W-5Ta合金的高温自离子损伤及热回复试验研究  

High-Temperature Self-Ion Damage and Defect Recovery in Tungsten-5 Tantalum

作　　者：易晓鸥 张高伟[1] 韩文妥[1] 刘平平[1] 詹倩[1] 万发荣[1] YI Xiaoou;ZHANG Gaowei;HAN Wentuo;LIU Pingping;ZHAN Qian;WAN Farong(School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《中国钨业》2022年第3期24-30,共7页China Tungsten Industry

基　　金：国家自然科学基金(51701014,12175013)。

摘　　要：钨-钽(W-Ta)合金研究对聚变堆钨基材料的研发与服役可靠性评价具有重要意义。本研究围绕热锻W-5%Ta(质量分数)合金开展了高温自离子辐照损伤(2 MeV W^(+),800℃/1.2 dpa)及热回复试验(1000℃/1 h)。采用透射电镜显微缺陷表征方法,证实了高温辐照态样品中出现了大量位错环,其中部分位错环的空间分布表现出“筏型组态”特征。经统计分析,在高温辐照态样品中位错环平均尺寸和数密度分别达到(7.1±1.8)nm和(1.5±0.2)×10^(22)m^(-3);而在辐照后退火态样品中,位错环平均尺寸增加至(10.4±6.5)nm,数密度下降至(1.1±0.1)×10^(22)m^(-3),辐照孔洞开始出现。结合相关文献,依据辐照缺陷的尺寸、数密度指标讨论了金属W中辐照缺陷在第Ⅳ、Ⅴ回复阶段下的演化机制以及Ta元素的作用。比较发现Ta的钉扎作用延缓了辐照位错环的尺寸粗化与数密度下降趋势,而Ta对辐照孔洞的演化影响甚小。The research of W-Ta alloy is of great significance to the development of W-based materials for fusion reactors and the service reliability evaluation.In this study,high temperature self-ion irradiation damage(2 MeV W^(+),800℃/1.2dpa)and thermal recovery test(1000℃/1 h)were carried out around hot forging W-5%Ta(mass fraction)alloy.By means of transmission electron microscope(TEM)microscopic defect characterization,it was confirmed that a large number of dislocation loops appeared in the high-temperature irradiated samples,and the spatial distribution of some dislocation loops showed the characteristics of"raft configuration".According to statistical analysis,the average size and number density of dislocation loops in high-temperature irradiated samples are(7.1±1.8)nm and(1.5±0.2)×10^(22)m^(-3),respectively.However,in the annealed samples after irradiation,the average size of dislocation loops increased to(10.4±6.5)nm,the number density decreased to(1.1±0.1)×10^(22)m^(-3),and irradiation holes began to appear.According to the size and number density index of irradiation defects,the evolution mechanism of irradiation defects in metal W at the Ⅳ and Ⅴ recovery stages and the role of Ta were discussed.It was found that the pinning effect of Ta delayed the coarsening of the size and the decreasing trend of the number density of irradiated dislocation loops,while Ta had little effect on the evolution of irradiated holes.

关 键 词：聚变堆材料 W-5Ta合金 自离子损伤 辐照缺陷 热回复 

分 类 号：TG146.4[一般工业技术—材料科学与工程] TL62[金属学及工艺—金属材料]