ZrB_2–SiC/ZrSi_2 ceramics containing 30 vol% carbon fiber(Cf) additive were fabricated by hot pressing at low temperature(1500 ℃) using submicron ZrB_2 powders, and their microstructural evolution and performance we...ZrB_2–SiC/ZrSi_2 ceramics containing 30 vol% carbon fiber(Cf) additive were fabricated by hot pressing at low temperature(1500 ℃) using submicron ZrB_2 powders, and their microstructural evolution and performance were investigated. The addition of SiC or ZrSi_2 significantly reduced the onset sintering temperature and enhanced the densification of ZrB_2. ZrB_2–ZrSi_2–Cf showed poor performance owing to the serious fiber degradation, while the fiber degradation was effectively inhibited in ZrB_2–SiC–Cf resulting in high fracture toughness, substantial fiber pull-out, and non-brittle fracture mode for such material. The critical thermal shock temperature difference of ZrB_2–SiC–Cf was up to 741 ℃, significantly higher than those of ZrB_2–SiC/ZrSi_2 and ZrB_2–ZrSi_2–Cf. Moreover, this composite displayed a good oxidation resistance at 1500 ℃ in air.展开更多
基金provided by Scientific Research Starting Foundation of Anhui Polytechnic University of China (No.2017YQQ009)the Fundamental Research Funds for the Central Universities (Grant No.HIT.BRETIII.201506)
文摘ZrB_2–SiC/ZrSi_2 ceramics containing 30 vol% carbon fiber(Cf) additive were fabricated by hot pressing at low temperature(1500 ℃) using submicron ZrB_2 powders, and their microstructural evolution and performance were investigated. The addition of SiC or ZrSi_2 significantly reduced the onset sintering temperature and enhanced the densification of ZrB_2. ZrB_2–ZrSi_2–Cf showed poor performance owing to the serious fiber degradation, while the fiber degradation was effectively inhibited in ZrB_2–SiC–Cf resulting in high fracture toughness, substantial fiber pull-out, and non-brittle fracture mode for such material. The critical thermal shock temperature difference of ZrB_2–SiC–Cf was up to 741 ℃, significantly higher than those of ZrB_2–SiC/ZrSi_2 and ZrB_2–ZrSi_2–Cf. Moreover, this composite displayed a good oxidation resistance at 1500 ℃ in air.
