标题：Influence of YAG-based composite sintering AIDS on gas pressure sintered BNw/Si3N4composites
作者：Wang, Xianli ;Gong, Hongyu ;Zhang, Yujun ;Che, Songwei
作者机构：[Wang, Xianli ;Gong, Hongyu ;Zhang, Yujun ;Che, Songwei ] Key Lab. for Liquid-solid Structural Evolution and Processing of Materials of Ministry of Ed 更多
会议名称：5th International Congress on Ceramics, ICC 2014
会议日期：August 17, 2014 - August 21, 2014
来源：Key Engineering Materials
摘要：BNw/Si3N4composites were fabricated by gas pressure sintering process using α-Si3N4powder and self-made BN whisker as principal raw materials. The effects of different sintering additives such as YAG, MgO+YAG and RE2O3+YAG(RE=La, Sm, Dy) on the apparent porosity, microstructure, phase composition, mechanical performance and dielectric properties of the composites were analysed. The results revealed that composite sintering aids at certain ratio (MgO/RE2O3:YAG=1:5) was more conducive to ceramic densification than single YAG additive. The BNw/Si3N4sintered with La2O3+YAG acquired the highest density and the maximum bending strength (272.46 MPa) and fracture toughness(4.9 MPam1/2). It was speculated that ceramic densification process was related to formation of different eutectic liquid phases with different viscosity. Additionally, when the apparent porosity of BNw/Si3N4composites was 20% or less, dielectric properties of the material were mainly influenced by the porosity and the value of the permittivity and dielectric loss decreased with the increase of ceramic porosity.
© (2015) Trans Tech Publications, Switzerland.