多晶六硼化铈的制备及性能

Preparation and properties of polycrystalline cerium hexaboride

采用放电等离子烧结技术(SPS)制备了高致密度CeB6多晶块体,考察了烧结工艺参数对多晶CeB6样品性能的影响。结果表明,随着烧结温度和烧结压力的升高,样品的致密度逐渐增大,力学性能显著提升。最佳烧结工艺参数为T=1 900℃,P=50 MPa,t=5 min,该工艺下多晶CeB6样品的致密度为95.88%,硬度为(19.37±0.65)GPa,抗弯强度为(124.82±6.24)MPa。分别在1 500,1 600,1 700℃条件下,测试了该样品的热发射电流密度,结果表明随着阴极温度的升高,多晶CeB6的最大热电子发射电流密度从3.14 A/cm2上升到18.45A/cm2,最小逸出功为3.05eV。

Science and Engineering9Hefei University of Technology,Hefei230009,China)Abstract:In this paper9a high density CeB6polycrystalline bulk has been prepared by spark plasma sintering technology9and the effects of sintering process parameters on the properties of CeB6specimen were investiga-ted.The result showed that the improvements of the density and the mechanical properties of the samples were ascribed to the increase of the sintering temperature and pressure.The optimized process parameters was T1900OC,P=50MPa“=5min,under which CeB6specimen with density of95.88%9hardness of(19.37+0.65)GPa and bend strength of(124.82+6.24)MPa was obtained.The thermal electron emission current den-sity of CeB6specimen was tested at1500,1600and1700OC,respectively.As the cathode temperature in-creased9the maximum current density increased from3.14to18.45A/cm29and the minimum work function of3.05eV was obtained.