The Li_(2)O-Al_(2)O_(3)-SiO_(2) (LAS) glass-ceramics with low lithium content were prepared from spodumene mineral by melting method.XRD,DSC,and FTIR were used to study the crystallization process and structure of the...The Li_(2)O-Al_(2)O_(3)-SiO_(2) (LAS) glass-ceramics with low lithium content were prepared from spodumene mineral by melting method.XRD,DSC,and FTIR were used to study the crystallization process and structure of the samples.The results showed that the addition of Na_(2)O promoted the precipitation of β-quartz solid solution and its transformation to β-spodumene solid solution.Mechanical performance tests and FESEM indicated that the larger grain size and inhomogeneous grain dispersion caused by the increase of Na_(2)O content led to lower mechanical properties.In addition,low expansion glass-ceramics were prepared by an appropriate heat treatment according to DSC result,and when Na_(2)O content was in the range of 1.22 wt% to 2.41 wt%,the average coefficient of thermal expansion (CTE) (30-300 ℃) increased from-5.810 ×10^(-7 )to 5.322×10^(-7)℃^(-1).展开更多
通过FTIR、Raman、27 Al NMR、XRD、DSC等测试方法,研究了ZnO含量对Bi2O3-B2O3-ZnO-SiO2-Al2O3系统低熔点玻璃结构及热性能的影响。结果表明:当ZnO含量小于12wt%时,Zn^2+与自由氧结合形成[ZnO 4]四面体,增强网络结构,玻璃化转变温度增大...通过FTIR、Raman、27 Al NMR、XRD、DSC等测试方法,研究了ZnO含量对Bi2O3-B2O3-ZnO-SiO2-Al2O3系统低熔点玻璃结构及热性能的影响。结果表明:当ZnO含量小于12wt%时,Zn^2+与自由氧结合形成[ZnO 4]四面体,增强网络结构,玻璃化转变温度增大,热膨胀系数减小;当ZnO含量大于12wt%时,锌氧多面体由四配位[ZnO4]转变为六配位[ZnO6],破坏网络结构,玻璃化转变温度减小,热膨胀系数增大;ZnO含量的提高和热处理温度的升高对玻璃析晶能力没有明显的促进作用。展开更多
The adventitious carbon located at 284.8 eV was used to calibrate samples without the carbon themselves.When the carbon is as a major part of the inorganic material,the adventitious carbon should be identified and use...The adventitious carbon located at 284.8 eV was used to calibrate samples without the carbon themselves.When the carbon is as a major part of the inorganic material,the adventitious carbon should be identified and used as the reference.There is no adventitious carbon on the surfaces of the polymer materials,so using C1s of the carbon in the polymer itself to calibrate the charging effect is reasonable.Furthermore,compared with gold and argon,a more practical and convenient method based on C1s is proposed to get the right positions for binding energy peaks.展开更多
Influence of aluminum addition on the structures and properties of SiO_2-B_2O_3-Al_2O_3-CaO vitrified bond at low sintering temperature and high strength was discussed. FTIR and XRD analyses were used to characterize ...Influence of aluminum addition on the structures and properties of SiO_2-B_2O_3-Al_2O_3-CaO vitrified bond at low sintering temperature and high strength was discussed. FTIR and XRD analyses were used to characterize the structures of the basic vitrified bond with different contents of aluminum. The bending strength and the thermal expansion coefficients were also tested. Meanwhile, the microstructures of composite specimens at sintering temperature of 660 ℃ were observed by scanning electron microscope（SEM）. The experimental results showed that the properties of vitrified bond with 1wt% aluminum were improved significantly, where the bending strength, Rockwell hardness, and thermal expansion coefficient of the vitrified bond reached 132 MPa, 63 HRB, and 6.73×10^（-6） ℃^（-1）, respectively.展开更多
基金Funded by Research Fund of Center for Materials Research and Analysis,Wuhan University of Technology (No.2018KFJJ11)。
文摘The Li_(2)O-Al_(2)O_(3)-SiO_(2) (LAS) glass-ceramics with low lithium content were prepared from spodumene mineral by melting method.XRD,DSC,and FTIR were used to study the crystallization process and structure of the samples.The results showed that the addition of Na_(2)O promoted the precipitation of β-quartz solid solution and its transformation to β-spodumene solid solution.Mechanical performance tests and FESEM indicated that the larger grain size and inhomogeneous grain dispersion caused by the increase of Na_(2)O content led to lower mechanical properties.In addition,low expansion glass-ceramics were prepared by an appropriate heat treatment according to DSC result,and when Na_(2)O content was in the range of 1.22 wt% to 2.41 wt%,the average coefficient of thermal expansion (CTE) (30-300 ℃) increased from-5.810 ×10^(-7 )to 5.322×10^(-7)℃^(-1).
文摘通过FTIR、Raman、27 Al NMR、XRD、DSC等测试方法,研究了ZnO含量对Bi2O3-B2O3-ZnO-SiO2-Al2O3系统低熔点玻璃结构及热性能的影响。结果表明:当ZnO含量小于12wt%时,Zn^2+与自由氧结合形成[ZnO 4]四面体,增强网络结构,玻璃化转变温度增大,热膨胀系数减小;当ZnO含量大于12wt%时,锌氧多面体由四配位[ZnO4]转变为六配位[ZnO6],破坏网络结构,玻璃化转变温度减小,热膨胀系数增大;ZnO含量的提高和热处理温度的升高对玻璃析晶能力没有明显的促进作用。
基金Funded by the National Key R&D Program of China(2017YFC0210802)the Fundamental Research Funds for the Central Universities(WUT 2019III015GX)。
文摘The adventitious carbon located at 284.8 eV was used to calibrate samples without the carbon themselves.When the carbon is as a major part of the inorganic material,the adventitious carbon should be identified and used as the reference.There is no adventitious carbon on the surfaces of the polymer materials,so using C1s of the carbon in the polymer itself to calibrate the charging effect is reasonable.Furthermore,compared with gold and argon,a more practical and convenient method based on C1s is proposed to get the right positions for binding energy peaks.
基金Funded by the National“Twelfth Five-Year”Plan for Science&Technology Support of China(2012BAA08B00)
文摘Influence of aluminum addition on the structures and properties of SiO_2-B_2O_3-Al_2O_3-CaO vitrified bond at low sintering temperature and high strength was discussed. FTIR and XRD analyses were used to characterize the structures of the basic vitrified bond with different contents of aluminum. The bending strength and the thermal expansion coefficients were also tested. Meanwhile, the microstructures of composite specimens at sintering temperature of 660 ℃ were observed by scanning electron microscope（SEM）. The experimental results showed that the properties of vitrified bond with 1wt% aluminum were improved significantly, where the bending strength, Rockwell hardness, and thermal expansion coefficient of the vitrified bond reached 132 MPa, 63 HRB, and 6.73×10^（-6） ℃^（-1）, respectively.
