碳纤维添加量对MgO-ZrO_2陶瓷抗热震性能和烧结性能的影响

Effects of Carbon Fiber Addition Amount on Thermal Shock Resistance and Sintering Performance of MgO-ZrO_2 Ceramics

以纳米MgO粉和ZrO_2纤维为原料,以短切碳纤维为添加剂,采用无压烧结工艺制备碳纤维增强MgO-ZrO_2陶瓷,研究了碳纤维添加量对陶瓷烧结性能、物相组成、抗热震性能和显微结构的影响.结果表明:随碳纤维添加量的增加,陶瓷的相对密度和线收缩率降低,显气孔率增大,碳纤维的添加不利于MgO-ZrO_2陶瓷的烧结;抗弯强度随碳纤维添加量的增加先增大后减小,当碳纤维的体积分数为20%时,陶瓷的抗弯强度最大,为287.15 MPa;碳纤维的添加能提高MgO-ZrO_2陶瓷的抗热震性能,当碳纤维体积分数为15%时,陶瓷的抗热震性能最佳.

Carbon fiber enhanced MgO-ZrO2 ceramics were prepared by pressureless sintering with magnesia nano-powder and ZrO2 fiber as raw materials and chopped carbon fiber as additive.The effects of carbon fiber addition amount on sintering performance,phase composition,thermal shock resistance and microstructure of the ceramics were investigated.The results show that with increasing carbon fiber addition amount,the relative density and linear shrinkage rate of the ceramics decreased while the apparent porosity increased,indicating that the addition of carbon fiber was bad for the sintering of MgO-ZrO2 ceramics.The flexural strength first increased and then decreased with increasing carbon fiber addition amount and reached the largest value of 287.15 MPa with 20 vol%carbon fiber.The addition of carbon fiber increased the thermal shock resistance of the MgO-ZrO2 ceramics.When the volume fraction of carbon fiber was 15%,the thermal shock resistance of the ceramics was the best.