高结晶度透明微晶玻璃的制备

Preparation of transparent glass-ceramics with high crystallinity

制备掺杂Nd2O3的Na2O-CaO-SiO2（NCS）系高结晶度透明微晶玻璃。通过DSC测定,确定基础玻璃的核化与晶化制度。采用XRD、FTIR和SEM等方法研究NCS系微晶玻璃的结晶性能、组织结构和透明性能。结果表明：NCS系玻璃经热处理后析出成分接近于Na6Ca3Si6O18的微晶体。当玻璃在（630℃,10 h）＋（800℃,1 h）条件下处理时,结晶度达79.86%,晶粒为球形,尺寸为1-2μm,3 mm厚试样在710 nm波长下的透光率为68.8%;继续延长热处理时间,晶相和玻璃相的化学组成连续变化,玻璃几乎完全析晶,晶粒尺寸达250μm,3 mm厚试样在710 nm波长下的透光率达65.5%。

The transparent Nd2O3 doped Na2O-CaO-SiO2（NCS） glass-ceramics with high crystallinity were prepared.The nucleation and crystallization conditions of precursor glass were determined by DSC.The crystal phase,crystallite size,morphology and transparency were examined by XRD,IR,SEM and UV-VIS.The results show that the compositions of crystals are close to Na6Ca3Si6O18 when NCS glass is heat-treated under different conditions.When the NCS glass is heat-treated at（630 ℃,10 h）＋（800 ℃,1 h）,the spherical crystals with grain size of about 1-2 μm are obtained,the crystallinity and the transmittance of 3 mm thick sample reach up to 79.86% and 68.8% at λ=710 nm,respectively.By prolonging the thermal treatment time,the crystallization is almost complete with grain size about 250 μm,and the transmittance of 3 mm thick sample still remains 65.5% at λ=710 nm.