Structural design and energy absorption mechanism of laminated SiC/BN ceramics
Structural design and energy absorption mechanism of laminated SiC/BN ceramics
复制标题
SiC/BN层状陶瓷的结构设计及吸能机理
DOI：
10.1016/j.jeurceramsoc.2018.04.052
复制
发表时间：
2018-09-01
影响因子：
5.7
通讯作者：
Cheng, Laifei
中科院分区：
文献类型：
--
作者：
Sun, Mengyong;Bai, Yuhang;Cheng, Laifei
采用无压烧结技术，在1900℃氩气中烧结1 h，制备了不同结构设计的碳化硅/氮化硼（SiC/BN）复合陶瓷。氧化铝（Al2O3）和钇（III）氧化物（Y2O3）掺杂的SiC陶瓷表现出明显的晶间断裂行为，这可归因于位于晶界的钇铝石榴石（YAG）相。用弯曲强度和断裂韧性表征裂纹扩展，包括分层裂纹、裂纹扭结和裂纹挠曲。裂纹扩展过程中的能量吸收以断裂功和阻尼能力表征。裂纹扩展模式随BN层结构和BN含量的变化而变化。分层裂纹主要发生在氮化硼层内部或碳化硅与氮化硼层的界面处。梯度结构试样在界面和BN层内部同时出现分层裂纹，最大WOF为2.43 KJ m(-2)，抗弯强度为300 MPa，断裂韧性为8.5 MPa m（1/2）。阻尼能力随结构和振幅的变化而变化。梯度结构样品的阻尼能力为0.088，最大损耗模量为9.758 GPa。
The laminated silicon carbide/boron nitride (SiC/BN) ceramics with different structural designs were fabricated by pressureless sintering at 1900 degrees C for 1 h in argon flow. The alumina (Al2O3)-and yttrium(III) oxide (Y2O3) doped SiC ceramic exhibited a significant intergranular fracture behavior, which could be attributed to the yttrium aluminum garnet (YAG) phase located at the grains boundaries. The bending strength and fracture toughness were used to characterize the crack propagation including the delamination cracking, crack kinking, and crack deflection. The energy absorption in the process of crack propagation was characterized by the work of fracture (WOF) and damping capacity. The mode of crack propagation changed with the change in the structure and variation of BN content in the BN layer. The delamination cracks occurred inside the BN layer or at the interface between SiC and BN layers. The sample with a gradient structure exhibited the combination of delamination cracks occurring at the interface and inside the BN layer, which showed the maximum WOF of 2.43 KJ m(-2), bending strength of 300 MPa, and fracture toughness of 8.5 MPa m(1/2). The damping capacity varied with the change of the structure and the amplitude. The sample with a gradient structure exhibited the damping capacity of 0.088 and the maximum loss modulus of 9.758 GPa.