초록
The effects of TiO2 addition as a nucleating agent on the cordierite glass-ceramics were investigated. The glass compositiion was stoichiometric cordierite composition of 13.7MgO-34.9Al2O3-51.4SiO2(wt%), and TiO2 as a nucleating agent was added by 5, 10 and 15wt% in addition. The optimum amount of TiO2 addition and appropriate heat treatment schedule were determined by using dilatometer, DTA, XRDA and SEM. The composition containing 10wt% TiO2 was proved to be the best among the investigated compositions. And the optimum heat treatment schedule was 840℃-2h for the nucleation and 1140℃-2h for the crystallization. The properties were as follows. The crystallinity was ∼75%, thermal expansion coefficient 33×10-7/℃(25∼700℃), dielectric constant 7.6(1KHz) and Vicker's hardness 5.1GPa.