CRYSTALLIZATION AND SOLIDIFICATION STUDIES IN CALCIA-ALUMINA FIBERS FORMED VIA INVISCID MELT-SPINNING (IMS)

Differential thermal analysis (DTA) is used to study solidification ph enomena in 46.5 wt% CaO-53.5 wt% Al2O3 (m.p.=1392 degrees C) fibres fo rmed via inviscid melt spinning (IMS), After an initial heating cycle at 20 degrees C min(-1) in nitrogen to 1600 degrees C showing crystall ization of the amorphous fibres, cooling curves indicate a solidificat ion exotherm at 1403 degrees C, followed by two small exotherms, belie ved to be solidification of sub-solidus liquid. Subsequent heating cyc les show no crystallization transformations, indicating near complete crystallization upon cooling between heating cycles. XRD results obtai ned after a final cooling step show two anhydrous calcium aluminate ph ases are present: CaAl2O4 and Ca3Al2O6. (C) 1997 Elsevier Science Limi ted and Techna S.r.l.