산화리튬의 치환에 따른 붕규산 유리의 분상에 관한 연구 양중식 경희대학교 화공과 The Phase Separation of Low Alkali Borosilicate Glass by Substituting $Li_2O$ for $Na_2O$ ABSTRACT The phase separation of low-alkali borosilicate glass with the composition of $6.25Na_2O$.$18.75B_2O_3$.$75.00SiO_2$(mole%) substituting $Li_2O$ for $Na_2O$ was studied. The phase separation in the temperature range of transformation was examined with various heating temperatures and soaking times. Durability to water, thermal expansion and specific density of the specimen were investigated and the microstructure of the separated phase was also observed by transmission electron micrograph techniques. The maximum alkali extraction result with the best phase separation effect was obtained when $Na_2O$ of the base glass was replaced with $1.88Li_2O$ (mole %) and electron micrograph of carbon film replica of $1.88Li_2O$$4.37Na_2O.18.75B_2O_3.75.00SiO_2 (mole %) glass showed that the glass consisted of homogeneous two phases. The minimum specific density was shown with the specimen treated at 570^{circ}C and it was also shown that the longer the treating time the lower the specific density. The apparent activation energies of approximately 45 kcal/mole by the alkali extraction and 43kcal/mole by the thermal expansion method were derived from the Arrhenius plots, respectively. TOOLS PDF Links Full text via DOI Download Citation CrossRef TDM E-Mail Share: METRICS  698 View  10 Download  Related articles The Study on Chemical Durable Zinc-phosphate Glasses with B_2$$O_3$Addition  2001 ;38(6) The Effect of Diluent Gases of $H_2$ or $N_2$ on the Growth Behavior of CVD SiC  1998 ;35(7) Formation of Magnetite Using $Fe^{2+}$ and $Fe^{3+}$ Hydroxide  1994 ;31(11) Interaction of Alkali Oxide and $SO_3$ on $3CaO.SiO_2$ Formation and Microstructure  1993 ;30(12) Phase Separation and their Structures in $BaO-B_2O_3$ Glasses  1986 ;23(6)