Effect of Na2O on Crystallization and Properties of Lithium Aluminum Silicate Glass-Ceramics
Transparent lithium aluminum silicon glass-ceramics with different Na2O content was prepared by melting method,and the effect of different Na2O content on the crystallization and properties of the glass were studied by DSC,XRD,FESEM and other test methods.The results show that the introduction of Na2O can significantly reduce the transition temperature and crystallization temperature of glass,and inhibit the precipitation of LiAlSi4O10 crystalline phase.However,the introduction of Na2O leads to the precipitation of a new Li2Si2O5 phase in glass-ceramics,and with the increase of Na2O content,Li2Si2O5 transforms into the main crystal phase.Since the crystal size is in the nanometer range,the change of main crystal phase has little effect on transmittance,and the visible light transmittance of glass-ceramics is higher than 85％.The transition of main crystal phase significantly enhances the mechanical properties of glass-ceramics,and the flexural strength increases from 300 MPa to 331 MPa.The introduction of Na2O effectively enhances the Na-K exchange.When the LAS glass-ceramics with Na2O content of 4％(mass fraction)exchanges in KNO3 molten salt at 410℃for 6 h,the Vickers hardness increases from 7.108 GPa to 7.403 GPa,and the flexural strength increases from 331 MPa to 470 MPa.
国家科技期刊平台
NSTL
万方数据
