Ion irradiation induced grain growth in nanocrystalline Fe and Fe (Zr)

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 1994-05, Vol.179, p.582-586
• Main Authors: Karpe, N, Bøttiger, J, Chechenin, N.G, Krog, J.P
• Format: Article
• Language: English
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/0921-5093(94)90271-2

Thin films of nanocrystalline Fe and Fe 95Zr 5 were prepared by electron-beam evaporation. Grain growth induced by 500 keV Ar + and Xe + irradiation was investigated using dark-field electron microscopy and X-ray diffraction. After irradiation with different ions, a large difference in overall grain growth is found for similar amounts of displacement per atom (as estimated from TRIM computer simulations). Rapid grain growth is oberved only for 500 ke V Xe + irradiation, which causes dense collision cascades. This observation provides new support for earlier suggestions of radiation induced grain growth being associated with diffusion during the quenching of atomic-collision cascades. In contradiction to earlier assumptions about irradiation induced grain growth, the grain-boundary mobility in nanocrystalline Fe is found not to be proportional to the elastically deposited energy F D. The data appear to be in agreement with a F D 2 dependence as suggested from a thermal-spike model recently proposed by Alexander and Was.