Pub Date : 2023-03-28DOI: 10.55713/jmmm.v33i1.1588
M. Farooq, S. Muhammad, A. Sorour
In this study, the corrosion behavior of a Fe-Cr-Mo-B-C alloy, fabricated by spark plasma sintering of an amorphous alloy powder, in 3.5% NaCl solution was analyzed. Electrochemical impedance spectroscopy and potentiodynamic polarization are techniques which were used for electrochemical performance estimation of samples and the results were further compared with conventional alloys: 1080 carbon steel and 304 stainless steel. Corrosion surface products were characterized through Scanning electron microscopy, Energy dispersive x-ray spectroscopy and X-ray photoelectron spectroscopy. Specimens sintered at 800℃ (S1-800) had achieved 94% densification approximately while the sample sintered at 900℃ (S2-900), had densified more which was 98% approximately. S2-900 had better corrosion resistance than S1-800 while in comparison to conventional alloys; it was inferior to 304 stainless steel. It was concluded that the increase in density of sintered samples favoured the formation of more uniform surface products and enhanced the formation of the passive chromium oxide (Cr2O3) layer.
{"title":"Corrosion of a spark plasma sintered Fe-Cr-Mo-B-C alloy in 3.5% NaCl solution","authors":"M. Farooq, S. Muhammad, A. Sorour","doi":"10.55713/jmmm.v33i1.1588","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1588","url":null,"abstract":"In this study, the corrosion behavior of a Fe-Cr-Mo-B-C alloy, fabricated by spark plasma sintering of an amorphous alloy powder, in 3.5% NaCl solution was analyzed. Electrochemical impedance spectroscopy and potentiodynamic polarization are techniques which were used for electrochemical performance estimation of samples and the results were further compared with conventional alloys: 1080 carbon steel and 304 stainless steel. Corrosion surface products were characterized through Scanning electron microscopy, Energy dispersive x-ray spectroscopy and X-ray photoelectron spectroscopy. Specimens sintered at 800℃ (S1-800) had achieved 94% densification approximately while the sample sintered at 900℃ (S2-900), had densified more which was 98% approximately. S2-900 had better corrosion resistance than S1-800 while in comparison to conventional alloys; it was inferior to 304 stainless steel. It was concluded that the increase in density of sintered samples favoured the formation of more uniform surface products and enhanced the formation of the passive chromium oxide (Cr2O3) layer.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"86 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83970945","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 : 2023-03-28DOI: 10.55713/jmmm.v33i1.1614
N. Kulrat, C. Busabok, Saweat Intarasiri, S. Dangtip, Wasana Khongwong
Magnesium aluminate spinel (MAS) glass-ceramics composite has excellent mechanical and optical properties. It can be obtained from porous ceramic by infiltrating the proper choice of glass. In this study, porous MAS ceramic was prepared by conventional sintering from MAS powder to reach a bulk density of 2.48 g∙cm-3 (70.1% of relative density). The porous MAS ceramic was then infiltrated with molten lithium tetraborate glass (Li2B4O7; LTB) at 950℃ for 30 (IF30) and 60 (IF60) min. They were left to cool down to 700℃ inside the furnace before being taken out to quench in ambient. The glass-ceramics composite was obtained with 98.7% and 92.1% relative density for IF30 and IF60 cases, respectively. SEM images reveal a lower degree of porosity in the IF30 case, which achieves higher flexural strength of 119.7 MPa. X-ray diffraction and Raman spectroscopy indicate that Mg2B2O5 phase (at 2q =35°) and B2O5 functional group (at 847 cm-1) are formed during infiltration. Consequently, their micro vickers hardness increased (3.41®5.53®6.16 GPa).
{"title":"Fabrication of glass-ceramics composite by infiltration of lithium tetraborate glass into porous magnesium aluminate spinel ceramic","authors":"N. Kulrat, C. Busabok, Saweat Intarasiri, S. Dangtip, Wasana Khongwong","doi":"10.55713/jmmm.v33i1.1614","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1614","url":null,"abstract":"Magnesium aluminate spinel (MAS) glass-ceramics composite has excellent mechanical and optical properties. It can be obtained from porous ceramic by infiltrating the proper choice of glass. In this study, porous MAS ceramic was prepared by conventional sintering from MAS powder to reach a bulk density of 2.48 g∙cm-3 (70.1% of relative density). The porous MAS ceramic was then infiltrated with molten lithium tetraborate glass (Li2B4O7; LTB) at 950℃ for 30 (IF30) and 60 (IF60) min. They were left to cool down to 700℃ inside the furnace before being taken out to quench in ambient. The glass-ceramics composite was obtained with 98.7% and 92.1% relative density for IF30 and IF60 cases, respectively. SEM images reveal a lower degree of porosity in the IF30 case, which achieves higher flexural strength of 119.7 MPa. X-ray diffraction and Raman spectroscopy indicate that Mg2B2O5 phase (at 2q =35°) and B2O5 functional group (at 847 cm-1) are formed during infiltration. Consequently, their micro vickers hardness increased (3.41®5.53®6.16 GPa).","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79653699","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 : 2023-03-28DOI: 10.55713/jmmm.v33i1.1594
Jurarat Sawangpan, Sansot Panich, Tanakorn Jantarasricha, A. Khantachawana
Shot peening is one type of modified surface treatment that produces a residual compressive stress on the material subsurface and improves surface properties while generating plastic deformation on the surface. This research work aims to improve surface properties, which include the enhanced material formability of aluminum alloy 2024-T3 sheet having 1.2 mm of thickness, by providing residual compressive stress on the surface using the shot peening process, which uses silica particles of 0.1 mm in diameter. First, shot peening was performed using various process parameters: compressed air, distance from nozzle to target, and duration time. Based on the obtained peening sheet, the surface hardness and roughness tests were experimentally performed on the peened surfaces. Additionally, the residual tension created in the sheet after the shot peening is calculated using the X-ray diffraction technique. Consequently, the shot-peened and unpeened sheets were put through hole expansion and Erichsen cupping tests to compare the results of the formability between the shot-peened and unpeened sheets. It was found that peened sheets had a low surface roughness and increased surface hardness, which is better than the unpeened sheet. Moreover, the residual compressive stresses were higher than on the original sheet. Last, the shot peening condition, which changed the surface properties the most, was tested on the hole expansion and Ericshen cupping tests, where the formability results were very significant.
{"title":"Investigation of surface hardness and roughness on formability of aluminum alloy sheet AA2024-T3 subjected to the shot peening process by silica shots","authors":"Jurarat Sawangpan, Sansot Panich, Tanakorn Jantarasricha, A. Khantachawana","doi":"10.55713/jmmm.v33i1.1594","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1594","url":null,"abstract":"Shot peening is one type of modified surface treatment that produces a residual compressive stress on the material subsurface and improves surface properties while generating plastic deformation on the surface. This research work aims to improve surface properties, which include the enhanced material formability of aluminum alloy 2024-T3 sheet having 1.2 mm of thickness, by providing residual compressive stress on the surface using the shot peening process, which uses silica particles of 0.1 mm in diameter. First, shot peening was performed using various process parameters: compressed air, distance from nozzle to target, and duration time. Based on the obtained peening sheet, the surface hardness and roughness tests were experimentally performed on the peened surfaces. Additionally, the residual tension created in the sheet after the shot peening is calculated using the X-ray diffraction technique. Consequently, the shot-peened and unpeened sheets were put through hole expansion and Erichsen cupping tests to compare the results of the formability between the shot-peened and unpeened sheets. It was found that peened sheets had a low surface roughness and increased surface hardness, which is better than the unpeened sheet. Moreover, the residual compressive stresses were higher than on the original sheet. Last, the shot peening condition, which changed the surface properties the most, was tested on the hole expansion and Ericshen cupping tests, where the formability results were very significant.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"3 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85753150","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 : 2023-03-28DOI: 10.55713/jmmm.v33i1.1589
Aumphol Yanil, P. Visuttipitukul, E. Nisaratanaporn, Charasphat Preuksarattanawut
The effects of Indium (In) and Gallium (Ga) ratio on tarnish resistance, corrosion and mechanical properties of 950 silver alloy were studied. 950 Silver alloy with aluminium (Al), silica (Si) and germanium (Ge) were added with In and Ga at the range of 0.44 to 1.90 weight percent. The increment of secondary structure with Ge-Si rich phase in Ag-Al alloy increases hardness, but reduces ultimate tensile strength. The addition of In and Ga improves tarnish and corrosion resistance. The color differences as indicated by Delta E tolerances (DE*) of Ag-Al alloys are in the range of 8.64 to 11.40 while this property of Ag-Cu is 39.37. Ecorr of Ag-Al alloys are in the range of -0.068 to -0.010 V which are higher than that of Ag-Cu Alloy (-0.147 V). Besides, Ga is more effective for tarnish and corrosion resistance than In. However, Ga/In co-addition reduces these properties by the formation of Ge-Si-Ga-In phase. The protective thin film of Ag-Al alloy was detected by XPS. The Al2O3, In2O3 and Ga2O3 films were found. When the proportion of Ga in Ag-Al alloys increases, the hardness marginally increases while the tensile strength slightly reduces. The additions of Al, Ga, In, Ge and Si reduce the melting point of Ag-Al alloys comparing with Ag-Cu alloy and simultaneously improve the casting quality.
{"title":"Effects of Indium and Gallium ratio on tarnish resistance, corrosion and mechanical properties of 950 silver alloy","authors":"Aumphol Yanil, P. Visuttipitukul, E. Nisaratanaporn, Charasphat Preuksarattanawut","doi":"10.55713/jmmm.v33i1.1589","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1589","url":null,"abstract":"The effects of Indium (In) and Gallium (Ga) ratio on tarnish resistance, corrosion and mechanical properties of 950 silver alloy were studied. 950 Silver alloy with aluminium (Al), silica (Si) and germanium (Ge) were added with In and Ga at the range of 0.44 to 1.90 weight percent. The increment of secondary structure with Ge-Si rich phase in Ag-Al alloy increases hardness, but reduces ultimate tensile strength. The addition of In and Ga improves tarnish and corrosion resistance. The color differences as indicated by Delta E tolerances (DE*) of Ag-Al alloys are in the range of 8.64 to 11.40 while this property of Ag-Cu is 39.37. Ecorr of Ag-Al alloys are in the range of -0.068 to -0.010 V which are higher than that of Ag-Cu Alloy (-0.147 V). Besides, Ga is more effective for tarnish and corrosion resistance than In. However, Ga/In co-addition reduces these properties by the formation of Ge-Si-Ga-In phase. The protective thin film of Ag-Al alloy was detected by XPS. The Al2O3, In2O3 and Ga2O3 films were found. When the proportion of Ga in Ag-Al alloys increases, the hardness marginally increases while the tensile strength slightly reduces. The additions of Al, Ga, In, Ge and Si reduce the melting point of Ag-Al alloys comparing with Ag-Cu alloy and simultaneously improve the casting quality.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"277 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75404968","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}
Stainless steel is widely used for many components and parts in coal-fired thermal power plants. AISI 430 ferritic stainless steel (FSS) is one common grade to combat the degradation at high temperatures in coal combustion atmospheres containing flue gas, coal ash, and soot (impure solid carbon particles). However, the effect of the solid carbon particles on the degradation of FSS needs to be clarified. Graphite powder was used to simulate solid carbon atmospheres for investigating the degradation of AISI 430 at high temperatures of 1150℃ to 1350℃ in coal-fired boilers. After the carbothermic reduction, the mass gain of a pre-oxidized sample at 750℃ was approximately 0.0793 mg⸳cm-2 and increased when increasing the reduction temperature. The peak of Fe2O3 and Cr7C3 were detected by X˗ray diffraction (XRD) after the oxidation and reduction test, respectively. Besides, the degree of sensitivity (%DoS) of the samples was measured by double loop electrochemical potentiokinetic reactivation (DL-EPR) technique and increased around 30 times after heating the pre-oxidized sample to 1150℃.
{"title":"The high temperature degradation of ferritic stainless steel in solid carbon atmospheres","authors":"Prakeaw Ngamsri, Suwijak Pokwitidkul, Paweena Treewiriyakitja, Penpisuth Thongyoug, Ratchapon Nilprapa, Jennarong Tungtrongpairoj","doi":"10.55713/jmmm.v33i1.1574","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1574","url":null,"abstract":"Stainless steel is widely used for many components and parts in coal-fired thermal power plants. AISI 430 ferritic stainless steel (FSS) is one common grade to combat the degradation at high temperatures in coal combustion atmospheres containing flue gas, coal ash, and soot (impure solid carbon particles). However, the effect of the solid carbon particles on the degradation of FSS needs to be clarified. Graphite powder was used to simulate solid carbon atmospheres for investigating the degradation of AISI 430 at high temperatures of 1150℃ to 1350℃ in coal-fired boilers. After the carbothermic reduction, the mass gain of a pre-oxidized sample at 750℃ was approximately 0.0793 mg⸳cm-2 and increased when increasing the reduction temperature. The peak of Fe2O3 and Cr7C3 were detected by X˗ray diffraction (XRD) after the oxidation and reduction test, respectively. Besides, the degree of sensitivity (%DoS) of the samples was measured by double loop electrochemical potentiokinetic reactivation (DL-EPR) technique and increased around 30 times after heating the pre-oxidized sample to 1150℃.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"40 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86932825","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}
Silver is a well-known effective antibacterial and disinfectant material with relatively few side effects. Nanosilver derived from it, have strong antibacterial, antifungal and broad-spectrum antiviral properties. This study describes how the microwave synthesis durations of silver nanoparticles affect their shape, and the effect of the shapes of these nanoparticles on their antibacterial activity. The optical properties of the nanosilver were examined through UV-Vis absorption spectroscopy. The morphology of the grain was determined by transmission electron microscopy (TEM), and the crystallinity of the nanosilver was confirmed by X-ray diffraction (XRD). The antibacterial activities were assessed using bacterial pathogens Bacillus cereus and Bacillus megaterium, and were performed using the disk diffusion method. The obtained results show that (i) the shape and size of the nanosilver change when the microwave time is increased. They are of various sizes but almost all circular in shape when microwaved for 1.5 min, of larger sizes and different non-spherical geometric shapes after 3 min of microwave, and converted to nanowires after 5 min of microwave. (ii) Bacillus cereus and Bacillus megaterium were sensitive to all nanosilver but the antibacterial activity was more potent when the nanosilver possessed a defined shape than when they were silver nanowires.
{"title":"Impact of microwave synthesis time on the shape of silver nanostructures and their antibacterial activity","authors":"Nhat Hieu Hoang, V. Nguyen, TH. Nguyen, Thi Mong Diep Nguyen","doi":"10.55713/jmmm.v33i1.1631","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1631","url":null,"abstract":"Silver is a well-known effective antibacterial and disinfectant material with relatively few side effects. Nanosilver derived from it, have strong antibacterial, antifungal and broad-spectrum antiviral properties. This study describes how the microwave synthesis durations of silver nanoparticles affect their shape, and the effect of the shapes of these nanoparticles on their antibacterial activity. The optical properties of the nanosilver were examined through UV-Vis absorption spectroscopy. The morphology of the grain was determined by transmission electron microscopy (TEM), and the crystallinity of the nanosilver was confirmed by X-ray diffraction (XRD). The antibacterial activities were assessed using bacterial pathogens Bacillus cereus and Bacillus megaterium, and were performed using the disk diffusion method. The obtained results show that (i) the shape and size of the nanosilver change when the microwave time is increased. They are of various sizes but almost all circular in shape when microwaved for 1.5 min, of larger sizes and different non-spherical geometric shapes after 3 min of microwave, and converted to nanowires after 5 min of microwave. (ii) Bacillus cereus and Bacillus megaterium were sensitive to all nanosilver but the antibacterial activity was more potent when the nanosilver possessed a defined shape than when they were silver nanowires.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"11 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75461853","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 : 2023-03-28DOI: 10.55713/jmmm.v33i1.1596
C. Udawatte, Sunil Abeyweera, L. R. K. Perera, S. Illangasinghe, C. Weerasooriya, C. Sutthirat, Naleen Jayasinghe, T. Dharmaratne, S. Diyabalanage
Most of natural topaz is colorless; thus, methods of color enhancement are widely used for coloring this mineral. Currently, blue color is obtained by cobalt diffusion due to drawbacks in existing coloration methods. In this study, optimum conditions suitable for Cobalt diffusion in Sri Lankan colorless topaz were investigated and coloration mechanism was elucidated. The diffusion agent was prepared by mixing CoCO3 with Na2CO3, CaCO3 and carbon powder and diffusion was carried-out by varying the temperature and soaking time. Chemical analysis, UV-Vis absorption spectrum, infrared absorption spectra, and Raman peaks of diffused and non-diffused topaz were tested. The results clearly indicated that the optimum condition for Co diffusion in Sri Lankan topaz is 950℃ for 11 h. The EPMA analysis showed that the Co concentration in the diffused sample varied from 0.001 wt% to 0.027 wt% while colorless topaz showed <0.001 wt%. The UV-Vis spectrum of Co diffused blue topaz gave three absorption peaks at 556, 588, and 627 nm corresponding to three spin-allowed electronic transitions of Co2+ ion in teterahedaral coordination. In case of Co diffused topaz, one additional new broader IR absorption peak was noticed around 6640 cm-1 presumably arising by optical transitions of 4A2 → 4T1 in Co2+ (4F). Our results lead to the conclusion that, blue color of the Co diffused topaz is arising by spin-allowed electronic transitions of Co2+ ions in tetrahedral site of topaz matrix through substitution of Si4+ ions.
{"title":"Optimized conditions for cobalt diffusion in Sri Lankan colorless topaz and coloration mechanism elucidation through spectro-chemical investigation","authors":"C. Udawatte, Sunil Abeyweera, L. R. K. Perera, S. Illangasinghe, C. Weerasooriya, C. Sutthirat, Naleen Jayasinghe, T. Dharmaratne, S. Diyabalanage","doi":"10.55713/jmmm.v33i1.1596","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1596","url":null,"abstract":"Most of natural topaz is colorless; thus, methods of color enhancement are widely used for coloring this mineral. Currently, blue color is obtained by cobalt diffusion due to drawbacks in existing coloration methods. In this study, optimum conditions suitable for Cobalt diffusion in Sri Lankan colorless topaz were investigated and coloration mechanism was elucidated. The diffusion agent was prepared by mixing CoCO3 with Na2CO3, CaCO3 and carbon powder and diffusion was carried-out by varying the temperature and soaking time. Chemical analysis, UV-Vis absorption spectrum, infrared absorption spectra, and Raman peaks of diffused and non-diffused topaz were tested. The results clearly indicated that the optimum condition for Co diffusion in Sri Lankan topaz is 950℃ for 11 h. The EPMA analysis showed that the Co concentration in the diffused sample varied from 0.001 wt% to 0.027 wt% while colorless topaz showed <0.001 wt%. The UV-Vis spectrum of Co diffused blue topaz gave three absorption peaks at 556, 588, and 627 nm corresponding to three spin-allowed electronic transitions of Co2+ ion in teterahedaral coordination. In case of Co diffused topaz, one additional new broader IR absorption peak was noticed around 6640 cm-1 presumably arising by optical transitions of 4A2 → 4T1 in Co2+ (4F). Our results lead to the conclusion that, blue color of the Co diffused topaz is arising by spin-allowed electronic transitions of Co2+ ions in tetrahedral site of topaz matrix through substitution of Si4+ ions.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"29 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75007257","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 : 2023-03-28DOI: 10.55713/jmmm.v33i1.1576
T. Patcharawit, C. Kansomket, Woranittha Kritsarikun, Ketmanee Taseela, Chonthicha Paernaphan, Thiwavan Laphosin, Teerawut Tannukit, S. Khumkoa
Recycling of spent silver electroplating solutions has been investigated via electrowinning and electrorefining in comparison to zinc cementation technique in this research. Two different compositions of transparent and dark waste solutions were used having the remaining silver contents of 17.71 g⸳L-1 and 33.36 g⸳L-1 respectively. The waste solutions were used as an electrolyte in the first step of electrowinning at low current density of 0.015 A⸳cm-2. It was found that increasing electrowinning time from 4 h to 24 h increased the recovery of silver cathode for both types of waste solutions. The optimum electrowinning time was higher than 8 h, giving the recovery of higher than 97.5% and 98.5% purity for 24 h electrowinning. Through the subsequent electrorefining, the electrowon silver cathode was set as the anode, while HNO3 + AgNO3 electrolyte containing high silver content of 120 g Ag/L was used. By controlling the potential at 0.8 V, silver crystal of high purity > 99.9% was obtained. The highest recovery was 99.11% when using silver cathode obtained from electrowinning of the transparent waste solution. Zinc cementation however led to loss of silver in the precipitate form on the zinc metal surface, giving only 86.16% recovery.
{"title":"Recovery of pure silver from spent silver electroplating solutions via electrochemical process and zinc cementation","authors":"T. Patcharawit, C. Kansomket, Woranittha Kritsarikun, Ketmanee Taseela, Chonthicha Paernaphan, Thiwavan Laphosin, Teerawut Tannukit, S. Khumkoa","doi":"10.55713/jmmm.v33i1.1576","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1576","url":null,"abstract":"Recycling of spent silver electroplating solutions has been investigated via electrowinning and electrorefining in comparison to zinc cementation technique in this research. Two different compositions of transparent and dark waste solutions were used having the remaining silver contents of 17.71 g⸳L-1 and 33.36 g⸳L-1 respectively. The waste solutions were used as an electrolyte in the first step of electrowinning at low current density of 0.015 A⸳cm-2. It was found that increasing electrowinning time from 4 h to 24 h increased the recovery of silver cathode for both types of waste solutions. The optimum electrowinning time was higher than 8 h, giving the recovery of higher than 97.5% and 98.5% purity for 24 h electrowinning. Through the subsequent electrorefining, the electrowon silver cathode was set as the anode, while HNO3 + AgNO3 electrolyte containing high silver content of 120 g Ag/L was used. By controlling the potential at 0.8 V, silver crystal of high purity > 99.9% was obtained. The highest recovery was 99.11% when using silver cathode obtained from electrowinning of the transparent waste solution. Zinc cementation however led to loss of silver in the precipitate form on the zinc metal surface, giving only 86.16% recovery.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"37 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84486122","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 : 2023-03-28DOI: 10.55713/jmmm.v33i1.1669
T. Mutuk, Kerem Arpacioğlu, S. Alisir, Gökhan Demir
Many problems such as the increase in the world population, global drought, and greenhouse gases have caused materials used in industries to be reconsidered. This is how the concept of green composite material emerged. Using natural fibers to obtain such materials is important in terms of sustainability. This study is aimed to use hemp fiber and banana fiber as natural fiber additives in the gypsum composite to produce green bio-composite. Natural fibers are chemically modified with 5% NaOH solution. In this way, a good fiber/matrix interface interaction is provided. The composite hardness test result of 5 wt% HB fiber added sample is obtained as 50.4. Compared to the control plaster sample test result, which is 53.6, a slight decrease can be seen. However, it is observed that the fibers held the structure together and sopped the crack propagation. The increase in the porous structure with fiber addition caused a decrease in the thermal conductivity of the composite. Comparing thermal conductivity result of 5 wt% HB fiber reinforced gypsum composite (0.131 W⸳mK-1) with respect to pure gypsum result (0.237 W⸳mK-1), it gave a promising result as an insulation material.
{"title":"Thermal and mechanical evaluation of natural fibers reinforced gypsum plaster composite","authors":"T. Mutuk, Kerem Arpacioğlu, S. Alisir, Gökhan Demir","doi":"10.55713/jmmm.v33i1.1669","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1669","url":null,"abstract":"Many problems such as the increase in the world population, global drought, and greenhouse gases have caused materials used in industries to be reconsidered. This is how the concept of green composite material emerged. Using natural fibers to obtain such materials is important in terms of sustainability. This study is aimed to use hemp fiber and banana fiber as natural fiber additives in the gypsum composite to produce green bio-composite. Natural fibers are chemically modified with 5% NaOH solution. In this way, a good fiber/matrix interface interaction is provided. The composite hardness test result of 5 wt% HB fiber added sample is obtained as 50.4. Compared to the control plaster sample test result, which is 53.6, a slight decrease can be seen. However, it is observed that the fibers held the structure together and sopped the crack propagation. The increase in the porous structure with fiber addition caused a decrease in the thermal conductivity of the composite. Comparing thermal conductivity result of 5 wt% HB fiber reinforced gypsum composite (0.131 W⸳mK-1) with respect to pure gypsum result (0.237 W⸳mK-1), it gave a promising result as an insulation material.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"62 6 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79052533","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 : 2023-03-28DOI: 10.55713/jmmm.v33i1.1568
Mustafa Tekin, F. Muhaffel, H. Kotan, Murat Çağlar Baydoğan
In this study, in-situ oxide dispersion strengthened (ODS) Fe91Ni8Zr1 and Fe88Ni8Zr4 alloys were produced by combination of high energy mechanical alloying (HEMA) and high temperature equal channel angular extrusion (HT-ECAE). The wear behaviors of the consolidated samples were investigated under different loads from 1 N to 4 N by reciprocating wear tests at room temperature. The Scanning electron microscopy (SEM) was used to examine the wear tracks to analyze the wear characteristics as a function of applied loads. The relative comparison of the wear results showed that under the lower loads of 1 N and 2 N, Fe88Ni8Zr4 alloy has lower wear rate than Fe91Ni8Zr1 alloy whereas under the higher loads of 3 N and 4 N, it is vice versa. Additionally, the friction coefficient of Fe91Ni8Zr1 alloy was found to be lower than that of Fe88Ni8Zr4 alloy under all the applied loads. The results were comparatively discussed with respect to microstructural features of 1 at% Zr and 4 at% Zr containing ODS alloys produced by HEMA followed by ECAE. The obtained results of ODS alloys with different grain size, precipitate size, and number density of the precipitates, may disclose a new sight for using such alloys in wear applications just as cutting tools, turbine blades, and discs.
{"title":"Wear behavior of in-situ oxide dispersion strengthened Fe-8Ni alloy with Zr additions","authors":"Mustafa Tekin, F. Muhaffel, H. Kotan, Murat Çağlar Baydoğan","doi":"10.55713/jmmm.v33i1.1568","DOIUrl":"https://doi.org/10.55713/jmmm.v33i1.1568","url":null,"abstract":"In this study, in-situ oxide dispersion strengthened (ODS) Fe91Ni8Zr1 and Fe88Ni8Zr4 alloys were produced by combination of high energy mechanical alloying (HEMA) and high temperature equal channel angular extrusion (HT-ECAE). The wear behaviors of the consolidated samples were investigated under different loads from 1 N to 4 N by reciprocating wear tests at room temperature. The Scanning electron microscopy (SEM) was used to examine the wear tracks to analyze the wear characteristics as a function of applied loads. The relative comparison of the wear results showed that under the lower loads of 1 N and 2 N, Fe88Ni8Zr4 alloy has lower wear rate than Fe91Ni8Zr1 alloy whereas under the higher loads of 3 N and 4 N, it is vice versa. Additionally, the friction coefficient of Fe91Ni8Zr1 alloy was found to be lower than that of Fe88Ni8Zr4 alloy under all the applied loads. The results were comparatively discussed with respect to microstructural features of 1 at% Zr and 4 at% Zr containing ODS alloys produced by HEMA followed by ECAE. The obtained results of ODS alloys with different grain size, precipitate size, and number density of the precipitates, may disclose a new sight for using such alloys in wear applications just as cutting tools, turbine blades, and discs.","PeriodicalId":16459,"journal":{"name":"Journal of metals, materials and minerals","volume":"78 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77427059","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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