Effect of particle size on the polycrystalline CeB_6 cathode prepared by spark plasma sintering  

作　　者：包黎红 张久兴 周身林 

机构地区：[1]Key Laboratory of Advanced Functional Materials, Ministry of Education, College of Materials Science and Engineering, Beijing University of Technology

出　　处：《Journal of Rare Earths》2011年第6期580-584,共5页稀土学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (50871002)

摘　　要：The full densification polycrystalline cerium hexaboride （CeB6） cathode material was prepared by using the spark plasma sintering （SPS） method in an oxygen free system. The starting precursor nanopowders with an average grain size of 50 nm were prepared by high-energy ball milling. The ball-milled nanopowder was fully densified at 1550 °C under 50 MPa, which was about 350 °C lower than the conventional hot-pressing method and it was also lower than that of coarse powder under the same sintering condition. The mechanical properties of nanopowder sintered samples were significantly better than that of coarse powder, e.g., the flexural strength and Vickers hardness were 211% and 51% higher than that of coarse powder, respectively. The electron backscattered diffraction （EBSD） result showed that the （100） fiber texture could be fabricated by the ball-milled nanopowder sintered at 1550 °C and the thermionic emission current density was measured to be 16.04 A/cm2 at a cathode temperature of 1873 K.The full densification polycrystalline cerium hexaboride （CeB6） cathode material was prepared by using the spark plasma sintering （SPS） method in an oxygen free system. The starting precursor nanopowders with an average grain size of 50 nm were prepared by high-energy ball milling. The ball-milled nanopowder was fully densified at 1550 °C under 50 MPa, which was about 350 °C lower than the conventional hot-pressing method and it was also lower than that of coarse powder under the same sintering condition. The mechanical properties of nanopowder sintered samples were significantly better than that of coarse powder, e.g., the flexural strength and Vickers hardness were 211% and 51% higher than that of coarse powder, respectively. The electron backscattered diffraction （EBSD） result showed that the （100） fiber texture could be fabricated by the ball-milled nanopowder sintered at 1550 °C and the thermionic emission current density was measured to be 16.04 A/cm2 at a cathode temperature of 1873 K.

关 键 词：cerium hexaboride spark plasma sintering thermionic emission particle size rare earths 

分 类 号：TF124.5[冶金工程—粉末冶金]