Study of the Performance and Microstructure of CeB6/B4C Ceramic Composite via in-situ Synthesis

摘要

CeB6<,6>/B<,4>C ceramic composite was fabricated by hot-pressed sintering via in-situ synthesis reaction among B<,4>C, CeO<,2> and C. The effects of CeB<,6> content on the performance and microstructure of CeB <,3>/B<,4>C composites were investigated. As the content of CeB<,6> was 2.42%, the microhardness of CeB<,6>/B<,4>C composite reached the maximum of 40.64GPa, which was higher than that of monolithic B <,>C by 52.5%. As the content of CeB<,> was 4.89%, the flexibility strength and the fracture toughness of CeB<,6>/B<,4>C composite reached the peak values of 346.7MPa and 5.95MPa·m<'1/2> respectively, which were higher than those of monolithic B<,4>C by 17.96% and 61.7% respectively. The integrated mechanical property of CeB<,6>/B<,4> C ceramic composite with the 4.89% CeB<,6>, content is optimal. It was also found that as in-situ synthesis of CeB<,6>, the crystal grain growth was inhibited, and crystallite arrangement was so compact that the pores gradually reduced. The main fracture mode of CeB <,6>/B<,4>Cceramic composite was intercrystalline rupture, while the transcrystalline rupture was minor.