Pub Date : 2023-07-25DOI: 10.55713/jmmm.v33i3.1675
Krittaprot Thongkam, N. Chaiyut, M. Panapoy, B. Ksapabutr
Nitrogen-doped activated carbon (N-AC) was prepared from water hyacinth stems for loading polyaniline (PANI) by in-situ polymerization to synthesize N-AC/PANI composites for utilization as electrode materials in supercapacitors. Using potassium hydroxide as the activating agent, stems of water hyacinth were carbonized and activated in a single step to produce N-AC powders. Raman, FTIR, SEM, BET, TGA, and XPS techniques were used to characterize the resultant N-AC materials. The findings revealed that the N-AC materials had a porous structure and high specific surface area. Neat PANI was synthesized by varying the reaction time to 8, 16, and 24 h. During the reaction time of 16 h, the maximum specific capacitance was obtained. For the synthesis of N-AC/PANI composites, in-situ polymerization of aniline was performed for 16 h. Tests of cyclic voltammetry and galvanostatic charge/ discharge were conducted on the electrode materials to assess their electrochemical performance for supercapacitors. Because of the synergistic effect of PANI and N-AC, the produced N-AC/PANI composite showed good supercapacitor performance compared with neat PANI and N-AC. In the case of the N-AC/PANI composite, the specific capacitance was determined by the electrochemical double-layer capacitance (EDLC) of N-AC and the pseudocapacitance resulting from the redox reaction of PANI.
{"title":"Biomass-based nitrogen-doped carbon/polyaniline composite as electrode material for supercapacitor devices","authors":"Krittaprot Thongkam, N. Chaiyut, M. Panapoy, B. Ksapabutr","doi":"10.55713/jmmm.v33i3.1675","DOIUrl":"https://doi.org/10.55713/jmmm.v33i3.1675","url":null,"abstract":"Nitrogen-doped activated carbon (N-AC) was prepared from water hyacinth stems for loading polyaniline (PANI) by in-situ polymerization to synthesize N-AC/PANI composites for utilization as electrode materials in supercapacitors. Using potassium hydroxide as the activating agent, stems of water hyacinth were carbonized and activated in a single step to produce N-AC powders. Raman, FTIR, SEM, BET, TGA, and XPS techniques were used to characterize the resultant N-AC materials. The findings revealed that the N-AC materials had a porous structure and high specific surface area. Neat PANI was synthesized by varying the reaction time to 8, 16, and 24 h. During the reaction time of 16 h, the maximum specific capacitance was obtained. For the synthesis of N-AC/PANI composites, in-situ polymerization of aniline was performed for 16 h. Tests of cyclic voltammetry and galvanostatic charge/ discharge were conducted on the electrode materials to assess their electrochemical performance for supercapacitors. Because of the synergistic effect of PANI and N-AC, the produced N-AC/PANI composite showed good supercapacitor performance compared with neat PANI and N-AC. In the case of the N-AC/PANI composite, the specific capacitance was determined by the electrochemical double-layer capacitance (EDLC) of N-AC and the pseudocapacitance resulting from the redox reaction of PANI.\u0000 ","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"65 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90174130","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}
Pub Date : 2023-07-25DOI: 10.55713/jmmm.v33i3.1693
Rujira Phumma, Chutima Vanichvattanadecha, S. Ummartyotin
Recycled polyethylene terephthalate is successfully prepared. This project is involved for “Circular economy” policy. It is successfully prepared into powder form by nano-grinder technique. 10 phr of PP-g-MA and 1 phr to 5 phr of TPOSS are added for compatibilizer and mechanical properties enhancement, respectively. PP-g-MA can form the chemical linkage of the anhydride groups with the polyamide end groups. 20 wt% of recycled polyethylene terephthalate powder and polypropylene based compound is successfully fabricated by melt mixing. Then, it is fabricated by melting spinning technique. Fourier transform infrared presents Si-O-Si linkage in binary blend compound. X-ray diffraction pattern reports that single phase is obtained. Adding TPOSS can be induced to crystallinity enhancement. No significant change of thermal properties was observed from room temperature to 300℃. Scanning electron microscope reports that with the PP-g-MA provides smoothness of surface. Recycled polyethylene terephthalate is uniformly distributed. Melting and crystallization temperatures are reported to be 162℃ to 167℃ and 115℃ to 120℃, respectively. All of throughput rate is reported to be 1.8 g⸳min-1 to 2.3 g⸳min-1. With the existence of TPOSS, the mechanical properties of compound are slightly increased. TPOSS are added for mechanical properties enhancement. The polymer compound presents the excellent properties. It is remarkable to note that recycled polyethylene terephthalate is considered as an excellent candidate for use as raw material for polymer compound production.
{"title":"Effect of trisilanol isobutyl polyhedral oligomeric silsesquioxane (TPOSS) in recycled PET (rPET) and polypropylene based compound: Investigation on mechanical properties","authors":"Rujira Phumma, Chutima Vanichvattanadecha, S. Ummartyotin","doi":"10.55713/jmmm.v33i3.1693","DOIUrl":"https://doi.org/10.55713/jmmm.v33i3.1693","url":null,"abstract":"Recycled polyethylene terephthalate is successfully prepared. This project is involved for “Circular economy” policy. It is successfully prepared into powder form by nano-grinder technique. 10 phr of PP-g-MA and 1 phr to 5 phr of TPOSS are added for compatibilizer and mechanical properties enhancement, respectively. PP-g-MA can form the chemical linkage of the anhydride groups with the polyamide end groups. 20 wt% of recycled polyethylene terephthalate powder and polypropylene based compound is successfully fabricated by melt mixing. Then, it is fabricated by melting spinning technique. Fourier transform infrared presents Si-O-Si linkage in binary blend compound. X-ray diffraction pattern reports that single phase is obtained. Adding TPOSS can be induced to crystallinity enhancement. No significant change of thermal properties was observed from room temperature to 300℃. Scanning electron microscope reports that with the PP-g-MA provides smoothness of surface. Recycled polyethylene terephthalate is uniformly distributed. Melting and crystallization temperatures are reported to be 162℃ to 167℃ and 115℃ to 120℃, respectively. All of throughput rate is reported to be 1.8 g⸳min-1 to 2.3 g⸳min-1. With the existence of TPOSS, the mechanical properties of compound are slightly increased. TPOSS are added for mechanical properties enhancement. The polymer compound presents the excellent properties. It is remarkable to note that recycled polyethylene terephthalate is considered as an excellent candidate for use as raw material for polymer compound production.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"2495 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86581029","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}
Pub Date : 2023-07-25DOI: 10.55713/jmmm.v33i3.1618
P. Masakul, S. Nilmoung, S. Sonsupap, Lumpoon Laorach
The water hyacinth (WH)-based activated carbon (WHac) has been prepared by an acid treatment, pyrolytic carbonization, and alkali activation processes for using as electrode materials of electrochemical energy storage devices. The pyrolytic carbonization process was performed at a variety of temperature (600, 700, and 800℃) for 2 h. The ash-prepared samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET). The benefits of activated carbon with large uniform surface area leading to maximum specific capacitance of 98.3 F⸳g-1 and good cycling stability. Attributed to low-cost make the water hyacinth activated carbon has the potential for use as electrode materials of energy storage devices. Moreover, the decreasing of water hyacinths maintains environmental equilibrium and is sustainable.
{"title":"The electrochemical properties of water hyacinth-derived activated carbon","authors":"P. Masakul, S. Nilmoung, S. Sonsupap, Lumpoon Laorach","doi":"10.55713/jmmm.v33i3.1618","DOIUrl":"https://doi.org/10.55713/jmmm.v33i3.1618","url":null,"abstract":"The water hyacinth (WH)-based activated carbon (WHac) has been prepared by an acid treatment, pyrolytic carbonization, and alkali activation processes for using as electrode materials of electrochemical energy storage devices. The pyrolytic carbonization process was performed at a variety of temperature (600, 700, and 800℃) for 2 h. The ash-prepared samples were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET). The benefits of activated carbon with large uniform surface area leading to maximum specific capacitance of 98.3 F⸳g-1 and good cycling stability. Attributed to low-cost make the water hyacinth activated carbon has the potential for use as electrode materials of energy storage devices. Moreover, the decreasing of water hyacinths maintains environmental equilibrium and is sustainable.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90748023","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}
Pub Date : 2023-07-25DOI: 10.55713/jmmm.v33i3.1617
P. Whangdee, W. Saenrang, N. Pangpaiboon, P. Masakul, D. P. Kashima
The TiO2 anodized films generated at low current density after annealing are good candidates for surface coating, as a hydrophilicity is a crucial characteristic that determines dental implant applications. In this study, the hydrophilicity of TiO2 anodized films annealed at various temperatures was examined. It was found that increasing the annealing temperature during the anodization procedure improves the hydrophilicity of the TiO2 anodized films. This is related to the evolution of the TiO2 anodized film structure produced by raising the annealing temperature, which converts the TiO2 anodized amorphous phase to rutile phases. Moreover, increased annealing temperature results in more oxygen vacancies, hydroxyl groups, and roughness, which further improves hydrophilicity.
{"title":"Effect of annealing temperature on the TiO2 anodized films properties for dental implant application","authors":"P. Whangdee, W. Saenrang, N. Pangpaiboon, P. Masakul, D. P. Kashima","doi":"10.55713/jmmm.v33i3.1617","DOIUrl":"https://doi.org/10.55713/jmmm.v33i3.1617","url":null,"abstract":"The TiO2 anodized films generated at low current density after annealing are good candidates for surface coating, as a hydrophilicity is a crucial characteristic that determines dental implant applications. In this study, the hydrophilicity of TiO2 anodized films annealed at various temperatures was examined. It was found that increasing the annealing temperature during the anodization procedure improves the hydrophilicity of the TiO2 anodized films. This is related to the evolution of the TiO2 anodized film structure produced by raising the annealing temperature, which converts the TiO2 anodized amorphous phase to rutile phases. Moreover, increased annealing temperature results in more oxygen vacancies, hydroxyl groups, and roughness, which further improves hydrophilicity.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"124 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87873425","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}
Pub Date : 2023-07-25DOI: 10.55713/jmmm.v33i3.1619
D. Aksenov, R. Asfandiyarov, G. Raab, Yulia R Sementeeva, E. Fakhretdinova
This paper presents the results of the development of a promising method for manufacturing contact wires for high-speed railways. The developed method is based on the principles of severe plastic deformation and the combination of metal-forming processes. The solution obtained is a combination of equal-channel angular pressing with the forming of a shaped contact wire with a cross-sectional area of 120 mm2 in one tooling. A feature of the work is that with the help of a comprehensive study by the methods of finite element computer modeling and a physical experiment, not only the stress-strain state of the deformation zone was investigated but also an analysis was made of the effect of deformation heating, which plays an important role when working with dispersion-hardened alloys, such as Cu-0.65Cr. It was established that the temperature in the equal-channel angular pressing zone reached 490℃ to 505℃, and during shaping, it rose to 510℃ to 530℃. In the course of a physical experiment, a laboratory sample of a contact wire with a tensile strength of 410 ± 8 MPa and an electrical conductivity of 35 ± 2% IACS was obtained. Post-deformation aging led to an increase in tensile strength up to 540 ± 20 MPa and restoration of electrical conductivity up to 76 ± 2% IACS. Due to the formation of a stripe structure of a grain-subgrain type with recrystallized grains along the boundaries, the plasticity of the contact wire sample reached 20%.
{"title":"Structure and properties of the contact wire obtained by ECAP with forming","authors":"D. Aksenov, R. Asfandiyarov, G. Raab, Yulia R Sementeeva, E. Fakhretdinova","doi":"10.55713/jmmm.v33i3.1619","DOIUrl":"https://doi.org/10.55713/jmmm.v33i3.1619","url":null,"abstract":"This paper presents the results of the development of a promising method for manufacturing contact wires for high-speed railways. The developed method is based on the principles of severe plastic deformation and the combination of metal-forming processes. The solution obtained is a combination of equal-channel angular pressing with the forming of a shaped contact wire with a cross-sectional area of 120 mm2 in one tooling. A feature of the work is that with the help of a comprehensive study by the methods of finite element computer modeling and a physical experiment, not only the stress-strain state of the deformation zone was investigated but also an analysis was made of the effect of deformation heating, which plays an important role when working with dispersion-hardened alloys, such as Cu-0.65Cr. It was established that the temperature in the equal-channel angular pressing zone reached 490℃ to 505℃, and during shaping, it rose to 510℃ to 530℃. In the course of a physical experiment, a laboratory sample of a contact wire with a tensile strength of 410 ± 8 MPa and an electrical conductivity of 35 ± 2% IACS was obtained. Post-deformation aging led to an increase in tensile strength up to 540 ± 20 MPa and restoration of electrical conductivity up to 76 ± 2% IACS. Due to the formation of a stripe structure of a grain-subgrain type with recrystallized grains along the boundaries, the plasticity of the contact wire sample reached 20%.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"11 suppl_1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78390392","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}
Pub Date : 2023-07-25DOI: 10.55713/jmmm.v33i3.1680
Chantana Aiempanakit, Pathomporn Junbang, Watchara Suphap, K. Aiempanakit
TiO2 nanotubes (TNTs) and bamboo-type TNTs structure films were synthesized via anodization from sputtered titanium (Ti) films on indium tin oxide (ITO) glass. Herein, the anodization process was adjusted electrolyte with different amounts of deionized water and ethylene glycol. The optical and structural properties of all films before and after annealing were investigated, which affected electrochromic application. The increasing deionized water content in electrolytes resulted in an increase in the average diameter and a decrease in the average length of TNTs. Furthermore, the bamboo-type TNTs structure was produced at the deionized water volume condition of 3 vol%. The crystallite size of annealed TNTs (a-TNTs) was calculated from the Scherrer equation, which was enhanced when increasing deionized water. TNTs conditions before annealing showed that the amorphous structure and high energy band gap (Eg) exhibited more electrochromic phenomena than the crystal structure. Due to the disordered arrangement of structures, it was easy to insert ions in TNTs. The bamboo-like structure with separate tubes increased the surface area of the reaction, thus exhibiting the best electrochromic properties with ΔT equal to 12.58%.
{"title":"Influence of water content on structural and electrochromic properties of TiO2 nanotube prepared by anodization","authors":"Chantana Aiempanakit, Pathomporn Junbang, Watchara Suphap, K. Aiempanakit","doi":"10.55713/jmmm.v33i3.1680","DOIUrl":"https://doi.org/10.55713/jmmm.v33i3.1680","url":null,"abstract":"TiO2 nanotubes (TNTs) and bamboo-type TNTs structure films were synthesized via anodization from sputtered titanium (Ti) films on indium tin oxide (ITO) glass. Herein, the anodization process was adjusted electrolyte with different amounts of deionized water and ethylene glycol. The optical and structural properties of all films before and after annealing were investigated, which affected electrochromic application. The increasing deionized water content in electrolytes resulted in an increase in the average diameter and a decrease in the average length of TNTs. Furthermore, the bamboo-type TNTs structure was produced at the deionized water volume condition of 3 vol%. The crystallite size of annealed TNTs (a-TNTs) was calculated from the Scherrer equation, which was enhanced when increasing deionized water. TNTs conditions before annealing showed that the amorphous structure and high energy band gap (Eg) exhibited more electrochromic phenomena than the crystal structure. Due to the disordered arrangement of structures, it was easy to insert ions in TNTs. The bamboo-like structure with separate tubes increased the surface area of the reaction, thus exhibiting the best electrochromic properties with ΔT equal to 12.58%.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"7 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90547035","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}
Iron oxide scale generally forms on low-carbon steel surfaces during the hot rolling processes andproduces as solid waste more than 100 thousand tons per year. The utilization of the iron oxide scaleis one possible way to reduce the production cost for steel plants and promote environmental protection. Acrylonitrile-Butadiene-Styrol-Copolymer (ABS) is widely used as engineering plastic for automotive parts because of its high strength and wear resistance. The recycling of iron oxide waste as reinforcement particles for enhancing the tensile strength of ABS composite was studied. The iron oxides were recycled by carbon powder at a high temperature between 1150℃ to 1350℃ up to 120 min. After the reduction process, the reduced iron from an optimal condition with the iron-rich fraction was ground to powder. Afterward, the 0.3 vol% to 1.3 vol% powders were mixed with ABS polymer powder and formed as composite filaments for additive manufacturing (FDM 3D printing). The tensile strength of pure ABS filament increased to 37.16 ± 2.37 MPa when added recycled iron powders. The regular distribution and 13.68 ± 9.78 µm of recycled-iron particle sizes on the ABS matrix were investigated and correlated to the mechanical properties.
{"title":"Recycling of iron oxide waste by carbothermic reduction to utilize in FDM 3D printing materials","authors":"Korbkaroon Doungkeaw, Peeraphat Suttipong, Phachai Kungwankrai, Suksan Muengto, Boonlom Thavornyutikarn, Jennarong Tungtrongpairoj","doi":"10.55713/jmmm.v33i2.1584","DOIUrl":"https://doi.org/10.55713/jmmm.v33i2.1584","url":null,"abstract":"Iron oxide scale generally forms on low-carbon steel surfaces during the hot rolling processes andproduces as solid waste more than 100 thousand tons per year. The utilization of the iron oxide scaleis one possible way to reduce the production cost for steel plants and promote environmental protection. Acrylonitrile-Butadiene-Styrol-Copolymer (ABS) is widely used as engineering plastic for automotive parts because of its high strength and wear resistance. The recycling of iron oxide waste as reinforcement particles for enhancing the tensile strength of ABS composite was studied. The iron oxides were recycled by carbon powder at a high temperature between 1150℃ to 1350℃ up to 120 min. After the reduction process, the reduced iron from an optimal condition with the iron-rich fraction was ground to powder. Afterward, the 0.3 vol% to 1.3 vol% powders were mixed with ABS polymer powder and formed as composite filaments for additive manufacturing (FDM 3D printing). The tensile strength of pure ABS filament increased to 37.16 ± 2.37 MPa when added recycled iron powders. The regular distribution and 13.68 ± 9.78 µm of recycled-iron particle sizes on the ABS matrix were investigated and correlated to the mechanical properties.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"2 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79165641","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}
Pub Date : 2023-06-27DOI: 10.55713/jmmm.v33i2.1579
Seksan Singthanu, P. Surin, Manop Pipathattakul, T. Nilsonthi
This article addresses applying a tensile test with a CCD camera to assess scale adhesion on hot-rolled steel as a function of hot-rolled coil position. The scale adhesion in this study was shown in the value of the strain initiating the first scale spallation. The result of strain initiating the first scale spallation was confirmed with an acoustic emission (AE) method. The as-received hot-rolled coil was studied at the head, middle, and tail positions. A scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to examine the scale morphology and phase identification respectively. The results show that the oxide scale comprises hematite and magnetite layers. It was found that the higher strain initiating the first scale spallation was revealed on the scale formed on the hot-rolled coil at the head and middle positions. This indicates that the oxide scale was more difficult to remove than at the tail position of the coil. The scale growth and cooling affects the stresses on the oxide layer and the steel substrate. A thin oxide layer on tail position of the hot-rolled coil will easily first crack and then buckle and followed by spallation, while a thick scale on head and middle positions of the hot-rolled coil was harder than that thin scale.
{"title":"Investigation of oxide scale adhesion on hot-rolled steel using the tensile test and acoustic emission","authors":"Seksan Singthanu, P. Surin, Manop Pipathattakul, T. Nilsonthi","doi":"10.55713/jmmm.v33i2.1579","DOIUrl":"https://doi.org/10.55713/jmmm.v33i2.1579","url":null,"abstract":"This article addresses applying a tensile test with a CCD camera to assess scale adhesion on hot-rolled steel as a function of hot-rolled coil position. The scale adhesion in this study was shown in the value of the strain initiating the first scale spallation. The result of strain initiating the first scale spallation was confirmed with an acoustic emission (AE) method. The as-received hot-rolled coil was studied at the head, middle, and tail positions. A scanning electron microscope (SEM) and X-ray diffraction (XRD) were used to examine the scale morphology and phase identification respectively. The results show that the oxide scale comprises hematite and magnetite layers. It was found that the higher strain initiating the first scale spallation was revealed on the scale formed on the hot-rolled coil at the head and middle positions. This indicates that the oxide scale was more difficult to remove than at the tail position of the coil. The scale growth and cooling affects the stresses on the oxide layer and the steel substrate. A thin oxide layer on tail position of the hot-rolled coil will easily first crack and then buckle and followed by spallation, while a thick scale on head and middle positions of the hot-rolled coil was harder than that thin scale.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"125 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77515134","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}
Pub Date : 2023-06-27DOI: 10.55713/jmmm.v33i2.1575
Wannapha Issaard, T. Nilsonthi
Defects can be caused by the thermal oxide scale that forms on the surface of steel during the hot rolling process. The oxidation and adhesion of scale on silicon-containing hot-rolled steel were investigated in a flowing 20% O2-N2 gas mixture at 900°C. Scale spallation was observed using a tensile testing machine equipped with a CCD camera. The thickness of the scale was 3.45 μm for the higher silicon steel and 4.86 μm for the lower silicon steel. The oxide scale consists of hematite, magnetite, wustite, and iron. The strain that caused the first spallation was used to calculate the mechanical adhesion energy, which indicated the behaviour of the scale adhesion on a steel substrate. The strain initiation of the first spallation of scale on higher silicon steel was 5.57% which was higher than 4.57% for lower silicon hot-rolled steel. The calculated adhesion energy on the studied steel was shown to be in the range of 281 J.m-2 to 334 J.m-2. It can be noted that the higher amounts of silicon content in hot-rolled steel increased steel-scale interface adherence. This was due to the precipitated silicon oxide near steel-scale interface might be exhibited as a reinforcing phase.
{"title":"Adhesion of thermal oxide scale formed on silicon-containing hot-rolled steel oxidised in oxygen","authors":"Wannapha Issaard, T. Nilsonthi","doi":"10.55713/jmmm.v33i2.1575","DOIUrl":"https://doi.org/10.55713/jmmm.v33i2.1575","url":null,"abstract":"Defects can be caused by the thermal oxide scale that forms on the surface of steel during the hot rolling process. The oxidation and adhesion of scale on silicon-containing hot-rolled steel were investigated in a flowing 20% O2-N2 gas mixture at 900°C. Scale spallation was observed using a tensile testing machine equipped with a CCD camera. The thickness of the scale was 3.45 μm for the higher silicon steel and 4.86 μm for the lower silicon steel. The oxide scale consists of hematite, magnetite, wustite, and iron. The strain that caused the first spallation was used to calculate the mechanical adhesion energy, which indicated the behaviour of the scale adhesion on a steel substrate. The strain initiation of the first spallation of scale on higher silicon steel was 5.57% which was higher than 4.57% for lower silicon hot-rolled steel. The calculated adhesion energy on the studied steel was shown to be in the range of 281 J.m-2 to 334 J.m-2. It can be noted that the higher amounts of silicon content in hot-rolled steel increased steel-scale interface adherence. This was due to the precipitated silicon oxide near steel-scale interface might be exhibited as a reinforcing phase.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"86 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80983556","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}
Pub Date : 2023-06-27DOI: 10.55713/jmmm.v33i2.1610
G. Gowda, G. V. A. Reddy, B. Eraiah, Chinnappa Reddy Devaraja
This manuscript intends to the structural modifications, and physical and optical properties of a set of heavy metal alkali boro-tellurite glasses doped with Eu2O3. These glasses were produced by a conservative melt-quenching method. The existence of non-crystalline properties in the glasses was ascertained by X-ray diffraction analysis. The structural modifications were noticed by MAS-NMR spectroscopic investigation. Physical properties such as density, molar volume, oxygen packing density, average boron-boron separation, interionic distance, and polaron radius have been calculated by a suitable approach. The optical absorption studies were made through UV-visible absorption spectroscopy in the 350 nm to 800 nm wavelength range. The optical properties namely, optical energy bandgap, Urbach energy, optical basicity, electronegativity, and electric susceptibility, were also determined by using appropriate methods. The MAS-NMR spectroscopic experiments reveal that fewer BO4 units are converted to BO3 units and those NBOs are turned into bridging oxygen at a lower rate. The optical refractive index values and optical dielectric constant range from 2.241 to 2.358, and 5.0220 to 5.5601, respectively. The obtained energy band gap values (Eg(d): 3.367 eV to 3.597 eV and Eg(ind) 2.109 eV to 2.863 eV) and other significant optical parameters suggest that the investigated glasses are potential candidates for europium-doped fiber amplifier applications and possible optical switching applications.
{"title":"Investigations of structural modifications, physical and optical properties of lead boro-tellurite glasses doped with europium trioxide for possible optical switching applications","authors":"G. Gowda, G. V. A. Reddy, B. Eraiah, Chinnappa Reddy Devaraja","doi":"10.55713/jmmm.v33i2.1610","DOIUrl":"https://doi.org/10.55713/jmmm.v33i2.1610","url":null,"abstract":"This manuscript intends to the structural modifications, and physical and optical properties of a set of heavy metal alkali boro-tellurite glasses doped with Eu2O3. These glasses were produced by a conservative melt-quenching method. The existence of non-crystalline properties in the glasses was ascertained by X-ray diffraction analysis. The structural modifications were noticed by MAS-NMR spectroscopic investigation. Physical properties such as density, molar volume, oxygen packing density, average boron-boron separation, interionic distance, and polaron radius have been calculated by a suitable approach. The optical absorption studies were made through UV-visible absorption spectroscopy in the 350 nm to 800 nm wavelength range. The optical properties namely, optical energy bandgap, Urbach energy, optical basicity, electronegativity, and electric susceptibility, were also determined by using appropriate methods. The MAS-NMR spectroscopic experiments reveal that fewer BO4 units are converted to BO3 units and those NBOs are turned into bridging oxygen at a lower rate. The optical refractive index values and optical dielectric constant range from 2.241 to 2.358, and 5.0220 to 5.5601, respectively. The obtained energy band gap values (Eg(d): 3.367 eV to 3.597 eV and Eg(ind) 2.109 eV to 2.863 eV) and other significant optical parameters suggest that the investigated glasses are potential candidates for europium-doped fiber amplifier applications and possible optical switching applications.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"5 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88852864","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：