摘要
用微波烧结技术和常规无压烧结技术烧结了 Si_3N_4陶瓷。用 XRD,TEM 等方法研究了不同技术烧结的 Si_3N_4样品的组成和显微结构;用三点弯曲和压痕法分别测量了两类样品的抗弯强度和断裂轫性。结果表明,N_2气压的引入可有效地控制微波烧结过程中 Si_3N_4的分解,微波烧结可大幅度降低 Si_3N_4的致密化温度,提高相转变速度,缩短烧结时间,其力学性能也明显地提高。
The Si_3N_4 ceramics(91wt-% Si_3N_4+5wt-% Y_2O_3+4wt-% Al_20_3)of room tem-perature strength 620-760 MPa and fracture toughness 7MPa·m^(1/2)were prepared bymicrowave sintering and their phase composition,microstructure and mechanical propertieswere studied.The experiment results shown that the higher N_2 pressure(392kPa)is necessaryfor microwave sintering of Si_3N_4 ceramics;microwave sintering can greatly cut down the sinter-ing temperature to 1500℃,and increase transformation rate of α to β-Si_3N_4,and reduce thetotal sintering time to about 1h.The mechanical properties of Si_3N_4 ceramics sintered bymicrowave are better than that by conventional pressureless sintering.
基金
国家高技术研究项目
关键词
微波烧结
氮化硅
烧结
microwave sintering
creamics
silicon nitride
