Pore and microstructure change induced by SiC whiskers and particles in porous TiB₂-TiC-Ti₃SiC₂ composites

详细信息    查看全文

• 作者：Hongzhi Cui ; ^{cuihongzhi1965@163.com" class="auth_mail" title="E-mail the corresponding author} ; Yanfeng Zhang ; Guosong Zhang ; Wei Liu ; Xiaojie Song ; Na Wei
• 关键词：Porous composites ; TiB2&ndash ; TiC ; SiC whiskers ; SiC particles ; Reactive synthesis
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：15 May 2016
• 年：2016
• 卷：42
• 期：7
• 页码：8376-8384
• 全文大小：5324 K

文摘

TiB₂–TiC–Ti₃SiC₂ porous composites were prepared through a plasma heating reaction using powder mixtures of Ti, B₄C SiC whiskers (SiC_w) and SiC particles (SiC_p). The effects of the SiC_w and SiC_p content on pore structures, phase constituents, microstructure, and crystal morphology of TiC were studied. The results show that TiC, TiB, Ti₃B₄ phases are formed within the 5Ti+B₄C system. With the addition of SiC_w and SiC_p, the TiB and Ti₃B₄ phases are reduced, sometimes even disappeared. Interestingly, the content of TiB₂ and TiC increased, resulting in Ti₃SiC₂ and TiSi₂ being formed. The porosity of composites increases notably with the addition of SiC_w. However, with the increase of SiC_p, the porosity of the composites first decreases, followed by an increase. After adding the specified amount of SiC_w/SiC_p, the compressive strength of composites are improved significantly. Additionally, the pore size of the composites are decreased significantly with the addition of SiC_w/SiC_p. During the plasma heating process, some Si atoms will diffuse into the TiC lattice, which in turn made the cubic TiC grains into hexagonal lamellar TiC or Ti₃SiC₂ grains.