稀土掺杂锌硼硅玻璃高温熔体物性的研究

发布时间：2018-06-21 15:52

本文选题：锌硼硅玻璃 + 稀土　；参考：《内蒙古科技大学》2015年硕士论文

【摘要】：本文以锌硼硅玻璃为研究对象，外加不同含量的氧化镧和氧化钇，利用高温旋转粘度计测试玻璃的高温粘度，通过热膨胀测试、差热分析测定玻璃的特征温度，利用傅里叶红外检测结构，研究了不同含量的氧化镧、氧化钇掺杂对锌硼硅玻璃的结构和高温熔体物性的影响。对于锌硼硅玻璃（55ZnO-40B2O3-5SiO2，摩尔分数），从结构上来说，外加氧化镧和氧化钇，对玻璃的作用是双向的。少量引入，稀土离子位于网络空隙，具有较高的配位数，高场强，促进了[BO3]三角体向[BO4]四面体的转化，有助于网络结构变得紧密。但在稀土掺杂量继续上升时，由于Y3+的半径比La3+的半径小，Y3+的场强比La3+大，给出游离氧的能力小，因此当氧化镧掺杂量大于1.0%，氧化钇大于1.5%，稀土氧化物促进[BO3]和非桥氧的生成，起断网作用，破坏了玻璃的网络结构，使结构变得疏松。氧化镧与氧化钇的掺杂导致锌硼硅玻璃的结构发生变化，影响了玻璃的高温熔体物性。在少量掺杂时，锌硼硅玻璃的自由体积分数减小，自由体积减少，结构变得紧密，粘度提高，玻璃的热膨胀系数减小，动力学脆性指数减小，动力学脆性下降，成玻能力增大；但掺杂过量后，锌硼硅玻璃的自由体积分数增大，自由体积增多，结构变得疏松，粘度下降，玻璃的热膨胀系数增大，动力学脆性指数增大，动力学脆性上升，成玻能力减小。在补充实验中，选定摩尔组分55ZnO-40B2O3-5SiO2为基础组分，研究了Al2O3部分取代B2O3对锌硼硅玻璃的结构和高温熔体物性的影响。随着氧化铝对氧化硼的替代，B/Al比下降，Al3+夺取游离氧形成[AlO4]进入网络结构，促进桥氧的生成，[BO3]三角体与[BO4]四面体相互链接形成高硼基团，把断网重新连接起来，使玻璃结构网络聚集更加紧密。随着加入锌硼硅玻璃的氧化铝含量从摩尔百分数0增加到4，B/Al比下降，锌硼硅玻璃的自由体积分数减小，玻璃的自由体积减少，结构变得紧密，使玻璃粘度上升，玻璃的动力学脆性指数下降，动力学脆性下降，成玻能力增大，，成形温度范围扩大，熔体随温度变化时其粘度变化速率变慢。
[Abstract]:In this paper, zinc-borosilicate glass is used as the research object, with different contents of lanthanum oxide and yttrium oxide added, the high temperature viscosity of the glass is measured by high temperature rotary viscometer, the characteristic temperature of the glass is measured by thermal expansion test, and the characteristic temperature of glass is measured by differential thermal analysis. The effects of different contents of lanthanum oxide and yttrium oxide on the structure and physical properties of zinc-borosilicate glass were studied by Fourier transform infrared spectroscopy (FTIR). For zinc-borosilicate glass (55ZnO-40B _ 2O _ 3-5SiO _ 2), the effect of addition of lanthanum oxide and yttrium oxide on the glass structure is bidirectional. A small amount of rare earth ions is introduced in the network space with high coordination number and high field strength, which promotes the transformation of [BO3] triangle to [BO4] tetrahedron, and helps to make the network structure close. However, when the rare-earth doping amount continues to rise, because the radius of Y _ 3 is smaller than that of La _ 3 and the field strength of Y _ 3 is larger than that of La _ 3, the ability of free oxygen is smaller. Therefore, when the doping amount of lanthanum oxide is greater than 1.0 and the amount of yttrium oxide is greater than 1.5, rare earth oxides promote the formation of [BO3] and unbridged oxygen. It breaks the network, destroys the network structure of glass, and makes the structure loose. The doping of lanthanum oxide and yttrium oxide leads to the change of the structure of Zn-Borosilicate glass and affects the physical properties of the glass melt at high temperature. With a small amount of doping, the free volume fraction and free volume of Zn-Borosilicate glass decrease, the structure becomes compact, the viscosity increases, the thermal expansion coefficient of the glass decreases, the dynamic brittleness index decreases, the dynamic brittleness decreases, and the glassy forming ability increases. But after excessive doping, the free volume fraction and free volume increased, the structure became loose, the viscosity decreased, the thermal expansion coefficient of the glass increased, the dynamic brittleness index increased, the dynamic brittleness increased, and the glassy forming ability decreased. In the supplementary experiment, the effect of partial substitution of Al _ 2O _ 3 on the structure of Zn-Borosilicate glass and the physical properties of high temperature melt was studied by selecting 55ZnO-40B _ 2O _ 3-5SiO _ 2 as the basic component. As Al _ 2O _ 3 replaces boron oxide with B / Al ratio, Al _ 3 grabs free oxygen to form [AlO _ 4] into the network structure, which promotes the formation of bridge oxygen, [BO _ 3] triangle and [BO _ 4] tetrahedron are linked to each other to form high boron group, and the broken network is reconnected. Make the glass structure network closer together. With the increase of Al _ 2O _ 3 content in Zn-Borosilicate glass from 0 mol% to 4 W / Al ratio, the free volume fraction of Zn-Borosilicate glass decreases, the free volume of the glass decreases, the structure becomes compact, and the viscosity of the glass increases. The dynamic brittleness index of glass decreases, the dynamic brittleness decreases, the glassy forming ability increases, the forming temperature range is enlarged, and the viscosity of the melt slows down with the change of temperature.
【学位授予单位】：内蒙古科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ171.1

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