MgO引入量对反应烧结ZrO_2增韧Al_2O_3复相陶瓷性能的影响

Effect of MgO addition on properties of reaction-sintered ZrO_2-toughened Al_2O_3 multiphase ceramic

以锆英石粉和α-Al_2O_3粉为原料,同时引入不同量的MgO(分别占ZrO_2含量的0、3.5%、5%、8%、10%和20%)作烧结助剂和t-ZrO2的稳定剂,采用反应烧结法,分别于1500℃、1550℃、1600℃和1650℃保温4h制备了ZrO2增韧Al2O3复相陶瓷。结果表明:MgO的引入能促进ZrO_2增韧Al_2O_3复相陶瓷的烧结,并提高了t-ZrO_2的含量,但同时对生成物相产生影响,抑制了莫来石的生成;在ZrO_2含量为5%(w),MgO引入量为ZrO_2含量的8%时,试样经1600℃烧成后,性能达到最佳,常温抗折强度和断裂韧性分别达到220MPa和6.2MPa·m1/2。

Zirconia-toughened Al2O3 composite ceramic was prepared using zircon powder and α-Al2O3 powder as main starting materials and adding MgO as sintering aids and stabilizer of t-ZrO2 by in-situ reaction sintering at 1500℃ for 4 h, 1550 ℃ for 4 h, 1600℃ for 4 h and 1650 ℃ for 4 h respectively. It was shown that the added MgO had promoted the sintering of the ceramic and increased the content of t-ZrO2. Meanwhile, MgO had affected resultant phases and inhibited the formation of mullite. In multiphase ceramic with 5wt% ZrO2 by doping ZrSiO4 ,and the addition of MgO accounted for 8% of ZrO2 addition,the ceramic sintered at 1600℃ had the maximum cold MOR of 220 MPa and the fracture touahness of 6.2 MPa·m^1/2.