快堆MOX燃料中模浮动压制技术研究  

Research of Medium Model Floating Pressing Technology in Fast Reactor MOX Fuel

作　　者：张寒 朱桐宇[1] 张顺孝 王军平 屠振华 ZHANG Han;ZHU Tongyu;ZHANG Shunxiao;WANG Junping;TU Zhenhua(The 404 Company Limited,CNNC,Lanzhou 732850,China)

机构地区：[1]中核四0四有限公司,甘肃兰州732850

出　　处：《原子能科学技术》2023年第5期1007-1015,共9页Atomic Energy Science and Technology

摘　　要：MOX燃料首次在国内采用中模浮动压制,为系统掌握中模浮动压制技术,本文以Al2O3为模拟料,研究了压制压力、压制时间和硬脂酸锌含量对生坯和芯块的影响。结果表明:随着压制压力的增大,生坯密度、芯块密度、生坯轴向强度和径向强度显著提高,生坯轴向强度远大于径向强度,但芯块强度与生坯强度关系较小,生坯压制曲线与粉末压制曲线和黄培云双对数方程符合较好;随着烧结温度的提高,芯块密度显著提高,1 650℃烧结下芯块微观组织晶界清晰可见,空隙较小,表明芯块密度较高、压力较高使生坯和芯块的微观表面均出现裂纹;保压时间和硬脂酸锌含量对生坯密度无明显影响。综上所述,生坯密度和生坯强度与中模浮动压制压力有关,芯块密度与烧结温度和压制压力有关。Green pellets pressing is critical step in the MOX fuel production which decides density,strength and microstructure of green pellets and pellets.MOX fuel is pressed by medium mode floating pressing technology for the first time in China,in order to master the medium mode floating pressing technology systematically,Al 2O 3 was used as the simulation material to study the effect of pressing pressure,pressing time and zinc stearate content on the green billet and pellets.The results show that the density,axial strength,radial strength of green pellets increase significantly with the increase of pressing pressure,and the axial strength is much larger than the radial strength.With the increase of pressing pressure,the arrangement and deformation of particles become more sufficient.As a result,the porosity between particles reduces,and the density of green pellets increases gradually.When the pressing pressure increases,the displacement and deformation of the powder particles become more significant which makes the bonding between the particles closer.The strength of the green pellets is obviously improved.The pressing curve is in good agreement with the powder pressing curve and Huang Peiyun’s double logarithmic equation.The results show that Al 2O 3 is an inelastic compression in the pressing process,and there are work hardening and friction in the medium mode.The pellet density increases with the increase of pressing pressure and sintering temperature.The pellet density is determined by the diffusion of the sintering process.The diffusion coefficients of volume diffusion and surface diffusion are proportional to the sintering temperature.Therefore,with the increase of sintering temperature,the diffusion rate and the pellet density increase,but pellets strength is independent of green pellets strength.The microstructure of pellets has clear grain boundaries and smaller voids which indicates that pellets have high density in sintering temperature 1650℃.The high pressing pressure causes cracks on the surface of th

关 键 词：浮动压制技术 压制压力 压制时间 硬脂酸锌含量 烧结 强度 密度 

分 类 号：TL352[核科学技术—核技术及应用]