火山凝灰岩微晶玻璃的研究

以火山凝灰岩为主要原料研制成了以β－硅灰石为主晶相的微晶玻璃。高ＣａＯ含量玻璃核化、晶化后整体均匀结晶成为乳白色或浅黄色微晶化制品；低ＣａＯ含量玻璃烧结、晶化后成为花纹清晰的微晶玻璃大理石。高ＣａＯ含量玻璃由于ＣａＯ含量高，热处理时严重分相，分相有利于玻璃整体均匀析晶；低ＣａＯ含量玻璃在大量析晶之前基本烧结，由于表面效应在玻璃颗粒表面诱发β－硅灰石晶体，并由表及里长大为针状晶体。     

K_2O对CaO－Al_2O_3－SiO_2系统微晶玻璃晶化与烧结性能的影响

研究了ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系统微晶玻璃的Ｋ２Ｏ含量对析晶及烧结过程随热处理温度的变化规律的影响。结果表明：Ｋ２Ｏ含量的增加不利于晶化，Ｋ２Ｏ含量（ｗｔ％）超过２．０％时将出现分相现象，并阻碍烧结致密化进程     

K2O对CaO—Al2O3—SiO2系统微晶玻璃晶化与烧结性能的影响

研究了ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系统微晶玻璃的Ｋ２Ｏ含量以析晶及烧结过程随热处理温度的变化规律的影响，结果表明：Ｋ２Ｏ含量的增加不利晶化，Ｋ２Ｏ含量（ｗｔ％）超过２．０％时将出现分相现象，并阻碍烧结致密化进程。     

钙磷酸盐玻璃析晶与分相的研究

ＣａＯ－Ｐ２Ｏ５物质的量比为１的钙磷酸盐玻璃,经７４０℃和８００℃热处理后发生分相和析晶。液滴状分相存在于整个样品范围内,而析晶则是从表面开始,析晶层厚度随热处理温度的提高而增大,析晶不是分相作用的结果。由于析出的晶体δ－Ｃａ（ＰＯ３）２的密度大于基础玻璃,从而导致析出的晶体与周围基质玻璃间出现空隙。     

Na2O对微晶玻璃装饰板烧结和析晶的影响

研究了Ｎａ２Ｏ３含量对ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系统微晶玻璃装饰板析晶温度、析晶相、烧结收缩及表面气泡的影响。确定了合适的Ｎａ２Ｏ含量及烧结温度范围。     

钢渣微晶玻璃的研究

探讨了ＣａＯ－ＭｇＯ－Ａｌ２Ｏ３－ＳｉＯ２系统钢渣微晶玻璃的烧结法制备工艺，研究了玻璃成分对烧结和晶化过程，结构和性质的影响，讨论了烧结和表面成核机理。     

氧化铝对微量玻璃装饰板烧结及晶化影响

研究了Ａｌ２Ｏ３含量的变化对ＣａＯ－Ａｌ２Ｏ３－ＳｉＯ２系统微晶玻璃的烧结和析晶的影响规律,结合工业化生产,确定了合适的Ａｌ２Ｏ３含量范围。     

SiO_2对磷酸盐玻璃晶化性能的影响

磷酸盐系统是生物活性微晶玻璃常用系统之一。本文研究了Ｎａ２Ｏ－ＣａＯ－ＡＩ２Ｏ３－Ｐ２Ｏ５系统玻璃引入ＳｉＯ２。前后的晶化性能，以讨论ＳｉＯ２对系统玻璃晶化行为的影响。本文利用ＤＴＡ，ＳＥＭ，ＸＲＤ，ＥＰ－ＭＡ，ＦＴ－ＩＲ等手段进行了研究。研究发现：ＳｉＯ２能促进ＡｌＰＯ４晶体的析出，并且使系统产生分相进而改善了该系统玻璃的晶化特性。     

Si3N4—MgO—CeO2陶瓷烧结过程中MgO的自动析晶

作者首次发现了Ｓｉ３Ｎ４－ＭｇＯ－ＣｅＯ２系陶瓷在烧结过程中玻璃相自动析晶这一独特现象。对于Ｓｉ３Ｎ４－ＭｇＯ－ＣｅＯ２系陶瓷在１４５０℃，ＭｇＯ－ＣｅＯ２就会与Ｓｉ３Ｎ４颗粒表面ＳｉＯ２反应形成硅酸盐液相，冷却后则成为玻璃相保留在烧结体中；当烧结温度高于１５５０℃时，作者发现，ＣｅＯ２仍留在玻璃相中，但ＭｇＯ会自动析晶出来，其结果是大大减少了烧结体中严重影响其高温性能的玻璃相的含量，对于提高烧结     

组成对花岗岩尾矿微晶玻璃结构及性能的影响

以一种花岗岩尾矿为主要原料,采用烧结法研制大掺量花岗岩尾矿微晶玻璃。通过基础玻璃的示差扫描量热法(DSC)曲线,确定样品的玻璃转变温度Tg、初始晶化温度Tx和晶化峰值温度Tp。借助X射线衍射分析(XRD)和扫描电子显微镜(SEM),对晶化试样的物相进行测定和微观结构分析。探讨了花岗岩尾矿掺入量及组成变化对样品烧结、晶化及外观的影响。结果表明:当花岗岩尾矿掺入量为质量分数40%,可制得主晶相为β-硅灰石的花岗岩尾矿微晶玻璃,其晶体形貌为柱状且分布均匀,析晶温度范围为1 080～1 160℃;而随着花岗岩尾矿掺入量质量分数的增加(40%～70%),析晶下限温度提高,析晶温度范围变窄,析出的主晶相仍为β-硅灰石,但晶相含量逐渐降低。     

TiO_2和Cr_2O_3复合晶核剂对微晶玻璃晶化行为的影响

通过差热分析、X射线衍射分析、偏光显微镜和扫描电镜观察等测试方法 ,研究了TiO2 和Cr2 O3作晶核剂对金属尾矿微晶玻璃晶化行为的影响 .研究表明 :Cr2 O3 和TiO2 复合晶核剂能有效地促进CaO -MgO -Al2 O3-SiO2 系统玻璃在较低温度下即开始晶化 ,且形成以透辉石为主晶相的微晶玻璃 ,晶核剂质量浓度不同对玻璃析晶的影响不同 .     

Influence of ZrO2 on sintering and crystallization of CaO-Al2O3-SiO2 glass-ceramics

ZrO2 was added into CaO-Al2O3-SiO2 glass-ceramics and the effect of ZrO2 on sintering and crystallization of CaO-Al2O3-SiO2 glass ceramics was investigated. The results show that the sintering shrinkage ratio of glass particles decreases with the increase of the content of ZrO2. ZrO2 has an unfavourable effect on sintering shrinkage ratio of glass particles. The sintering shrinkage ratio of glass particles increases with the increase of sintering temperature. The increase of sintering temperature favors the decrease of the liquid phase viscosity of glass particles. ZrO2 has little effect on crystallization of main crystalline phase （β-wollastonite）. However, it promotes the crystallization at relatively low temperature.     

Structure of Bi2O3-ZnO-B2O3 system low-melting sealing glass

Bi_2O_3-ZnO-B_2O_3 system glass is a kind of lead-free low melting sealing glasses. The structure of Bi_2O_3-ZnO-B_2O_3 system low-melting sealing glass was investigated by DSC, FT-IR, XRD and SEM. The results show that with the increase of B_2O_3 content, the transition temperature Tg and softening temperature T_f of Bi_2O_3-ZnO-B_2O_3 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 [BO_3] pyramidal and [BiO_6] octahedral units and B-O from [BO_3] and [BO_4] units. With the decrease of B_2O_3 content, the crystallization tendency of the glass increases. In glass samples B_1 and B_2, crystallization starts at 460 ℃ and 540 ℃, respectively. Both of them precipitate Bi-(24)B_2O_(39) phases.     

Li2O-Al2O3-SiO2系统低膨胀微晶玻璃性能研究

Li2O-Al2O3-SiO2系统微晶玻璃是一种具有耐高温、耐热冲击、热膨胀系数低等性能的新型玻璃材料,受到科研人员的广泛关注.通过改变Li2O-Al2O3-SiO2系统微晶玻璃的基础配方以及热处理制度,制备了具有较低热膨胀系数的Li2O-Al2O3-SiO2系统微晶玻璃.结合运用差热热重、X射线衍射、扫描电镜等测试分析方法,研究性能与其组分、微观结构和热处理制度之间的相互联系.结果表明:通过对热处理制度的调整,促进了玻璃的析晶过程,核化温度和晶化温度有所降低.玻璃析出的主晶相为LiXAlXSi1-XO2,最低热膨胀系数达到25.365×10-7℃-1.     

Effect of heat treatment method on microstructure of tailings glass ceramics

A Cao-Mgo-Al2O3-SiO2 quaternary system was established with the main crystal phase design based on Diopside, and the effect of once-through sintering heat treatment on microstructure of iron railings glass ceramics was studied by using DTA, SEM along with measurement of microhardness and volume density. The experimental results show that, when the total amount of FeO and Fe2O3 exceeds 10wt%, a large number of fine nuclei are produced in the annealing process, and the phenomenon of nucleus resorption happens during the process of nucleation heat treatment, which is unfavorable for preparing iron tailings glass ceramics through once-through sintering method. When the annealing temperature from 1250 ℃ to 830 ℃, setting crystallization time for 4h, without heat treatment, crystals are well grown with arrangement and interlocking in glass phase. At 830 ℃ the crystals are well developed, well distributed and of good size; with crystallization time of 4 h the crystals with radial shape have high content and regular arrangement.     

Effect of nucleating agent on the crystallization of tailings glass ceramics prepared by one-time sintering

Glass ceramics was made by the one-time sintering method using the main raw material of iron tailings. On the basis of quaternary system of CaO-MgO-Al₂O₃-SiO₂, using DTA, XRD and SEM, the effects of different nucleating agents and mixing amounts as well as heat treatment on the crystallization of tailings glass ceramics were studied. The experimental results show that, nucleating agent and heat treatment are two necessary conditions for one-time sintering preparation of tailings glass ceramics namely, only adding nucleating agent or experiencing heat treatment, the quaternary system can not crystallize. The composite nucleating agent consisting of Cr₂O₃ and TiO₂ can further lead to the crystallization of the CaO-MgO-Al₂O₃-SiO₂ quaternary system at the lower temperature, with the major phase of diopside. In the range of mass content, 0%–4%, crystal intensity and crystal content grow. But when mass content is more than 4%, the crystal size will become coarser and the crystal distribution will be less regular. Different heat treatment regimes do not change the composition of the crystalline major phase in the glass ceramics crystallization of CaO-MgO-Al₂O₃-SiO₂ system. In the range of 30–60 minutes, with the extension of nucleation and crystallization, crystallization degree enhanced, but if the holding time surpasses 60 minutes, the crystallization is worse. Funded by The National Key Technology R & D Program of China for the 11^th Five-Year Plan(2006BAJ04A04)     

火山灰微孔玻璃的分相研究

以火山灰为主要原料制备的Na_2O—CaO—Al_2O_3—B_2O_3—SiO_2玻璃,在一定条件下热处理后产生分相,沥滤后得到微孔玻璃。本文利用扫描电镜、红外线光谱等分析了该系统中CaO、Al_2O_3对分相的影响。通过调整组成和控制热处理工艺条件获得不同的分相结构,为制定微孔玻璃生产工艺提供了依据。     

Crystallization Mechanism of Na2O-CaO-Al2O3-SiO2-F Glass Containing Cr2O3

The effect of Cr2O3 on the nucleation and crystallization of Na2O-CaO-Al2O3-SiO2-F- glass has been investigated by means of ESR(Electron Spin Resonance), SEM(Scanning Electron Microscope), EDS(Energy Dispersive Specrometer) and so on. Computer pattern recognition is applied to optimize the heat-treatment schedules. The experimental results show that the base glass containing more than 1 .5 % (mass fraction) Cr2O3 can be nucleated internally and converted to spheroidal crystal glass materials. The spheroidal crystal consisted of fibrous wollastonite crystals radiating from a center. The residual glass phase filled in the interstices between the fibers and between the spherulites. During heat treatment process, the valence states ofchromium changed from Cr6- to Cr3-, and the Cr-spinel solidsolution [CaCr2O4] precipitated followed this valence change. At the primary stage of crystallization, the Cr-spinel could act as a nucleating center on which the principal or}stalline phase β-CaSiO3 grew epitaxially.     

Properties of Aluminosilicate Glasses Prepared by Red Mud with Various [Al<Subscript>2</Subscript>O<Subscript>3</Subscript>]/[CaO] Mass Ratios

By introducing other oxide materials (SiO₂, Al₂O₃, CaO) into the red mud, all materials were melted into aluminosilicate glasses. On the basis of 17.2Fe₂O₃-5.7CaO-18.2Al₂O₃-50SiO₂-5.9Na₂O-3TiO₂ system glasses, [Al₂O₃]/[CaO] mass ratio changed further. For each sample, the assignment of IR absorption bands for aluminosilicate glasses was investigated by Fourier transform infrared spectroscopy and the glasstransition temperature and high temperature molten state were studied by differential scanning calorimetry. According to X-Ray diffraction and differential scanning calorimetry, the behavior of crystallization was analyzed. The results show that the glass structures of three-dimensional network are depolymerized and the amount of non-bridging oxygens increases gradually with network modifier CaO replacing network intermediate Al₂O₃ when [Al₂O₃]/[CaO] ratio of aluminosilicate glass decreases from 4.05 to 0.66, resulting in decreasing density, melting temperature, crystallization peak temperature and glass-transition temperature. As [Al₂O₃]/[CaO] mass ratio decreases, the concentration of crystallized phase maghemite (γ-Fe₂O₃) will increase which provides the possibility for production of black glass-ceramic further.     

Influences of heat treatments on crystallization in SiO<Subscript>2</Subscript>-Al<Subscript>2</Subscript>O<Subscript>3</Subscript>-MgO-K<Subscript>2</Subscript>O-F glass-ceramics

Five kinds of heating treatment processing were chosen according to the experiment result of differential scanning calorimeter to prepare SiO2-Al2O3-MgO-K2O-F glass ceramics samples.The effects of heat treatment processing on the crystallization of these samples were explored by X-ray diffraction and scanning electron microscopy techniques.The results indicate that phase separations can occur in the bulk regions of the glass sample when holding at 670 ℃ for 3 h.The phase separation can accelerate the precip...