氦离子辐照铝合金的SRIM模拟及微观结构研究

通过SRIM软件对入射He⁺离子在1060铝合金中的射程及分布进行了模拟,利用扫描电子显微镜(Scanning electron microscopy,SEM)和透射电子显微镜(Transmission electron microscopy,TEM)对离子辐照在合金中所诱发的表面形貌、微观结构及其形成机制进行了研究。结果表明,He⁺离子辐照会导致试样表面出现辐照坑状结构,提高辐照剂量会增加辐照坑的尺寸。辐照合金中会出现杂质元素的区域富集现象,其中Si元素的富集尤为明显,在较高剂量辐照合金中这一现象越显著。此外,辐照还会导致合金中形成位错、位错环、气泡等微观结构及相应的演化结构。由于表面和这些微观结构在原子扩散的过程中可以作为缺陷阱捕获尺寸较小的杂质原子,因而这也是He⁺离子辐照铝合金中出现Si元素富集的主要机制。

Microstructures of 1060 Al-Alloy Irradiated by High Energy He+-Ion Beam:A Simulation and Experimental Study

The irradiation of high energy He⁺-ion beam on 1060 Al-alloy,an advanced material for aerospace and nuclear industries,was mathematically modeled,theoretically analyzed,numerically simulated with SRIM software and experimentally evaluated to deepen the understanding of irradiation damages.The influence of the He⁺-ion dosage on the microstructures,surface reactions and depth profile of He⁺-ion was investigated with scanning/transmission electron microscopy(SEM/TEM) and energy dispersive spectroscopy.The results show that at 50 keV,He⁺-ion dosage had a major impact.To be specific,the He⁺-ion had an increase-decrease depth profile; as the He⁺-ion dosage increased,the size/depth of the irradiation-pit increased,accompanied by an increasing enrichment of Si-impurity,possibly because of Si surface segregation.Moreover,the He⁺-ion irradiation resulted in formation of quite a few He-bubbles/dislocations/dislocation-loops,which continuously trapped the diffusing and segregating impurities in He⁺-ion bombardment.