TY - GEN
T1 - Melting and evaporating sodium tellurite melts in low gravity drop shaft
AU - Makihara, Masaki
AU - Ray, Chandra S.
AU - Day, Delbert E.
PY - 1999
Y1 - 1999
N2 - Glasses of Na2O · xTeO2(x=2,4, and 6) compositions were remelted and evaporated while supported by a platinum heater coil in the low gravity (approx. 10-5 g) drop shaft at the Japan Microgravity Center (JAMIC). The evaporating species from all the melts, which formed a spherical cloud surrounding the melt during the few seconds low gravity time were identified to be amorphous particles of TeO2. These particles were highly spherical, 5 to 10μm in diameter, and were, on the average, 6 to 8 times larger than the particles grown from similar experiments at 1-g. The melt remaining after evaporation was splattered on to a glass plate positioned at about 3.5 cm directly below the melt during the high-g (approx. 8 to 10 g) deceleration of the drop capsule and crystallized almost instantaneously. The chemical composition of the crystallized splatters was same as that of the starting glass. The crystallization tendency of these sodium tellurite splatters was estimated to be at least 1000 times greater than that of an identical melt at 1-g. No suitable explanation was found for the high crystallization tendency of the drop shaft splatters, but a sudden 5 orders of magnitude increase in the gravity level is suspected to be a contributing factor for this effect.
AB - Glasses of Na2O · xTeO2(x=2,4, and 6) compositions were remelted and evaporated while supported by a platinum heater coil in the low gravity (approx. 10-5 g) drop shaft at the Japan Microgravity Center (JAMIC). The evaporating species from all the melts, which formed a spherical cloud surrounding the melt during the few seconds low gravity time were identified to be amorphous particles of TeO2. These particles were highly spherical, 5 to 10μm in diameter, and were, on the average, 6 to 8 times larger than the particles grown from similar experiments at 1-g. The melt remaining after evaporation was splattered on to a glass plate positioned at about 3.5 cm directly below the melt during the high-g (approx. 8 to 10 g) deceleration of the drop capsule and crystallized almost instantaneously. The chemical composition of the crystallized splatters was same as that of the starting glass. The crystallization tendency of these sodium tellurite splatters was estimated to be at least 1000 times greater than that of an identical melt at 1-g. No suitable explanation was found for the high crystallization tendency of the drop shaft splatters, but a sudden 5 orders of magnitude increase in the gravity level is suspected to be a contributing factor for this effect.
UR - http://www.scopus.com/inward/record.url?scp=0032632020&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0032632020&partnerID=8YFLogxK
U2 - 10.1117/12.351279
DO - 10.1117/12.351279
M3 - Conference contribution
AN - SCOPUS:0032632020
SN - 0819432784
SN - 9780819432780
T3 - Proceedings of SPIE - The International Society for Optical Engineering
SP - 209
EP - 217
BT - Proceedings of SPIE - The International Society for Optical Engineering
PB - Society of Photo-Optical Instrumentation Engineers
T2 - Proceedings of the 1999 Materials Research in Low Gravity II
Y2 - 19 July 1999 through 21 July 1999
ER -