添加Al_2O_3和ZrO_2的Si_3N_4陶瓷的氧化行为以及氧化对强度的影响

OXIDATION BEHAVIOR AND EFFECT OF OXIDATION ON STRENGTH OF A1_2O_3 AND ZrO_2 DOPED Si_3N_4 CERAMICS

研究了添加Al_2O_3和ZrO_2的Si_3N_4陶瓷材料的氧化行为,同时探讨了氧化对陶瓷材料室温强度和高温强度的影响。实验结果表明,Si_3N_4陶瓷材料在空气中的氧化行为服从抛物线规律。另外、Si_3N_4陶瓷材料在1200℃的空气中氧化后其室温强度随着氧化时间的增加呈现先增加后下降的趋势,其中在1200℃的空气中氧化50h后其室温强度提高了8％。当在1300℃的空气中氧化后其高温强度随着氧化的进行有较明显的增加,其中在1300℃的空气中氧化75h后其高温强度提高了15％。

The Oxidation behavior and the effect of oxidation on the strength of A1_2O_3 and ZrO_2 doped Si_3N_4 ceramics at room and high temperature have been investigated. The results indicate that oxidation behavior in air for the samples is in good agreement with the parabolic law. In addition, the room-temperature strength of Si_3N_4 ceramics oxidized at 1200℃ in air firstly increases, then decreases with the oxidation time. For example, the strength increases by 8% after oxidation for 50 h. The high-temperature strength of Si_3N_4 ceramics oxidized at 1300℃ in air obviously increases with the oxidation time. For example, the strength increases by 15% after oxidation for 75h.