摘要
采用差热分析仪(DSC),X射线衍射仪(XRD)及扫描电子显微镜(SEM)等测试手段,研究了不同烧结制度下19MgO-23Al_2O_3-53SiO_2-4TiO_2-2.5B_2O_3(wt%,M-A-S-T-B)系微晶玻璃样品的析晶过程、相成分与含量及微观形貌,并分析了核化与晶化时间对材料微波介电性能的影响关系。结果表明,根据玻璃受控析晶机制,当热处理制度为850℃/2 h+950℃/2 h时,斜顽辉石(MgSiO_3)相得以较好的析出,且伴随有α-堇青石(Mg_2Al_4Si_5O_(18))、镁铝硅酸盐(x MgO-y Al_2O_3-z SiO_2)和方石英(α-SiO_2)相的析出。随着核化时间的延长,M-A-S-T-B体系各晶相种类及析出量变化不明显;而随着晶化时间的延长(20 h),材料的晶化程度提高,品质因数(Q×f)得以提升,颗粒状晶粒析出趋于显著;但当晶化时间进一步延长至30 h时,样品致密度降低,介电损耗略有增大。在热处理制度为850℃/2 h+950℃/20 h下,样品获得的微波介电性能较优:ε_r=3.85、τ_f≈–5.37×10^(–6)/℃和Q×f≈12740 GHz(f_0=13.973 GHz)。
Effects of different heat-treatment process on the crystallization, phase composition and content, and micro- structure of 19MgO-23Al 2 O 3 -53SiO 2 -4TiO 2 -2.5B 2 O 3 (wt%, M-A-S-T-B) were studied by means of differential scanning calorimeter (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The influence of dif- ferent nucleation and crystallization time on the microwave dielectric properties were discussed as well. The results showed that, based on the controlled crystallization mechanism of glass, MgSiO 3 phase was precipitated adequately for M-A-S-T-B samples heat-treated at 850℃/2 h + 950℃/2 h, and also, the α-cordierite, xMgO-yAl 2 O 3 -zSiO 2 and α-SiO 2 phases could be precipitated from matrix phase. Additionally, with the increase of nucleation time, types of crystalline and phase content were found no discernible changes in the M-A-S-T-B glass-ceramics. While crystallization time increased to 20 h, the crystallized volume fraction of the glass increased, leading to the improvement of the quality factor (Q×f) and the obvious precipitation of granular grains. However, the dielectric loss slightly increased and the relative density of specimens decreased with further increase of crystallization time (30 h). Wherein, the M-A-S-T-B glass-ceramic sample heat-treated at 850℃/2 h + 950℃/20 h exhibited the excellent microwave dielectric properties of ε r ~ 3.85, Q×f ~ 12740 GHz(at 13.973 GHz) and τ f ~–5.37×10^-6 /℃.
作者
屈婧婧
魏星
刘飞
袁昌来
陈国华
黄先培
QU Jing-Jing;WEI Xing;LIU Fei;YUAN Chang-Lai;CHEN Guo-Hua;HUANG Xian-Pei(School of Mechanical and Electrical Engineering, Guilin University of Electronic Technology, Guilin 541004, China;Department of Science and technology, Guilin University of Aerospace Technology, Guilin 541004, China;Guangxi Key Laboratory of Information Materials, Guilin University of Electronic Technology, Guilin 541004, China)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2018年第12期1309-1315,共7页
Journal of Inorganic Materials
基金
广西自然科学基金(2017GXNSFBA198093)
国家自然科学基金(11464006)~~
关键词
热处理
微晶玻璃
MgSiO3
微波介电性能
heat-treatment
glass-ceramics
MgSiO 3
microwave dielectric properties
