碱金属对CaO—Al2O3—SiO2—R2O—ZnO红色微晶玻璃的影响

研究了碱金属ＮａＯ和Ｋ２Ｏ对ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２－Ｒ２Ｏ－ＺｎＯ红色微晶玻璃着色,烧结和析晶的影响与作用,以及微晶玻璃烧结和析晶随热处理温度变化的规律。     

CaO—Al2O3—SiO2系烧结微晶玻璃的初始相变

本文采用ＸＲＤ和ＳＥＭ对ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系烧结微晶玻璃的初始相变进行了分析,测定了具有不同起始颗粒尺寸的玻璃的析晶Ｃ曲线。实验结果表明,玻璃的初始相变与玻璃粘度,烧结温度和颗粒尺寸有关,在不同温度区域烧结,析晶的孕育期不同,高温区烧结对析晶有抑制作用。     

Cu2O—Al2O3—SiO2系统低膨胀微晶玻璃的研究

本文研究了含Ｃｕ＾＋离子的Ｃｕ２Ｏ－Ａｌ２Ｏ３－ＳｉＯ２系统微晶玻璃的组成，通过对玻璃的差热曲线分析，制定了适当的热处理制度，用ＸＲＤ和光学显微镜研究了该系统的主晶相，讨论了组成，结构和性能之间的关系。     

Li2O—Al2O3—SiO2系统低膨胀耐热微晶玻璃的研究

本文研究了添加剂对Ｌｉ２Ｏ—Ａｌ２Ｏ３—ＳｉＯ２系统低膨胀耐热微晶玻璃的工艺和结构性能的影响。研究所得的微晶玻璃具有较低的熔制温度和较好的成型性能，且能保证较低的热膨胀系数（α＝５～２５×１０－７／℃）和较高的机械强度．并利用ＤＴＡ，ＸＲＤ和ＳＥＭ研究了添加剂对玻璃晶化和主晶相的影响。研究结果表明：添加剂可以降低玻璃的熔制温度（与不加添加剂玻璃相比降低１００～１５０℃），使晶化过程容易进行，但不会影响晶化过程析出锂辉石型固溶体的主晶相。     

Cu2O—Al2O3—SiO2系统低膨胀微晶玻璃的研究

研究了含Ｃｕ＾２＋离子的Ｃｕ２Ｏ－Ａｌ;２Ｏ３－ＳｉＯ２系统微晶玻璃的组成,通过对玻璃的差热曲线分析,制定了适当的热处理制度,用ＸＲＤ和光学显微镜研究了该系统的主晶相。讨论了组成,结构和性能之间的关系。     

Na2O—Al2O3—SiO2系统霞石微晶玻璃化学稳定性的研究

Ｎａ２Ｏ－Ａｌ２Ｏ３－ＳｉＯ２系统霞石微晶玻璃的化学稳定性是该材料的重要性能之一。采用酸碱溶液侵蚀的方法,在比较霞石微晶玻璃试样与基玻璃试样侵蚀失重的基础上,分析了霞石微晶玻璃在酸,碱溶液中的侵蚀机理,同时,研究了侵蚀时间和酸,碱溶液浓度对霞石微晶玻璃试样侵蚀失重的影响。     

SiO2—BaO—MgO—MgF2—K2O系片状微晶玻璃的研究

以ＳｉＯ２－ＢａＯ－ＭｇＯ－ＭｇＦ２－Ｋ２Ｏ系为基础成发,以ＴｉＯ２为晶核剂,通过添加Ａｌ２Ｏ３、ＺｎＯ、ＣｕＯ和改变微晶化工艺制度,研制出了有一定机械强度和良好可切生及抗热冲击性的片状微晶玻璃。用Ｘ射线衍射仪以及其它测试手段,测定了微晶玻璃中晶相的种类以及有关性能,对其实验进行了分析。     

增加TiO2,Nb2O5晶核剂对烧结微晶玻璃结构与性能的影响

在Ｌｉ２Ｏ－ＭｇＯ－Ａｌ２Ｏ３－ＳｉＯ２系玻璃中，加入不同含量的ＴｉＯ２或Ｎｂ２Ｏ５为晶核剂，经过粉碎，混和，成型，烧结能制得致密的微晶玻璃，微晶玻璃的强度比示添加ＴｉＯ２或Ｎｂ２Ｏ５的样品有所提高，当ＴｉＯ２，Ｎｂ２Ｏ５含量增加，微晶玻璃强度也相应增加，加入ＴｉＯ２或Ｎｂ２Ｏ５添加物对微晶玻璃的热膨胀系数影响较小，电子显微归咎表明，晶体颗粒随着添加物ＴｉＯ２或Ｎｂ２Ｏ５的增加而减小，Ｘ光衍射结果     

CeO2对CaO—MgO—Fe2O3—Al2O3—SiO2系玻璃晶化的影响

本文阐述了制备以ＣｅＯ２为晶核剂的ＣａＯ－ＭｇＯ－Ｆｅ２Ｏ３－Ａｌ２Ｏ３－ＳｉＯ２系微晶玻璃,采用ＳＥＭ,ＸＲＤ和ＤＴＡ等技术,研究了ＣｅＯ２对玻璃成核与晶化的影响,确定了析出的晶相,讨论了加入ＣｅＯ２后玻璃析晶活化能的变化,结果表明,ＣｅＯ２的加入能降低玻璃晶化活化能,促进玻璃相分离使制得的微晶玻璃强度增大,但析出的主晶相仍为钙铁辉石。     

金尾砂烧结微晶玻璃的研制

本文叙述了以金尾砂为主要原料，采用ＣａＯ－ＭｇＯ－Ａｌ２Ｏ３－ＳｉＯ２玻璃系统，制备了烧结型微晶玻璃花岗岩，讨论了烧结和析晶的关系，分析了玻璃颗粒尺寸，分布及形状对烧结的影响，确定了最佳颗粒级配及烧结温度制度。     

Bi2O3-ZnO-B2O3低熔点封接玻璃的烧结特性

利用X射线衍射、扫描电子显微镜对Bi2O3-ZnO-B2O3系统低熔点玻璃的烧结性能、结晶特性以及烧结后玻璃试样的结构进行了研究.结果表明:随着B2O3含量的增加,玻璃的转变温度与软化温度都随之提高,影响了玻璃的烧结.Bi2O3-ZnO-B2O3系统低熔点玻璃粉末的烧结有黏性液相参与,使得玻璃试样的致密化更加有效,效率更高.当B2O3含量为5.24%(以质量计)时,玻璃的析晶倾向增大,试样中析出了Bi2482O39晶相.当温度继续升高时,试样的烧结收缩出现了"滞缓",有大量的液相出现,且在表面张力的作用F出现了流散.     

Y2O3掺杂CaO-Al2O3-SiO2系微晶玻璃的研究

在CaO-Al2O3-SiO2(CAS)系统微晶玻璃中引入稀土氧化物Y2O3,结合XRD、SEM等测试手段,研究了Y2O3的引入对微晶玻璃烧结过程、微观结构以及性能的影响。实验结果表明:随着Y2O3的引入,微晶玻璃烧结温度降低,烧结时间变短。当Y2O3质量分数为3.25%时,CAS微晶玻璃具有最佳的制备工艺和最好的力学性能。     

添加Li_2O的CaO-B_2O_3-SiO_2系微晶玻璃的性能研究

以Li_2O为烧结助剂,采用DTA、XRD、SEM等分析手段研究了添加1.0～2.5 wt%Li_2O对CaO-B_2O_3-SiO_2(CBS)系微晶玻璃性能的影响.结果表明:Li_2O降低了CBS系微晶玻璃的玻璃转变温度和析晶温度.未添加Li_2O的试样在930 ℃烧结,而添加Li_2O的试样可以在820 ℃以下烧结,Li_2O显著降低了试样的烧结温度.当Li_2O添加量为1.0wt%时,试样可以在760～820 ℃范围内烧结,800 ℃烧结试样介电常数为5.71,介电损耗为0.0024(测试频率为10 MHz).     

CaO对CaO-Al2O3-SiO2微晶玻璃晶化过程活化能的影响

CaO对CaO-Al2O3-SiO2系统微晶玻璃的烧结及析晶性能有较大影响,从而影响了微晶玻璃的结构及性能.本文运用DTA、烧结收缩率分别测定了CaO-A12O3-SiO2系统微晶玻璃的烧结活化能及析晶活化能,研究了这两者的变化趋势.     

Li2O-Al2O3-SiO2系统玻璃的晶化和烧结

采用差热分析（DTA）,X射线衍射分析（XRD）和扫描电子显微镜（SEM）等分析手段研究了Li2O-Al2O3—SiO2 （LAS）系统玻璃的烧结和析晶.通过实验确定了最佳烧结温度,并获得主晶相为β—锂辉石的Li2O-Al2O3—SiO2 （LAS）的微晶玻璃.结合烧结体的体积密度、显气孔率和吸水率的数据,分析说明了粘结剂PVA的加入对玻璃粉烧结体性能的影响.     

The role of K2O on sintering and crystallization of glass powder compacts in the Li2O–K2O–Al2O3–SiO2 system

The effects of K₂O content on sintering and crystallization of glass powder compacts in the Li₂O–K₂O–Al₂O₃–SiO₂ system were investigated. Glasses featuring SiO₂/Li₂O molar ratios of 2.69–3.13, far beyond the lithium disilicate (LD-Li₂Si₂O₅) stoichiometry, were produced by conventional melt-quenching technique. The sintering and crystallization behaviour of glass powders was explored using hot stage microscopy (HSM), scanning electron microscopy (SEM), differential thermal (DTA) and X-ray diffraction (XRD) analyses. Increasing K₂O content at the expense of SiO₂ was shown to lower the temperature of maximum shrinkage, eventually resulting in early densification of the glass-powder compacts. Lithium metasilicate was the main crystalline phase formed upon heat treating the glass powders with higher amounts of K₂O. In contrast, lithium disilicate predominantly crystallized from the compositions with lower K₂O contents resulting in strong glass–ceramics with high chemical and electrical resistance. The total content of K₂O should be kept below 4.63 mol% for obtaining LD-based glass–ceramics.     

Synthesis of glass-ceramics in the Na2O/K2O-CaO-MgO-SiO2-P2O5-CaF2 system as candidate materials for dental applications

This study reports on the sintering behavior, crystallization process, and mechanical properties of novel glass-ceramics (CGs) produced by the glass powder compact consolidation method. Substitution of K₂O for Na₂O and MgO for CaO was attempted in the parent glasses belonging to Na₂O-CaO-MgO-SiO₂-P₂O₅-CaF₂ system. Glass powder compacts were heat treated at various temperatures between 700°C and 900°C, taking under consideration the glass transition (T_g) and the crystallization peak (T_p) temperatures, which were experimentally determined for each investigated glass by thermal analysis (dilatometry and differential scanning calorimetry). The experimental results showed that sintering always preceded crystallization, regardless of the type of substitution. In the case of MgO substitution for CaO, crystallization was advanced in the range of 800°C-850°C, resulting in the formation of an assembly of crystalline phases, such as diopside, fluorapatite, and wollastonite. The substitution of K₂O for Na₂O increased the activation energy for crystallization, shifting crystallization process to a high temperature region, with the formation of alpha-potassium magnesium silicate, instead of wollastonite. The GCs produced had values of 22-31 GPa regarding the modulus of elasticity, 5.0-6.1 GPa concerning the microhardness, and 1.4-1.9 MPa⋅m^0.5 as regard the fracture toughness, which are similar to those of the human jawbone.     

CaO-MgO-Al2O3-SiO2系统玻璃表面析晶的研究

以浮选法黄金生产过程中排放的尾砂为主要原料，综合运用差热分析、X射线衍射、光学显微镜等测试手段，对CaO-MgO-Al2O3-SiO2系统玻璃的表面析晶行为及其动力学等内容进行了研究，其结果对进一步探索该系统玻璃粉末的烧结过程有一定的指导作用，对于合理利用固体废弃物，开发环保型烧结微晶玻璃材料具有实际意义 。     

Effect of Al2O3 and K2O content on structure,properties and devitrification of glasses in the Li2O–SiO2 system

The effect of Al₂O₃ and K₂O content on structure, sintering and devitrification behaviour of glasses in the Li₂O–SiO₂ system along with the properties of the resultant glass–ceramics (GCs) was investigated. Glasses containing Al₂O₃ and K₂O and featuring SiO₂/Li₂O molar ratios (3.13–4.88) far beyond that of lithium disilicate (Li₂Si₂O₅) stoichiometry were produced by conventional melt-quenching technique along with a bicomponent glass with a composition 23Li₂O–77SiO₂ (mol.%) (L₂₃S₇₇). The GCs were produced through two different methods: (a) nucleation and crystallization of monolithic bulk glass, (b) sintering and crystallization of glass powder compacts.Scanning electron microscopy (SEM) examination of as cast non-annealed monolithic glasses revealed precipitation of nanosize droplet phase in glassy matrices suggesting the occurrence of phase separation in all investigated compositions. The extent of segregation, as judged from the mean droplet diameter and the packing density of droplet phase, decreased with increasing Al₂O₃ and K₂O content in the glasses. The crystallization of glasses richer in Al₂O₃ and K₂O was dominated by surface nucleation leading to crystallization of lithium metasilicate (Li₂SiO₃) within the temperature range of 550–900 °C. On the other hand, the glass with lowest amount of Al₂O₃ and K₂O and glass L₂₃S₇₇ were prone to volume nucleation and crystallization, resulting in formation of Li₂Si₂O₅ within the temperature interval of 650–800 °C.Sintering and crystallization behaviour of glass powders was followed by hot stage microscopy (HSM) and differential thermal analysis (DTA), respectively. GCs from composition L₂₃S₇₇ demonstrated high fragility along with low flexural strength and density. The addition of Al₂O₃ and K₂O to Li₂O–SiO₂ system resulted in improved densification and mechanical strength.     

Al2O3含量对PbO-CaO-B2O3-SiO2系玻璃析晶行为与烧结性能的影响

PbO-CaO-B₂O₃-SiO₂系玻璃粉体是耐高过载低温共烧陶瓷(LTCC)生瓷带的主要组成部分。玻璃粉体的析晶行为影响烧结性能,进而决定基板的使用性能。本文研究了Al₂O₃含量对PbO-CaO-B₂O₃-SiO₂系玻璃析晶行为与烧结性能的影响。结果表明:向PbO-CaO-B₂O₃-SiO₂系玻璃中引入Al₂O₃可抑制玻璃析晶,防止高膨胀晶相的析出,并提高玻璃烧结密度;不含Al₂O₃的PbO-CaO-B₂O₃-SiO₂玻璃粉体析晶峰温度为862 ℃,烧结过程中析出方石英晶相,20~200 ℃的平均线膨胀系数高达260.8×10^-7 ℃^-1;引入2.1%(质量分数)Al₂O₃可显著抑制玻璃析晶,700 ℃烧结后膨胀系数降低至72.9×10^-7 ℃^-1,介电常数显著增大,由6.30提高至7.02。