Microstructure and mechanical properties of in situ synthesized (TiB2 + TiC)/Ti3SiC2 composites
Microstructure and mechanical properties of in situ synthesized (TiB2 + TiC)/Ti3SiC2 composites
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DOI：
10.1016/j.ceramint.2011.06.066
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发表时间：
2012
影响因子：
5.2
通讯作者：
Jian Yang;Limei Pan;W. Gu;T. Qiu;Yuzhe Zhang;Shemin Zhu
中科院分区：
文献类型：
--
作者：
Jian Yang;Limei Pan;W. Gu;T. Qiu;Yuzhe Zhang;Shemin Zhu
在热力学分析的基础上，采用1500°C热压原位合成法制备了不同TiB 2体积含量的高致密（TiB 2 +TiC）/Ti 3SiC 2复相陶瓷。显微组织观察表明，Ti 3SiC 2晶粒呈片状，TiB 2晶粒呈柱状，TiC晶粒呈等轴状，晶界清晰。TiB 2体积含量的增加显著抑制了Ti 3SiC 2基体的晶粒长大。随着TiB 2含量从5vol.%至20体积%，复合材料的抗弯强度和断裂韧性均先增大后减小，而维氏硬度则从6.13GPa线性增大到11.5GPa。复合材料与10 vol.% TiB 2具有最佳的显微组织和最佳的力学性能：抗弯强度为700 MPa，断裂韧性为9.55MPam1/2。这是由于柱状TiB 2晶粒和等轴TiC晶粒的颗粒增强、裂纹偏转、晶粒拔出和细晶增韧等机制的协同作用所致。
Based on thermodynamic analysis, highly dense (TiB2+TiC)/Ti3SiC2composite ceramics with different TiB2volume contents were in situ fabricated in situ by hot-pressing at 1500°C. Laminar Ti3SiC2grains, columnar TiB2grains and equiaxed TiC grains were clearly identified from microstructural observation; grain boundaries were clean. The increase of TiB2volume content significantly restrains the grain growth of the Ti3SiC2matrix. As the content of TiB2increases from 5vol.% to 20vol.%, the bending strength and fracture toughness of the composites both increase and then decrease, whereas the Vickers hardness increases linearly from 6.13GPa to 11.5GPa. The composite with 10vol.% TiB2shows the optimized microstructure and optimal mechanical properties: 700MPa for bending strength; 9.55MPam1/2for fracture toughness. These are attributed to the synergistic action of strengthening and toughening mechanisms such as particulate reinforcement, crack deflection, grain's pull-out and fine-grain toughening, caused by the columnar TiB2grains and equiaxed TiC grains.