摘要
本研究以Al_(2)O_(3)和Nd_(2)O_(3)为烧结助剂,采用热压烧结法制备Si_(3)N_(4)陶瓷,系统研究了添加BaTiO_(3)对Si_(3)N_(4)陶瓷力学和介电性能的影响。研究结果表明,随着BaTiO_(3)含量的增加,相对密度、抗弯强度和维氏硬度都随之降低,而断裂韧性有所升高;即使添加5wt%~20wt%的BaTiO_(3),Si_(3)N_(4)陶瓷的抗弯强度依然可以保持在600 MPa以上。Si3N4陶瓷的介电常数可以提高到9.26~11.50,而介电损耗保持在10^(–3)量级。在Si3N4陶瓷中未检测到BaTiO_(3)结晶相,可以认为Si_(3)N_(4)陶瓷介电常数的提高主要来源于烧结过程中形成的TiN。这些结果有助于拓展Si_(3)N_(4)陶瓷的应用领域。
Si_(3)N_(4)ceramics with improved and tailorable dielectric constant are desirable for microwave dielectric substrate application in harsh environment.Effect of BaTiO_(3)addition on the mechanical and dielectric properties of the hot-pressed Si_(3)N_(4)ceramics with Al_(2)O_(3)and Nd_(2)O_(3)as sintering additives were investigated.Relative density,flexural strength and Vickers’hardness of Si_(3)N_(4)ceramics all decreased,while indentation fracture toughness increased monotonically with the increase of BaTiO3 content.Flexural strength of Si_(3)N_(4)ceramics was higher than 600 MPa and dielectric constant of Si_(3)N_(4)ceramics increased to 9.26–11.50 when 5wt%–20wt%of BaTiO_(3)was added.The dielectric loss was at the level of 10^(–3).The improvement of dielectric constant was attributed to the formation of TiN during hot pressing,as crystalline BaTiO_(3)was not detected in the sintered samples.These findings can make a significant contribution to the new applications of Si_(3)N_(4)ceramics.
作者
梁汉琴
尹金伟
左开慧
夏咏锋
姚冬旭
曾宇平
LIANG Hanqin;YIN Jinwei;ZUO Kaihui;XIA Yongfeng;YAO Dongxu;ZENG Yuping(State Key Lab of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China)
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2021年第5期535-540,共6页
Journal of Inorganic Materials
基金
National Natural Science Foundation of China(51902327)。
关键词
氮化硅
断裂韧性
抗弯强度
介电常数
热压烧结
Si_(3)N_(4)
fracture toughness
flexural strength
dielectric constant
hot pressing
