New High Zirconia fused cast material for high quality glass without low temperature oxygen blistering

New High Zirconia fused cast material for high quality glass without low temperature oxygen blistering ICF Technical meeting, Sienna November 05th , 2007 New High Zirconia fused cast material for high quality Glass without low temperature oxygen blistering Topics of the presentation  Main interest of HZFC material in high quality glass  Low temperature oxygen blistering phenomenon  Hypothesis of mechanism with HZFC  How to prevent oxygen blistering  Properties of new HZFC  Influence of crystal glass composition evolution regarding AZS and HZFC materials Interest of HZFC in quality glass High Zirconia Fused Cast Microstructure Typical composition Al2O3: 0.4 - % ZrO2 > 90 % SiO2: - % Na2O: – 0.4 % B2O3: – % Zirconia microprobe mapping Al2O3 SiO2 Glassy phase Na2O 100 µm ZrO2 Fused Cast AZS Microstructure Typical composition Al2O3: 46 % ZrO2: 41% SiO2: 12 % Na2O: 1% Zirconia microprobe mapping Al2O3 ZrO2 Glassy phase Corundum / Zirconia eutectic SiO2 Na2O Main interest of using HZFC material Low level of glass contact defects  low level of Crystallized or vitreous defect HZFC origin of defects in convective area as : AZS (41% ZrO2) 10% Al203, 2% ZrO2, 11% PbO, 16%K2O, 0.8% Na2O Leucite (Al203-K2O-4SiO2) with zirconia nodule Glass contact AZS interface, primary ZrO2 Clear Knot Main interest of using HZFC material Low level of glass contact defects  low level of blistering at high temperature Test condition : TV/PDP glass, Temperature :1450°C, Crucible test HZFC AZS (41% ZrO2) Duration :70H Low temperature oxygen blistering phenomenon low temperature oxygen blistering phenomenon High quality glass  extended use of HZFC materials in the furnace final part (fining, feeder, …)  To solve some corrosion problem (borosilicate, crystal glass … )  To prevent Glass contact defect related to chemical composition of the glass (compare alpha/béta alumina product, or AZS product ) Glass SiO2 Na2O K2O CaO Wt % 58-69 4–5 - 10 – – 5–7 Ba0 SrO Oxygen blistering phenomenon MgO Al2O3 0–2 1–7 ZrO2 2–4 Low temperature oxygen blistering phenomenon  Blistering phenomenon with high efficiency Blistering crucible test at 1120°C , 30 hours , alkali test glass Necessary conditions to obtain high oxygen blistering  Air outside crucible  Temperature < 1130°C  Alkalii inside the glass Glassy phase properties measurements in the SiO2-Al2O3-Na2O-Y2O3 system  simulation  Thermal expansion Températ ure mesurée (°C) Glassy phase modification with Y2O3 addition 1700 1600 1500 1400 1300  Glass transition temperature, crystallization  High température viscosity 1200 1100 1000 900 800 Supérieur de recuisson T pour une viscosité de Log10=4 T pour une viscosité de Log10=4,5 T pour une viscosité de Log10=3,5 T Littleton 700 600 500 500 T Annealing (fibre) 700 900 T1100 Strain 1300 1500 1700 Température calculée (°C) To design the right level of SiO2, Na20 and Al2O3 for a given Y2O3 % New HZFC materials : First industrial results Cut block Low level of internal defect SiO2 = – %, Al2O3 = 0.7 -1.2 %, Na2O = 0.4- 0.8%, Y2O3 = 0.8 – 1% Blistering test results on industrial products : Crucible test : 1100°C , 30 hours HZFC Display panel glass High alkalii test glass New HZYFC Display panel glass High alkalii test glass No oxygen bubles with the new product at 1100°C Blistering test results on industrial products : Crucible test : 1000°C , 30 hours HZFC Display panel glass High alkalii test glass New HZYFC Display panel glass High alkalii test glass  No oxygen blistering up to 1000°C with new HZFC  Secure solution with display panel glass (no blistering up to crystallization temperature) Glass contact properties Static corrosion test (T-test) HZFC New HZFC stone (droplet ) 1-2 1-2 1-2 1-2 Stone (crucible) 0 0-1 Indice global 1 1 Conditions of the test : Temperature : 1500°C Duration : 48 heures Glass : PDP Dynamic corrosion test (test MGR) HZFC Indice 100 New HZFC 105 83 Conditions d’essais : Température : 1500°C Duration : 48 heures Glass : PDP 88 Influence of crystal glass composition evolution regarding AZS and HZFC materials Crystal glass composition evolution  Evolution to lead free Glass Typical PbO Crystal Glass Lead free Glass (BaO) Lead free Glass (w/o BaO) Na2O 3-5 7,5-11 8,6-10,9 K2O 10-14 5-7 8,7-10 5,9-8,9     BaO Al2O3