The Properties And Structure Of Tin Phosphate Glasses Modified With Other Oxides

Author : Yongren Benjamin Peng
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (232 download)

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Download or read book High Thermal Expansion Phosphorus Oxide and Oxynitride Glasses written by Yongren Benjamin Peng and published by . This book was released on 1990 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The chemical durability of phosphate glasses in general can be improved by the incorporation of chemically dissolved nitrogen and/or addition of oxides such AI2O3. Over 100 oxide and oxynitride glass compositions were evaluated. The general compositions investigated were the following: 1. P2O5" xH2O; 2. MPO3 where M = K, Na, Ag; 3. M2O-AI2O3 -P2O5, where M = K, Na and Ag; 4. 3OK2O-10M2O3-60P2O5, where M = Al, Ga, In, La, B, Fe and Bi; 5. Glasses of general composition M2O-MO-M2O3-P2O5, where M2O stands for K2O, Na2O, Li2O and Ag2O, MO for BaO, CaO, ZnO and PbO, and M2O3 for A12O3, B2O3, Fe2O3, etc; 6 . Oxynitrides of the above compositions 7. Other glass compositions such as PbO containing glasses These glasses were investigated for the purposes of (a) identifying phosphate glasses whose thermal expansion and chemical durability make them suitable for sealing to high expansion metals like aluminum alloys and stainless steels, (b) learning more about how the dissolution of nitrogen in a glass can be affected by the processing conditions and glass compositions, (c) gaining more fundamental information for the structural role of nitrogen in phosphorus oxynitride glasses and its correlation with the properties of by oxynitride glasses, (d) investigating how oxide addition is compared to nitrogen dissolution in a glass in terms of chemical durability, thermal expansion and glass forming characteristics. The maximum nitrogen content achievable in phosphate glasses nitrided in ammonia depended not only on the time and temperature of remelting in ammonia, but also on the melt composition and the water content of the nitriding atmosphere. The presence of MO, M2O3 oxides, especially M2O3 oxides, in a glass melt limits the maximum nitrogen dissolution in the melt. The nitrogen content of some PONH glasses obtained from nitriding ammonium phosphate reached 17.8 wt%, while a glass containing ~ 10 mole% AL2O3 typically had a nitrogen content 1-3 wt%. Glasses containing Ag2O, PbO, Bi2O3 and Fe2O3 were not nitridable in dry ammonia. Metallic Ag, Pb and Bi were formed after nitriding in ammonia at 750-800°C for only 30 min. Many glass compositions in the system M2O-MO-M2O3 -P2O5 had a thermal expansion coefficient> 180xl0−7/°C and a dissolution rate in deionized water at 30°C 10−8gm/cm2" in and at 70°C