多成分系無アルカリ方ラスの粘性特性と結晶化挙動(<小特集>セラミック材料)

概要

論文の詳細を見る
Critical cooling rate Q^* for glass formation was determined by means of DTA method for a non-alkali multicomponent System of 39.8SiO_2・10.1A1_2O_3・24.4CaO・12.6ZnO・11.1TiO_2・2.0B_2O_3 mol% composition. Q^* was found to be l.5×10^<-2>℃/sec. Viscosity of the system was measured by the beam bending and the counterbalancing method. The liquidust emperature T_1 of the system was determined by DTA method. From the viscosity and T_1 data, the Liquidus viscosity η_1 was detbained (logη_1/PaS=0.94) . The Q ^* -η_1 relationship of the non-alkali system was compared with those of alkali silicate and alkali borate systems. It was found that the presentnon alkali system basacritical cooling rateequivalent to 94SiO_2・6Li_2O, 75B_2O_3・25Li_2O or 85B_2O_3 15Na_2O glass. The fusion entropy △S_f was calculated from eq. (2) using the values of liquid parameters of the non-alkali system. It became apparent that then on-alkali system has a considerably high △S_f Value compared witht be alkali borate or alkali silicate system. This was regarded to indicate that the present system is composed of various polyhedra, including SiO_4, AlO_4 or TiO_4 tetrabedra, thus easing a glass formation of a SiO_2 poor melt.
社団法人日本材料学会の論文
1991-04-15