Cr_(2)O_(3)掺杂UO_(2)芯块晶粒生长动力学研究  

Study on Grain Growth Dynamics of Cr_(2)O_(3)-doped UO_(2)Pellet

作　　者：郑新海[1] 吴学志[1] 尹邦跃[1] ZHENG Xinhai;WU Xuezhi;YIN Bangyue(China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院,北京102413

出　　处：《材料导报》2024年第S02期5-10,共6页Materials Reports

摘　　要：本工作采用恒速升温和等温烧结实验方法研究了不同Cr_(2)O_(3)掺杂量UO_(2)芯块的晶粒生长动力学。结果表明,掺杂少量Cr_(2)O_(3)可以提高UO_(2)烧结速度,降低烧结温度。1500~1750℃下烧结,添加0.1wt%、0.5wt%Cr_(2)O_(3)均可以加速芯块致密化进程,添加Cr_(2)O_(3)后,烧结温度可以降低至1600℃,而标准UO_(2)烧结温度需在1700℃以上。掺杂Cr_(2)O_(3)可以明显促进UO_(2)晶粒生长,Cr_(2)O_(3)掺杂量越多,温度越高,UO_(2)晶粒生长速度越快。掺杂0.1wt%Cr_(2)O_(3)的UO_(2)芯块的晶粒生长动力学符合3次方模型,晶粒生长指数n=3,激活能Q=454.2 kJ/mol,掺杂0.5wt%Cr_(2)O_(3)的UO_(2)芯块的晶粒生长动力学符合2.2次方模型,晶粒生长指数n=2.2,激活能Q=371.3 kJ/mol。The grain growth dynamics of UO_(2)pellet was studied by constant speed heating and isothermal sintering.It is shown that doping a small amount of Cr_(2)O_(3)can improve the UO_(2)sintering rate and reduce the sintering temperature.From 1500℃to 1750℃,adding 0.1wt%and 0.5wt%Cr_(2)O_(3)can accelerate the process of pellet.After adding Cr_(2)O_(3),the sintering temperature can be reduced to 1600℃,while the standard UO_(2)sintering temperature should reach more than 1700℃.Doped Cr_(2)O_(3)can obviously promote the growth of UO_(2)grains,the more Cr_(2)O_(3)doping,the higher the temperature,the faster the UO_(2)grain growth rate.The grain growth kinetics of the UO_(2)pellet doped with 0.1wt%Cr_(2)O_(3)conform to the 3 power model,grain growth index n=3,activation energy Q=454.2 kJ/mol,and the UO_(2)pellet doped with 0.5wt%Cr_(2)O_(3)fit the 2.2 power model,grain growth index n=2.2,and activation energy Q=371.3 kJ/mol.

关 键 词：掺杂Cr_(2)O_(3) UO_(2)芯块 晶粒尺寸 晶粒生长动力学 晶粒生长指数 激活能 

分 类 号：TL352.1[核科学技术—核技术及应用]