M. Cocić, M. Logar, V. Tasić, B. Matović, Milica Miletic-Svircev
The paper deals with the characteristics of synthesized glass-ceramics obtained by sintering a mixture of final flotation waste (FFW) with tuff at 1260?C for 7 h, followed by the annealing of pressed samples at 1080oC for 36 h. The experiments were done in order to find the possibility for the valorization of waste material (FFW). By thermal treatment of mixtures of T20 (20 % tuff, 80 % FFW) and T40 (40 % tuff, 60 % FFW) to a temperature of 1260oC over a period of 7 hours, is obtained glass-ceramics with dendritic structure. The synthesized glass-ceramics consists of two phases: iron oxide crystals (maghemite, magnetite, and hematite) and glass with an approximate ratio of phases 32/68 (T20) and 23/77 (T40), respectively. The relatively small shrinkage of the synthesized material (up to 7 %) enables reliable control when designing a given shape indicating that such glass-ceramics can be used as a basis for obtaining construction material. The synthesis of pressed samples of mixtures (T20 and T40) at 1080oC for 36 h produces glass-ceramics that have a high coefficient of sound attenuation, which indicates good acoustic insulating properties.
{"title":"Characterization of material sintered from the final flotation waste and zeolitic tuff","authors":"M. Cocić, M. Logar, V. Tasić, B. Matović, Milica Miletic-Svircev","doi":"10.2298/sos2201059c","DOIUrl":"https://doi.org/10.2298/sos2201059c","url":null,"abstract":"The paper deals with the characteristics of synthesized glass-ceramics obtained by sintering a mixture of final flotation waste (FFW) with tuff at 1260?C for 7 h, followed by the annealing of pressed samples at 1080oC for 36 h. The experiments were done in order to find the possibility for the valorization of waste material (FFW). By thermal treatment of mixtures of T20 (20 % tuff, 80 % FFW) and T40 (40 % tuff, 60 % FFW) to a temperature of 1260oC over a period of 7 hours, is obtained glass-ceramics with dendritic structure. The synthesized glass-ceramics consists of two phases: iron oxide crystals (maghemite, magnetite, and hematite) and glass with an approximate ratio of phases 32/68 (T20) and 23/77 (T40), respectively. The relatively small shrinkage of the synthesized material (up to 7 %) enables reliable control when designing a given shape indicating that such glass-ceramics can be used as a basis for obtaining construction material. The synthesis of pressed samples of mixtures (T20 and T40) at 1080oC for 36 h produces glass-ceramics that have a high coefficient of sound attenuation, which indicates good acoustic insulating properties.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"12 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68808457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Šaponjić, S. Gyoshev, Z. Baščarević, Ljiljana Janković-Mandić, Gorica Ljubenov, Maja Kokunesoski
Diatomite (diatomaceous earth) and clay minerals deposits from the mining basin Kolubara, Serbia, are natural materials with high economic potential in many fields. As received and treated materials, diatomite and clay were characterized using X-ray diffraction, mercury intrusion porosimetry, particle size distribution, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Activity concentrations for natural radionuclides 40K, 226Ra and 232Th and anthropogenic radionuclide 137Cs in diatomite and clay were determined by gamma spectrometry with HPGe detector. For diatomite and clay, the mean activity concentrations of 226Ra, 232Th and 40K were found to be 9, 26 and 173 Bq kg-1 and 19, 26 and 470 Bq kg-1, respectively. In the present study was to show that these materials are environmentally safe for further use in many fields.
{"title":"Characterization of sedimentary minerals from Kolubara mining basin, Serbia, with the determination of natural radioactivity","authors":"A. Šaponjić, S. Gyoshev, Z. Baščarević, Ljiljana Janković-Mandić, Gorica Ljubenov, Maja Kokunesoski","doi":"10.2298/sos2201039s","DOIUrl":"https://doi.org/10.2298/sos2201039s","url":null,"abstract":"Diatomite (diatomaceous earth) and clay minerals deposits from the mining basin Kolubara, Serbia, are natural materials with high economic potential in many fields. As received and treated materials, diatomite and clay were characterized using X-ray diffraction, mercury intrusion porosimetry, particle size distribution, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Activity concentrations for natural radionuclides 40K, 226Ra and 232Th and anthropogenic radionuclide 137Cs in diatomite and clay were determined by gamma spectrometry with HPGe detector. For diatomite and clay, the mean activity concentrations of 226Ra, 232Th and 40K were found to be 9, 26 and 173 Bq kg-1 and 19, 26 and 470 Bq kg-1, respectively. In the present study was to show that these materials are environmentally safe for further use in many fields.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68808823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, the effect of Cu content on the microstructures, mechanical properties and electrical conductivity of Nb-V added microalloyed powder metallurgy (PM) steels were investigated. Microalloyed steel samples were pressed at 750 MPa and sintered at 1400oC in argon atmosphere for 1 h. The grain size and phase distribution of the microalloy steels were determined by optical microscope. The precipitates and fracture surface of samples were analyzed with the help of SEM and EDS analyses. Tensile test, hardness test and electrical conductivity measurement were carried out for the Nb-V added microalloyed steel with different Cu content. Results indicated that 10 wt.% Cu added PM microalloyed steel showed the highest values in yield strength (YS) and ultimate tensile strength (UTS). However, when the amount of Cu content increased from 10 to 15 wt.%, YS and UTS decreased. Elongation also tends to decrease with increasing Cu content. Although the electrical conductivity in general increased with the addition of Cu, a decrease in some conductivity was observed in the addition of 15 wt.% Cu.
{"title":"The investigation of the effect of cu addition on the Nb-V microalloyed steel produced by powder metallurgy","authors":"M. Erden, A. Erer, Çağrı Odabaşı, S. Gündüz","doi":"10.2298/sos2202153e","DOIUrl":"https://doi.org/10.2298/sos2202153e","url":null,"abstract":"In this work, the effect of Cu content on the microstructures, mechanical properties and electrical conductivity of Nb-V added microalloyed powder metallurgy (PM) steels were investigated. Microalloyed steel samples were pressed at 750 MPa and sintered at 1400oC in argon atmosphere for 1 h. The grain size and phase distribution of the microalloy steels were determined by optical microscope. The precipitates and fracture surface of samples were analyzed with the help of SEM and EDS analyses. Tensile test, hardness test and electrical conductivity measurement were carried out for the Nb-V added microalloyed steel with different Cu content. Results indicated that 10 wt.% Cu added PM microalloyed steel showed the highest values in yield strength (YS) and ultimate tensile strength (UTS). However, when the amount of Cu content increased from 10 to 15 wt.%, YS and UTS decreased. Elongation also tends to decrease with increasing Cu content. Although the electrical conductivity in general increased with the addition of Cu, a decrease in some conductivity was observed in the addition of 15 wt.% Cu.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68808852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Isaak Trajković, M. Milosevic, M. Travica, M. Rakin, G. Mladenović, L. Kudrjavceva, B. Medjo
This paper presents a part of development of a non-standard method for testing of cylindrical test specimens for measurement of fracture properties of pipeline materials. This method for testing of cylindrical structures working under pressure is based on determining of fracture mechanics parameters on SENT (Single Edge Notched Tension) specimens and new PRNT (Pipe Ring Notched Tension) specimens. In this work, both types of specimens required for this testing were manufactured from polyamide PA12 by using SLS (selective laser sintering) additive manufacturing method. Testing of the specimens is performed on the universal device for testing of mechanical properties of materials Shimadzu, AGS-X 100 kN. The tensile testing is accompanied by GOM Aramis 2M system, used for digital image correlation. By using these two systems, test results are obtained for ring-shaped and SENT specimens, including forces, displacements and fracture mechanics parameters CMOD (Crack Mouth Opening Displacement) and CTOD-?5 (Crack Tip Opening Displacement obtained by ?5 technique), as well as crack growth. Repeatability of this process, along with valid result consistency, represent the basis for further development of the new method, including the determining of energy-based fracture mechanics parameters: J integral and stress intensity factor.
{"title":"Novel method for measurement of pipeline materials fracture resistance-examination on selective laser sintered cylindrical specimens","authors":"Isaak Trajković, M. Milosevic, M. Travica, M. Rakin, G. Mladenović, L. Kudrjavceva, B. Medjo","doi":"10.2298/sos2203373t","DOIUrl":"https://doi.org/10.2298/sos2203373t","url":null,"abstract":"This paper presents a part of development of a non-standard method for testing of cylindrical test specimens for measurement of fracture properties of pipeline materials. This method for testing of cylindrical structures working under pressure is based on determining of fracture mechanics parameters on SENT (Single Edge Notched Tension) specimens and new PRNT (Pipe Ring Notched Tension) specimens. In this work, both types of specimens required for this testing were manufactured from polyamide PA12 by using SLS (selective laser sintering) additive manufacturing method. Testing of the specimens is performed on the universal device for testing of mechanical properties of materials Shimadzu, AGS-X 100 kN. The tensile testing is accompanied by GOM Aramis 2M system, used for digital image correlation. By using these two systems, test results are obtained for ring-shaped and SENT specimens, including forces, displacements and fracture mechanics parameters CMOD (Crack Mouth Opening Displacement) and CTOD-?5 (Crack Tip Opening Displacement obtained by ?5 technique), as well as crack growth. Repeatability of this process, along with valid result consistency, represent the basis for further development of the new method, including the determining of energy-based fracture mechanics parameters: J integral and stress intensity factor.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68809439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, Mg-0.5Ca alloy was produced in a newly designed unit during the metal injection molding process. 40?mD90 Mg powder and 500nmD90 Ca powder were used in accordance with injection molding and powder sintering rules. In the injection phase, Polyethylene-glycol (PEG) and Poly-methyl-methacrylate (PMMA) and stearic acid (SA) polymers act as binders and lubricants. In the experimental phase, X-ray Diffractometer (XRD), Thermal Gravimetric Analyze (TGA), Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy Mapping (EDS and MAP), and Vickers microhardness (HV) examinations were performed. The samples produced were subjected to the sintering process at different temperatures and times. Conventional powder sinter stages point, neck, and joining structures were obtained at different temperatures and durations. As a result, it was determined that Mg-0.5Ca alloy reached a metallic form with the specified polymer structure only at 600oC temperature and after 5 h sintering. Grain boundaries were formed in the sintered sample and the presence of the Mg2Ca phase was observed. The hardness of the metallic structure obtained was measured as 49.9 HV0.1 on average.
{"title":"Investigation of microstructural evolution of gas-assisted metal injection molded and sintered Mg-0.5Ca alloy","authors":"B. Cicek, Yavuz Sun, Y. Turen, H. Ahlatçı","doi":"10.2298/sos2201025c","DOIUrl":"https://doi.org/10.2298/sos2201025c","url":null,"abstract":"In this study, Mg-0.5Ca alloy was produced in a newly designed unit during the metal injection molding process. 40?mD90 Mg powder and 500nmD90 Ca powder were used in accordance with injection molding and powder sintering rules. In the injection phase, Polyethylene-glycol (PEG) and Poly-methyl-methacrylate (PMMA) and stearic acid (SA) polymers act as binders and lubricants. In the experimental phase, X-ray Diffractometer (XRD), Thermal Gravimetric Analyze (TGA), Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectroscopy Mapping (EDS and MAP), and Vickers microhardness (HV) examinations were performed. The samples produced were subjected to the sintering process at different temperatures and times. Conventional powder sinter stages point, neck, and joining structures were obtained at different temperatures and durations. As a result, it was determined that Mg-0.5Ca alloy reached a metallic form with the specified polymer structure only at 600oC temperature and after 5 h sintering. Grain boundaries were formed in the sintered sample and the presence of the Mg2Ca phase was observed. The hardness of the metallic structure obtained was measured as 49.9 HV0.1 on average.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68808756","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Martinez-Garcia, K. Navarro-Mtz, E. Lopez-Vazquez, M. Valera-Zaragoza, E. Juarez-Arellano
The mechanosynthesis of hexagonal chromium nitride (?-Cr2N) is explored by the high-energy ball-milling of Cr and h-BN. The ?-Cr2N onset formation is observed after 20 min of milling, although the complete reaction is achieved at 100 min of milling. Two different 1Cr:1BN and 2Cr:1BN molar ratios were evaluated, observing that the molar ratio plays an essential role in the end products during mechanosynthesis. The products were characterized by XRD, FTIR and Raman spectroscopy, thermal analysis (TGA and DSC), SEM, and surface area (BET). A preliminary phase stability map vs. accumulative energy (?Evaccum) has been constructed. The accumulative energy needed for the complete ?-Cr2N formation is ?Evaccum > 720 kJ/g.
{"title":"Mechanosynthesis of β-Cr2N using BN as the nitrogen source","authors":"A. Martinez-Garcia, K. Navarro-Mtz, E. Lopez-Vazquez, M. Valera-Zaragoza, E. Juarez-Arellano","doi":"10.2298/sos2203305m","DOIUrl":"https://doi.org/10.2298/sos2203305m","url":null,"abstract":"The mechanosynthesis of hexagonal chromium nitride (?-Cr2N) is explored by the high-energy ball-milling of Cr and h-BN. The ?-Cr2N onset formation is observed after 20 min of milling, although the complete reaction is achieved at 100 min of milling. Two different 1Cr:1BN and 2Cr:1BN molar ratios were evaluated, observing that the molar ratio plays an essential role in the end products during mechanosynthesis. The products were characterized by XRD, FTIR and Raman spectroscopy, thermal analysis (TGA and DSC), SEM, and surface area (BET). A preliminary phase stability map vs. accumulative energy (?Evaccum) has been constructed. The accumulative energy needed for the complete ?-Cr2N formation is ?Evaccum > 720 kJ/g.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68809095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The aim of this study is to investigate the microstructure and wear properties of nickel (Ni) matrix boron carbide (B4C) and carbon nanofiber (CNF)-reinforced composite materials. Microstructure and phase composition of the composites manufactured by powder metallurgy (PM) method were determined by SEM-EDS and XRD analysis. While hardness values of the composites were determined by Vickers hardness measurement method, their wear properties were determined by using pin-on-disc method. SEM images showed that B4C was homogeneously distributed, but CNF accumulated in some areas, even though it was slight. Addition of B4C and CNF to the matrix significantly increased it. The increase was quite high in B4C addition, and hardness was slightly lower in the addition of CNF. According to the results of the wear test carried out under dry conditions, the reinforcement to the Ni matrix reduced the wear rate and friction coefficient.
{"title":"Wear and microstructural properties of Ni-B4C/CNF composites","authors":"S. Islak, V. Koç, A. Gariba","doi":"10.2298/sos2204439i","DOIUrl":"https://doi.org/10.2298/sos2204439i","url":null,"abstract":"The aim of this study is to investigate the microstructure and wear properties of nickel (Ni) matrix boron carbide (B4C) and carbon nanofiber (CNF)-reinforced composite materials. Microstructure and phase composition of the composites manufactured by powder metallurgy (PM) method were determined by SEM-EDS and XRD analysis. While hardness values of the composites were determined by Vickers hardness measurement method, their wear properties were determined by using pin-on-disc method. SEM images showed that B4C was homogeneously distributed, but CNF accumulated in some areas, even though it was slight. Addition of B4C and CNF to the matrix significantly increased it. The increase was quite high in B4C addition, and hardness was slightly lower in the addition of CNF. According to the results of the wear test carried out under dry conditions, the reinforcement to the Ni matrix reduced the wear rate and friction coefficient.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68809461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ruth Alvarez-Carrizal, Elizabeth Refugio-García, R. Garcia, M.F. Hernández, E. Rocha-Rangel
An Al2O3-1 wt.% Ti composite was prepared by powder techniques with the intention of analyzing its mechanical and chemical properties for its possible application as a biomaterial. Alumina was synthesized using the reaction bonding aluminum oxide (RBAO) process. The powders resulting from the milling stage present sizes minor than 1.5 microns. With the help of X-ray diffraction and differential thermal analysis, it was determined that aluminum oxidizes in both solid and liquid states during the RBAO process. It was also found that the alumina formation reaction in this process is completed at 1,100oC. From the measurements of mechanical properties (HV, KIC, E) in the Al2O3-1 wt.% Ti composite, it was determined that these properties are better than the same properties of compact bone. Electrochemical impedance spectroscopy, indicates that additions of 1 wt.% Ti on Al2O3 enhance its corrosion resistance. The bioactivation of a Al2O3-1 wt.% Ti composite was successful using a biomimetic method, because after 21 days, hydroxyapatite begins to proliferate on the surface of the substrate. With all these results it can be commented that it is feasible to use Al2O3-1 wt.% Ti composite in the elaboration of synthetic bone for its application as a biomaterial.
{"title":"Fabrication of an al2o3-1% ti composite with some characteristics of a biomaterial","authors":"Ruth Alvarez-Carrizal, Elizabeth Refugio-García, R. Garcia, M.F. Hernández, E. Rocha-Rangel","doi":"10.2298/sos2204415a","DOIUrl":"https://doi.org/10.2298/sos2204415a","url":null,"abstract":"An Al2O3-1 wt.% Ti composite was prepared by powder techniques with the intention of analyzing its mechanical and chemical properties for its possible application as a biomaterial. Alumina was synthesized using the reaction bonding aluminum oxide (RBAO) process. The powders resulting from the milling stage present sizes minor than 1.5 microns. With the help of X-ray diffraction and differential thermal analysis, it was determined that aluminum oxidizes in both solid and liquid states during the RBAO process. It was also found that the alumina formation reaction in this process is completed at 1,100oC. From the measurements of mechanical properties (HV, KIC, E) in the Al2O3-1 wt.% Ti composite, it was determined that these properties are better than the same properties of compact bone. Electrochemical impedance spectroscopy, indicates that additions of 1 wt.% Ti on Al2O3 enhance its corrosion resistance. The bioactivation of a Al2O3-1 wt.% Ti composite was successful using a biomimetic method, because after 21 days, hydroxyapatite begins to proliferate on the surface of the substrate. With all these results it can be commented that it is feasible to use Al2O3-1 wt.% Ti composite in the elaboration of synthetic bone for its application as a biomaterial.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68809669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arianit A. Reka, D. Kosanović, Egzon Ademi, P. Aggrey, Avni Berisha, B. Pavlovski, G. Jovanovski, Besnik Rexhepi, Ahmed Jashari, P. Makreski
The raw diatomaceous earth from the vicinity of Bitola (North Macedonia) showed low bulk density (0.61-0.69 g/cm3), high-water absorption (75-81%) and porosity (66- 72%). The chemical composition was determined with ICP-MS, revealing the following results for the diatomaceous earth: SiO2 (63.69 wt%), Al2O3 (11.79 wt%), Fe2O3 (5.95 wt%), MnO (0.15 wt%), TiO2 (0.65 wt%), CaO (1.51 wt%), MgO (2.24 wt%), P2O5 (0.13 wt%), K2O (1.64 wt%), Na2O (0.93 wt%), LOI (11.21 wt%). XRPD data of the examined sample of clayey diatomite mainly depicted crystalline behavior with a small presence of amorphous phase. The crystalline mineral phases mainly comprise: silica (quartz), feldspars (plagioclase), mica (muscovite), chlorites and dolomite. SEM and TEM results show cased presence of micro- and nanostructures with pores ranging from 250 to 600 nm. The clayey diatomite was sintered at three temperatures (900, 1000 and 1100?C) for a period of 1 h. XRPD of the sintered samples at 1100?C showed certain thermal stability and formation of new phases (mullite and tridymite) that makes the analyzed diatomaceous earth suitable for production of various types of ceramic, construction and thermal insulating materials.
{"title":"Fabrication of ceramic monoliths from diatomaceous earth: effects of calcination temperature on silica phase transformation","authors":"Arianit A. Reka, D. Kosanović, Egzon Ademi, P. Aggrey, Avni Berisha, B. Pavlovski, G. Jovanovski, Besnik Rexhepi, Ahmed Jashari, P. Makreski","doi":"10.2298/sos2204495r","DOIUrl":"https://doi.org/10.2298/sos2204495r","url":null,"abstract":"The raw diatomaceous earth from the vicinity of Bitola (North Macedonia) showed low bulk density (0.61-0.69 g/cm3), high-water absorption (75-81%) and porosity (66- 72%). The chemical composition was determined with ICP-MS, revealing the following results for the diatomaceous earth: SiO2 (63.69 wt%), Al2O3 (11.79 wt%), Fe2O3 (5.95 wt%), MnO (0.15 wt%), TiO2 (0.65 wt%), CaO (1.51 wt%), MgO (2.24 wt%), P2O5 (0.13 wt%), K2O (1.64 wt%), Na2O (0.93 wt%), LOI (11.21 wt%). XRPD data of the examined sample of clayey diatomite mainly depicted crystalline behavior with a small presence of amorphous phase. The crystalline mineral phases mainly comprise: silica (quartz), feldspars (plagioclase), mica (muscovite), chlorites and dolomite. SEM and TEM results show cased presence of micro- and nanostructures with pores ranging from 250 to 600 nm. The clayey diatomite was sintered at three temperatures (900, 1000 and 1100?C) for a period of 1 h. XRPD of the sintered samples at 1100?C showed certain thermal stability and formation of new phases (mullite and tridymite) that makes the analyzed diatomaceous earth suitable for production of various types of ceramic, construction and thermal insulating materials.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"1 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68809954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dunja Djukić, M. Šuljagić, L. Andjelković, V. Pavlović, D. Bučevac, Boško Vrbica, M. Mirković
The effect of Ca2+ amount and sintering temperature on mechanical properties of geopolymer-brushite (GPB) binders was investigated. Brushite and raw abandoned kaolinite clay thermally transformed into metakaolin were used for GPB synthesis. The complete phase and structural analyses were performed by X-ray powder diffraction, and Fourier transforms infrared spectroscopy (FT-IR). The pore-filling effect as a consequence of Ca2+ ions incorporation into the hybrid geopolymer networks improved the compressive strength. On the other hand, the chosen biscuit sintering at 800 and 900oC caused the phase transformation of brushite into calcium pyrophosphate, which negatively affected the compressive strength of such materials. The obtained results indicate that the usage of relatively high sintering temperatures is not always the necessary step for producing geopolymer-based types of cement with prominent mechanical properties.
{"title":"Effect of sintering temperature and calcium amount on compressive strength of brushite-metakaolin polymer materials","authors":"Dunja Djukić, M. Šuljagić, L. Andjelković, V. Pavlović, D. Bučevac, Boško Vrbica, M. Mirković","doi":"10.2298/sos2203287d","DOIUrl":"https://doi.org/10.2298/sos2203287d","url":null,"abstract":"The effect of Ca2+ amount and sintering temperature on mechanical properties of geopolymer-brushite (GPB) binders was investigated. Brushite and raw abandoned kaolinite clay thermally transformed into metakaolin were used for GPB synthesis. The complete phase and structural analyses were performed by X-ray powder diffraction, and Fourier transforms infrared spectroscopy (FT-IR). The pore-filling effect as a consequence of Ca2+ ions incorporation into the hybrid geopolymer networks improved the compressive strength. On the other hand, the chosen biscuit sintering at 800 and 900oC caused the phase transformation of brushite into calcium pyrophosphate, which negatively affected the compressive strength of such materials. The obtained results indicate that the usage of relatively high sintering temperatures is not always the necessary step for producing geopolymer-based types of cement with prominent mechanical properties.","PeriodicalId":21592,"journal":{"name":"Science of Sintering","volume":"38 1","pages":""},"PeriodicalIF":1.5,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68809031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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