Abstract:

To obtain the low dielectric ceramic with low temperature and low cost, the nature pyrophyllite is applied as raw material, BaCO₃, MgO and SiC as accessories, to prepare the dielectric ceramic by the method of sintering. The influences of accessories on ceramic properties are discussed by testing their macroscopic properties, dielectric properties, thermal expansion coefficient and mechanical properties. The result indicates that BaCO₃, and MgO can improve the sintering, dielectric as well as thermal expansion properties of ceramic, and SiC can increase the mechanical properties of ceramic. On the basis of processing parameters optimization, the dielectric ceramic is obtained, with such high-quality properties as (1.34-19.28)×10¹¹Ω·cm of electrical resistivity, 2-4 of dielectric constant, less than 0.004（1 kHz） of dielectric loss, less than 1% of porosity, (4-5)×10^-6K^-1 of thermal expansion, and approximate 400 MPa of flexural strength.

Key words: pyrophyllite, dielectric ceramic, process, ceramic