盐助燃烧合成法大规模制备超细LaB_(6)粉体及其烧结性能  

Research on the Large-scale Preparation of Ultrafine LaB_(6) Powders by Salt-assisted Combustion Synthesis and Its Sintered Properties

作　　者：安宁[1] 吴浩恺 朱敏 郑月红 占发奇 喇培清[1,2] AN Ning;WU Haokai;ZHU Min;ZHENG Yuehong;ZHAN Faqi;LA Peiqing(State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,Lanzhou University of Technology,Lanzhou 730050,China;School of Material Science and Engineering,Lanzhou University of Technology,Lanzhou 730050,China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,兰州730050 [2]兰州理工大学材料科学与工程学院,兰州730050

出　　处：《材料导报》2022年第11期54-60,共7页Materials Reports

基　　金：甘肃省科技计划项目(18YF1WA069)。

摘　　要：LaB_(6)是一种优异的阴极发射材料,抗辐射能力和抗中毒污染能力强,被广泛应用于航空航天、电子工业、仪表仪器、医疗器械等军事和高科技领域。采用盐助燃烧合成法一次性成功制备了公斤级的LaB_(6)粉体,通过X射线衍射(XRD)、冷场发射型扫描电镜(SEM)、透射电子显微镜(TEM)、X射线光电子能谱(XPS)等对其进行表征,结果表明,LaB_(6)颗粒为立方晶型,平均粒径为345~890 nm、纯度高于99.9%。然后采用放电等离子烧结(SPS)和热压烧结两种方式,在相同的烧结压力(35 MPa)及不同的烧结温度(1600~1800℃、1800~1900℃)下获得LaB_(6)块体材料。对SPS和热压烧结的块体材料的致密化行为进行分析,获得相对密度达93.50%和95.75%的烧结材料。用HBRVU-187.5型布洛维氏光学硬度计测得1900℃热压烧结样品的维氏硬度为(14.83±1)GPa,采用三点弯曲法计算得到此温度下样品的抗弯强度为137.04 MPa。LaB_(6)is an excellent cathode material for field emission,with strong anti-radiation and anti-poisoning pollution capabilities.It is widely used in military and high-tech fields such as aerospace,electronic industry,instrumentation and medical equipment.In this work,kilogram-scale LaB_(6)powders were successfully prepared by the salt-assisted combustion synthesis method.The LaB_(6)powder was characterized by X-ray diffraction(XRD),cold field emission scanning electron microscope(SEM),transmission electron microscope(TEM)and X-ray photoelectron spectroscopy(XPS).LaB_(6)particles adopted the cubic phase with the average particle size of 345—890 nm,and the purity is higher than 99.9%.Then,the LaB_(6)bulk materials were obtained by spark plasma sintering(SPS)and hot sintering under the same sintering pressure of 35 MPa at different sintering temperatures of 1600—1800℃and 1800—1900℃respectively.As a result,the sintered materials with relative densities of 93.50%and 95.75%were obtained.The Vickers hardness of the hot pressed sample at 1900℃was measured to be(14.83±1)GPa by HBRVU-187.5 Brinell Rockwell&Vickers optical hardness tester,and the flexural strength of the sample was calculated to be 137.04 MPa by the three-point bending method.

关 键 词：盐助燃烧合成法 LaB_(6)粉体 SPS 热压烧结 相对致密度 

分 类 号：TG139.8[一般工业技术—材料科学与工程]