Fabrication of ZrB2-SiC composite with arrayed ZrB2 micro rods by reactive arc-melting process
ZrB2-SiC composite is fabricated from a powder mixture of Zr,B4C and SiC under arc melting.The ZrB2-SiC composite has unique textured microstructures with rod like ZrB2 grains embedded in the SiC matrix with well combined interface.The ZrB2 rods align in a direction perpendicular to the ceramic surface corresponding to heat dissipation direction,indicating the directional solidification of ZrB2 grains under the rapid cooling process.By this process,composites with various compositions can be obtained by varying the ratio of the components in the starting powders.The rod-like textured microstructure has distinct strengthening and toughening effects on the composites.Vickers hardness measurement of the ZrB2-17wt.%SiC composite gives a hardness of 24.0±0.8 GPa and fracture toughness of 6.7±0.7 MPa m1/2,higher than those of ZrB2-SiC composites fabricated by traditional sintering methods (15.4~22.8 GPa,2~6 MPa m1/2).Based on this research,the controlled method is prospective to fabricate other ultra high temperature ceramics with improved properties by designing novel microstructures.
ZrB2-SiC microstructure arc-melting hardness fracture toughness
Ren Zhe Wang Li-jun Li Ya-li Kang Yan-ru Guo Li-jie Su dong
Key laboratory of Advanced Ceramics and Machining Technology,Ministry of Education,Tianjin University,Tianjin 300072,China
国内会议
北京
英文
55-61
2013-09-10（万方平台首次上网日期，不代表论文的发表时间）