ZnO·Al_(2)O_(3)·n SiO_(2)玻璃抗裂纹萌生能力反常演化的结构起源探索  

Structural Origin Revealing of Abnormal Evolution of Crack Initiation Resistance in ZnO·Al_(2)O_(3)·n SiO_(2) Glasses

作　　者：徐美姿 王兵兵 顾少轩[1] 黄欣[1] 陶海征[1] XU Meizi;WANG Bingbing;GU Shaoxuan;HUANG Xin;TAO Haizheng(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070

出　　处：《硅酸盐通报》2022年第11期4067-4074,共8页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(52172007)。

摘　　要：为探究ZnO·Al_(2)O_(3)·n SiO_(2)玻璃抗裂纹萌生能力(C_(R))随SiO_(2)含量变化的演化规律,制备了一系列不同n值(n=2,2.35,2.5,2.65,3,3.5)的样品。基于C_(R)和结构表征发现,C_(R)随着n的增加呈先增大后减小的反常演化,并于n=2.5时出现极值(31.1 N)。这是源于随着n增大:(1)原子堆积份数逐渐减小,可致密化体积逐渐增加,从而导致C_(R)逐步提高;(2)Al—O多面体结构单元含量逐步减少,导致C_(R)逐步下降;(3)考虑到相界面对裂纹生长的强阻挡能力,中程异构分相(富Al和富Si相)致相界面数量呈先增多后减少的变化趋势,导致C_(R)产生类似的非单调演化。上述三个因素的竞争和协同作用是该体系中C_(R)呈反常演化的结构起源,但考虑到极值点附近较小的组分变化,中程异构致相界面数量随n增加呈现的非单调演变才应是C_(R)呈反常演化的主要结构根源。To explore the evolution law of crack initiation resistance(C_(R))in ZnO·Al_(2)O_(3)·n SiO_(2)(n=2,2.35,2.5,2.65,3,3.5)glasses varies with SiO_(2) content,series of glass samples were prepared by the conventional melt-quenching method.By characterizing C_(R) and the microstructure of these aluminosilicate glasses in detail,the results shows that an abnormal evolution that C_(R) increases first and then decreases with the increase of SiO_(2) content,and arrives the maximum value of 31.1 N at n=2.5.With the increase of n:(1)the atomic packing density decreases gradually,which induces the increase in C_(R) due to the increase in volume available for densification;(2)the quantity of Al—O polyhedra decreases,which leads to the drop in C_(R) due to the higher damage resistance of Al—O polyhedra compared to the SiO_(4) units;(3)considering the strong retarding upon crack initiation originated from phase interfaces,the non-monotonic change in the quantity of phase interfaces induces the corresponding abnormal evolution in C_(R) for the aluminosilicate glasses.The competition and synergy of the above three factors are the structural origin of the abnormal evolution of C_(R) in this system.Finally,considering the insignificant change in composition near the maximum value,the non-monotonic change in the quantity of phase interfaces varies with n should be the main structual origin of the abnormal evolution in C_(R).

关 键 词：锌铝硅酸盐玻璃 抗裂纹萌生能力 玻璃结构 原子堆积份数 Al—O多面体 相界面 

分 类 号：TQ171[化学工程—玻璃工业]