摘要
MgO-Al_(2)O_(3)-SiO_(2)(MAS)系统微晶玻璃具有较高的机械强度、较低的介电损耗以及良好的化学稳定性和热稳定性等优点,在电子、军事、建筑等领域表现出极大的应用价值。采用熔融法,通过控制Mg_(0.6)Al_(1.2)Si_(1.8)O_(6)固溶体晶相的析出以制备MAS透明微晶玻璃。采用XRD、SEM和UV-Vis-NIR等测试手段研究了晶化制度对微晶玻璃结构和性能的影响。结果表明:晶化温度从950℃升高到1020℃,试样中析出Mg_(0.6)Al_(1.2)Si_(1.8)O_(6),微晶玻璃透明;当晶化温度为1050℃及更高温度时,试样中析出堇青石,微晶玻璃失透。随晶化温度的升高,玻璃发生Mg_(0.6)Al_(1.2)Si_(1.8)O_(6)向堇青石的晶相转变。与堇青石相比,Mg_(0.6)Al_(1.2)Si_(1.8)O_(6)晶相折射率更接近玻璃相折射率。晶化时间由2 h延长至10 h,微晶玻璃的晶相含量由42.9%(质量分数)提高至97.5%;晶化4~10 h的微晶玻璃中晶粒平均尺寸由17.50μm增大至30.58μm。随着晶化时间的延长,微晶玻璃透光率呈现缓慢下降的趋势,热膨胀系数缓慢增加,维氏硬度呈现先增大后平缓的趋势,抗折强度先增加后减小。微晶玻璃最佳晶化制度为晶化温度1020℃,晶化时间8 h。最佳晶化制度下的微晶玻璃具有较好的综合性能,其可见光区的透光率为83%,热膨胀系数为3.857×10^(-6)/℃(600℃),维氏硬度为10.2 GPa,抗折强度为200 MPa。
MgO-Al_(2)O_(3)-SiO_(2)(MAS)system glass-ceramics have the properties of high mechanical,low dielectric loss,excellent chemical stability and thermal stability,showing great application value in electron,military,architecture and other fields.MAS transparent glass-ceramics were prepared by controlling the precipitation of Mg_(0.6)Al_(1.2)Si_(1.8)O_(6)solid solution crystalline phase by melt quenching method.Effect of crystallization schedule on the microstructure and properties of glass-ceramics was investigated by XRD,SEM,hardness meter,bending strength tester and UV-Vis-NIR.The results show that when crystallization temperature increases from 950℃to 1020℃,the crystalline phase of glass-ceramics is Mg_(0.6)Al_(1.2)Si_(1.8)O_(6)solid solution,and the glass-ceramics are transparent.When crystallization temperature rises to 1050℃and higher,the crystalline phase is cordierite and the glass-ceramics are opaque.Mg_(0.6)Al_(1.2)Si_(1.8)O_(6)phase transforms to cordierite phase when crystallization temperature increase.Compared with the cordierite,the refractive index of Mg_(0.6)Al_(1.2)Si_(1.8)O_(6)phase is closer to that of glass phase.The crystalline phase content of glass-ceramics increases from 42.9wt%to 97.5wt%with the increase of crystallization time from 2 h to 10 h.The average grain size of glass-ceramics increases from 17.50μm to 30.58μm with the increase of crystallization time from 4 h to 10 h.The light transmittance of glass-ceramics slowly decreases with prolonging crystallization time.The thermal expansion coefficient slowly increases with prolonging crystallization time.The Vickers hardness increases first and then flattens,and the bending strength increases first and then decreases with prolonging crystallization time.The suitable crystallization temperature is determined as 1020℃,and the suitable crystallization time is determined as 8 h.When heat-treated at optimum crystallization schedule,the glass-ceramics have the best comprehensive properties,which have light transmittance of 83%in visible light region,thermal expansion coefficient of 3.857×10^(-6)/℃(600℃),Vickers hardness of 10.2 GPa,and bending strength of 200 MPa.
作者
包镇红
罗薇
苗立锋
江伟辉
BAO Zhenhong;LUO Wei;MIAO Lifeng;JIANG Weihui(National Engineering Research Center for Domestic and Building Ceramics,Jingdezhen Ceramic University,Jingdezhen 333001,Jiangxi,China;Jiaxing Glead Electronics Co.,Ltd.,Jiaxing 314000,Zhejiang,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2024年第13期68-73,共6页
Materials Reports
基金
国家自然科学基金(52262008)
江西省自然科学基金(20212BAB204035)
江西省高校人文社科重点研究基地项目(JD21082)
江西省教育厅科学技术研究项目(GJJ201325)
江西省重点研发项目(20224BBE51050)。
