Processing sodium tellurite melts in low gravity drop shaft: Part II Melt solidification and glass formation

摘要: The effect of gravity on glass formation and crystallization the Na2Ocdot;8TeO2 (NT8) Na2Oċ4TeO2 (NT4) melts were investigated using low drop shaft at Japan Microgravity Center (JAMIC). This produces a <10−3 g for ∼10 s during free-fall about 8 to 10 ∼5 deceleration capsule. initially adhered small platinum heating coil was re-melted in gravity. melt detached from high-g period solidified after being splattered plate (substrate) located ∼4 cm below coil. parameters that varied experiments temperature substrate material which splattered. Like what observed 1-g (ground), NT8 splatters always formed glass, independent used. NT4 partially crystallized all experiments, even though this is an excellent former 1-g. splatter higher cooling ability such as copper had smaller amount crystals than or alumina. transition temperature, heat capacity region, activation energy infrared (IR) spectra not significantly different those similar prepared However, 5 10°C lower their counterparts. result suggests under conditions are less resistant