摘要
锇靶是制备M型阴极常用的一类靶材,须具有纯度高、致密度高、晶粒细小等特性,然而,传统工艺烧结因烧结温度较高获得的靶材晶粒较粗大,对阴极覆膜沉积不利。本研究对锇粉模压成圆饼压坯,之后采用微波烧结压坯。微波烧结锇压坯过程中以碳化硅、氧化锆作为辅助加热材料,氧化铝作为保温材料,升温速率在20~30 min/℃之间。结果表明,当随着压强从100增加到300 MPa,微波烧结1500℃保温60 min后,样品相对密度从80.61%快速增加到93.44%。当压强继续增加到400 MPa时,相对密度随着压强的增长变缓达到94.25%。当压强从400增加到500 MPa,烧结后样品的相对密度增长不明显,并有裂纹出现。锇烧结体的相对密度和直径收缩率随着保温时间的延长先快速增加,然后缓慢增加,最后增加趋于平缓。在微波烧结1500℃下,随着保温时间的延长直径收缩率从11.67%快速增加到14.99%,然后缓慢增加到15.56%,相对密度从87.97%快速增加到93.78%,然后缓慢增加到94.25%,而孔隙的数量和尺寸随着保温时间的延长而减小,最终呈球形,晶粒尺寸在1μm左右。
The osmium target is commonly used for M-type cathodes,which is required to be of high purity,high density with fine grains.However,the grain size of the target material obtained in conventional sintering process is relatively large due to the high sintering temperature,which is detrimental to cathode coating.In this experiment,osmium powders are molded into round cake compacts and sintered by microwave.SiC and ZrO 2 are used as auxiliary heating materials,alumina is used as insulation material,and the heating rate is 20~30 min/℃.The results show that when the pressure increases from 100 to 300 MPa,the relative density of the sample increases rapidly from 80.61%to 93.44%with 1500℃sintering for 60 min.When the pressure continues to 400 MPa,the relative density slowly increases to 94.25%;while from 400 to 500 MPa,the relative density doesn t increase obviously and cracks are appeared.In addition,the relative density and relative shrinkage of the sintered body increase first rapidly,then slowly until to saturation with sintering time.With the extension of holding time in 1500℃sintering,the diameter shrinkage rate increased rapidly from 11.67%to 14.99%,then slowly to 15.56%;the relative density increased rapidly from 87.97%to 93.78%,then slowly to 94.25%;the number and size of the pores decrease,and finally the pores become spherical.The grain size is about 1μm.
作者
李世磊
刘伟
王金淑
周帆
谢元峰
夏扬
吕宏
张超
杨韵斐
张小可
LI Shi-lei;LIU Wei;WANG Jin-shu;ZHOU Fan;XIE Yuan-feng;XIA Yang;LV Hong;ZHANG Chao;YANG Yun-fei;ZHANG Xiao-ke(Key Laboratory of Advanced Functional Materials,Ministry of Education,Beijing University of Technology,Beijing 100124,China;GRIMAT Engineering Institute Co.,Ltd.,Beijing 101407,China)
出处
《真空电子技术》
2021年第3期54-59,共6页
Vacuum Electronics
基金
国家自然科学基金资助项目。
关键词
锇
M型阴极
微波烧结
靶材
Osmium
M-type cathodes
Microwave sintering
Target material
