离子交换对磷酸盐玻璃表面裂纹扩展的影响  

Effect of Ion Exchange on Surface Crack Propagation of Phosphate Glass

作　　者：黄利[1,2] 张磊[1,2] 陈伟[1] 胡丽丽[1] 

机构地区：[1]中国科学院上海光学精密机械研究所,强激光材料重点实验室,上海201800 [2]中国科学院研究生院,北京100039

出　　处：《硅酸盐学报》2011年第1期104-109,共6页Journal of The Chinese Ceramic Society

基　　金：国家高技术863–804资助项目

摘　　要：采用LiNO3和NaNO3混合熔盐在250℃对N31型磷酸盐玻璃表面进行离子交换处理,研究了小离子交换大离子对玻璃表面和亚表面裂纹的扩张作用。利用偏光显微镜、扫描电子显微镜、能谱仪对离子交换前后玻璃表面形貌和成分进行了测试,根据有限源扩散动力学和离子交换表面应力分布理论,分析了离子交换时间和H2O对裂纹扩张的影响。结果表明:在4 h离子交换时间内,随着时间的增加,表面微裂纹的数量、尺寸、深度均有相应的增加;在表面离子半径差效应所产生的张应力作用下,裂纹能够发生扩张;在H2O与玻璃表面裂纹反应的作用下,裂纹将进一步扩展。这种采用离子半径较小的阳离子将玻璃表面离子半径较大的阳离子交换出来的方法,可以用来显示那些难以被观测到的表面和亚表面微裂纹。N31-type phosphate glass was treated by an ion exchange method in a mixed melt of LiNO3 and NaNO3 at 250 ℃.The effect of cation substitution（larger by smaller） on the crack propagation on the surface and subsurface was investigated.The surface morphology and composition distribution before and after the ion exchange process were determined by polarizing microscope,scan-ning electron microscope and energy dispersive spectrometer.The effects of ion exchange time and water cleaning on the crack propagation were analyzed based on the diffusion kinetics for a finite source and the theory of surface stress distribution.The quantity,length,width and depth for crack on the surface increased in the range of ion exchange time from 0 to 4 h.The crack propagation on the surface resulted from the accumulation of surface tensile stress due to the difference between ionic radii,and the interaction of water with surface crack could produce a further extension for the surface crack.The results show that the ion exchange（i.e.,substitu-tion of larger cations by smaller cations） should be an efficient method to make some unexposed cracks on the surface or subsurface appearance.

关 键 词：离子交换 磷酸盐玻璃 表面和亚表面 裂纹扩张 张应力 

分 类 号：TQ171[化学工程—玻璃工业]