强流脉冲电子束辐照诱发多晶纯铝中的空位缺陷簇结构  

The vacancy defect clusters in polycrystalline pure aluminum induced by high-current pulsed electron beam

作　　者：关庆丰[1] 程笃庆[1] 邱冬华[1] 朱健[1] 王雪涛[1] 程秀围[1] 

机构地区：[1]江苏大学材料科学与工程学院,镇江212013

出　　处：《物理学报》2009年第7期4846-4852,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:50671042);江苏大学科技创新团队及高级人才基金(07JDG032)资助的课题~~

摘　　要：利用强流脉冲电子束(HCPEB)技术对多晶纯铝样品进行辐照,采用透射电子显微镜详细分析了辐照诱发的空位簇缺陷.HCPEP辐照后,在辐照表层内形成了大量的四方形空位胞,其间包含位错圈和堆垛层错四面体(SFT)等类型的空位簇缺陷.1次辐照后,空位胞内产生空位型位错圈,5次辐照则主要产生SFT;10次辐照后,空位胞内产生的空位簇缺陷主要是位错圈,局部区域也观察到了SFT缺陷,在产生SFT的附近区域具有很低的位错密度或者几乎无位错出现.HCPEB辐照产生的瞬间加热和冷却诱发了幅值极大且应变速率极高的应力,这一因素导致的整个原子平面的位移可能是SFT形成的原因所在.The specimens of polycrystalline pure aluminum were irradiated with high-current pulsed electron beam （HCPEB）. The microstructure of vacancy defect clusters has been investigated in detail by using transmission electron microscopy （TEM）. The results reveal that large numbers of vacancy cells including dislocation loop and even stacking fault tetrahedra （SFT） can be formed in the specimens of polycrystalline pure aluminum irradiated with HCPEB. For the specimen irradiated with one pulse, vacancy dislocation loops were formed in the vacancy cells. SITs became the dominating structures after five pulses. For the specimen irradiated with ten pulses, dislocation loops were frequently present and SFTs were only formed in some local zones of vacancy cells. In the vicinity of SFT formation, dislocation-free or very low dislocation densities were observed. It is suggested that high stress and strain rate induced by rapid heating and cooling due to HCPEB irradiation could cause the shifting of whole atomic planes synchronously. This is the more probable mechanism of the formation of SFTs.

关 键 词：强流脉冲电子束 多晶纯铝 空位簇缺陷 堆垛层错四面体 

分 类 号：TG146.21[一般工业技术—材料科学与工程]