Feng Jiang, Junling Yu, Guo Feng, Tao Wang, Xiaojun Zhang, Quan Zhang, Rongchi Zhang, Qian Wu, Qing Hu, Yun Yu, Jianmin Liu
Novel (Cr,V)-ZrSiO4 jewel green pigments were synthesized by in situ mineralization at 900?C. The effects of Cr/Si molar ratio were investigated via DTA-TG, XRD, FE-SEM, TEM, UV-Vis-NIR, colorimeter and etc. The obtained results referred that the colour of pigment exhibits blue to jewel green, and then to dark green as the Cr/Si molar ratio increases from 0 to 0.4. When the Cr/Si molar ratio is 0.2, the (Cr,V)-ZrSiO4 pigment exhibits a jewel green hue (L* = 56.69, a* = ?18.52, b* = ?9.28), showing good rendering performance. In addition, the obtained pigment shows good thermal stability in the base glaze synthesized at 1200?C and near-infrared reflection performance. The results of this study show great potential for using the pigments for heat insulation.
{"title":"Synthesis and near-infrared reflection performance of (Cr,V)-ZrSiO4 jewel green pigments","authors":"Feng Jiang, Junling Yu, Guo Feng, Tao Wang, Xiaojun Zhang, Quan Zhang, Rongchi Zhang, Qian Wu, Qing Hu, Yun Yu, Jianmin Liu","doi":"10.2298/pac2303295j","DOIUrl":"https://doi.org/10.2298/pac2303295j","url":null,"abstract":"Novel (Cr,V)-ZrSiO4 jewel green pigments were synthesized by in situ mineralization at 900?C. The effects of Cr/Si molar ratio were investigated via DTA-TG, XRD, FE-SEM, TEM, UV-Vis-NIR, colorimeter and etc. The obtained results referred that the colour of pigment exhibits blue to jewel green, and then to dark green as the Cr/Si molar ratio increases from 0 to 0.4. When the Cr/Si molar ratio is 0.2, the (Cr,V)-ZrSiO4 pigment exhibits a jewel green hue (L* = 56.69, a* = ?18.52, b* = ?9.28), showing good rendering performance. In addition, the obtained pigment shows good thermal stability in the base glaze synthesized at 1200?C and near-infrared reflection performance. The results of this study show great potential for using the pigments for heat insulation.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135263158","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}
Shuang Zhao, Feiyue Yang, Jun Chen, Kunfeng Li, Zhifang Fei, Zichun Yang
?-Si3N4 nanowires with diameters of 100-180 nm (Si3N4-W1) and 420-510 nm (Si3N4-W2) were synthesized by a modified chemical vapour deposition (CVD) method and their microstructure changes after high-temperature oxidation were studied. The results showed that both Si3N4 nanowires were not significantly oxidized when the temperature was lower than 900?C. However, the Si3N4-W1 microstructure began to change significantly after oxidation at 1200?C, while the Si3N4-W2 microstructure remained almost unchanged. Moreover, the Si3N4- W1 and Si3N4-W2 nanowires oxidized significantly after treatment at 1400?C, with weight gain of 26.4% and 13.7%, respectively.
{"title":"High-temperature oxidation behaviour of si3n4 nanowires with different diameters","authors":"Shuang Zhao, Feiyue Yang, Jun Chen, Kunfeng Li, Zhifang Fei, Zichun Yang","doi":"10.2298/pac2301039z","DOIUrl":"https://doi.org/10.2298/pac2301039z","url":null,"abstract":"?-Si3N4 nanowires with diameters of 100-180 nm (Si3N4-W1) and 420-510 nm (Si3N4-W2) were synthesized by a modified chemical vapour deposition (CVD) method and their microstructure changes after high-temperature oxidation were studied. The results showed that both Si3N4 nanowires were not significantly oxidized when the temperature was lower than 900?C. However, the Si3N4-W1 microstructure began to change significantly after oxidation at 1200?C, while the Si3N4-W2 microstructure remained almost unchanged. Moreover, the Si3N4- W1 and Si3N4-W2 nanowires oxidized significantly after treatment at 1400?C, with weight gain of 26.4% and 13.7%, respectively.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582730","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}
Yichao Gong, Xin Chen, K. Kang, Yuefei Wang, Qingze Na, S. Ren, Guojun Zhang
Li4SiO4 has been widely studied as tritium breeder and high temperature CO2 capture material. Tritium breeding rate and CO2 adsorption capacity are closely related to lithium content and microstructure. Since high sintering temperatures result in grain coarsening and lithium sublimation, it is a great challenge to prepare Li4SiO4 ceramics with a satisfactory mechanical strength at low sintering temperature. In this work, mesoporous silica was used as Si source to prepare Li4SiO4 spheres. The mesoporous structure might provide more reaction sites for lithium ions, thereby facilitating the reaction between LiOH and mesoporous silica. The sintering temperature of Li4SiO4 spheres was greatly reduced by using mesoporous silica as Si source. The Li4SiO4 spheres with a homogenous fine-grained microstructure (the average grain size of 2.2 ?m) and high crushing load (41.65N) could be obtained at 675?C.
{"title":"Low-temperature sintering of Li4SiO4 spheres with high crushing load using mesoporous silica as Si sources","authors":"Yichao Gong, Xin Chen, K. Kang, Yuefei Wang, Qingze Na, S. Ren, Guojun Zhang","doi":"10.2298/pac2301055g","DOIUrl":"https://doi.org/10.2298/pac2301055g","url":null,"abstract":"Li4SiO4 has been widely studied as tritium breeder and high temperature CO2 capture material. Tritium breeding rate and CO2 adsorption capacity are closely related to lithium content and microstructure. Since high sintering temperatures result in grain coarsening and lithium sublimation, it is a great challenge to prepare Li4SiO4 ceramics with a satisfactory mechanical strength at low sintering temperature. In this work, mesoporous silica was used as Si source to prepare Li4SiO4 spheres. The mesoporous structure might provide more reaction sites for lithium ions, thereby facilitating the reaction between LiOH and mesoporous silica. The sintering temperature of Li4SiO4 spheres was greatly reduced by using mesoporous silica as Si source. The Li4SiO4 spheres with a homogenous fine-grained microstructure (the average grain size of 2.2 ?m) and high crushing load (41.65N) could be obtained at 675?C.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582762","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}
B. Costa, M.I.A. De Silva, C. Tarley, E. Ribeiro, M. Segatelli
This paper describes the structural and textural characteristics of silicon oxycarbide ceramics obtained from three different hybrid polymers by varying pyrolysis temperature. The first polymer was prepared by hydrosilylation between poly(hydromethylsiloxane) and divinylbenzene in stoichiometric proportions; the second was similarly obtained, but with excess of divinylbenzene (60 wt.%) and the third was also synthesized with 60 wt.% divinylbenzene, involving simultaneously hydrosilylation and radical reactions. Precursors were pyrolysed under argon at 1000, 1200 and 1500?C to produce silicon oxycarbide-based ceramics. Silicon carbide phase development and devitrification resistance were influenced by the disordered and ordered residual carbon fraction, which was directly related to the polymer structure. High specific surface area and pore volume values were obtained in C-richer ceramics at 1500?C derived from poly(divinylbenzene) network-containing precursor. Silicon oxycarbide matrices, derived from hybrid polymers containing graphitic carbon and silicon carbide phases together with different amount of porosity, revealed desirable features for electrochemical applications and adsorbent systems.
{"title":"Influence of polymer synthesis route and organic fraction content on structure and porosity of silicon oxycarbide ceramics","authors":"B. Costa, M.I.A. De Silva, C. Tarley, E. Ribeiro, M. Segatelli","doi":"10.2298/pac2302118c","DOIUrl":"https://doi.org/10.2298/pac2302118c","url":null,"abstract":"This paper describes the structural and textural characteristics of silicon oxycarbide ceramics obtained from three different hybrid polymers by varying pyrolysis temperature. The first polymer was prepared by hydrosilylation between poly(hydromethylsiloxane) and divinylbenzene in stoichiometric proportions; the second was similarly obtained, but with excess of divinylbenzene (60 wt.%) and the third was also synthesized with 60 wt.% divinylbenzene, involving simultaneously hydrosilylation and radical reactions. Precursors were pyrolysed under argon at 1000, 1200 and 1500?C to produce silicon oxycarbide-based ceramics. Silicon carbide phase development and devitrification resistance were influenced by the disordered and ordered residual carbon fraction, which was directly related to the polymer structure. High specific surface area and pore volume values were obtained in C-richer ceramics at 1500?C derived from poly(divinylbenzene) network-containing precursor. Silicon oxycarbide matrices, derived from hybrid polymers containing graphitic carbon and silicon carbide phases together with different amount of porosity, revealed desirable features for electrochemical applications and adsorbent systems.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582879","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}
One of the essential phases in the MgO-Al2O3-SiO2 (MAS) system, cordierite, has the chemical formula 2MgO? 2 Al2O3 ? 5 SiO2. Therefore, cordierite is generally produced from natural raw materials by liquid phase sintering. In this study, dense cordierite and cordierite-based/ZrO2 ceramic composites were produced economically from natural zeolite at a temperature as low as 1250 ?C. Phase analyses with XRD and microstructure examinations with SEM/FESEM were performed. The hot salt corrosion behaviour of ZrSiO4 crystals in a cordierite matrix was also tested. It was determined that the addition of ZrO2 to reduce the average grain size had a positive effect on wear and corrosion resistance. Density, porosity, hardness, flexural strength and wear behaviour of the cordierite-based/ZrO2 ceramic composites were determined. In addition, the hardness values of the zirconia free sample, the samples containing 10 and 20 wt.% zirconia were measured as 11.29, 12.60 and 12.91GPa, respectively, while the specific wear rates were identified as 5.097 ? 10?3, 6.302 ? 10?6 and 3.393 ? 10?7 mm3/Nm, respectively. The hardness increased and the wear resistance changed with the addition of zirconia.
{"title":"An investigation about the mechanical and corrosion properties of cordierite based ceramic composites","authors":"Tuğba Parlak, Ediz Ercenk, Abdülkadir Akyol, Sevcan Ceylan, Ayşe Demirkiran","doi":"10.2298/pac2303271p","DOIUrl":"https://doi.org/10.2298/pac2303271p","url":null,"abstract":"One of the essential phases in the MgO-Al2O3-SiO2 (MAS) system, cordierite, has the chemical formula 2MgO? 2 Al2O3 ? 5 SiO2. Therefore, cordierite is generally produced from natural raw materials by liquid phase sintering. In this study, dense cordierite and cordierite-based/ZrO2 ceramic composites were produced economically from natural zeolite at a temperature as low as 1250 ?C. Phase analyses with XRD and microstructure examinations with SEM/FESEM were performed. The hot salt corrosion behaviour of ZrSiO4 crystals in a cordierite matrix was also tested. It was determined that the addition of ZrO2 to reduce the average grain size had a positive effect on wear and corrosion resistance. Density, porosity, hardness, flexural strength and wear behaviour of the cordierite-based/ZrO2 ceramic composites were determined. In addition, the hardness values of the zirconia free sample, the samples containing 10 and 20 wt.% zirconia were measured as 11.29, 12.60 and 12.91GPa, respectively, while the specific wear rates were identified as 5.097 ? 10?3, 6.302 ? 10?6 and 3.393 ? 10?7 mm3/Nm, respectively. The hardness increased and the wear resistance changed with the addition of zirconia.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135269123","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}
Xuanli Wang, Jinxing Xing, Min Xie, R. Mu, Xi-wen Song
In this work, Er3+ was selected to replace Y3+ in the yttrium aluminium garnet (YAG) in order to improve its mechanical and thermophysical properties. A series of (ErxY1-x)3Al5O12 (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) ceramics were prepared by solid-state synthesis method at 1000 ?C and finally sintered at 1600 ?C for 5 h. The microstructure and morphology of the prepared ceramics were investigated. The results showed that all Er3+ doped Y3Al5O12 ceramics exhibited single garnet-type YAG phase and good compactness. With the increase of Er3+ doping concentration, the thermal conductivity of the (ErxY1-x)3Al5O12 ceramics decreased slowly and then increased subsequently. Among the investigated specimens, the (Er0.7Y0.3)3Al5O12 had the lowest thermal conductivity (1.51W/m?K, at 1000 ?C), which was about 28% lower than that of the pure YAG (2.1W/m?K, at 1000 ?C). As the Er3+ doping concentration increased, the thermal expansion coefficient of the (ErxY1-x)3Al5O12 ceramics hardly changed, remaining around 9.08 ? 10?6 K?1 at 1200 ?C. Moreover, when the Er3+ doping concentration exceeded 0.5, the mechanical properties of the (ErxY1-x)3Al5O12 ceramics increased suddenly. Specifically, the hardness increased from 14.28 to 16.53GPa and the bending strength increased from 231.74 to 324.49MPa.
{"title":"Influence of Er3+ doping on the mechanical and thermophysical properties of (ErxY1-x)3Al5O12 ceramics","authors":"Xuanli Wang, Jinxing Xing, Min Xie, R. Mu, Xi-wen Song","doi":"10.2298/pac2301023w","DOIUrl":"https://doi.org/10.2298/pac2301023w","url":null,"abstract":"In this work, Er3+ was selected to replace Y3+ in the yttrium aluminium garnet (YAG) in order to improve its mechanical and thermophysical properties. A series of (ErxY1-x)3Al5O12 (x = 0, 0.1, 0.3, 0.5, 0.7, 0.9 and 1.0) ceramics were prepared by solid-state synthesis method at 1000 ?C and finally sintered at 1600 ?C for 5 h. The microstructure and morphology of the prepared ceramics were investigated. The results showed that all Er3+ doped Y3Al5O12 ceramics exhibited single garnet-type YAG phase and good compactness. With the increase of Er3+ doping concentration, the thermal conductivity of the (ErxY1-x)3Al5O12 ceramics decreased slowly and then increased subsequently. Among the investigated specimens, the (Er0.7Y0.3)3Al5O12 had the lowest thermal conductivity (1.51W/m?K, at 1000 ?C), which was about 28% lower than that of the pure YAG (2.1W/m?K, at 1000 ?C). As the Er3+ doping concentration increased, the thermal expansion coefficient of the (ErxY1-x)3Al5O12 ceramics hardly changed, remaining around 9.08 ? 10?6 K?1 at 1200 ?C. Moreover, when the Er3+ doping concentration exceeded 0.5, the mechanical properties of the (ErxY1-x)3Al5O12 ceramics increased suddenly. Specifically, the hardness increased from 14.28 to 16.53GPa and the bending strength increased from 231.74 to 324.49MPa.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582651","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}
Zhangfu Yuan, Mei Lu, Xuan Peng, Bing-sheng Xu, Yuantao Shi, Hongxin Zhao
Asymmetric composite tubular membranes were prepared with SiC as the support body and mullite as the membrane layer. The asymmetric mullite/SiC composite filter tube membranes were characterized by different analytic techniques. The mullite membrane was prepared as a layer on the SiC support with a thickness of about 175 ?m, pore size of about 1-10 ?m and porosity of 9.9%. The SiC support tube had a pore size of about 20-150 ?m and porosity of 19.0%. After 360 days of high-temperature flue gas filtration, the most available pore size of the mullite/SiC composite filter tube membrane reduces from 45.2 to 36.4 ?m (the reduction rate of about 19.4%). Analysis of the dust collected by back-blowing revealed that the dust particle size range was between 0.1-100 ?m and about 50%of the dust particles were below 2.5 ?m in size. The average capture rate of dust can reach 98.4%, indicating that the asymmetric mullite/SiC composite filter tube membrane has excellent filtration performance for the dust below PM2.5 in the high-temperature complex flue gas.
{"title":"Performance and purification mechanism of the mullite/SiC composite filter tube membrane","authors":"Zhangfu Yuan, Mei Lu, Xuan Peng, Bing-sheng Xu, Yuantao Shi, Hongxin Zhao","doi":"10.2298/pac2301061y","DOIUrl":"https://doi.org/10.2298/pac2301061y","url":null,"abstract":"Asymmetric composite tubular membranes were prepared with SiC as the support body and mullite as the membrane layer. The asymmetric mullite/SiC composite filter tube membranes were characterized by different analytic techniques. The mullite membrane was prepared as a layer on the SiC support with a thickness of about 175 ?m, pore size of about 1-10 ?m and porosity of 9.9%. The SiC support tube had a pore size of about 20-150 ?m and porosity of 19.0%. After 360 days of high-temperature flue gas filtration, the most available pore size of the mullite/SiC composite filter tube membrane reduces from 45.2 to 36.4 ?m (the reduction rate of about 19.4%). Analysis of the dust collected by back-blowing revealed that the dust particle size range was between 0.1-100 ?m and about 50%of the dust particles were below 2.5 ?m in size. The average capture rate of dust can reach 98.4%, indicating that the asymmetric mullite/SiC composite filter tube membrane has excellent filtration performance for the dust below PM2.5 in the high-temperature complex flue gas.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68582775","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}
E. Bódis, I. Cora, Z. Fogarassy, M. Veres, P. Németh
Diamond-SiC composites are attractive for improving the catastrophic fracture behaviour of SiC. However, fundamental knowledge is missing about the structure of this system and the mechanism of diamond graphitization. We used spark plasma sintering to study the diamond-Si-SiC system between 1600 and 2000?C in the function of nanocrystalline (ND) and microcrystalline (MD) diamond addition as well as the quantity of Sibonding phase. Increasing sintering temperature induces intense graphitization and formation of nano-onions, few-layered graphene and well-ordered graphite in the prepared composites at elevated temperature. High resolution transmission electron microscopy study demonstrates the occurrence of the previously erroneously identified 5H-SiC polytype in the samples prepared at 2000?C. Regardless of Si and diamond contents, SiC formation is not confirmed even at high temperature.
{"title":"High-temperature evolution of diamond-SiC composites","authors":"E. Bódis, I. Cora, Z. Fogarassy, M. Veres, P. Németh","doi":"10.2298/pac2201069b","DOIUrl":"https://doi.org/10.2298/pac2201069b","url":null,"abstract":"Diamond-SiC composites are attractive for improving the catastrophic fracture behaviour of SiC. However, fundamental knowledge is missing about the structure of this system and the mechanism of diamond graphitization. We used spark plasma sintering to study the diamond-Si-SiC system between 1600 and 2000?C in the function of nanocrystalline (ND) and microcrystalline (MD) diamond addition as well as the quantity of Sibonding phase. Increasing sintering temperature induces intense graphitization and formation of nano-onions, few-layered graphene and well-ordered graphite in the prepared composites at elevated temperature. High resolution transmission electron microscopy study demonstrates the occurrence of the previously erroneously identified 5H-SiC polytype in the samples prepared at 2000?C. Regardless of Si and diamond contents, SiC formation is not confirmed even at high temperature.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68580134","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}
I. Milanović, Sanja Milosevic-Govedarovic, Miodrag J. Lukić, Z. Jovanović, Jelena Rmus, Andjela Mitrovic-Rajic, J. Grbovic-Novakovic, S. Kurko
LiAlH4 was modified by mechanical milling and with the addition of 5 wt.% Fe2O3 in order to improve its hydrogen desorption properties. The composite was milled for 1, 3, 5, 7 or 15min, and depending on the milling time, various phenomena took place. Up to a milling time of 5min, the particle size of the composite decreases. Further milling leads to the particles agglomeration reaching the size of the starting material after 15min. Moreover, the mechanical milling process leads to the transformation of AlH - 4 to AlH 3 - 6 structure as a result of partial hydrogen desorption. Hydrogen desorption during the milling is the most pronounced in the sample milled for 15min, so this sample has only one hydrogen desorption peak in the temperature-programmed desorption measurements.Mechanical milling with the addition of Fe2O3 for up to 15min improves LiAlH4 hydrogen desorption properties as hydrogen desorption temperature and apparent activation energies decrease.
{"title":"Study of milling time impact on hydrogen desorption from LiAlH4-Fe2O3 composites","authors":"I. Milanović, Sanja Milosevic-Govedarovic, Miodrag J. Lukić, Z. Jovanović, Jelena Rmus, Andjela Mitrovic-Rajic, J. Grbovic-Novakovic, S. Kurko","doi":"10.2298/pac2203259m","DOIUrl":"https://doi.org/10.2298/pac2203259m","url":null,"abstract":"LiAlH4 was modified by mechanical milling and with the addition of 5 wt.% Fe2O3 in order to improve its hydrogen desorption properties. The composite was milled for 1, 3, 5, 7 or 15min, and depending on the milling time, various phenomena took place. Up to a milling time of 5min, the particle size of the composite decreases. Further milling leads to the particles agglomeration reaching the size of the starting material after 15min. Moreover, the mechanical milling process leads to the transformation of AlH - 4 to AlH 3 - 6 structure as a result of partial hydrogen desorption. Hydrogen desorption during the milling is the most pronounced in the sample milled for 15min, so this sample has only one hydrogen desorption peak in the temperature-programmed desorption measurements.Mechanical milling with the addition of Fe2O3 for up to 15min improves LiAlH4 hydrogen desorption properties as hydrogen desorption temperature and apparent activation energies decrease.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"1 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68581462","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 effect of V2O5 and B2O3 additions on sintering behaviour and physical properties of ZnO ceramics was investigated. XRD studies revealed ZnO as main phase with a hexagonal wurtzite-type structure. The V2O5 addition is the reason for an increase in grain size and some grains of oblong shape morphology in the ZnO ceramics. The dual addition of V2O5-B2O3 improved the liquid-assisted sintering of ZnO ceramics and resulted in further increase in grain size with more uniform grain growth. The reduction of sintering temperature to 900?C for ZnO ceramics was observed with the dual addition of V2O5 and B2O3. The room temperature PL spectra of the Z (ZnO), ZV (ZnO with 0.5mol% V2O5) and ZVB (ZnO with 0.5mol% V2O5 and 0.5mol% B2O3) ceramics revealed broad visible emission band because of impurities and defects in ZnO ceramics caused by oxygen vacancies due to vanadium and boron additions, as well as zinc interstitials. This emission band between 450-750 nm includes the entire visible region from blue to red.
{"title":"Influence of V2O5 and B2O3 addition on the sintering behaviour and physical properties of ZnO ceramics","authors":"Price Yüksel, Gökhan Hardal, B. Kınacı","doi":"10.2298/pac2201048y","DOIUrl":"https://doi.org/10.2298/pac2201048y","url":null,"abstract":"The effect of V2O5 and B2O3 additions on sintering behaviour and physical properties of ZnO ceramics was investigated. XRD studies revealed ZnO as main phase with a hexagonal wurtzite-type structure. The V2O5 addition is the reason for an increase in grain size and some grains of oblong shape morphology in the ZnO ceramics. The dual addition of V2O5-B2O3 improved the liquid-assisted sintering of ZnO ceramics and resulted in further increase in grain size with more uniform grain growth. The reduction of sintering temperature to 900?C for ZnO ceramics was observed with the dual addition of V2O5 and B2O3. The room temperature PL spectra of the Z (ZnO), ZV (ZnO with 0.5mol% V2O5) and ZVB (ZnO with 0.5mol% V2O5 and 0.5mol% B2O3) ceramics revealed broad visible emission band because of impurities and defects in ZnO ceramics caused by oxygen vacancies due to vanadium and boron additions, as well as zinc interstitials. This emission band between 450-750 nm includes the entire visible region from blue to red.","PeriodicalId":20596,"journal":{"name":"Processing and Application of Ceramics","volume":"29 1","pages":""},"PeriodicalIF":1.1,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"68579972","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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