低温低介电陶瓷的制备及其性能影响因素

Preparation of Low Dielectric & Low Temperature Ceramic and the Influence Factors of Its Property

为了获得低温、低介电、低成本的优质陶瓷,采用高温固相反应法、以天然叶蜡石为原料,以BaCO3、MgO和SiC等为助剂制备了介电陶瓷。通过对陶瓷的宏观性能、介电性能、热学性能和力学性能等的测试,探讨了助剂对陶瓷性能的影响。结果为一定量的BaCO3和MgO可以改善陶瓷的烧结性、电学性能和热膨胀性,而SiC则可以改善陶瓷的增韧作用。在优化工艺条件的基础上获得了电阻率为(1.34～19.28)×1011Ω.cm、介电常数为2～4(1kHz时)、介质损耗小于0.004(1kHz时)、气孔率小于1%、热膨胀系数为(4～5)×10-6K-1,抗弯强度近400MPa的优质介电陶瓷。

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）×10^11Ω·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.