SPS反应烧结制备多元稀土硼化物阴极(Sm_xBa_(1-x))B_6的晶体结构及其表征

Crystal Structure and Characterization of RE Multiple Boride Cathodes(Sm_xBa_(1-x))B_6 Prepared by Reactive Spark Plasma Sintering

应用直流电弧蒸发冷凝+放电等离子烧结(SPS)法制备多晶(SmxBa1-x)B6(x=0.2,0.6,0.8)块体阴极。采用XRD、EBSD研究烧结体的相、晶体结构及晶粒取向,并测试部分性能。结果表明,SPS液相反应烧结制备的高纯(SmxBa1-x)B6为单相结构,属无序替代固溶体,晶格常数随Ba含量的增加而增加。(SmxBa1-x)B6烧结体的晶粒细小,致密度高,具有优秀的力学性能。60MPa,1400℃保温5minSPS烧结制备的(Sm0.2Ba0.8)B6及(Sm0.8Ba0.2)B6形成了有利于提高发射性能的丝织构。

The polycrystalline（SmxBa1-x）B6（x=0.2,0.6,0.8） bulk cathodes were synthesized by arc plasma and spark plasma sintering（SPS）.The phase,crystal structure and grain orientations of sintered bodies were investigated with XRD and EBSD,and the partial properties were tested.The results indicate that the（SmxBa1-x）B6 with high-purity prepared by SPS are random substitution solid solutions which exhibit a single phase structure.The lattice parameters increase with the increase of Ba content.The（SmxBa1-x）B6 sintered bodies with a fine grain structure have high-density and excellent mechanical properties.The（Sm0.2Ba0.8）B6 and（Sm0.8Ba0.2）B6 sintered at 60 MPa and 1400℃ for 5 min form some fiber textures which will enhance the emitting property.