Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with ...Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with the increase of B2O3 content, the transition temperature Tg and softening temperature Tf of Bi2O3-ZnO-B2O3 system low-melting sealing glasses increase, which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass. With increasing the heat treatment temperature, a large number of liquid phases appear in samples and the sinter efficiency of the samples increases. The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi--O bond from [BO3] pyramidal and [BiO6] octahedral units and B--O from [BO3] and [BO4] units. With the decrease of B203 content, the crystallization tendency of the glass increases. In glass samples Bl and B〉 crystallization starts at 460 ℃ and 540 ℃, respectively. Both of them precipitate Bi24B2O39 phases.展开更多
Glasses based on ZnO-Bi_2O_3-B_2O_3 system are expected to be a new kind of sealing glasses because of their low melting temperature and other properties.In order to reveal the effect of B_2O_3 on the rheological beha...Glasses based on ZnO-Bi_2O_3-B_2O_3 system are expected to be a new kind of sealing glasses because of their low melting temperature and other properties.In order to reveal the effect of B_2O_3 on the rheological behavior of ZnO-Bi_2O_3-B_2O_3 system glass melt,the properties of viscosity,thermal expansion,fluxion property and wetting process between cylinder samples and stainless steel were investigated with the rotating crucible viscometer,dilato meter and high-temperature microscope.The structure of sintered glass samples was investigated with scanning electron microscope.The results show that the B_2O_3 content increasing in B_1-B_3 at the given temperature between 400 ℃ and 500 ℃ leads to the increasing of the sample viscosity.When the amount of B_2O_3 increases from 5.24%to 9.24%(mass fraction),the coefficients of thermal expansion of glass samples decrease smoothly from 10.94×10^(-6) to10.71×10^(-6) and 10.38×10^(-6) ℃^(-1) respectively.In the case of sealing temperature,its value increases from 453 ℃ to 494 ℃.ZnO-Bi_2O_3-B_2O_3 system low-melting glass powder sintering was with viscous liquid to participate,which could make the densification of glass sample more effective and more efficient.With the content of B_2O_3 increasing,the wetting angle between the glasses samples and stainless steel could also increase,and the resulting appropriate sealing temperature range is 460-490 ℃.展开更多
A series of glass are synthesized via a melt quenching technique based on the Li_(2)O-Ni O-P_(2)O_(5) system.The concentration of nickel oxide varies from 5%to 15%in molar fraction.XRD pattern verifies the amorphous n...A series of glass are synthesized via a melt quenching technique based on the Li_(2)O-Ni O-P_(2)O_(5) system.The concentration of nickel oxide varies from 5%to 15%in molar fraction.XRD pattern verifies the amorphous nature of prepared glass samples with 5%,and 10%nickel oxide in molar fraction.While Li_(3)P and Ni_(2)P_(4)O_(12)phases are precipitated with a high nickel content up to 15%in molar fraction.As nickel is substituted for lithium,a systematic increase in glass transition temperature(T_(g))and glass softening temperatures(T_(s))is observed.This is greatly related to the increased structure,coherence in the glass network.Structural investigation showed that Ni_(2+) spectra are present in both octahedral and tetrahedral sites.Physical properties such as glass density((2.38±0.1)-(2.46±0.1)g/cm^(3)),and molar volume((42.28±0.1)-(39.15±0.1)cm^(3)/mol)are examined.The NiO/Li_(2)O replacements led to a decrease in the dissolution rate of the resultant amorphous materials from 1.53×10^(-5)to 3.20×10^(-6)g/(cm^(2)·min).Thermal expansion coefficients CTE of the glasses are diverse from 157×10^(-7) to 96×10^(-7)℃^(-1) over the temperature range of 25-250℃.The prepared glasses are expected to be useful as a low-temperature sealing material.展开更多
Glasses of the SiO_2-Al_2O_3-BaO-MgO and SiO_2-Al_2O_3-ZrO_2-CaO-Na_2O systems were synthesized in the perspective to apply them as sealants in SOFC at operating temperatures of 700-900 °C. Thermal properties of ...Glasses of the SiO_2-Al_2O_3-BaO-MgO and SiO_2-Al_2O_3-ZrO_2-CaO-Na_2O systems were synthesized in the perspective to apply them as sealants in SOFC at operating temperatures of 700-900 °C. Thermal properties of the chosen glass compositions and their compatibility with the SOFC materials(YSZ-electrolyte and alloy-interconnector Crofer22 APU, 15Х25Т) were investigated by means of synchronic thermal analysis and high-temperature dilatometry. The elemental analysis was performed by atomic emission spectroscopy. The average values of the temperature coefficients of the linear extension are 10.0×10^(-6) °С^(-1) for glass 45%SiO_2-15%Al_2O_3-25%BaO-15%MgO and 9.5×10^(-6) °С^(-1) for glass 60%SiO_2-10%Al_2O_3-10%ZrO_2-5%CaO-15%Na_2O. The gluing microstructure in YSZ/glass/Crofer22 APU was studied by scanning electron microscopy. The crystallization process of silicate phases was revealed to occur in the SiO_2-Al_2O_3-BaO-MgO glass. The analysis of the crystallization products was performed by Raman spectroscopy and X-ray diffraction. Glassy ceramics was proved to possess better parameters in comparison with amorphous glass to be used as a sealant in electrochemical sensors and oxygen sensors. The SiO_2-Al_2O_3-ZrO_2-CaO-Na_2O low-temperature amorphous glass can be applied in SOFC.展开更多
基金Project(50272043) supported by the National Natural Science Foundation of China
文摘Bi2O3-ZnO-B2O3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with the increase of B2O3 content, the transition temperature Tg and softening temperature Tf of Bi2O3-ZnO-B2O3 system low-melting sealing glasses increase, which leads to the liquid phase precipitation temperature increasing and promotes the structure stability in the glass. With increasing the heat treatment temperature, a large number of liquid phases appear in samples and the sinter efficiency of the samples increases. The FT-IR spectra of the glasses show the presence of some bands that are assigned to vibrations of Bi--O bond from [BO3] pyramidal and [BiO6] octahedral units and B--O from [BO3] and [BO4] units. With the decrease of B203 content, the crystallization tendency of the glass increases. In glass samples Bl and B〉 crystallization starts at 460 ℃ and 540 ℃, respectively. Both of them precipitate Bi24B2O39 phases.
基金Project(2012BAA08B04)supported by the National“Twelfth Five-Year”Plan for Science&Technology Support of China
文摘Glasses based on ZnO-Bi_2O_3-B_2O_3 system are expected to be a new kind of sealing glasses because of their low melting temperature and other properties.In order to reveal the effect of B_2O_3 on the rheological behavior of ZnO-Bi_2O_3-B_2O_3 system glass melt,the properties of viscosity,thermal expansion,fluxion property and wetting process between cylinder samples and stainless steel were investigated with the rotating crucible viscometer,dilato meter and high-temperature microscope.The structure of sintered glass samples was investigated with scanning electron microscope.The results show that the B_2O_3 content increasing in B_1-B_3 at the given temperature between 400 ℃ and 500 ℃ leads to the increasing of the sample viscosity.When the amount of B_2O_3 increases from 5.24%to 9.24%(mass fraction),the coefficients of thermal expansion of glass samples decrease smoothly from 10.94×10^(-6) to10.71×10^(-6) and 10.38×10^(-6) ℃^(-1) respectively.In the case of sealing temperature,its value increases from 453 ℃ to 494 ℃.ZnO-Bi_2O_3-B_2O_3 system low-melting glass powder sintering was with viscous liquid to participate,which could make the densification of glass sample more effective and more efficient.With the content of B_2O_3 increasing,the wetting angle between the glasses samples and stainless steel could also increase,and the resulting appropriate sealing temperature range is 460-490 ℃.
文摘A series of glass are synthesized via a melt quenching technique based on the Li_(2)O-Ni O-P_(2)O_(5) system.The concentration of nickel oxide varies from 5%to 15%in molar fraction.XRD pattern verifies the amorphous nature of prepared glass samples with 5%,and 10%nickel oxide in molar fraction.While Li_(3)P and Ni_(2)P_(4)O_(12)phases are precipitated with a high nickel content up to 15%in molar fraction.As nickel is substituted for lithium,a systematic increase in glass transition temperature(T_(g))and glass softening temperatures(T_(s))is observed.This is greatly related to the increased structure,coherence in the glass network.Structural investigation showed that Ni_(2+) spectra are present in both octahedral and tetrahedral sites.Physical properties such as glass density((2.38±0.1)-(2.46±0.1)g/cm^(3)),and molar volume((42.28±0.1)-(39.15±0.1)cm^(3)/mol)are examined.The NiO/Li_(2)O replacements led to a decrease in the dissolution rate of the resultant amorphous materials from 1.53×10^(-5)to 3.20×10^(-6)g/(cm^(2)·min).Thermal expansion coefficients CTE of the glasses are diverse from 157×10^(-7) to 96×10^(-7)℃^(-1) over the temperature range of 25-250℃.The prepared glasses are expected to be useful as a low-temperature sealing material.
基金supported by the program “Fundamental research program for the development of the Arctic zone of the Russian Federation”the Russian Foundation for Basic Research, project No. 14-29-04009+2 种基金supported by Act 211 of Government of the Russian Federation, agreement No. 02.A03.21.0006Russian President scholarship 2015-2017 CⅡ-1572.2015.1 and СⅡ-1663.2015.1the co-worker of Research and Advanced Development in the framework of the project “Development and creation of high-technological manufactory of autonomic multipurpose power sources based of domestic high-technological solid oxide fuel cells” (No. 02.G25.31.0198 by 27.04.2016) under financial support of the Ministry of Education and Science of Russian Federation in accordance with Government of Russian Federation Decree by 09.04.2010 N 218
文摘Glasses of the SiO_2-Al_2O_3-BaO-MgO and SiO_2-Al_2O_3-ZrO_2-CaO-Na_2O systems were synthesized in the perspective to apply them as sealants in SOFC at operating temperatures of 700-900 °C. Thermal properties of the chosen glass compositions and their compatibility with the SOFC materials(YSZ-electrolyte and alloy-interconnector Crofer22 APU, 15Х25Т) were investigated by means of synchronic thermal analysis and high-temperature dilatometry. The elemental analysis was performed by atomic emission spectroscopy. The average values of the temperature coefficients of the linear extension are 10.0×10^(-6) °С^(-1) for glass 45%SiO_2-15%Al_2O_3-25%BaO-15%MgO and 9.5×10^(-6) °С^(-1) for glass 60%SiO_2-10%Al_2O_3-10%ZrO_2-5%CaO-15%Na_2O. The gluing microstructure in YSZ/glass/Crofer22 APU was studied by scanning electron microscopy. The crystallization process of silicate phases was revealed to occur in the SiO_2-Al_2O_3-BaO-MgO glass. The analysis of the crystallization products was performed by Raman spectroscopy and X-ray diffraction. Glassy ceramics was proved to possess better parameters in comparison with amorphous glass to be used as a sealant in electrochemical sensors and oxygen sensors. The SiO_2-Al_2O_3-ZrO_2-CaO-Na_2O low-temperature amorphous glass can be applied in SOFC.
