile fracture behavior.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68610738","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 hot deformation behavior of the heat-treated AA6061 and AA 6063 aluminum alloys by T6-1, T6-2 artificial aging treatment, and O annealing treatment were studied by compression testing over a temperature range of 350–550°C and strain rates of 0.005-0.1 s-1. It was observed that the flow stresses of the studied aluminum alloys treated by the T6-1 and T6-2 heat treatments were significantly higher than those of the O annealing treatment. Moreover, the stress-strain curves of the heat-treated alloys by the T6-1, T6-2, and O heat treatments demonstrated significant softening during deformation at the lowest strain rate under any of the deformation conditions. For several strains, the activation energy of hot deformation was specified and obtained to vary significantly with strain for the heat-treated alloys by the T6-1 and T6-2 treatments. The stress-strain data calculated from a linear equation, with strain-dependent parameters, shows a great fit with the experimental data for the heat-treated aluminum alloys.
{"title":"Influence of Heat Treatment on the AA6061 and AA6063 Aluminum Alloys Behavior at Elevated Deformation Temperature","authors":"M. Mohammadi, H. R. Ashtiani","doi":"10.22068/IJMSE.1890","DOIUrl":"https://doi.org/10.22068/IJMSE.1890","url":null,"abstract":"The hot deformation behavior of the heat-treated AA6061 and AA 6063 aluminum alloys by T6-1, T6-2 artificial aging treatment, and O annealing treatment were studied by compression testing over a temperature range of 350–550°C and strain rates of 0.005-0.1 s-1. It was observed that the flow stresses of the studied aluminum alloys treated by the T6-1 and T6-2 heat treatments were significantly higher than those of the O annealing treatment. Moreover, the stress-strain curves of the heat-treated alloys by the T6-1, T6-2, and O heat treatments demonstrated significant softening during deformation at the lowest strain rate under any of the deformation conditions. For several strains, the activation energy of hot deformation was specified and obtained to vary significantly with strain for the heat-treated alloys by the T6-1 and T6-2 treatments. The stress-strain data calculated from a linear equation, with strain-dependent parameters, shows a great fit with the experimental data for the heat-treated aluminum alloys.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44983428","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}
Prabhakar Kuppahalli, R. Keshavamurthy, P. Sriram, Ahobal Narayana
The present investigation aims to synthesize RB031, RB032 Manganese Bronze alloys equivalent to HTB1 and HTB2 alloys with the addition of silicon and to characterize them with the help of Microstructure and Mechanical properties. The methodology involves melting of alloys in a 300kg coreless medium frequency induction furnace, casting them in Permanent and Shell molds with optimum values of Zinc equivalent and retaining their high mechanical properties. The study includes the development and mechanical property measurements of the alloys synthesized. Characterization has been carried out using optical microscopy and scanning electron microscopy with EDAX analysis for investigation of compositional variations and inquisition of hardness measurement & tensile properties. It is concluded from this work that RB032 alloy cast in Permanent molds has superior hardness and tensile properties compared to Shell molds which far exceeds that of NAB (AB2) alloys processed under similar conditions. Further, this investigation includes grain refinement by suitable Heat treatment studies to combat hot tearing since the strength is adequate enough with RB032 exhibiting higher hardness than other two alloys.
{"title":"Influence of Silicon Additions on Microstructure and Mechanical Properties of Manganese Bronze Alloys","authors":"Prabhakar Kuppahalli, R. Keshavamurthy, P. Sriram, Ahobal Narayana","doi":"10.22068/IJMSE.2063","DOIUrl":"https://doi.org/10.22068/IJMSE.2063","url":null,"abstract":"The present investigation aims to synthesize RB031, RB032 Manganese Bronze alloys equivalent to HTB1 and HTB2 alloys with the addition of silicon and to characterize them with the help of Microstructure and Mechanical properties. The methodology involves melting of alloys in a 300kg coreless medium frequency induction furnace, casting them in Permanent and Shell molds with optimum values of Zinc equivalent and retaining their high mechanical properties. The study includes the development and mechanical property measurements of the alloys synthesized. Characterization has been carried out using optical microscopy and scanning electron microscopy with EDAX analysis for investigation of compositional variations and inquisition of hardness measurement & tensile properties. It is concluded from this work that RB032 alloy cast in Permanent molds has superior hardness and tensile properties compared to Shell molds which far exceeds that of NAB (AB2) alloys processed under similar conditions. Further, this investigation includes grain refinement by suitable Heat treatment studies to combat hot tearing since the strength is adequate enough with RB032 exhibiting higher hardness than other two alloys.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47659754","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 research, expanded graphite (EG) was successfully fabricated using a simple ball milling process followed by hydrofluoric (HF, 10 wt. %) leaching. The effect of ball milling time (0-15 h) and leaching time (1-24 h) on the exfoliation of graphite were examined by XRD and Raman spectroscopy. Furthermore, the morphological evaluation of the obtained expanded graphite samples was carried out by scanning electron microscopy (SEM). The XRD results of the ball-milled and HF treated samples showed a slight peak shift and broadening of (002) plane for expanded graphitein in comparison to the precursor and HF-treated samples. Moreover, the intensity of the (002) planes remarkably decreased by the ball milling process but remained constant after HF treatment. Raman spectra of the samples confirmed the ordering process only in HF-treated specimens. Moreover, the intensity ratio of 2D1 to 2D2 band gradually increased with enhancing the HF treatment time up to 5 hrs, indicating a decrement in the number of graphite layers by leaching in the HF solution
{"title":"Structural and Morphological Characterization of the Expanded Graphite Obtained by Ball Milling and HF Leaching","authors":"S. Karimi, A. Heidarpour, S. Ghasemi","doi":"10.22068/IJMSE.2131","DOIUrl":"https://doi.org/10.22068/IJMSE.2131","url":null,"abstract":"In this research, expanded graphite (EG) was successfully fabricated using a simple ball milling process followed by hydrofluoric (HF, 10 wt. %) leaching. The effect of ball milling time (0-15 h) and leaching time (1-24 h) on the exfoliation of graphite were examined by XRD and Raman spectroscopy. Furthermore, the morphological evaluation of the obtained expanded graphite samples was carried out by scanning electron microscopy (SEM). The XRD results of the ball-milled and HF treated samples showed a slight peak shift and broadening of (002) plane for expanded graphitein in comparison to the precursor and HF-treated samples. Moreover, the intensity of the (002) planes remarkably decreased by the ball milling process but remained constant after HF treatment. Raman spectra of the samples confirmed the ordering process only in HF-treated specimens. Moreover, the intensity ratio of 2D1 to 2D2 band gradually increased with enhancing the HF treatment time up to 5 hrs, indicating a decrement in the number of graphite layers by leaching in the HF solution","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42198887","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. Maghsoudlou, R. Isfahani, S. Saber-Samandari, M. Sadighi
: The low velocity impact (LVI) response of a pure and glass fiber reinforced polymer composites (GFRP) with 0.1, 0.3 and 0.5 wt.% of functionalized single-walled carbon nanotubes (SWCNTs) was experimentally investigated. LS-DYNA simulation was used to model the impact test of pure and incorporated GFRP with 0.3 wt. % of SWCNT in order to compare experimental and numerical results of LVI tests. All tests were performed at two different levels of energy. At 30J energy, the specimen containing 0.5 wt. % SWCNT was completely destructed. The results showed that the incorporated GFRP with 0.3 wt. % SWCNT had the highest energy absorption and the back-face damage area of this sample was smaller than other specimens. TEM images from specimens were also analyzed and showed the incorporation of well-dispersed 0.1 and 0.3 wt. % of SWCNT, while in specimens containing 0.5 wt.% of CNT, tubes tended to be agglomerated causing a drop in the LVI response of the specimen. The contact time of the impactor in numerical and experimental results was approximately equal. However, as the conditions in numerical modeling are considered ideal, the maximum contact forces in LS DYNA simulation results were higher than the experimental results.
{"title":"The Response of GFRP Nanocomposites Reinforced with Functionalized SWCNT Under Low Velocity Impact: Experimental and LS-DYNA Simulation Investigations","authors":"M. Maghsoudlou, R. Isfahani, S. Saber-Samandari, M. Sadighi","doi":"10.22068/IJMSE.1985","DOIUrl":"https://doi.org/10.22068/IJMSE.1985","url":null,"abstract":": The low velocity impact (LVI) response of a pure and glass fiber reinforced polymer composites (GFRP) with 0.1, 0.3 and 0.5 wt.% of functionalized single-walled carbon nanotubes (SWCNTs) was experimentally investigated. LS-DYNA simulation was used to model the impact test of pure and incorporated GFRP with 0.3 wt. % of SWCNT in order to compare experimental and numerical results of LVI tests. All tests were performed at two different levels of energy. At 30J energy, the specimen containing 0.5 wt. % SWCNT was completely destructed. The results showed that the incorporated GFRP with 0.3 wt. % SWCNT had the highest energy absorption and the back-face damage area of this sample was smaller than other specimens. TEM images from specimens were also analyzed and showed the incorporation of well-dispersed 0.1 and 0.3 wt. % of SWCNT, while in specimens containing 0.5 wt.% of CNT, tubes tended to be agglomerated causing a drop in the LVI response of the specimen. The contact time of the impactor in numerical and experimental results was approximately equal. However, as the conditions in numerical modeling are considered ideal, the maximum contact forces in LS DYNA simulation results were higher than the experimental results.","PeriodicalId":14603,"journal":{"name":"Iranian Journal of Materials Science and Engineering","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41284309","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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