If the shape of ZnO grains disperse

If the shape of ZnO grains dispersed in liquid isdetermined by an equilibrium condition, it will besame as that of a trapped liquid shown in Fig. I. Theshape of ZnO grains in the specimens of second seriesis, therefore, expected to show a changc from angular1o spherical with temperature. Figure 2(a) and (b)show the microstructures of 92ZnO-7Bi2O3-lLi2O specimens sintered at 1410 and 1000℃. respectively .The average size of ZnO grains was 93 and 25 um.respectively. After the sintering at 1400℃ [Fig. 2(a).the grains ire all very nearly spherical like the liquidin a solid grain trappcd at 1450℃ (Fig. l(a)]. As thesintering temperature is lowered to 1000 [Fig.2(b)]， most scctions of the yrains are prismatic with flatedges and sharp corners. It is noted about 20% of thegrains at this condition showed a hexagonal section.