抄録
Two metaphosphate glass melts, i. e. CaP2O6 (49.6CaO ·49.6P2O5·0.8SiO2 in mol%) and NaPoLi (25Na2O·25Li2O·50P2O5 in mol%), were chosen as objects of the present study. Both of them have a “polymer-chain like structure” but different valence bonding state. Flow curves and viscosity values of CaP2O6 melt were acquired using a capillary rheometer. Those of NaPoLi melt were measured using both capilliary and plate-plate viscometer. For comparison, the flow data of a silicate melt, namely, NCS melt (16Na2O·10CaO·74SiO2 in mol%) with a three-dimensional network structure were obtained using parallel-plate viscometer. All three melts displayed a remarkable non-Newtonian pseudoplastic flow behaviour, so-called “shear thinning effect”. However, the degree of shear thinning of the three melts is different and increases in such a quantitative sequence: NCS→NaPoLi→CaP2O6 melt. It was found that such an increasing sequence is in agreement with that of the fragility of these melts.
