The crystallization behavior of Li_(2)O-Al_(2)O_(3)-SiO_(2) glasses with various concentration of Li2O were investigated by DSC,XRD,and FE-SEM.The h/l-quartz s.s.is the main crystalline phase for all of the glass with...The crystallization behavior of Li_(2)O-Al_(2)O_(3)-SiO_(2) glasses with various concentration of Li2O were investigated by DSC,XRD,and FE-SEM.The h/l-quartz s.s.is the main crystalline phase for all of the glass with the heat treatment of 720℃/3 h+800℃/1.5 h while the crystallinity and crystal size increase with the increase of Li2O contents.Due to the negative thermal expansion coefficient of h/l-quartz s.s.,the thermal expansion coefficient of glass-ceramics decreases with the increasing of Li2O contents.When the Li2O content is 9mol%,the near-zero CTE20-700℃=-0.09×10^(-6)℃^(-1) is obtained upon the heat treatment of 720℃/3 h+800℃/1.5 h.The crystallization activation energy of the glass with 9mol%Li2O is about 351 kJ/mol,and the crystallization mechanism is volume crystallization.展开更多
基金Funded by the Opening Project of State Key Laboratory of Special Glass and the National Natural Science Foundation of China(No.52072278)。
文摘The crystallization behavior of Li_(2)O-Al_(2)O_(3)-SiO_(2) glasses with various concentration of Li2O were investigated by DSC,XRD,and FE-SEM.The h/l-quartz s.s.is the main crystalline phase for all of the glass with the heat treatment of 720℃/3 h+800℃/1.5 h while the crystallinity and crystal size increase with the increase of Li2O contents.Due to the negative thermal expansion coefficient of h/l-quartz s.s.,the thermal expansion coefficient of glass-ceramics decreases with the increasing of Li2O contents.When the Li2O content is 9mol%,the near-zero CTE20-700℃=-0.09×10^(-6)℃^(-1) is obtained upon the heat treatment of 720℃/3 h+800℃/1.5 h.The crystallization activation energy of the glass with 9mol%Li2O is about 351 kJ/mol,and the crystallization mechanism is volume crystallization.
