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半导体行业产生的氟化钙(CaF2)污泥量大且含有絮凝剂等杂质,资源化利用难度大,现阶段主要处理方式为填埋。本文提出了将CaF2污泥回收制备上转换发光微晶玻璃的资源化技术。将SiO2、稀土Er2O3和Yb2O3引入到CaF2污泥中,通过高温固相熔融法制备了一系列上转换发光微晶玻璃。采用X射线衍射、扫描电镜、荧光光谱等表征手段研究了不同含量CaF2污泥和不同晶化温度对所得上转换发光微晶玻璃的结构、形貌、上转换发光峰位置、强度和荧光寿命等的作用规律。所得CaF2基上转换发光微晶玻璃在980 nm激光激发下,能够发射出绿光(523和539 nm)和红光(655 nm)。原料质量配比为84.5%CaF2污泥-10%SiO2-0.5%Er2O3-5%Yb2O3 相似文献
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采用DTA,XRD,SEM,TEM研究了MgO-Al2O3-SiO2-Li2O-R2O-F(R=Na,K)玻璃系统晶化过程中的晶相与显微结构演变.结果表明,基础玻璃的分相自650℃开始;700℃以下,初期云母相出现;750℃β-锂辉石开始形成;850~950℃之间,随着Mg2+,K+,F-的扩散进入,β-锂辉石与玻璃相产生交代反应,以过渡相形式转变成云母类固溶体;在950℃以上;β-锂辉石不断转化为锂云母固溶体,云母晶体尺寸长大明显. 相似文献
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Xiaojing Chen Robert Hill Natalia Karpukhina 《International Journal of Applied Glass Science》2014,5(3):207-216
Apatite glass-ceramics are attractive for medical and dental applications, and fluorapatite glass-ceramics based on aluminosilicate glasses have been extensively studied. This study is the first study of chlorapatite glass-ceramics based on calcium chloride-containing Q2 bioactive phosphosilicate glasses. The crystallization behavior of oxychloride glasses is examined and compared with mixed oxychloride/fluoride and oxyfluoride glasses. The glass transition temperature decreased for all three series with increasing halogen content. On increasing the halogen content, there was an increasing tendency of the glasses to crystallize. The halogen-free glass surface crystallized to pseudowollastonite and an apatite. On incorporating a halide, the glasses exhibited largely bulk crystallization to a haloapatite. In the case of chloride, the glasses crystallized to chlorapatite. This is the first time to our knowledge that chlorapatite has been shown to crystallize from a glass. Chlorapatite is very attractive for medical applications because it converts to hydroxyapatite the mineral phase of tooth and bone on immersion in water. 相似文献
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Nanophase Glass-Ceramics 总被引:29,自引:0,他引:29
Future applications for glass-ceramics are likely to capitalize on designed-in, highly specialized properties for the transmission, display, and storage of information. Glass-ceramics with microstructures comprised of uniformly dispersed crystals <100 nm in size offer promise for many potential new applications as well as provide unique attributes for many current products. This paper focuses on two types of nanocrystalline glass-ceramics: transparent glass-ceramics and tough, high-modulus glass-ceramics with precisely engineered surfaces. Transparent glass-ceramics are formed from certain aluminosilicate glasses capable of efficient crystal nucleation and slow growth. The key crystalline phases include β-quartz solid solutions, characterized by low-thermal-expansion behavior; spinel, with high hardness and elastic modulus; and mullite, which shows unique chromium-luminescence behavior. 相似文献
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High-Strength Mica-Containing Glass-Ceramics 总被引:13,自引:0,他引:13
Tomoko Uno Toshihiro Kasuga Kiichi Nakajima 《Journal of the American Ceramic Society》1991,74(12):3139-3141
Glass-ceramics containing barium–mica in the system Ba0.5 Mg3 (Si3 AIO10 )F2 –2MgO · 2Al2 O3 · 5SiO2 –Ca3 (PO4 )2 are two to three times stronger than conventional mica-containing glass-ceramics. Moreover, the barium-mica glass-ceramics are easier to machine, as confirmed by a drilling test using conventional steel tools. Such mechanical properties are attributable to the microstructure of the barium–mica glass-ceramics. Very fine, interlocking mica crystals are precipitated in the glass, and a crack-deflection mechanism is observed by scanning electron microscopy. 相似文献
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Matthew J. Dejneka Christy Powell Nick Borrelli Dimitre Ouzounov Alex Gaeta 《Journal of the American Ceramic Society》2005,88(9):2435-2441
Transparent magnetic glass-ceramics were produced by infiltrating nano-porous glass with nitrate salts and firing. The resultant glass-ceramics contained spinel ferrite nanocrystals that exhibited ferromagnetic and superparamagnetic behavior depending on composition and firing temperature. Transparency in the near infrared was obtained when oxidizing conditions were used to prevent Fe2+ formation, while the porous matrix ensured nano-sized crystallites to limit scattering losses. MnFe2 O4 glass-ceramics treated at 1000°C offered the best combination of magnetic and optical properties with a saturation magnetization of 5.6 emu/g, a Verdet constant of 16.5°/cm, and losses below 3 dB/mm at 1550 nm. 相似文献
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Ahmed Wagdi A. El-Shennawi Mohamed A. Mandour Morsi M. Morsi Salwa A. M. Abdel-Hameed 《Journal of the American Ceramic Society》1999,82(5):1181-1186
Uniform, ultrafine, microcrystalline, hard, pyroxenic glass-ceramic materials have been obtained successfully from basalt rock; instead of adding nucleation catalysts, the FeO:Fe2 O3 , CaO:Na2 O, and CaO:MgO ratios have been rectified. This process has been accomplished by deliberately adding the smallest permissible amounts of oxidizers, limestone, dolomite, and soda ash (as additives) that are necessary to fulfill the monominerality requirements; these requirements affect the melting, workability, crystallization, and microstructure of the glass-ceramics. The melting temperature decreases as the ratios decrease (beyond certain limits); in addition, the workability, crystallization, and microstructure also improve as the ratios decrease. An almost-stable solid solution of augite or aegirine-augite composition is the only crystalline phase that is formed. The minimal FeO:Fe2 O3 ratio and the likelihood of a greater affinity of the Na+ cation for the Fe3+ cation, rather than the Al3+ cation, may be responsible for increasing the stability and widening of the crystallization field of the complex aluminum-bearing pyroxene solid solution. 相似文献
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DAVID C. CRANMER 《Journal of the American Ceramic Society》1984,67(9):180-C
Tribological properties of five glass-ceramics are reported. The materials were tested unlubricated against themselves. Testing was performed using a simulated inertial sample dynamometer. Sliding speeds were between 0.5 and 1.8 m /S with an applied load of 225 N. Average friction coefficients were in the range 0.07 to 0.5. The wear rate of a lithium aluminosilicate was 43 ×10–14 m3/N.m, in good agreemen2 with previous pin-on-disk results. Wear surfaces exhibited cracking, ploughing, delamination, and viscous flow or plastic deformation. 相似文献
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Bioactivity of Zirconia-Toughened Glass-Ceramics 总被引:1,自引:0,他引:1
Toshihiro Kasuga Masahiro Yoshida Akira J. Ikushima Maki Tuchiya Haruka Kusakari 《Journal of the American Ceramic Society》1992,75(7):1884-1888
Bioactivity of zirconia-toughened glass-ceramic composites was evaluated by their surface reaction in simulated body fluid and the bonding strength to living bone. The composite containing 30 vol% zirconia showed high bioactivity, whereas that containing 50 vol% zirconia, extremely low. TEM observation indicated that Ca in the glass-ceramic particles reacted with the zirconia during sintering. It was found that the decrease in Ca in the particles degraded the bioactivity of the composite. In this study, the optimum composition was determined for high-strength and bioactive ceramic. 相似文献
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M. H. LEWIS J. METCALF-JOHANSEN P. S. BELL 《Journal of the American Ceramic Society》1979,62(5-6):278-288
Transmission electron microscopy, electron diffraction, and microprobe X-ray analysis were used to study crystallization of glasses in the systems Li2 O-SiO2 , BaO-SiO2 , and Li2 O-A12 O3 -SO2 . The ternary system, with 4 mol% TiO2 added to an Li2 O-Al2 O3 -4SiO2 composition, crystallizes with a simple morphology of equiaxed grains of the β-quartz metastable phase which transforms at higher temperatures to the stable β-spodumene structure. The binary systems exhibit a more complex crystallization morphology dictated by crystal anisotropy, temperature, impurity content, and susceptibility either to intermediate-phase formation (BaO-SiO2 ) or to liquid immiscibility (Li2 O-SiO2 ). The initial crystal growth units formed in these systems are frequently two-phase branched morphologies many micrometers in diameter. They may be recrystallized to form polycrystalline glass-ceramics with submicrometer grain sizes. 相似文献