Microstructure, Thermal, Mechanical, and Dielectric Properties of BaO_CaO_Al2O3_B2O3_SiO2 Glass-Ceramics

5th Annual International Conference on Material Science and Engineering

Li, Bo^1,2,3 ; Bian, Haibo^1 ; Fang, Yi^1

School of Microelectronics and Solid-State Electronics, University of Electronic Science and Technology of China, Chengdu

610054, China^1

State Key Laboratory of Electronic Thin Films and Integrated Devices, Chengdu

610054, China^2

National Engineering Research Center of Electromagnetic Radiation Control Materials, Chengdu

610054, China^3

关键词: Controlled crystallization;    Cristobalites;    Crystal phase;    Crystal phasis;    High flexural strength;    Low CTE;    Phase evolutions;    Thermal expansion curve;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/275/1/012032/pdf
DOI  :  10.1088/1757-899X/275/1/012032

来源: IOP

【 摘 要 】

BaO-CaO-Al2O3-B2O3-SiO2(BCABS) glass-ceramics were prepared via the method of controlled crystallization. The effect of CaO modification on the microstructure, phase evolution, as well as thermal, mechanical, and dielectric properties was investigated. XRD identified that quartz is the major crystal phase; cristobalite and bazirite are the minor crystal phases. Moreover, the increase of CaO could inhibit the phase transformation from quartz to cristobalite, but excessive CaO would increase the porosity of the ceramics. Additionally, with increasing the amount of CaO, the thermal expansion curve tends to be linear, and subsequently the CTE value decreases gradually, which is attributed to the decrease of cristobalite with high CTE and the formation of CaSiO3with low CTE. The results indicated that a moderate amount of CaO helps attaining excellent mechanical, thermal, and dielectric properties, that is, the specimen with 9 wt% CaO sintered at 950 °C has a high CTE value (11.5 × 10-6/°C), a high flexural strength (165.7 MPa), and good dielectric properties (r= 6.2, tanδ = 1.8 × 10-4, ρ = 4.6 × 1011Ωcm).