He离子注入对Cu/Cr和Cu/Nb纳米金属多层膜力学性能的影响

u/Nb and Cu/Cr nanostructured multilayers have multi-interface and good mechanical properties. It is possible for them to effectively block incident ions and maintain good mechanical properties after irradiation. In this article, we use 5×1016cm-2，40keVHe+to implant Cu/Nb and Cu/Cr multilayers,which have a modulation period of 5nm to 250nm.We find that with the decrease of the modulation period gradually 1.the range of implanted He ions gradually decrease;2.the size of He bubbles formed by irradiatoin gradually increases;3.the hardness of the two kind of films before and after He ions implantation decreases and the increased hardness induced by irradiation deceases.We have explained the reasons for the occurance of the above phenomena by using the rules that the interface energy of multilayers changes with the modulation period.