scholarly journals Devitrification Behavior of SRL Defense Waste Glass

1983 ◽  
Vol 26 ◽  
Author(s):  
Dennis F. Bickford ◽  
Carol M. Jantzen
Keyword(s):  
Aluminum Content ◽  
Waste Glass ◽  
Minor Effect ◽  
Cooling Curves ◽  
Volume Percent ◽  
Similar Composition ◽  
Heat Treated ◽  
Temperature Transformation ◽  
Transformation Diagrams ◽  
Normal Processing

ABSTRACTSimulated SRL waste was prepared with compositions varying in iron and aluminum content. Two batches with similar composition were produced with different amounts of reducing agent added. Samples were isothermally heat treated and used to derive time-temperature-transformation diagrams. Supplementary samples were cooled in a manner programmed to simulate the cooling curves of production canisters. Less than 10% total devitrification occurs during normal processing. However, when waste glass 165 was purposely devitrified, un to 30 volume percent total spinel and acmite formed. Formation of these species had minor effect on leachability in MCC-1 and accelerated leach tests.

Characterization of Highly Waste Loaded Glass for HLW

1994 ◽  
Vol 353 ◽  
Author(s):  
Kazuhiro Kawamura ◽  
Jin Ohuchi
Keyword(s):  
Waste Glass ◽  
Apatite Crystal ◽  
Borosilicate Glasses ◽  
Good Thermal Stability ◽  
Leach Rate ◽  
Heat Treated ◽  
Simulated Waste ◽  
Temperature Transformation ◽  
Thermal Stability Of

AbstractPossibility of highly waste loaded borosilicate glasses up to 65wt% were investigated for HLW. In the case the waste was loaded at a content higher than 45wt%, apatite crystal was identified in the glasses. Adding above 2.5wt% of M0O3, yellow phase was observed in the 45wt% waste glass. In the case the composition of actual waste was simulated, waste(25–45wt%) glasses were characterized. Chemical durability of 45wt% waste glass was equivalent to that of 25wt% waste glass under the condition of Na20 content lower than 12wt%. Rheological behavior of 45wt% waste glass was equivalent to that of 25wt% waste glass in the range of melting temperature. Electrical resistivity of 45wt% waste glass were a little lower than that of 25wt% waste glass and it depended on the noble metal content. The Time-Temperature-Transformation (T-T-T) diagram and the leach rate of heat treated glass indicated a good thermal stability of highly waste loaded glass below the glass transition temperature. Possibility of high waste loading up to 45wt% was elucidated.

Reaction-induced phase separation in poly(butylene terephthalate)-epoxy systems: 1. Conversion-temperature transformation diagrams

Polymer ◽  
1996 ◽  
Vol 37 (14) ◽  
pp. 3079-3085 ◽  
Author(s):  
P.A. Oyanguren ◽  
P.M. Frontini ◽  
R.J.J. Williams ◽  
E. Girard-Reydet ◽  
J.P. Pascault
Keyword(s):  
Phase Separation ◽  
Butylene Terephthalate ◽  
Temperature Transformation ◽  
Transformation Diagrams ◽  
Epoxy Systems ◽  
Conversion Temperature

Experimental petrology, Reconstruction of rock cooling paths from kinetic data on the Fe 2 +—Mg exchange reaction in anthophyllite

1977 ◽  
Vol 286 (1336) ◽  
pp. 303-311 ◽  
Keyword(s):  
Simple Model ◽  
Exchange Reaction ◽  
Kinetic Data ◽  
Experimental Petrology ◽  
Cooling Rates ◽  
Temperature Transformation ◽  
Transformation Diagrams ◽  
Kinetics Of

The kinetics of the intracrystalline Fe-Mg exchange reaction in anthophyllite can be described by a simple model that permits extrapolation to lower temperatures. Rock cooling rates can be estimated in the vicinity of 300 °C from these data using time-temperature-transformation diagrams. Aluminous orthoamphiboles (gedrites) are expected to yield rock cooling rates at higher temperatures.

Solidification Modeling of Bulk Amorphous Alloys

2003 ◽  
Vol 806 ◽  
Author(s):  
Sang Bok Lee ◽  
Nack J. Kim
Keyword(s):  
Heterogeneous Nucleation ◽  
Amorphous Alloys ◽  
Nucleation Theory ◽  
Cooling Rates ◽  
Continuous Cooling ◽  
Wide Range ◽  
Temperature Transformation ◽  
Transformation Diagrams ◽  
Experimental Values ◽  
Kinetics Of

ABSTRACTClassical heterogeneous nucleation theory coupled with DTA data has been used to closely estimate the crystallization behavior of continuously cooled bulk metallic glass (BMG) alloys. Continuous cooling transformation and time temperature transformation diagrams of three BMG alloys, Zr41.2Ti13.8Cu12.5Ni10Be22.5, Cu47Ti33Zr11Ni6Si1Sn2 and Mg65Cu25Y10 alloys, have been calculated. The critical cooling rates Rc of three alloys were calculated to be 1.7 K/s, 242 K/s and 36 K/s for Zr41.2Ti13.8Cu12.5Ni10Be22.5, Cu47Ti33Zr11Ni6Si1Sn2 and of Mg65Cu25Y10 alloys, respectively, which match well with the experimental values. We conclude that heterogeneous nucleation is more favorable than homogeneous nucleation for the formation of crystals during cooling of BMG alloy liquids. Our approach can be applied to the analyses of crystallization kinetics of BMG alloys with a wide range of critical cooling rates during continuous cooling as well as isothermal annealing.

Thermal Stability of Hastelloy Alloy C-276

CORROSION ◽  
1969 ◽  
Vol 25 (5) ◽  
pp. 222-232 ◽  
Author(s):  
R. B. LEONARD
Keyword(s):  
Corrosion Resistance ◽  
Grain Boundary ◽  
Best Practice ◽  
Sharp Drop ◽  
Chemical Process Industry ◽  
Maximum Precipitation ◽  
Heavy Plate ◽  
Heat Treated ◽  
Stress Relieving ◽  
Temperature Transformation

Abstract Hastelloy Alloy C has long been of major importance to the chemical process industry, but in many applications, vessels fabricated from Alloy C had to be solution heat treated to remove harmful weld heat affected zone precipitates which reduced corrosion resistance. Modification of the chemical composition produced Hastelloy Alloy C-276, which is more resistant to the precipitation of grain boundary particles than Alloy C. In order to fully utilize the improved alloy, and to understand its responses to fabrication techniques, it is helpful to understand the time-temperature-transformation characteristics. Grain boundary precipitates can form in Alloy C-276 when it is exposed to temperatures from 1200 to 2000 F (649 to 1093 C). The precipitation characteristics of Alloy C-276 compared to those of Alloy C can be shown through the use of a time-temperature-transformation curve (T-T-T). The precipitates have been identified as either “P” or Ni7Mo6-type phases. No M6C precipitate was found in Alloy C-276, whereas a considerable amount is normally found in Alloy C. The maximum precipitation occurs at 1600 F (871 C) with a sharp drop at higher and lower temperatures. However, the times required to form these precipitates are at least 30 times longer than those of Alloy C. When precipitates form in Alloy C-276, they decrease its corrosion resistance in both oxidizing and reducing environments. In a ferric sulfate-sulfuric acid environment, the greatest loss in corrosion resistance was found in material heat treated at 1600 F (871 C). This is the temperature of maximum precipitation and indicates an impoverishment of chromium in the areas surrounding the precipitate. When a hydrochloric acid test is used, maximum loss in corrosion resistance occurs in material heat treated at 1400 F (760 C). This indicates a difference in the precipitation phenomenon at this temperature when compared to higher temperatures, and is confirmed through electron microscopy. Impoverishment of molybdenum in the matrix areas surrounding the precipitate could account for the loss of corrosion resistance in this environment. Even though precipitation may occur under certain conditions, the alloy can be used in the as-fabricated condition without solution heat treatment if the time-temperature relationships used during fabrication are controlled to prevent precipitation. Heavy plate of Alloy C-276 has been welded without loss of corrosion resistance. Vessel “heads” made of heavy plate have been hot formed without loss of corrosion resistance using the best practice determined from the T-T-T diagram. Similarly brazing, stress relieving of clad composites, roll bonding and braze bonding can be successfully adapted to Alloy C-276.

Effect of Glass Ceramic Crystallinity on the Formation of Simulated Apatite Layers

2006 ◽  
Vol 514-516 ◽  
pp. 1039-1043 ◽  
Author(s):  
Nuno A.F. Almeida ◽  
Maria Helena F.V. Fernandes
Keyword(s):  
Glass Ceramics ◽  
Apatite Layer ◽  
Silicate Glasses ◽  
Layer Formation ◽  
Volume Percent ◽  
Base Glass ◽  
Heat Treated ◽  
Phosphate Phase ◽  
Calcium Magnesium ◽  
Kinetics Of

In silicate glasses the kinetics of apatite layer formation is usually rapid but the adhesion to the base glass is poor. Glass ceramics promote a stronger bonding between layer and substrate but decrease the rate of the apatite layer formation. In this work a glass of composition (wt%) 54,89%C3P-24,81%SiO2-20,30%MgO has been studied. This glass was heat treated at four temperatures (840 °C, 870 °C, 890 °C and 910 °C) to obtain glass ceramics with different contents of the same crystalline phase. A calcium magnesium phosphate phase was formed in all glass ceramics in a volume percent increasing with temperature. The apatite layer precipitated after immersion in simulated body fluid (SBF) formed faster on the glass than on the glass ceramics and a decrease in the amount of apatite formed was observed with the increase in crystallinity. It was generally concluded that heat treatment can turn a reactive glass into glass ceramics of different surface behaviors, from bioactive to quasi bio inert materials.

Determination of new time–temperature-transformation diagrams for lead–calcium alloys

2008 ◽  
Vol 185 (2) ◽  
pp. 1465-1470 ◽  
Author(s):  
F. Rossi ◽  
M. Lambertin ◽  
L. Delfaut-Durut ◽  
A. Maitre ◽  
M. Vilasi
Keyword(s):  
Temperature Transformation ◽  
Transformation Diagrams ◽  
New Time
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