摘要
以Al_(2)O_(3)和ZrO_(2)作为复合烧结助剂,在1800℃、30 MPa的条件下,采用放电等离子烧结(SPS)技术制备高致密的SiC陶瓷。研究碳化硅晶须(SiC_(w))的不同添加量对SiC陶瓷微观结构、相组成和力学性能的影响。研究结果表明,样品主要包含β-SiC、t-ZrO_(2)、m-ZrO_(2)三种晶相。SiC_(w)的添加会阻碍SiC晶粒的生长,适量的SiC_(w)的添加,可显著提高样品的综合力学性能,当SiC_(w)含量为20 wt.%时,样品的断裂韧性和抗弯强度分别达到5.35 MPa·m^(1/2)和650 MPa。裂纹扩展路径表明,样品存在由SiC_(w)和ZrO_(2)协同作用引起的裂纹偏转和裂纹桥接等增韧机制,因而其强度和韧性获得了提高。
Al_(2)O_(3)and ZrO_(2)were employed as sintering aids for Si C ceramic composites.Spark plasma sintering(SPS)technology was used to prepare high-density Si C ceramics at 1800℃and 30 MPa.The effects of silicon carbide whiskers(Si Cw)on microstructure,phase composition and mechanical properties of the Si C ceramics were studied.It was found that the samples mainly consisted ofβ-Si C,t-ZrO_(2)and m-ZrO_(2).The addition of Si Cw hindered the grain growth of the Si C ceramics.With optimal concentration of Si Cw,the mechanical properties of the Si C ceramics were significantly improved.Specifically,as the content of Si Cw was 20 wt.%,the fracture toughness and flexural strength reached 5.35 MPa·m^(1/2) and 650 MPa,respectively.The toughening mechanisms included crack deflection and crack bridging,due to the synergistic effect of Si Cw and ZrO_(2),thereby enhancing the strength and toughness of the composite samples.
作者
熊顺进
黄荣厦
刘荣正
杜祖超
吴建波
冯津
XIONG Shunjin;HUANG Rongxia;LIU Rongzheng;DU Zuchao;WU JianBo;FENG Jin(School of Electromechanical Engineering,Guangdong University of Technology,Guangzhou 510006,Guangdong,China;Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China)
出处
《陶瓷学报》
CAS
北大核心
2021年第5期813-818,共6页
Journal of Ceramics
基金
国家自然科学基金(21771116,51832002)。
