Densities and microstructure of ultrahigh temperature ceramics ZrB₂-SiC prepared by explosive compaction

To study the effect of explosive on densities and microstructure of ultrahigh temperature ceramics ZrB₂-SiC, two kinds of ZrB₂ matrix toughened by SiC whisker or SiC nanoparticles were prepared by explosive compaction. When low speed explosive Ammonium or high speed RDX was chosen, the densities of ZrB₂-SiC ceramics were lower. While, when the hybrid explosive of Ammonium and RDX was chosen, their densities were higher. If the hybrid explosive of 225 g RDX and 75 g Ammonium was used, the maximum value of the densities of ZrB₂-SiCw ultrahigh temperature ceramics was 95.25%, and that of ZrB₂-SiCnm was 96.12%. The SiC nanoparticles or SiC whisker can be uniformly dispersed in the micrometer ZrB₂ matrix after mixing. Compared with ZrB₂-SiCw, the microstructure of ZrB₂-SiCnm is finer, more uniform and perfect without phase segregation.