晶核剂对CMAS系微晶玻璃结构和性能的影响  

Effect of Nucleating Agents on Structure and Properties of CMAS Glass-ceramics

作　　者：石永恒 芶立[1] SHI Yongheng;GOU Li(College of Materials Science and Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学材料科学与工程学院,成都610065

出　　处：《材料导报》2021年第5期5027-5031,共5页Materials Reports

基　　金：四川省科技计划(2018GZ0023)。

摘　　要：针对炉渣或者尾矿中存在晶核剂成分TiO_(2)和Fe_(2)O_(3),设计了TiO_(2)、TiO_(2)+ZrO 2和TiO_(2)+Fe_(2)O_(3)三种晶核剂组合。采用熔融法和两步结晶热处理制备了CaO-MgO-Al_(2)O_(3)-SiO_(2)(CMAS)系微晶玻璃。利用X射线衍射(XRD)、扫描电子显微镜(SEM)、显微硬度测试仪和宽频介电阻抗谱仪研究了CMAS系微晶玻璃晶相组成、显微结构、力学性能和介电性能。结果表明,TiO_(2)单独加入时会析出透辉石和钛酸镁;TiO_(2)和ZrO_(2)复合加入后析出了镁硅钙石相,当加入量增多后会额外析出钛酸锆;TiO_(2)和Fe_(2)O_(3)复合添加后则会析出四氧化三铁和褐斜闪石相。虽然晶相组成会随着晶核剂的种类改变,但晶粒尺寸均在200 nm以内,并且分布均匀,有利于提高微晶玻璃的力学性能。所有样品的维氏硬度(HV5)在8 GPa左右,断裂韧性在1.25 MPa·m^(1/2)左右。当TiO_(2)和Fe_(2)O_(3)复合加入量较多时,样品的维氏硬度可以达到8.15 GPa,有利于提高含钛或含铁固废的利用率。在合适的晶核剂含量下,样品的介电常数在11左右,介质损耗在10^(-3)数量级,表明这种微晶玻璃在电子封装或者移动通讯领域也具有应用前景。In view of the fact that TiO_(2)and Fe_(2)O_(3)in slag or tailings can be used as nucleating agent,three kinds of nucleating agent of TiO_(2),TiO_(2)+ZrO 2 and TiO_(2)+Fe_(2)O_(3)were designed to prepare CaO-MgO-Al_(2)O_(3)-SiO_(2)(CMAS)system glass ceramics by melting method and two-steps crystallization heat-treatment.The crystalline phase,microstructure,mechanical properties and dielectric properties of CMAS system glass-ceramics were investigated by X-ray diffraction(XRD),scanning electron microscope(SEM),microhardness tester and broadband dielectric impedance spectrometer,respectively.The results show that diopside and magnesium titanate occur when TiO_(2)is added solely;the merwinite is precipitated when TiO_(2)and ZrO 2 are added together,and zirconium titanate is precipitated additionally when the amount of TiO_(2)is increased;Fe 3O 4 and rhoenite occur when TiO_(2)and Fe_(2)O_(3)are added together.Although the phase composition changes with the type of nucleating agent,the grain size is within 200 nm with uniform distribution,giving rise to the mechanical properties of glass-ceramics.The Vickers hardness(HV5)of all samples is about 8 GPa,while the fracture toughness is around 1.25 MPa·m^(1/2).When the addition of TiO_(2)and Fe_(2)O_(3)increases,the Vickers hardness of the sample can reach 8.15 GPa,which is conducive to the abundant addition of solid waste containing titanium or iron.The dielectric constant of the sample is about 11 with the dielectric loss about 10^(-3) order of magnitude under the appropriate content of nucleating agent.It is indicated that this kind of glass-ceramics also has application prospect in the field of electronic packaging or mobile communication.

关 键 词：微晶玻璃 钙镁铝硅系 显微结构 力学性能 介电性能 

分 类 号：TQ171[化学工程—玻璃工业]